Document and Entity Information (USD $)	12 Months Ended
Document and Entity Information (USD $)	Dec. 31, 2014	Feb. 27, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2014
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	MGNX
Entity Registrant Name	MACROGENICS INC
Entity Central Index Key	0001125345
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		29,968,476
Entity Public Float			$ 437,213,185

Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 157,591	$ 116,481
Accounts receivable	2,935	2,004
Prepaid expenses	4,211	972
Total current assets	164,737	119,457
Restricted cash	300	405
Property and equipment, net	6,785	5,035
Other assets	2,064	885
Total assets	173,886	125,782
Current liabilities:
Accounts payable	1,669	3,169
Accrued expenses	7,930	3,584
Lease exit liability	1,642	1,439
Deferred revenue	14,248	20,267
Other liabilities	1,605	363
Total current liabilities	27,094	28,822
Lease exit liability, net of current portion	6,364	8,006
Deferred rent liability	2,670	2,904
Deferred revenue, net of current portion	16,472	7,136
Total liabilities	52,600	46,868
Stockholders' equity:
Common stock, $0.01 par value-125,000,000 shares authorized, 27,995,638 and 25,177,597 shares outstanding at December 31, 2014 and 2013, respectively	280	252
Treasury stock, at cost; 865 and 14,381 shares at December 31, 2014 and 2013, respectively	(19)	(58)
Additional paid-in capital	335,071	254,453
Accumulated deficit	(214,046)	(175,733)
Total stockholders' equity	121,286	78,914
Total liabilities and stockholders' equity	$ 173,886	$ 125,782

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares outstanding	27,995,638	25,177,597
Treasury stock, shares	865	14,381

Consolidated Statements of Operations and Comprehensive Income (Loss) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Revenue from collaborative research	$ 47,264	$ 56,753	$ 59,646
Grant revenue	533	1,282	4,180
Total revenues	47,797	58,035	63,826
Costs and expenses:
Research and development	70,186	46,582	45,433
General and administrative	15,926	11,087	10,188
Total costs and expenses	86,112	57,669	55,621
Income (loss) from operations	(38,315)	366	8,205
Other income (expense)	2	(627)	157
Net comprehensive income (loss)	$ (38,313)	$ (261)	$ 8,362
Basic and diluted net income (loss) per common share	$ (1.40)	$ (0.04)	$ 0.00
Basic and diluted weighted average number of common shares	27,384,990	6,847,697	1,083,276

Consolidated Statements of Stockholders' Equity (Deficit) (USD $) In Thousands, except Share data	Total	Series A-1 Convertible Preferred Stock [Member]	Series A-2 Convertible Preferred Stock [Member]	Series B Convertible Preferred Stock [Member]	Series C Convertible Preferred Stock [Member]	Series D-1 Convertible Preferred Stock [Member]	Series D-2 Convertible Preferred Stock [Member]	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2011	$ (17,484)	$ 269	$ 74	$ 714	$ 1,110	$ 144	$ 637	$ 10	$ (58)	$ 163,450	$ (183,834)
Beginning Balance, Shares at Dec. 31, 2011		26,874,792	7,364,582	71,401,237	110,952,217	14,446,227	63,681,176	1,049,030	14,381
Share-based compensation	838									838
Stock option exercises	46									46
Stock option exercises, Shares	863,176							49,884
Net income (loss)	8,362										8,362
Ending Balance at Dec. 31, 2012	(8,238)	269	74	714	1,110	144	637	10	(58)	164,334	(175,472)
Ending Balance, Shares at Dec. 31, 2012		26,874,792	7,364,582	71,401,237	110,952,217	14,446,227	63,681,176	1,098,914	14,381
Share-based compensation	862									862
Issuance of common stock, net of offering costs	83,623							58		83,565
Issuance of common stock, net of offering costs, Shares								5,750,000
Conversion of preferred stock to common stock	1,860	(269)	(74)	(714)	(1,110)	(144)	(637)	171		4,637
Conversion of preferred stock to common stock, Shares		(26,874,792)	(7,364,582)	(71,401,237)	(110,952,217)	(14,446,227)	(63,681,176)	17,060,634
Stock option exercises	1,068							13		1,055
Stock option exercises, Shares	1,268,049							1,268,049
Net income (loss)	(261)										(261)
Ending Balance at Dec. 31, 2013	78,914							252	(58)	254,453	(175,733)
Ending Balance, Shares at Dec. 31, 2013								25,177,597	14,381
Share-based compensation	3,244									3,244
Issuance of common stock, net of offering costs	76,716							22		76,694
Issuance of common stock, net of offering costs, Shares								2,250,000
Stock plan related activity, value of shares issued	725							6	(19)	738
Stock plan related activity, shares issued								568,041	865
Retirement of treasury stock									58	(58)
Stock option exercises, Shares	568,906
Retirement of treasury stock, Shares									(14,381)
Net income (loss)	(38,313)										(38,313)
Ending Balance at Dec. 31, 2014	$ 121,286							$ 280	$ (19)	$ 335,071	$ (214,046)
Ending Balance, Shares at Dec. 31, 2014								27,995,638	865

Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities
Net income (loss)	$ (38,313)	$ (261)	$ 8,362
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation expense	1,822	1,193	960
Share-based compensation	3,244	862	838
Fair value adjustment of warrant liability		626	(151)
Changes in operating assets and liabilities:
Accounts receivable	(931)	42	1,352
Prepaid expenses	(3,239)	(834)	(91)
Restricted cash	105		177
Other assets	(1,179)	(375)	1
Accounts payable	(1,500)	(570)	(7,312)
Accrued expenses	4,346	2,347	185
Lease exit liability	(1,439)	(629)	(534)
Deferred revenue	3,317	(16,676)	(10,810)
Deferred rent	(234)	103	441
Other liabilities	1,242
Net cash used in operating activities	(32,759)	(14,172)	(6,582)
Cash flows from investing activities
Purchases of property and equipment	(3,572)	(2,961)	(940)
Net cash used in investing activities	(3,572)	(2,961)	(940)
Cash flows from financing activities
Proceeds from issuance of common stock, net of offering costs	76,716	84,771
Proceeds from stock option exercises	744	1,100	47
Purchase of treasury stock	(19)
Net cash provided by financing activities	77,441	85,871	47
Net change in cash and cash equivalents	41,110	68,738	(7,475)
Cash and cash equivalents at beginning of period	116,481	47,743	55,218
Cash and cash equivalents at end of period	157,591	116,481	47,743
Noncash financing activities:
Conversion of preferred stock		$ 2,947

Organization and Nature of Operations	12 Months Ended
Organization and Nature of Operations	Dec. 31, 2014
Accounting Policies [Abstract]
Organization and Nature of Operations	1. Organization and Nature of Operations MacroGenics, Inc. (the “Company”) was incorporated in Delaware on August 14, 2000. The Company is a clinical-stage biopharmaceutical company focused on discovering and developing innovative monoclonal antibody-based therapeutics for the treatment of cancer, as well as various autoimmune disorders and infectious diseases. The Company generates its pipeline of product candidates from its proprietary suite of next-generation antibody technology platforms which it believes improve the performance of monoclonal antibodies and antibody-derived molecules. These product candidates, which the Company has identified through its understanding of disease biology and immune-mediated mechanisms, may address disease-specific challenges which are not currently being met by existing therapies.

- Definition

The entire disclosure for organization, consolidation and basis of presentation of financial statements disclosure.

+ References+ Details

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2014

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation and Principles of Consolidation

The consolidated financial statements include the accounts of MacroGenics, Inc. and its wholly owned subsidiaries, MacroGenics UK Limited and MacroGenics West, Inc. Effective December 22, 2014, MacroGenics West, Inc. was merged with and into MacroGenics, Inc. All intercompany accounts and transactions have been eliminated in consolidation. The Company currently operates in one operating segment. Operating segments are defined as components of an enterprise about which separate discrete information is available for the chief operating decision maker, or decision making group, in deciding how to allocate resources and assessing performance. The Company views its operations and manages its business in one segment, which is developing monoclonal antibody-based therapeutics for cancer, autoimmune and infectious diseases.

Use of Estimates

The preparation of the financial statements in accordance with generally accepted accounting principles (GAAP) requires the Company to make estimates and judgments in certain circumstances that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. In preparing these consolidated financial statements, management has made its best estimates and judgments of certain amounts included in the financial statements, giving due consideration to materiality. On an ongoing basis, the Company evaluates its estimates, including those related to revenue recognition, fair values of assets, stock-based compensation, preferred stock warrant liability, income taxes, pre-clinical study and clinical trial accruals and other contingencies. Management bases its estimates on historical experience or on various other assumptions that it believes to be reasonable under the circumstances. Actual results could differ from these estimates.

In addition, prior to the Company’s IPO in October 2013, the Company utilized estimates and assumptions in determining the fair value of its common stock. The Company granted stock options at exercise prices not less than the fair value of its common stock as determined by the Board of Directors, with input from management. Management used contemporaneous valuations in estimating the fair value of its common stock. The board of directors determined the estimated fair value of the common stock based on a number of objective and subjective factors, including external market considerations affecting the biotechnology industry and the historic prices at which the Company sold shares of its preferred stock.

Cash and Cash Equivalents

The Company considers all investments in highly liquid financial instruments with an original maturity of three months or less at the date of purchase to be cash equivalents. Cash and cash equivalents consist of certificates of deposit and investments in money market funds with commercial banks and financial institutions. Cash equivalents are stated at amortized cost, plus accrued interest, which approximates fair value.

Accounts Receivable

Accounts receivable that management has the intent and ability to collect are reported in the consolidated balance sheets at outstanding amounts, less an allowance for doubtful accounts. The Company writes off uncollectible receivables when the likelihood of collection is remote.

The Company evaluates the collectability of accounts receivable on a regular basis. The allowance, if any, is based upon various factors including the financial condition and payment history of customers, an overall review of collections experience on other accounts and economic factors or events expected to affect future collections experience. No allowance was recorded as of December 31, 2014 or 2013, as the Company has a history of collecting on all outstanding accounts.

Restricted Cash

The Company is required to maintain certificates of deposit that serve as collateral for various operating leases and corporate credit card accounts. Amounts classified as restricted cash on the consolidated balance sheets are $300,000 and $405,000 at December 31, 2014 and 2013, respectively.

Fair Value of Financial Instruments

The fair market values of the financial instruments included in the financial statements, which include cash equivalents and money market accounts, approximate their carrying values at December 31, 2014 and 2013, due to their short-term maturities. The Company accounts for recurring and non-recurring fair value measurements in accordance with the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 820, Fair Value Measurements and Disclosures (ASC 820). ASC 820 defines fair value, establishes a fair value hierarchy for assets and liabilities measured at fair value, and requires expanded disclosures about fair value measurements. The ASC 820 hierarchy ranks the quality of reliability of inputs, or assumptions, used in the determination of fair value and requires assets and liabilities carried at fair value to be classified and disclosed in one of the following three categories:

•

Level 1—Fair value is determined by using unadjusted quoted prices that are available in active markets for identical assets and liabilities.

•

Level 2—Fair value is determined by using inputs other than Level 1 quoted prices that are directly or indirectly observable. Inputs can include quoted prices for similar assets and liabilities in active markets or quoted prices for identical assets and liabilities in inactive markets. Related inputs can also include those used in valuation or other pricing models, such as interest rates and yield curves that can be corroborated by observable market data.

•

Level 3—Fair value is determined by inputs that are unobservable and not corroborated by market data. Use of these inputs involves significant and subjective judgments to be made by a reporting entity – e.g., determining an appropriate adjustment to a discount factor for illiquidity associated with a given security.

The Company evaluates financial assets and liabilities subject to fair value measurements on a recurring basis to determine the appropriate level at which to classify them each reporting period. This determination requires the Company to make subjective judgments as to the significance of inputs used in determining fair value and where such inputs lie within the ASC 820 hierarchy.

Financial assets and liabilities subject to fair value measurements were as follows (in thousands):


	Fair Value Measurements at December 31, 2014
			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	131,545	$	131,545	$	—	$	—
Money market funds		26,046		26,046		—		—
Restricted cash		300		300		—		—

Total Assets	$	157,891	$	157,891	$	—	$	—


	Fair Value Measurements at December 31, 2013
			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	90,434	$	90,434	$	—	$	—
Money market funds		26,047		26,047		—		—
Restricted cash		405		405		—		—

Total Assets	$	116,886	$	116,886	$	—	$	—

The Company’s Level 1 securities primarily consist of restricted cash, cash equivalents and money market funds. The Company determines the estimated fair value for its Level 1 securities using quoted (unadjusted) prices for identical assets or liabilities in active markets.

Concentration of Credit Risk

Substantially all of the Company’s cash and cash equivalents are maintained with major financial institutions in the United States. Deposits held with banks may exceed the amount of insurance provided on such deposits. Generally, these deposits may be redeemed upon demand and, therefore, bear minimal risk.

Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents, and accounts receivable. The counterparties are various corporations, financial institutions and government agencies of high credit standing.

For the years ended December 31, 2014, 2013 and 2012, the Company’s collaboration revenue relates to agreements with Takeda Pharmaceutical Company Limited (Takeda), Les Laboratoires Servier and Institut de Recherches Servier (collectively, Servier), Gilead Sciences, Inc. (Gilead), Boehringer Ingelheim GmbH (Boehringer), Pfizer, Inc. (Pfizer), Eli Lilly & Co. (Eli Lilly) and Green Cross Corp. (Green Cross). Grant revenue is related to contracts and research grants received from U.S. government agencies. The majority of the outstanding receivables are due from the Company’s collaborators and U.S. government agencies.

The following table includes those collaborators that represent more than 10% of total revenue earned in the periods indicated:


	Year Ended December 31,
	2014			2013			2012
Servier		36.4	%		51.6	%		17.3	%
Boehringer		28.6	%		24.8	%		18.4	%
Takeda		16.8	%		—			—
Gilead		11.4	%		13.8	%		—
Eli Lilly		0.9	%		1.4	%		48.9	%

The following table includes those collaborators that represent more than 10% of accounts receivable at the date indicated:


	December 31,
	2014			2013
Servier		33.3	%		6.4	%
Boehringer		21.2	%		12.2	%
Green Cross		17.9	%		—
Gilead		—			53.4	%
Pfizer		—			12.3	%

Property and Equipment

Property and equipment are stated at cost. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is credited or charged to operations. Repairs and maintenance costs are expensed as incurred. Depreciation is computed using the straight-line method over the following estimated useful lives:


Computer equipment		3 years
Software		3 years
Furniture		10 years
Laboratory and office equipment		5 years
Leasehold improvements		Shorter of lease term or useful life

Impairment of Long-Lived Assets

The Company assesses the recoverability of its long-lived assets in accordance with the provisions of ASC 360, Property, Plant and Equipment. ASC 360 requires that long-lived assets be reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of the long-lived asset is measured by a comparison of the carrying amount of the asset to future undiscounted net cash flows expected to be generated by the asset or asset group. If carrying value exceeds the sum of undiscounted cash flows, the Company then determines the fair value of the underlying asset group. Any impairment to be recognized is measured by the amount by which the carrying amount of the asset group exceeds the estimated fair value of the asset group. Assets to be disposed of are reported at the lower of the carrying amount or fair value, less costs to sell. As of December 31, 2014 and 2013, the Company determined that there were no impaired assets and had no assets held-for-sale.

Income Taxes

Deferred tax assets and liabilities are determined based on differences between the financial reporting and tax basis of assets and liabilities and are measured using the enacted tax rates and laws that are expected to be in effect when the differences are expected to reverse. The effect on deferred tax assets and liabilities of a change in tax rates is recognized as income in the period that such tax rate changes are enacted. The measurement of a deferred tax asset is reduced, if necessary, by a valuation allowance if it is more likely than not that some portion or all of the deferred tax asset will not be realized. Financial statement recognition of a tax position taken or expected to be taken in a tax return is determined based on a more-likely-than-not threshold of that position being sustained. If the tax position meets this threshold, the benefit to be recognized is measured as the largest amount that is more likely than not to be realized upon ultimate settlement. The Company’s policy is to record interest and penalties related to uncertain tax positions as a component of income tax expense.

Revenues

Revenue Recognition

The Company enters into collaboration and license agreements with collaborators for the development of monoclonal antibody-based therapeutics to treat cancer and other complex diseases. The terms of these agreements contain multiple deliverables which may include (i) licenses, or options to obtain licenses, to the Company’s technological platforms, such as its Fc Optimization and Dual-Affinity Re-Targeting (DART) technologies, (ii) rights to future technological improvements, (iii) research and development activities to be performed on behalf of the collaborator or as part of the collaboration, and (iv) the manufacture of pre-clinical or clinical materials for the collaborator. Payments to the Company under these agreements may include nonrefundable license fees, option fees, exercise fees, payments for research and development activities, payments for the manufacture of pre-clinical or clinical materials, license maintenance payments, payments based upon the achievement of certain milestones and royalties on product sales. Other benefits to the Company of these agreements include the right to sell products resulting from the collaborative efforts of the parties in specific geographic territories. The Company follows the provisions of the FASB ASC Topic 605-25, Revenue Recognition—Multiple-Element Arrangements, and ASC Topic 605-28, Revenue Recognition—Milestone Method, in accounting for these agreements. In order to account for these agreements, the Company must identify the deliverables included within the agreement and evaluate which deliverables represent separate units of accounting based on the achievement of certain criteria, including whether the delivered element has stand-alone value to the collaborator. The consideration received is allocated among the separate units of accounting, and the applicable revenue recognition criteria are applied to each of the separate units.

For the periods presented, the Company had the following two types of agreements: 1) exclusive development and commercialization licenses to use the Company’s technology and/or certain other intellectual property to develop compounds against specified targets (referred to herein as exclusive licenses); and 2) Option/research agreements to secure on established terms, development and commercialization licenses to therapeutic product candidates to collaborator-selected targets developed by the Company during an option period (referred to herein as right-to-develop agreements).

There are no performance, cancellation, termination or refund provisions in any of the arrangements that contain material financial consequences to the Company.

Exclusive Licenses

The deliverables under an exclusive license agreement generally include the exclusive license to the Company’s DART technology with respect to a specified antigen target, and may also include deliverables related to rights to future technological improvements, research and pre-clinical development activities to be performed on behalf of the collaborator. In some cases the Company may have an option to participate in the co-development of product candidates that result from such agreements.

Generally, exclusive license agreements contain nonrefundable terms for payments and, depending on the terms of the agreement, provide that the Company will (i) at the collaborator’s request, provide research and pre-clinical development services at negotiated prices which are generally consistent with what other third parties would charge, (ii) earn payments upon the achievement of certain milestones, (iii) earn royalty payments, and (iv) in some cases grant the Company an option to participate in the development and commercialization of products that result from such agreements. Royalty rates may vary over the royalty term depending on the Company’s intellectual property rights and whether the Company exercises any co-development and co-commercialization rights. The Company may provide technical assistance and share any technology improvements with its collaborators during the term of the collaboration agreements.

The Company does not directly control when any collaborator will achieve milestones or become liable for royalty payments.

When entering into a new collaboration arrangement or materially modifying an existing arrangement, the Company must identify the deliverables included within the agreement and evaluate which deliverables represent separate units of accounting based on the achievement of certain criteria, including whether the delivered element has stand-alone value to the collaborator. The selling prices of deliverables under an arrangement may be derived using third-party evidence (TPE), or a best estimate of selling price (BESP), if vendor specific objective evidence (VSOE) is not available. The objective of BESP is to determine the price at which the Company would transact a sale if the element within the license agreement was sold on a standalone basis. Establishing BESP involves management’s judgment and considers multiple factors, including market conditions and company-specific factors, including those factors contemplated in negotiating the agreements, as well as internally developed models that include assumptions related to market opportunity, discounted cash flows, estimated development costs, probability of success and the time needed to commercialize a product candidate pursuant to the license. In validating the BESP, management considers whether changes in key assumptions used to determine the BESP will have a significant effect on the allocation of the arrangement consideration between the multiple deliverables. Deliverables under the arrangement are separate units of accounting if (i) the delivered item has value to the customer on a standalone basis and (ii) if the arrangement includes a general right of return relative to the delivered item, delivery or performance of the undelivered item is considered probable and substantially within the Company’s control. The arrangement consideration that is fixed or determinable at the inception of the arrangement is allocated to the separate units of accounting based on their relative selling prices. The appropriate revenue recognition model is applied to each element and revenue is accordingly recognized as each element is delivered. Management exercises significant judgment in determining whether a deliverable is a separate unit of accounting.

In determining the separate units of accounting, the Company evaluates whether the exclusive license has standalone value to the collaborator based on consideration of the relevant facts and circumstances for each arrangement. Factors considered in this determination include the research and development capabilities of the collaborator and the availability of relevant research expertise in the marketplace. In addition, the Company considers whether or not (i) the collaborator could use the license for its intended purpose without the receipt of the remaining deliverables, (ii) the value of the license was dependent on the undelivered items and (iii) the collaborator or other vendors could provide the undelivered items. If the Company concludes that the license has stand-alone value and therefore will be accounted for as a separate unit of accounting, the Company then determines the estimated selling prices of the license and all other units of accounting based on market conditions, similar arrangements entered into by third parties, and entity-specific factors such as the terms of the Company’s previous collaboration agreements, recent pre-clinical and clinical testing results of therapeutic product candidates that use the Company’s technology platforms, the Company’s pricing practices and pricing objectives, the likelihood that technological improvements will be made, the likelihood that technological improvements made will be used by the Company’s collaborators and the nature of the research services to be performed on behalf of its collaborators and market rates for similar services. Total arrangement consideration is then allocated to each of the units of accounting using the relative-selling-price method. If facts and circumstances dictate that the exclusive license does not have stand-alone value, then the related payments are deferred and revenue is recognized throughout the period of performance.

Management reassesses the period of performance over which the Company recognizes deferred upfront license fees and makes adjustments as appropriate in the period in which a change in the estimated period of performance is identified. In the event a collaborator elects to discontinue development of a specific product candidate under a single target license, but retains its right to use the Company’s technology to develop an alternative product candidate to the same target or a target substitute, the Company would cease amortization of any remaining portion of the upfront fee until there is substantial pre-clinical activity on another product candidate and its remaining period of substantial involvement can be estimated. In the event that a single target license were to be terminated, the Company would recognize as revenue any portion of the upfront fee that had not previously been recorded as revenue, but was classified as deferred revenue, at the date of such termination or through the remaining substantial involvement in the wind down of the agreement.

Upfront payments on exclusive licenses may be recognized upon delivery of the license if facts and circumstances dictate that the license has stand-alone value from the undelivered elements, which generally include rights to future technological improvements, research services and the manufacture of pre-clinical and clinical materials.

The Company recognizes revenue related to research and pre-clinical development services that represent separate units of accounting as they are performed, as long as there is persuasive evidence of an arrangement, the fee is fixed or determinable, and collection of the related receivable is probable. The Company recognizes revenue related to the rights to future technological improvements over the estimated term of the applicable license.

The Company typically performs research activities and pre-clinical development services, including generating and engineering product candidates, on behalf of its licensees during the early evaluation and pre-clinical testing stages of drug development under its exclusive licenses. The Company records amounts received for research materials produced or services performed as revenue from collaborative research.

The Company’s license agreements have milestone payments which for reporting purposes are aggregated into three categories: (i) development milestones, (ii) regulatory milestones, and (iii) sales milestones. Development milestones are typically payable when a product candidate initiates or advances into different clinical trial phases. Regulatory milestones are typically payable upon submission for marketing approval with the U.S. Food and Drug Administration (FDA) or other countries’ regulatory authorities or on receipt of actual marketing approvals for the compound or for additional indications. Sales milestones are typically payable when annual sales reach certain levels.

At the inception of each agreement that includes milestone payments, the Company evaluates whether each milestone is substantive and at risk to both parties on the basis of the contingent nature of the milestone. This evaluation includes an assessment of whether (i) the consideration is commensurate with either (a) the entity’s performance to achieve the milestone, or (b) the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the entity’s performance to achieve the milestone, (ii) the consideration relates solely to past performance and (iii) the consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. The Company evaluates factors such as the scientific, regulatory, commercial and other risks that must be overcome to achieve the respective milestone, the level of effort and investment required to achieve the respective milestone and whether the milestone consideration is reasonable relative to all deliverables and payment terms in the arrangement in making this assessment.

Non-refundable development and regulatory milestones that are expected to be achieved as a result of the Company’s efforts during the period of substantial involvement are considered substantive and are recognized as revenue upon the achievement of the milestone, assuming all other revenue recognition criteria are met. Milestones that are not considered substantive because the Company does not contribute effort to the achievement of such milestones are generally achieved after the period of substantial involvement and are recognized as revenue upon achievement of the milestone, as there are no undelivered elements remaining and no continuing performance obligations, assuming all other revenue recognition criteria are met.

Right-to-Develop Agreements

The Company’s right-to-develop agreements provide collaborators with an exclusive option to obtain licenses to develop and commercialize in specified geographic territories product candidates developed by the Company under agreed upon research and pre-clinical development product programs. The product candidates resulting from each program are all directed to a specific target selected by the collaborator. Under these agreements, fees may be due to the Company (i) at the inception of the arrangement (referred to as “upfront” fees or payments), (ii) the selection of a target for a program, (iii) upon the exercise of an option to acquire a development and commercialization license (referred to as exercise fees or payments earned) for a program, or (iv) some combination of all of these fees.

The accounting for right-to-develop agreements is dependent on the nature of the options granted to the collaborator. Options are considered substantive if, at the inception of a right-to-develop agreement, the Company is at risk as to whether the collaborator will choose to exercise the options to secure development and commercialization licenses. Factors that are considered in evaluating whether options are substantive include the overall objective of the arrangement, the benefit the collaborator might obtain from the agreement without exercising the options, the cost to exercise the options relative to the total upfront consideration, and the additional financial commitments imposed on the collaborator as a result of exercising the options.

For right-to-develop agreements where the options to secure development and commercialization licenses to a product program are considered substantive, the Company does not consider the development and commercialization licenses to be a deliverable at the inception of the agreement, and therefore defers any upfront payments received and recognizes this revenue over the period during which the collaborator could elect to exercise options for development and commercialization licenses. These periods are specific to each collaboration agreement. If a collaborator selects a target for a product program, any substantive option fee is deferred and recognized over the life of the option. For right-to-develop agreements that include multiple deliverables, the Company determines the selling prices of deliverables under the arrangement using TPE or a BESP, if VSOE is not available. The objective of BESP is to determine the price at which the Company would transact a sale if the element within the right-to-develop agreement was sold on a standalone basis. Establishing BESP involves management’s judgment and considers multiple factors, including market conditions and company-specific factors, including those factors contemplated in negotiating the agreements, as well as internally developed models that include assumptions related to market opportunity, discounted cash flows, estimated development costs, probability of success and the time needed to commercialize a product candidate pursuant to the right-to-develop agreement. In validating the BESP, management considers whether changes in key assumptions used to determine the BESP will have a significant effect on the allocation of the arrangement consideration between the multiple deliverables. Deliverables under the arrangement are separate units of accounting if (i) the delivered item has value to the customer on a standalone basis and (ii) if the arrangement includes a general right of return relative to the delivered item, delivery or performance of the undelivered item is considered probable and substantially within the Company’s control. The arrangement consideration that is fixed or determinable at the inception of the arrangement is allocated to the separate units of accounting based on their relative selling prices. The appropriate revenue recognition model is applied to each element and revenue is accordingly recognized as each element is delivered. Management exercises significant judgment in determining whether a deliverable is a separate unit of accounting.

If a collaborator exercises an option and acquires a development and commercialization license to a product program, the Company attributes the exercise fee to the development and commercialization license. The Company determines the selling price of the option license, upon exercise, through management’s best estimate using the process for an exclusive license as described above.

Upon exercise of an option to acquire a development and commercialization license, the Company would also attribute any remaining deferred option fee, in addition to the consideration received for the license upon exercise of the option, to the development and commercialization license. The Company then applies the multiple-element revenue recognition criteria to the development and commercialization license and other deliverables, if any, to determine the appropriate revenue recognition method. This model is consistent with the Company’s accounting policy for upfront payments on exclusive licenses (discussed above). In the event a right-to-develop agreement were to be terminated, the Company would recognize as revenue any portion of the upfront fee that had not previously been recorded as revenue, but was classified as deferred revenue, at the date of such termination. The Company’s right-to-develop agreements have been determined to contain substantive options.

For right-to-develop agreements where the options to secure development and commercialization licenses to product programs are not considered substantive, the Company considers the development and commercialization licenses to be a deliverable at the inception of the agreement and applies the multiple-element revenue recognition criteria to determine the appropriate revenue recognition. The Company does not directly control when any collaborator will exercise its options for development and commercialization licenses.

Research and Development Costs

Research and development expenditures are expensed as incurred. Research and development costs primarily consist of employee related expenses, including salaries and benefits, expenses incurred under agreements with contract research organizations, investigative sites and consultants that conduct the Company’s clinical trials, the cost of acquiring and manufacturing clinical trial materials and other allocated expenses, license fees for and milestone payments related to in-licensed products and technologies, stock-based compensation expense, and costs associated with non-clinical activities and regulatory approvals.

Comprehensive Income (Loss)

Comprehensive income (loss) is comprised of the net income (loss) and other changes in equity that are excluded from net income (loss). Comprehensive income (loss) equals net income (loss) for the years ended December 31, 2014, 2013 and 2012.

Stock-based Compensation

Stock-based payments are accounted for in accordance with the provisions of ASC 718, Compensation—Stock Compensation. The fair value of stock-based payments is estimated, on the date of grant, using the Black-Scholes model. The resulting fair value is recognized ratably over the requisite service period, which is generally the vesting period of the option.

For all time-vesting awards granted, expense is amortized using the straight-line attribution method. For awards that contain a performance condition, expense is amortized using the accelerated attribution method. Recognition of stock-based compensation expense is based on the value of the portion of stock-based awards that is ultimately expected to vest during the period.

The Company utilizes the Black-Scholes model for estimating fair value of its stock options granted. Option valuation models, including the Black-Scholes model, require the input of highly subjective assumptions, and changes in the assumptions used can materially affect the grant-date fair value of an award. These assumptions include the risk-free rate of interest, expected dividend yield, expected volatility and the expected life of the award.

Net Income (Loss) Per Share

Basic income (loss) per common share is determined by dividing income (loss) attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration of common stock equivalents. Diluted income (loss) per share is computed by dividing the earnings (loss) attributable to common stockholders by the weighted-average number of common share equivalents outstanding for the period. The treasury stock method is used to determine the dilutive effect of the Company’s stock option grants, potential Employee Stock Purchase Plan awards and warrants and the if-converted method is used to determine the dilutive effect of the Company’s preferred stock.

For the year ended December 31, 2012, net income (loss) per share was calculated under the two-class method under which all earnings (distributed and undistributed) are allocated to each class of common stock and participating securities based on their respective rights to receive dividends. In the event that the Board of Directors declared a dividend payable in cash or other property on the then-outstanding shares of common stock, the holders of the Series A-1, A-2, B, C, D, and D-2 convertible preferred stock would be entitled to receive the amount of dividends per share of preferred stock that would be payable on the largest number of whole shares of common stock into which each share of preferred stock could then be converted. Therefore, the Series A-1, A-2, B, C, D and D-2 are participating securities. All of the outstanding shares of Series A-1, A-2, B, C, D, and D-2 convertible preferred stock converted to common stock upon the consummation of the Company’s IPO in October 2013.

Basic and diluted income (loss) per common share is computed as follows (in thousands except share and per share data):


	Year Ended December 31,
	2014			2013			2012
Net income (loss)	$	(38,313	)	$	(261	)	$	8,362
Less: undistributed earnings allocated to participating securities		—			—			(8,362	)

Net income (loss) allocable to common shares	$	(38,313	)	$	(261	)	$	—

Basic weighted average common shares outstanding		27,384,990			6,847,697			1,083,276
Basic income (loss) per common share	$	(1.40	)	$	(0.04	)	$	0.00
Net income (loss)	$	(38,313	)	$	(261	)	$	8,362
Less: undistributed earnings allocated to participating securities and other add-backs to net income (loss)		—			—			(8,362	)

Net income (loss) allocable to common shares	$	(38,313	)	$	(261	)	$	—

Basic weighted average common shares outstanding		27,384,990			6,847,697			1,083,276
Effect of dilutive securities		—			—			—

Diluted weighted average common shares outstanding		27,384,990			6,847,697			1,083,276

Diluted income (loss) per common share	$	(1.40	)	$	(0.04	)	$	0.00

The following common stock equivalents were excluded from the calculation of diluted net income (loss) per share because their effect would be anti-dilutive:


	Year Ended December 31,
	2014		2013		2012
Series A-1 Preferred Stock		—		—		2,156,114
Series A-2 Preferred Stock		—		—		392,274
Series B Preferred Stock		—		—		4,336,037
Series C Preferred Stock		—		—		5,909,906
Series D Preferred Stock		—		—		769,468
Series D-2 Preferred Stock		—		—		3,391,991
Effect of Converted Preferred Stock		—		13,189,920		—
Warrants to purchase Series D-2 Preferred Stock		—		—		180,784
Stock Options		2,094,904		2,313,970		3,249,702

Recently Issued Accounting Standards

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (ASU 2014-09). ASU 2014-09 will eliminate transaction- and industry-specific revenue recognition guidance under current GAAP and replace it with a principle-based approach for determining revenue recognition. ASU 2014-09 will require that companies recognize revenue based on the value of transferred goods or services as they occur in the contract. The ASU also will require additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016. Early adoption is not permitted. Entities can transition to the standard either retrospectively or as a cumulative effect adjustment as of the date of adoption. Management is currently assessing what effect the adoption of ASU 2014-09 will have on the Company’s consolidated financial statements and accompanying notes.

In July 2013, the FASB issued ASU No. 2013-11, which amended ASC Topic 740 regarding presentation of an unrecognized tax benefit when a net operating loss (NOL) carryforward, a similar tax loss, or a tax credit carryforward exists. The amendments in ASU No. 2013-11 require an entity to present an unrecognized tax benefit as a reduction of a deferred tax asset for an NOL carryforward, or similar tax loss or tax credit carryforward, rather than as a liability when (1) the uncertain tax position would reduce the NOL or other carryforward under the tax law of the applicable jurisdiction and (2) the entity intends to use the deferred tax asset for that purpose. The ASU does not require new recurring disclosures. This amendment was effective prospectively for fiscal years beginning after December 15, 2013, and did not have a material impact on the Company’s financial statements.

The Company has evaluated all other ASUs issued through the date the consolidated financials were issued and believes that the adoption of these will not have a material impact on the Company’s consolidated financial statements.

- Definition

The entire disclosure for all significant accounting policies of the reporting entity.

+ References+ Details

Property and Equipment

12 Months Ended

Dec. 31, 2014

Property, Plant and Equipment [Abstract]

Property and Equipment

3. Property and Equipment

Property and equipment consists of the following (in thousands):


	December 31,
	2014			2013
Computer equipment	$	2,596		$	2,379
Software		1,683			1,477
Furniture and office equipment		751			651
Lab equipment		13,917			11,166
Leasehold improvements		5,193			4,894

Property and equipment		24,140			20,567
Less accumulated depreciation		(17,355	)		(15,532	)

Property and equipment, net	$	6,785		$	5,035

Depreciation expense for the years ended December 31, 2014, 2013 and 2012 was $1.8 million, $1.2 million and $1.0 million, respectively.

- Definition

The entire disclosure for long-lived, physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, accounting policies and methodology, roll forwards, depreciation, depletion and amortization expense, including composite depreciation, accumulated depreciation, depletion and amortization expense, useful lives and method used, income statement disclosures, assets held for sale and public utility disclosures.

+ References+ Details

Stockholders' Equity	12 Months Ended
Stockholders' Equity	Dec. 31, 2014
Equity [Abstract]
Stockholders' Equity	4. Stockholders’ Equity During 2002 and 2003, the Company issued a total of 34,239,374 shares of Series A-1 and Series A-2 convertible preferred stock (Series A preferred stock) for $1.00 per share resulting in net proceeds of approximately $34.0 million. In October 2004, the Company entered into a series of transactions raising $30.3 million, net of related offering costs of approximately $238,000, from the sale of 71,401,237 shares of its Series B convertible preferred stock (Series B preferred stock). In connection with the Series B preferred stock offering, 13,604,016 shares of common stock were allocated to holders of Series A-1 preferred stock as an anti-dilution measure. In May 2006, the Company raised $44.9 million, net of related offering costs of $101,246, from the sale of 110,952,217 shares of its Series C convertible preferred stock (Series C preferred stock). In connection with the Series C preferred stock offering, 10,003,300 shares of common stock were allocated to holders of Series B preferred stock as an anti-dilution measure. In July 2008, the Company issued 12,466,039 shares of its Series D convertible preferred stock (Series D preferred stock) in exchange for all of the outstanding capital stock and convertible notes payable of Raven Biotechnologies, Inc. (Raven). Subsequently, in March 2011 a settlement was reached with the former Raven stockholders bringing the total Series D preferred stock issued in connection with the Raven acquisition to 14,446,227 shares. In September 2008, the Company raised $24.8 million, net of related offering costs of $156,788 from the sale of 38,337,678 shares of its Series D-2 convertible preferred stock (Series D-2 preferred stock). The Company also issued preferred stock warrants for the purchase of 2,875,327 shares of Series D-2 preferred stock. The preferred stock warrants were exercisable at any time prior to September 2018, but expired upon an IPO, and had a stated exercise price of $0.65 per warrant. On May 16, 2010, the Company exercised a put notice to Eli Lilly in accordance with the Series D-2 preferred stock purchase agreement, resulting in the issuance of 6,916,110 shares of Series D-2 preferred stock and a warrant to purchase 518,708 additional shares of Series D-2 preferred stock. On January 11, 2011, the Company raised gross proceeds of $12.0 million from the sale of 18,427,388 shares of its Series D-2 preferred stock. Due to certain provisions in the Series D-2 convertible preferred stock warrant agreement, these warrants were required to be classified as a liability. Management believed that the circumstances requiring cash settlement of the award were remote. The Series D-2 preferred stock warrant liability was recorded at fair value and has been adjusted to fair value at the end of each reporting period using the Option-Pricing Method, with changes in value recorded as “Other income (expense)” in the accompanying consolidated statements of operations and comprehensive income (loss). Prior to the Company’s IPO in October 2013, all the preferred stock warrants were exercised and subsequently were converted into shares of common stock in connection with the IPO. Dividends were noncumulative and accrued on the Series A, Series B, Series C, Series D and Series D-2 preferred stock at a rate of $0.08, $0.0341, $0.0324 and $0.0522 per annum, respectively, and were payable when and as declared by the Board of Directors. Dividends had to be declared so that the Series A, Series B, Series C and Series D preferred stock were paid in like-kind and participated equally to those of the Series D-2 preferred and common stock. No dividends had been declared prior to the conversion of the preferred stock to common stock in connection with the IPO. The Company’s Series A-1, Series A-2, Series B, Series C, Series D and Series D-2 preferred stock were initially convertible into 1.506, 1.00, 1.14, 1.00, 1.00 and 1.00 shares, respectively, of common stock at the option of the holder. The conversion ratio of certain series of preferred stock was subject to change in the event specified dilutive transactions occurred, which included the Company’s IPO. There were no anti-dilution protections for the Series A-2 preferred stock and no adjustment to the Series A-1 preferred stock conversion price was to be made if a common stock issuance was at a price per share greater than the conversion price of the Series C preferred stock. Upon consummation of the Company’s IPO in October 2013, all outstanding shares of preferred stock automatically converted to shares of the Company’s common stock at the applicable conversion ratios then in effect. The conversion price was $12.39, $18.77, $6.95, $7.70, $12.20 and $12.20 for each share of Series A-1, A-2, Series B, Series C, Series D and Series D-2 convertible preferred stock, respectively. On October 16, 2013, the Company completed its IPO, in which 5,000,000 shares of the Company’s common stock were sold at a price of $16.00 per share. Additionally, the underwriters of the Company’s IPO exercised the full amount of their over-allotment option resulting in the sale of an additional 750,000 shares of the Company’s common stock at a price of $16.00 per share. The Company received proceeds of $83.8 million from the IPO, net of underwriting discounts and commissions and other offering expenses. Upon consummation of the IPO, all outstanding shares of preferred stock automatically converted to common stock at the applicable conversion ratios then in effect. In connection with preparing for its IPO in October 2013, the Company’s Board of Directors and stockholders approved a 1-for-18.7739 reverse stock split of the Company’s common stock. The reverse stock split became effective on September 26, 2013. All share and per share amounts in the consolidated financial statements and notes thereto have been retroactively adjusted for all periods presented to give effect to this reverse stock split, including reclassifying an amount equal to the reduction in par value of common stock to additional paid-in capital. In addition, in September 2013, the Company’s Board of Directors and stockholders approved an amendment of the Company’s certificate of incorporation to, among other things, change the definition of a designated public offering to remove the per share price requirement. The amended and restated certificate of incorporation also changed the authorized number of shares of common stock from 425,000,000 to 125,000,000, and authorized 5,000,000 shares of undesignated preferred stock with a par value of $0.01 per share. There were no shares of undesignated preferred stock issued or outstanding as of December 31, 2014 or 2013. In February 2014, the Company completed a follow-on equity offering, in which the Company sold 1.8 million shares of its common stock at a price of $36.50 per share. Additionally, the underwriters of the offering exercised the full amount of their over-allotment option resulting in the sale of an additional 450,000 shares of the Company’s common stock at a price of $36.50 per share. The Company received proceeds of $76.7 million from this offering, net of underwriting discounts and commissions and other offering expenses.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29-31)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30, 31

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 4.E)

-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 4

-Subparagraph (SAB TOPIC 4.C)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Article 4

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 4

-Section C

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 4

-Section E

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(d),(e))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Preferred Stock

-URI http://asc.fasb.org/extlink&oid=6521494

Reference 11: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 12: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 13: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 14: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 15: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21564-112644

Reference 16: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21488-112644

Reference 17: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21484-112644

Reference 18: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph d

-Article 4

Reference 19: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 30

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23285-112656

+ Details

Stock-based Compensation

12 Months Ended

Dec. 31, 2014

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-based Compensation

5. Stock-based Compensation

The Company’s 2000 Stock Option and Incentive Plan (2000 Plan) allowed for the grant of awards in respect of an aggregate of 130,725 shares, which was increased to 150,297 shares, of the Company’s common stock in the form of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock and restricted stock units and other performance awards. As of December 31, 2014, under the 2000 Plan, there were options to purchase an aggregate of 19,705 shares of common stock outstanding at a weighted average exercise price of $0.81 per share. The 2000 Plan has expired, and no further awards may be issued under the plan. Any shares of common stock subject to awards under the 2000 Plan that expire, terminate, or are otherwise surrendered, canceled, forfeited or repurchased without having been fully exercised, or resulting in any common stock being issued, will become available for issuance under the 2013 Stock Incentive Plan (2013 Plan) up to a specified number of shares.

Effective February 2003, the Company implemented the 2003 Equity Incentive Plan (2003 Plan), and it was amended and approved by the Company’s stockholders in 2005. The 2003 Plan originally allowed for the grant of awards in respect of an aggregate of 2,051,644 shares of the Company’s common stock. Between 2006 and 2010 the maximum number of shares of common stock authorized to be issued by the Company under the 2003 Plan was increased by 1,739,116 shares to 3,790,760. During the year ended December 31, 2012, the maximum number of shares of common stock authorized to be issued by the Company under the 2003 Plan was increased by 545,970 shares to 4,336,730. Stock options granted under the 2003 Plan may be either incentive stock options as defined by the Internal Revenue Code (IRC), or non-qualified stock options.

As of December 31, 2014, under the 2003 Plan, there were options to purchase an aggregate of 2,008,474 shares of common stock outstanding at a weighted average exercise price of $1.64 per share. Upon the completion of the IPO, the 2003 Plan was terminated, and no further awards may be issued under the plan. Any shares of common stock subject to awards under the 2003 Plan that expire, terminate, or are otherwise surrendered, canceled, forfeited or repurchased without having been fully exercised, or resulting in any common stock being issued, will become available for issuance under the 2013 Plan, up to a specified number of shares.

In October 2013, the Company implemented the 2013 Plan. The 2013 Plan provides for the grant of stock options and other stock-based awards, as well as cash-based performance awards. The aggregate number of shares of common stock initially available for issuance pursuant to awards under the 2013 Plan is 1,960,168 shares. The number of shares of common stock reserved for issuance will automatically increase on January 1 of each year from January 1, 2014 through and including January 1, 2023, by the lesser of (a) 1,960,168 shares, (b) 4.0% of the total number of shares of common stock outstanding on December 31 of the preceding calendar year, or (c) the number of shares of common stock determined by the Board of Directors. During the year ended December 31, 2014, the maximum number of shares of common stock authorized to be issued by the Company under the 2013 Plan was increased to 2,967,272. If an option expires or terminates for any reason without having been fully exercised, if any shares of restricted stock are forfeited, or if any award terminates, expires or is settled without all or a portion of the shares of common stock covered by the award being issued, such shares are available for the grant of additional awards. However, any shares that are withheld (or delivered) to pay withholding taxes or to pay the exercise price of an option are not available for the grant of additional awards. As of December 31, 2014, under the 2013 Plan, there were options to purchase an aggregate of 1,543,937 shares of common stock outstanding at a weighted average exercise price of $24.22 per share.

The following stock-based compensation amounts were recognized for the periods indicated (in thousands):


	Year Ended December 31,
	2014		2013		2012
Research and development	$	1,562	$	507	$	472
General and administrative		1,682		355		366

Total stock-based compensation expense	$	3,244	$	862	$	838

Employee Stock Options

The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model using the assumptions in the following table:


	Year Ended December 31,
	2014	2013	2012
Expected dividend yield	0%	0%	0%
Expected volatility	67%	53% - 67%	51%
Risk-free interest rate	1.8% - 2.3%	1.2% - 2.2%	1.2%
Expected term.	6.25 years	7 years	7 years

Expected Dividend Yield—The Company has never declared or paid dividends and has no plans to do so in the foreseeable future.

Expected Volatility—Volatility is a measure of the amount by which a financial variable such as a share price has fluctuated (historical volatility) or is expected to fluctuate (expected volatility) during a period. As the Company does not yet have sufficient history of its own volatility, the Company has identified several public entities of similar size, complexity and stage of development and estimates volatility based on the volatility of these companies.

Risk-Free Interest Rate—This is the U.S. Treasury rate for the week of each option grant during the year, having a term that most closely resembles the expected life of the option.

Expected Term—This is the period of time that the options granted are expected to remain unexercised. Options granted have a maximum term of ten years. The Company estimates the expected life of the option term to be 6.25 years. The Company uses a simplified method to calculate the average expected term.

In addition to the assumptions above, the Company estimates the forfeiture rate based on turnover data with further consideration given to the class of the employees to whom the options were granted. The forfeiture rate is the estimated percentage of options granted that is expected to be forfeited or canceled on an annual basis before becoming fully vested.

The following table summarizes stock option and restricted stock unit (RSU) activity for 2014:


	Shares			Weighted- Average Exercise Price		Weighted-Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in thousands)
Outstanding, December 31, 2013		3,200,958		$	4.90		6.9
Granted		976,869			27.06
Exercised		(568,906	)		1.31
Forfeited or expired		(36,805	)		9.76

Outstanding, December 31, 2014		3,572,116			11.40		7.3	$	84,515

December 31, 2014:
Exercisable		1,668,962			3.24		5.3		53,122
Vested and expected to vest		3,341,192			11.03		7.2		80,323

During 2014, 2013 and 2012 the Company issued 568,906, 1,268,049 and 863,176 net shares of common stock, respectively, in conjunction with stock option exercises and RSU lapses. The Company received cash proceeds from the exercise of stock options of approximately $0.7 million, $1.1 million and $47,000 during 2014, 2013 and 2012, respectively.

The weighted-average grant-date fair value of options granted during 2014, 2013 and 2012 was $17.41, $6.91 and $0.94 per share, respectively. The total intrinsic value of options exercised during 2014, 2013 and 2012 was approximately $14.5 million, $5.4 million and $271,929, respectively. The total fair value of stock options which vested during 2014, 2013 and 2012 was $3.0 million, $487,603 and $879,024, respectively. As of December 31, 2014, the total unrecognized compensation expense related to non-vested stock options and RSUs, net of related forfeiture estimates, was $19.6 million, which the Company expects to recognize over a weighted-average period of approximately four years.

- Definition

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

+ References+ Details

Income Taxes

12 Months Ended

Dec. 31, 2014

Income Tax Disclosure [Abstract]

Income Taxes

6. Income Taxes

For the years ended December 31, 2014, 2013 and 2012 there was no current provision for federal or state income taxes due to the taxable losses which resulted or use of legacy NOL carryforwards.

The significant components of the Company’s deferred income tax assets (liabilities) were as follows (in thousands):


	December 31,
	2014			2013
Deferred income tax assets:
Federal U.S. net operating loss carryforward	$	55,358		$	36,561
State net operating loss carryforward		3,723			3,316
Research and development credit, net		7,177			3,786
Orphan drug credit, net		19,287			19,883
Deferred rent		4,069			5,132
Deferred revenue		3,989			8,217
Depreciation		1,337			1,438
Other		962			1,439

Gross deferred income tax assets		95,902			79,772
Valuation allowance		(94,297	)		(79,377	)

Net deferred income tax assets		1,605			395
Deferred income tax liabilities:
Prepaid expenditures		(1,605	)		(395	)

Gross deferred income tax liabilities		(1,605	)		(395	)
Net deferred income tax asset/(liability)	$	—		$	—

The Company recognizes valuation allowances to reduce deferred tax assets to the amount that is more likely than not to be realized. In assessing the likelihood of realization, management considers (i) future reversals of existing taxable temporary differences; (ii) future taxable income exclusive of reversing temporary difference and carryforwards; (iii) taxable income in prior carryback years if carryback is permitted under applicable tax law; and (iv) tax planning strategies. The Company’s net deferred income tax asset is not more likely than not to be utilized due to the lack of sufficient sources of future taxable income and cumulative book losses which have resulted over the years. The net increase in the valuation allowance in 2014 is due to the fact the Company generated research and development and orphan drug credits and NOL carryforwards which increased the net deferred tax asset. The increase in the credits and NOL carryforwards were offset by the decrease in deferred revenue and resulted in a net current year increase to the valuation allowance.

As of December 31, 2014, the Company had U.S. federal NOL carryforwards of approximately $158.9 million and approximately $103.4 million for state that will expire in various years beginning in 2020 through 2034. In addition, the Company has U.S. federal tax credits of $26.3 million which will expire in various years beginning in 2020 through 2034.

The use of the Company’s U.S. federal NOL and tax credit carryforwards in future years are restricted due to changes in the Company’s ownership and tax attributes acquired through the Company’s acquisitions. As of December 31, 2014, $7.1 million of the Company’s US Federal NOLs are limited for use over the years 2015-2027 in which a range of such amounts could be utilized on an annual basis of $0.2 million to $1.4 million. The remaining $151.8 million of NOLs is not limited and can be offset against future taxable income. Additionally, approximately $7.7 million of NOLs will be recognized as a benefit through additional-paid-in-capital when realized. Further, despite the NOL and credit carryforwards, the Company may have a future tax liability due to an alternative minimum tax or state tax requirements in which net operating losses do not exist.

Furthermore, the Company recorded $1.6 million of current deferred tax liability and $1.6 million of noncurrent deferred tax asset as a result of the requirement to allocate its valuation allowance against gross deferred tax assets. As such the balance sheet was grossed up but nets to zero deferred income tax assets/(liabilities).

The reconciliation of the reported estimated income tax benefit to the amount that would result by applying the U.S. federal statutory tax rate to the net income is as follows (in thousands):


	Year Ended December 31,
	2014			2013			2012
United States federal tax at statutory rate	$	(13,410	)	$	(91	)	$	2,927
State taxes (net of federal benefit)		(1,608	)		609			1,460
Deferred income tax adjustments		—			(855	)		(512	)
Deferred state blended rate adjustments		3,034			(344	)		—
Research credit, net		(2,228	)		(226	)		—
Transaction cost deduction		(379	)		—			—
Transaction cost deduction—prior year adjustment		(564	)		—			—
Orphan drug credit, net		(139	)		(843	)		(4,896	)
Other permanent items		(382	)		3			8
Equity-based compensation		756			241			279
Fair value adjustment of preferred stock warrant liability		—			219			(53	)
Change in valuation allowance		14,920			1,287			787

Income tax expense/(benefit)	$	—		$	—		$	—

A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows (in thousands):


	Year Ended December 31,
	2014		2013		2012
Beginning balance	$	1,708	$	1,592	$	1,534
Increases/(decreases) for current year tax positions		242		116		58
Increases/(decreases) for prior year tax positions		97		—		—
Decreases as a result of expiration of statute of limitations		—		—		—

Ending balance	$	2,047	$	1,708	$	1,592

As of December 31, 2014 and 2013, of the total gross unrecognized tax benefits, approximately $1.7 million and $1.3 million would favorably impact the Company’s effective income tax rate, respectively. Although, due to the Company’s determination that the deferred income tax asset would not more likely than not be realized, a valuation allowance would be recorded, therefore, zero net impact would result within the Company’s effective income tax rate. The Company’s uncertain income tax position liability has been recorded to deferred income taxes to offset the tax attribute carryforward amounts.

For the years ended December 31, 2014, 2013 and 2012, the Company has not recognized any interest or penalties related to the uncertain income tax positions due to the fact such position is related to tax attribute carryforwards which have not yet been utilized. The Company does not expect its unrecognized income tax position to significantly decrease within the next twelve months.

The Company’s U.S. Federal and state income tax returns from 2001 to 2014 remain subject to examination by the tax authorities. The Company’s 2001 through 2010 years remain open for examination, even though the statute of limitations has expired, due to the net operating losses and credits carried forward for use in prospective years.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References+ Details

Lease Exit Liability

12 Months Ended

Dec. 31, 2014

Restructuring and Related Activities [Abstract]

Lease Exit Liability

7. Lease Exit Liability

On July 16, 2008, the Company acquired Raven Biotechnologies, Inc. (Raven), a private South San Francisco-based company focused on the development of monoclonal antibody therapeutics for treating cancer. Raven was considered a development-stage enterprise as defined in ASC 915, Development Stage Entities. In connection with the acquisition, the Company issued 12,466,039 shares of its Series D convertible preferred stock in exchange for all of the outstanding capital stock and convertible notes payable of Raven.

The Company undertook restructuring activities related to the acquisition of Raven. These restructuring activities included reductions in staffing levels and the intended exit of leased facilities. All severance-related payments were completed in the year ended December 31, 2009.

In connection with these restructuring activities, as part of the cost of acquisition, the Company established a restructuring liability attributed to an existing operating lease. The terms of the operating lease extend through 2018.

Changes in the lease exit liability are as follows (in thousands):


Accrual balance at December 31, 2012.	$	10,074
Principal payments		(629	)

Accrual balance at December 31, 2013		9,445
Principal payments		(1,439	)

Accrual balance at December 31, 2014	$	8,006

Future principal payments to be made under the lease agreement as of December 31, 2014 are as follows (in thousands):


2015	$	1,642
2016		1,866
2017		2,113
2018		2,385

	$	8,006

The purchase agreement provides for a specified total of certain contingent milestones that are based on the achievement of certain product sales derived from the acquired Raven technology. Also, a onetime payment of $5.0 million will be made to the Raven stockholders upon the initiation of patient dosing in the first Phase 2 clinical trial of any product derived from the Raven “Cancer Stem Cell Program.” No payment shall be made if the Phase 2 trial start date has not occurred on or before July 15, 2018. Other consideration includes a percentage of revenue (excluding consideration for research and development and equity) received by the Company for license of a product derived from the Raven “Cancer Stem Cell Program” and a onetime payment ranging from $8.0 million to $12.0 million dependent upon a specified level of sales of products derived from the Raven “Cancer Stem Cell Program.”

The contingent consideration will be accounted for as additional purchase price and recorded as incremental in-process research and development expense when it is deemed probable that the contingencies will be attained. No additional amounts have been recorded during the years ended December 31, 2014, 2013 and 2012.

- Definition

The entire disclosure for restructuring and related activities. Description of restructuring activities such as exit and disposal activities, include facts and circumstances leading to the plan, the expected plan completion date, the major types of costs associated with the plan activities, total expected costs, the accrual balance at the end of the period, and the periods over which the remaining accrual will be settled.

+ References+ Details

Collaboration and License Agreements	12 Months Ended
Collaboration and License Agreements	Dec. 31, 2014
Text Block [Abstract]
Collaboration and License Agreements	8. Collaboration and License Agreements *Janssen Biotech, Inc.* In December 2014, the Company entered into a collaboration and license agreement with Janssen Biotech, Inc. (Janssen) for the development and commercialization of MGD011, a product candidate that incorporates the Company’s proprietary DART technology to simultaneously target CD19 and CD3 for the potential treatment of B-cell malignancies. The Company contemporaneously entered into a stock purchase agreement and investor agreement, each with Johnson & Johnson Innovation—JJDC, Inc. (JJDC), an affiliate of Janssen, under which JJDC agreed to purchase 1,923,077 new shares of the Company’s common stock at a price of $39.00 per share, representing proceeds of $75.0 million. The effectiveness of these agreements was subject to the early termination or expiration of any applicable waiting periods under Hart-Scott-Rodino Antitrust Improvements Act of 1976, which occurred in January 2015 (see Note 13). The Company is eligible to receive a $50.0 million upfront payment from Janssen after the collaboration and license agreement becomes effective. Janssen will be fully responsible for developing MGD011 following submission of the Investigational New Drug Application (IND), which is planned for 2015. Assuming successful development and commercialization, the Company could receive up to an additional $575.0 million in clinical, regulatory and commercialization milestone payments. The Company may elect to fund a portion of late-stage clinical development in exchange for a profit share in the U.S. and Canada. If commercialized, the Company would be eligible to receive double-digit royalties on any global net sales and has the option to co-promote the molecule with Janssen in the U.S. No revenue was recognized during the year ended December 31, 2014 under this agreement, and no related deferred revenue was recorded as of December 31, 2014. *Takeda* In May 2014, the Company entered into a license and option agreement with Takeda for the development and commercialization of MGD010, a product candidate that incorporates the Company’s proprietary DART technology to simultaneously engage CD32B and CD79B, which are two B-cell surface proteins. MGD010 is currently in pre-clinical development for the treatment of autoimmune diseases. Upon execution of the agreement, Takeda made a non-refundable payment of $15.0 million to the Company. Takeda has an option to obtain an exclusive worldwide license for MGD010 following the completion of a pre-defined Phase 1a study. The Company will lead all product development activities until that time. If Takeda exercises its option, it will assume responsibility for future development and pay the Company a license option fee that, along with an early development milestone, will total $18.0 million. Assuming successful development and commercialization of MGD010, the Company is eligible to receive up to an additional $468.5 million in development, regulatory and sales milestone payments. If commercialized, the Company would receive double-digit royalties on any global net sales and has the option to co-promote MGD010 with Takeda in the United States. Finally, the Company may elect to fund a portion of Phase 3 clinical development in exchange for a North American profit share. The Company evaluated the license and option agreement with Takeda and has determined that it is a revenue arrangement with multiple deliverables, or performance obligations. The Company’s substantive performance obligations under the license and option agreement include exclusivity, research and development services through the Phase 1a study and delivery of a future license for an initial research compound. The Company concluded that the MGD010 option is substantive and that the license fee payable upon exercise of the option is not a deliverable at the inception of the arrangement as there is considerable uncertainty that the option would be exercised. The Company has determined that each potential future development and regulatory milestone is substantive. Although sales milestones are not considered substantive, they are still recognized upon achievement of the milestone (assuming all other revenue recognition criteria have been met) because there are no undelivered elements that would preclude revenue recognition at that time. The Company determined that these performance obligations represent a single unit of accounting, because the exclusivity clause does not have stand-alone value to Takeda without the Company’s technical expertise and development through the pre-defined Phase 1a study. After identifying the deliverables included within the arrangement, the Company determined its best estimate of selling price. The Company allocated $10.0 million to the exclusivity clause to its technology and the research and development services and $5.0 million to the exclusive license for the initial research compound. The Company’s determination of best estimate of selling price for the research and development services relied upon other similar transactions. The Company relied upon the income approach (e.g., future cash flows) to determine the value of the license of the to-be-delivered compound along with other similar license transactions with differing indications but similar stage of development. The portion of the up-front fee allocated to the MGD010 option is being recognized over an initial 24-month period, which represents the expected period of development through the completion of a pre-defined Phase 1a study. The portion of the up-front fee allocated to the license for the initial research compound was deferred until the research collaboration and license option agreement was executed and the license delivered. The Company recognized revenue of approximately $3.0 million under the MGD010 agreement during the year ended December 31, 2014. At December 31, 2014, $7.1 million of revenue was deferred under this agreement, $5.0 million of which was current and $2.1 million of which was non-current. In September 2014, the Company and Takeda executed a research collaboration and license option agreement, which formalized the license for the initial research compound. Under the terms of the agreement, Takeda may identify up to three additional compounds, which will be subject to separate research and development plans. The Company determined that it could recognize the entire license fee as (1) the executed contract constituted persuasive evidence of an arrangement, (2) the delivery of the license occurred and the Company had no current or future performance obligations, (3) the total consideration for the license was fixed and known at the time of its execution and there were not any extended payment terms or rights of return, and (4) the cash was received. Therefore, the Company recognized $5.0 million in revenue during the year ended December 31, 2014 under this agreement. The Company is also entitled to receive reimbursements for research and development services provided to Takeda with respect to the initial research compound, subject to the execution of a separate research plan. *Gilead* In January 2013, the Company entered into an agreement with Gilead for Gilead to obtain exclusive worldwide rights for the research, development and commercialization of up to four DART molecules. For each molecule Gilead chooses to develop, the Company is entitled to receive a license grant fee of $7.5 million and is further eligible to receive up to an additional $20.0 million to $25.0 million in pre-clinical milestones and up to $240.0 million to $250.0 million in additional clinical, regulatory and sales milestones. Upon execution of the arrangement, Gilead identified one molecule to develop for which the Company granted Gilead a license in exchange for consideration of $7.5 million. The Company determined that any remaining licenses are conditional deliverables, which are substantive options that were not granted with a substantial discount. The Company has determined that each potential future clinical, development and regulatory milestone is substantive. Although sales milestones are not considered substantive, they are still recognized upon achievement of the milestone (assuming all other revenue recognition criteria have been met) because there are no undelivered elements that would preclude revenue recognition at that time. Gilead also provides funding for the Company’s internal and external research costs under the agreement. Additionally, Gilead would be obligated to pay the Company high single digit to low double digit royalties on product sales. The Company evaluated the research collaboration agreement with Gilead and has determined that it is a revenue arrangement with multiple deliverables, or performance obligations. The Company’s substantive performance obligations under this research collaboration include a license to its technology and research and development services. The Company concluded that the deliverables do not have stand alone value and therefore, represent a combined single unit of accounting. Due to the lack of standalone value for the license and research and development services, the combined unit of accounting (the upfront payment and the expected research and development reimbursements) was recognized ratably over a period of 21 months, which represented the expected development period. The Company and Gilead have also agreed to establish a joint research committee to facilitate the governance and oversight of the parties’ activities under the agreements. Management considered whether participation on the joint committee may be a deliverable and determined that it was not a deliverable. Had management considered participation on the joint committee as a deliverable, it would not have had a material impact on the accounting for the arrangement. The Company recognized revenues of approximately $5.5 million and $8.0 million under this agreement for the years ended December 31, 2014 and 2013, respectively. No milestones have been achieved under this agreement. At December 31, 2013, $3.6 million of revenue was deferred under this agreement, all of which was current. As of December 31, 2014, there was no remaining deferred revenue under this agreement. *Servier* In November 2011, the Company entered into a right-to-develop collaboration agreement with Servier for the development and commercialization of MGA271 in all countries other than the United States, Canada, Mexico, Japan, South Korea and India. Upon execution of the agreement, Servier made a nonrefundable payment of $20.0 million to the Company. The Company is eligible to receive up to $30.0 million in license grant fees, $47.0 million in clinical milestone payments, $140.0 million in regulatory milestone payments and $208.0 million in sales milestone payments if Servier exercises the option, obtains regulatory approval for and successfully commercializes MGA271. The Company concluded that the license option fees are not deliverables at the inception of the arrangement. The Company has determined that each potential future clinical, development and regulatory milestone is substantive. Although sales milestones are not considered substantive, they are still recognized upon achievement of the milestone (assuming all other revenue recognition criteria have been met) because there are no undelivered elements that would preclude revenue recognition at that time. In the event Servier exercises its option to continue development of MGA271, Servier must pay a license option fee. Under this agreement, Servier would be obligated to pay the Company from low double digit to mid-teen royalties on product sales in its territories. The Company evaluated the research collaboration agreement with Servier and has determined that it is a revenue arrangement with multiple deliverables, or performance obligations. The Company concluded that the option is substantive and that the license fees for this option is not a deliverable at the inception of the arrangement as there is considerable uncertainty that the option would be exercised and the additional fee to be paid upon exercise of the option represents its estimated selling price (i.e. no substantial discount was given). The Company’s substantive performance obligations under this research collaboration include an exclusivity clause to its technology, technical, scientific and intellectual property support to the research plan and participation on an executive committee and a research and development committee. The Company determined that these performance obligations represent a single unit of accounting, since the license does not have stand-alone value to Servier without the Company’s technical expertise and committee participation. As such, the initial upfront payment was deferred and was being recognized ratably over the initial 27-month period, which represented the expected period of development and the Company’s participation on the research and development committee. During 2014, the Company determined that the development period will last longer than originally estimated, and prospectively adjusted its period of recognition of the upfront payment to a 42-month period. During the years ended December 31, 2014, 2013 and 2012 the Company recognized revenue of $0.7 million, $21.3 million and $9.1 million, respectively, under this agreement. Revenue recognized in the year ended December 31, 2013 included a $10.0 million substantive milestone payment received upon dosing the first patient in a Phase 1 dose expansion cohort trial of MGA271. At December 31, 2014 and 2013, $0.1 million and $0.9 million of revenue remained deferred under this agreement, respectively, all of which was current. In September 2012, the Company entered into a second right-to-develop collaboration agreement with Servier and granted it options to obtain three separate exclusive licenses to develop and commercialize DART-based molecules, consisting of those designated by the Company as MGD006 and MGD007, as well as a third DART molecule, in all countries other than the United States, Canada, Mexico, Japan, South Korea and India. Upon execution of the agreement, Servier made a nonrefundable payment of $20.0 million to the Company. In addition, the Company will be eligible to receive up to $65.0 million in license grant fees, $98.0 million in clinical milestone payments, including $5.0 million upon IND acceptance for each of MGD006, MGD007 and a third DART molecule, $300.0 million in regulatory milestone payments and $630.0 million in sales milestone payments if Servier exercises all of the options and successfully develops, obtains regulatory approval for, and commercializes a product under each license. In addition to these milestones, the Company and Servier will share Phase 2 and Phase 3 development costs. The Company has determined that each potential future clinical, development and regulatory milestone is substantive. Although sales milestones are not considered substantive, they are still recognized upon achievement of the milestone (assuming all other revenue recognition criteria have been met) because there are no undelivered elements that would preclude revenue recognition at that time. Under this agreement, Servier would be obligated to pay the Company between high-single digit and mid-teen royalties on net product sales in its territories. The Company evaluated the research collaboration agreement with Servier and has determined that it is a revenue arrangement with multiple deliverables, or performance obligations. The Company concluded that each option is substantive and that the license fees for each option are not deliverables at the inception of the arrangement and were not issued with a substantial discount. The Company’s substantive performance obligations under this research collaboration include an exclusivity clause to its technology, technical, scientific and intellectual property support to the research plan during the first year of the agreement and participation on an executive committee and a research and development committee. The Company determined that the performance obligations with respect to the pre-clinical development represent a single unit of accounting, since the license does not have stand-alone value to Servier without the Company’s technical expertise and committee participation. As such, the initial upfront license payment was deferred and initially recognized ratably over a 29-month period, which represented the expected development period. During 2014, the Company and Servier further refined the research plan related to the three DARTs and as such, the development period was extended. Based on this revised development period, the Company prospectively adjusted its period of recognition of the upfront payment to a 75-month period. The impact of this change in accounting estimate reduced revenue that would have been recognized in 2014 by $3.7 million. During the year ended December 31, 2014, Servier exercised its exclusive option to develop and commercialize MGD006. As a result of the exercise, the Company received a $15.0 million payment from Servier for its license to develop and commercialize MGD006 in its territories. Upon exercise of the option, the Company evaluated its performance obligations with respect to the license for MGD006. The Company’s substantive performance obligations under this research collaboration include an exclusive license to its technology, technical, scientific and intellectual property support to the research plan and participation on an executive committee and a research and development committee. The Company determined that the performance obligations with respect to the clinical development represent a single unit of accounting, since the license does not have stand-alone value to Servier without the Company’s technical expertise and committee participation. As such, the $15.0 million license fee was deferred and is being recognized ratably over a period of 82 months, which represents the expected development period for MGD006. In accordance with the agreement, the Company and Servier will share costs incurred to develop MGD006. Reimbursement of research and development expenses received in connection with this collaborative cost-sharing agreement is recorded as a reduction to research and development expense. During the year ended December 31, 2014 the Company recorded approximately $1.0 million as an offset to research and development costs under this collaboration arrangement. No such offset was recorded in 2013 or 2012. As of December 31, 2014 the Company has a corresponding collaboration receivable, which is included in accounts receivable on the consolidated balance sheet, of $0.8 million. During the years ended December 31, 2014, 2013 and 2012 the Company recognized revenue of $16.7 million, $8.6 million, and $2.0 million, respectively, under this agreement. Revenue during the year ended December 31, 2014 includes two $5.0 million milestone payments from Servier upon the achievement of clinical milestones related to the IND applications for MGD006 and MGD007 clearing the 30-day review period by the U.S. FDA. No milestones were recognized under this agreement during the years ended December 31, 2013 or 2012. At December 31, 2014, $17.7 million of revenue was deferred under this agreement, $3.3 million of which was current and $14.4 million of which was long-term. At December 31, 2013, $9.4 million of revenue was deferred under this agreement, $8.6 million of which was current and $0.8 million of which was long-term. *Boehringer* In October 2010 the Company entered into a collaboration and license agreement with Boehringer to discover, develop and commercialize up to ten DART-based molecules which span multiple therapeutic areas. Under the terms of the agreement, the Company granted Boehringer an exclusive, worldwide, royalty-bearing, license under its intellectual property to research, develop, and market DARTs generated under the agreement throughout the world. Upon execution of the agreement, the Company received an upfront payment of $15.0 million. The Company subsequently received three annual maintenance payments. These maintenance payments are being recognized over the estimated period of development. The Company has the potential to earn milestone payments of approximately $41.0 million related to pre-clinical and clinical development, $89.0 million related to regulatory milestones and $83.0 million related to sales milestones for each of the DART programs under this agreement in the case of full commercial success of multiple DART products. The Company has determined that each potential future clinical, development and regulatory milestone is substantive. Although sales milestones are not considered substantive, they are still recognized upon achievement of the milestone (assuming all other revenue recognition criteria have been met) because there are no undelivered elements that would preclude revenue recognition at that time. Boehringer also provides funding for the Company’s internal and external research costs and is required to pay the Company mid-single digit royalties on product sales. The Company determined that the deliverables under the Boehringer agreement include the license, the research and development services to be performed by the Company, and the co-promotion/manufacturing services. The Company concluded that the co-promotional activities were optional and were subject to further negotiation upon reaching regulatory approval. As such, the co-promotional period is not included in the expected obligation period to perform services. The Company concluded that the undelivered element of research and development services had fair value. The Company concluded that the license does not have value on a standalone basis (e.g. absent the provision of the research and development services) and therefore does not represent a separate unit of accounting. The Company concluded that because the drug candidate has not yet been developed, the license is of no value to Boehringer without the ensuing research and development activities using the DART technology, which is proprietary to the Company. Likewise, Boehringer could not sell the license to another party (without the Company agreeing to provide the research and development activities for the other party). Therefore, the upfront license fee and research and development services were treated as a combined unit of accounting and recognized over the expected obligation period associated with the research and development services through September 2015, which represents the estimated period of development. The Company and Boehringer have also agreed to establish a joint research committee to facilitate the governance and oversight of the parties’ activities under the agreements. Management considered whether participation on the joint committee may be a deliverable and determined that it was not a deliverable. However, had management considered participation on the joint committee as a deliverable, it would not have had a material impact on the accounting for the arrangement as the period of participation in this committee matched the obligation period for the research and development services. The Company recognized revenues of approximately $13.7 million, $14.4 million and $11.7 million during the years ended December 31, 2014, 2013 and 2012, respectively, under this agreement. Revenue recognized in the years ended December 31, 2014, 2013 and 2012 included milestone payments of $2.0 million, $5.0 million and $2.0 million, respectively, for the achievement of clinical milestones. At December 31, 2014, $5.8 million of revenue was deferred under this agreement, all of which was current. At December 31, 2013, $12.8 million of revenue was deferred under this agreement, $7.0 million of which was current and $5.8 million of which was long-term. *Pfizer* In October 2010, the Company entered into a three year agreement with Pfizer to discover, develop and commercialize up to two DART-based molecules. The Company granted Pfizer a non-exclusive worldwide, royalty-bearing license and received an upfront payment of $5.0 million and has received milestone payments and funding for the Company’s internal and external research costs under the agreement. The Company is eligible to receive milestone payments of approximately $17.0 million related to pre-clinical and clinical development and $195.0 million related to commercialization and sales milestones for each DART program under this agreement. The Company has determined that each potential future technical and development milestone is substantive. Although sales milestones are not considered substantive, they are still recognized upon achievement of the milestone (assuming all other revenue recognition criteria have been met) because there are no undelivered elements that would preclude revenue recognition at that time. Pfizer is responsible for all pre-clinical and clinical development costs for the program. In addition, Pfizer is required to pay the Company mid-single digit to low-teen royalties on product sales. Under this collaboration, one DART program is currently being pursued and the Company completed its research obligations under this program in January 2014. The Company has evaluated the research collaboration agreement with Pfizer and has determined that it is a revenue arrangement with multiple deliverables, or performance obligations. The Company’s substantive performance obligations under this research collaboration include an exclusive license to its technology, research and development services and manufacturing services. The Company concluded that the manufacturing services were optional and were subject to further negotiation upon reaching regulatory approval. As such, the manufacturing services are not included in the expected obligation period to perform services. The Company determined that it had fair value of the undelivered element of the research and development services. However, the Company concluded that the license does not have value on a standalone basis (e.g. absent the provision of the research and development services) and therefore does not represent a separate unit of accounting. Facts that were considered included the development of the candidate noting that because the drug candidate has not yet been developed, the license is of no value to Pfizer without the ensuing research and development activities using the DART technology, which is proprietary to the Company. Likewise, Pfizer could not sell the license to another party (without the Company agreeing to provide the research and development activities for the other party). Therefore, the upfront license fee and research and development services were treated as a combined unit of accounting and recognized over the expected obligation period associated with the research and development services through January 2014, which represents the estimated period of development. The $5.0 million upfront payment received by the Company is non-refundable; therefore, there is no right of return for the license. The Company recognized revenue associated with this non-refundable up-front license fee through the expected obligation period associated with the research and development services, which ended in January 2014. The Company and Pfizer have also agreed to establish a joint research committee to facilitate the governance and oversight of the parties’ activities under the agreements. Management considered whether participation on the joint committee may be a deliverable and determined that it was not a deliverable because it is a participating right and not an obligation of the Company. However, had management considered participation on the joint committee as a deliverable, it would not have had a material impact on the accounting for the arrangement. The Company recognized revenues of approximately $0.1 million, $3.5 million and $5.5 million during the years ended December 31, 2014, 2013 and 2012, respectively. Included in the 2012 revenues are milestone payments totaling $0.5 million. No additional milestones have been achieved under this agreement through December 31, 2014. At December 31, 2013, deferred revenue under this agreement was approximately $7,000. As of December 31, 2014, there was no remaining deferred revenue under this agreement. *Green Cross* In June 2010, the Company entered into a collaboration agreement with Green Cross for the development of the Company’s anti-HER2 antibody margetuximab. This arrangement grants Green Cross an exclusive license to conduct specified Phase 1 and Phase 2 clinical trials and commercialize margetuximab in South Korea. In March 2014, the Company and Green Cross entered into an amendment to the original agreement, causing the terms of the original agreement to be materially modified. Upon execution of the amendment, the Company became eligible to receive reimbursement for costs incurred for Phase 2 and Phase 3 clinical trials up to $5.5 million as well as clinical development and commercial milestone payments of up to $2.5 million. The Company has determined that each potential clinical development and commercial milestone is substantive. The Company is also entitled to receive royalties on net sales of margetuximab in South Korea. The Company and Green Cross have formed a joint steering committee to coordinate and oversee activities on which the companies collaborate under the agreement. The Company has evaluated the collaboration agreement with Green Cross and has determined that it is a revenue arrangement with multiple deliverables or performance obligations. As a result of the material modification to the arrangement in March 2014, the Company reassessed the entire arrangement in accordance with the guidance provided by ASC 605-25, Multiple Element Arrangements (Revenue Recognition) as the original agreement was accounted for prior to adopting ASU 2009-13. The Company’s substantive performance obligations under this agreement include an exclusive license to its technologies, research and development services, and participation in a joint steering committee. The Company concluded that the license and the reimbursements for research and development services do not have value on a standalone basis and therefore do not represent a separate unit of accounting. The initial $1.0 million upfront payment received by the Company upon execution of the original agreement is non-refundable; as such, there is no right of return for the license. Therefore, the upfront license fee and participation on the joint steering committee were treated as a combined unit of accounting and will be recognized over the term of the agreement through June 2020. Further, due to the fact the research and development services are not deemed to have stand-alone value, revenue for those services should be recognized over the entire term of the agreement (through June 2020). As a result of reassessing the arrangement in accordance with ASC 605-25, the Company was required to record an adjustment on the date of the material modification to reflect the revenue that would have resulted had the entity applied the requirements of ASC 605-25 from the inception of the agreement. As a result, the Company recorded an additional $1.3 million of revenue during 2014. The Company recognized revenues of approximately $1.7 million and $100,000 under this agreement during the years ended December 31, 2014 and 2013, respectively. No milestones were achieved under this agreement during the years ended December 31, 2014 and 2013. At December 31, 2014, there was a $525,000 unbilled receivable balance under this agreement, which is included in other assets on the consolidated balance sheet. At December 31, 2013, $650,000 of revenue was deferred under this agreement, $100,000 of which was current and $550,000 of which was non-current. *Eli Lilly* In October 2007, the Company entered into an exclusive license and collaboration agreement (together, the Agreements) with Eli Lilly to jointly develop and commercialize teplizumab, a humanized anti-CD3 monoclonal antibody. As part of the Agreements, Eli Lilly acquired the exclusive rights to the molecule. Upon execution of the Agreements, Eli Lilly made a nonrefundable payment of $41.0 million to the Company. In May 2008, Eli Lilly paid the Company a milestone payment of $50.0 million and in May 2010, Eli Lilly paid an additional milestone of $5.0 million. On October 28, 2010, Lilly notified the Company of its decision to terminate the agreement after review of one year of clinical data from the Protégé trial in Type 1 diabetes patients treated with teplizumab. Such data failed to support the primary efficacy end point in the study. In February 2011, the Company reacquired the commercial rights to the molecule from Eli Lilly. During the year ended December 31, 2012, Eli Lilly satisfied its obligation related to the cost of monitoring patients under the Protégé and Encore trials. The Company’s obligations continued through September 2012, which represented the follow up period for enrolled patients and the Company’s final reporting of the trial’s results. There is no additional clinical trial activity under the Eli Lilly Agreements as it relates to such trials. However, Eli Lilly continues to reimburse the Company for monitoring patients in one currently active trial. During the years ended December 2014, 2013 and 2012, the Company recognized revenue of $0.4 million, $0.8 million and $31.2 million, respectively, under this agreement. No milestones were achieved under this agreement during the three years ended December 31, 2014.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2014

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

9. Commitments and Contingencies

Operating Leases

The Company leases office and laboratory space for its headquarters in Rockville, Maryland. In 2014, that lease was amended to extend its term from March 31, 2018 to January 31, 2020. In addition, in 2014, the Company leased additional office space adjacent to its headquarters, also through January 31, 2020. The Company has an option under each lease to continue the respective lease for five years under the same terms.

The Company leases a manufacturing facility in Rockville under a lease that originally expired on December 31, 2014. During 2014, the Company exercised its 5-year renewal option on the manufacturing facility. The Company also entered into a new four-year lease for additional space in the manufacturing facility effective April 1, 2014. This lease also has an option to continue the lease for five years under the same terms.

The Company also leases office and laboratory space in South San Francisco under a lease that expires on February 28, 2018.

All of the leases contain rent escalation clauses and certain leases contain rent abatements. For financial reporting purposes, rent expense is charged to operations on a straight-line basis over the term of the lease. As of December 31, 2014 and 2013, the Company had recorded a deferred rent liability of $2.7 million and $2.9 million, respectively. Rent expense for the years ended December 31, 2014, 2013 and 2012 was $2.0 million, $2.7 million and $2.7 million, respectively.

Future minimum lease payments under noncancelable operating leases as of December 31, 2014 are as follows (in thousands):


2015	$	3,945
2016		4,364
2017		4,495
2018		4,396
2019		1,873
Thereafter		116

	$	19,189

Contingencies

From time to time, the Company may be subject to various litigation and related matters arising in the ordinary course of business. The Company does not believe it is currently subject to any material matters where there is at least a reasonable possibility that a material loss may be incurred.

- Definition

The entire disclosure for commitments and contingencies.

+ References+ Details

Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plan	11. Employee Benefit Plan On September 25, 2002, the Company established the MacroGenics 401(k) Plan (the Plan) for its employees under Section 401(k) of the IRC. Under this Plan, all employees at least 21 years of age are eligible to participate in the Plan, starting on the first day of each month. Employees may contribute up to 100% of their salary, subject to government maximums. Employees are 100% vested in their contributions to the Plan. The Company’s contribution to the Plan, as determined by the Board of Directors, is discretionary. The Company’s contributions to the Plan totaled $318,390, $252,930 and $225,195 for the years ended December 31, 2014, 2013 and 2012, respectively.

- Definition

The entire disclosure for pension and other postretirement benefits.

+ References+ Details

Quarterly Financial Information

12 Months Ended

Dec. 31, 2014

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information

12. Quarterly Financial Information (unaudited)


	1^st Quarter			2^nd Quarter			3^rd Quarter			4^th Quarter
	(in thousands, except per share data)
2014
Revenue	$	14,719		$	9,220		$	18,382		$	5,476
Net loss		(3,108	)		(12,259	)		(3,928	)		(19,018	)
Net loss per share, basic and diluted	$	(0.12	)	$	(0.44	)	$	(0.14	)	$	(0.68	)
2013
Revenue	$	10,598		$	12,299		$	20,232		$	14,906
Net income (loss)		(3,366	)		(294	)		6,604			(3,205	)
Net income (loss) per share, basic	$	(2.93	)	$	(0.24	)	$	0.14		$	(0.14	)
Net income (loss) per share, diluted	$	(2.93	)	$	(0.24	)	$	0.01		$	(0.14	)

Net income (loss) per share includes the effects of income allocated to participating securities.

- Definition

The entire disclosure for the quarterly financial data in the annual financial statements. The disclosure may include a tabular presentation of financial information for each fiscal quarter for the current and previous year, including revenues, gross profit, income or loss before extraordinary items and earnings per share data. It also includes an indication if the information in the note is unaudited, comments on the aggregate effect of year-end adjustments, and an explanation of matters or transactions that affect comparability or are pertinent to an understanding of the information furnished.

+ References+ Details

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2014

Accounting Policies [Abstract]

Basis of Presentation and Principles of Consolidation

Basis of Presentation and Principles of Consolidation

Use of Estimates

Use of Estimates

Cash and Cash Equivalents

Cash and Cash Equivalents

Accounts Receivable

Accounts Receivable

Restricted Cash

Restricted Cash

Fair Value of Financial Instruments

Fair Value of Financial Instruments

•

Level 1—Fair value is determined by using unadjusted quoted prices that are available in active markets for identical assets and liabilities.

•

Financial assets and liabilities subject to fair value measurements were as follows (in thousands):


	Fair Value Measurements at December 31, 2014
			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	131,545	$	131,545	$	—	$	—
Money market funds		26,046		26,046		—		—
Restricted cash		300		300		—		—

Total Assets	$	157,891	$	157,891	$	—	$	—


	Fair Value Measurements at December 31, 2013
			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	90,434	$	90,434	$	—	$	—
Money market funds		26,047		26,047		—		—
Restricted cash		405		405		—		—

Total Assets	$	116,886	$	116,886	$	—	$	—

Concentration of Credit Risk

Concentration of Credit Risk

The following table includes those collaborators that represent more than 10% of total revenue earned in the periods indicated:


	Year Ended December 31,
	2014			2013			2012
Servier		36.4	%		51.6	%		17.3	%
Boehringer		28.6	%		24.8	%		18.4	%
Takeda		16.8	%		—			—
Gilead		11.4	%		13.8	%		—
Eli Lilly		0.9	%		1.4	%		48.9	%

The following table includes those collaborators that represent more than 10% of accounts receivable at the date indicated:


	December 31,
	2014			2013
Servier		33.3	%		6.4	%
Boehringer		21.2	%		12.2	%
Green Cross		17.9	%		—
Gilead		—			53.4	%
Pfizer		—			12.3	%

Property and Equipment

Property and Equipment


Computer equipment		3 years
Software		3 years
Furniture		10 years
Laboratory and office equipment		5 years
Leasehold improvements		Shorter of lease term or useful life

Impairment of Long-Lived Assets

Impairment of Long-Lived Assets

Income Taxes

Income Taxes

Revenues

Revenues

Revenue Recognition

There are no performance, cancellation, termination or refund provisions in any of the arrangements that contain material financial consequences to the Company.

Exclusive Licenses

The Company does not directly control when any collaborator will achieve milestones or become liable for royalty payments.

Right-to-Develop Agreements

Research and Development Costs

Research and Development Costs

Comprehensive Income (Loss)

Comprehensive Income (Loss)

Stock-based Compensation

Stock-based Compensation

Net Income (Loss) Per Share

Net Income (Loss) Per Share

Basic and diluted income (loss) per common share is computed as follows (in thousands except share and per share data):


	Year Ended December 31,
	2014			2013			2012
Net income (loss)	$	(38,313	)	$	(261	)	$	8,362
Less: undistributed earnings allocated to participating securities		—			—			(8,362	)

Net income (loss) allocable to common shares	$	(38,313	)	$	(261	)	$	—

Basic weighted average common shares outstanding		27,384,990			6,847,697			1,083,276
Basic income (loss) per common share	$	(1.40	)	$	(0.04	)	$	0.00
Net income (loss)	$	(38,313	)	$	(261	)	$	8,362
Less: undistributed earnings allocated to participating securities and other add-backs to net income (loss)		—			—			(8,362	)

Net income (loss) allocable to common shares	$	(38,313	)	$	(261	)	$	—

Basic weighted average common shares outstanding		27,384,990			6,847,697			1,083,276
Effect of dilutive securities		—			—			—

Diluted weighted average common shares outstanding		27,384,990			6,847,697			1,083,276

Diluted income (loss) per common share	$	(1.40	)	$	(0.04	)	$	0.00

The following common stock equivalents were excluded from the calculation of diluted net income (loss) per share because their effect would be anti-dilutive:


	Year Ended December 31,
	2014		2013		2012
Series A-1 Preferred Stock		—		—		2,156,114
Series A-2 Preferred Stock		—		—		392,274
Series B Preferred Stock		—		—		4,336,037
Series C Preferred Stock		—		—		5,909,906
Series D Preferred Stock		—		—		769,468
Series D-2 Preferred Stock		—		—		3,391,991
Effect of Converted Preferred Stock		—		13,189,920		—
Warrants to purchase Series D-2 Preferred Stock		—		—		180,784
Stock Options		2,094,904		2,313,970		3,249,702

Recently Issued Accounting Standards

Recently Issued Accounting Standards

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2014

Summary of Fair Value Measurement Financial Asset and Liabilities

Financial assets and liabilities subject to fair value measurements were as follows (in thousands):


	Fair Value Measurements at December 31, 2014
			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	131,545	$	131,545	$	—	$	—
Money market funds		26,046		26,046		—		—
Restricted cash		300		300		—		—

Total Assets	$	157,891	$	157,891	$	—	$	—


	Fair Value Measurements at December 31, 2013
			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		Level 1		Level 2		Level 3
Assets:
Cash and cash equivalents	$	90,434	$	90,434	$	—	$	—
Money market funds		26,047		26,047		—		—
Restricted cash		405		405		—		—

Total Assets	$	116,886	$	116,886	$	—	$	—

Estimated Useful Lives

Repairs and maintenance costs are expensed as incurred. Depreciation is computed using the straight-line method over the following estimated useful lives:


Computer equipment		3 years
Software		3 years
Furniture		10 years
Laboratory and office equipment		5 years
Leasehold improvements		Shorter of lease term or useful life

Computation of Basic and Diluted Income (Loss) Per Common Share

Basic and diluted income (loss) per common share is computed as follows (in thousands except share and per share data):


	Year Ended December 31,
	2014			2013			2012
Net income (loss)	$	(38,313	)	$	(261	)	$	8,362
Less: undistributed earnings allocated to participating securities		—			—			(8,362	)

Net income (loss) allocable to common shares	$	(38,313	)	$	(261	)	$	—

Basic weighted average common shares outstanding		27,384,990			6,847,697			1,083,276
Basic income (loss) per common share	$	(1.40	)	$	(0.04	)	$	0.00
Net income (loss)	$	(38,313	)	$	(261	)	$	8,362
Less: undistributed earnings allocated to participating securities and other add-backs to net income (loss)		—			—			(8,362	)

Net income (loss) allocable to common shares	$	(38,313	)	$	(261	)	$	—

Basic weighted average common shares outstanding		27,384,990			6,847,697			1,083,276
Effect of dilutive securities		—			—			—

Diluted weighted average common shares outstanding		27,384,990			6,847,697			1,083,276

Diluted income (loss) per common share	$	(1.40	)	$	(0.04	)	$	0.00

Schedule of Antidilutive Securities Excluded from the Calculation of Diluted Income (Loss) Per Share

The following common stock equivalents were excluded from the calculation of diluted net income (loss) per share because their effect would be anti-dilutive:


	Year Ended December 31,
	2014		2013		2012
Series A-1 Preferred Stock		—		—		2,156,114
Series A-2 Preferred Stock		—		—		392,274
Series B Preferred Stock		—		—		4,336,037
Series C Preferred Stock		—		—		5,909,906
Series D Preferred Stock		—		—		769,468
Series D-2 Preferred Stock		—		—		3,391,991
Effect of Converted Preferred Stock		—		13,189,920		—
Warrants to purchase Series D-2 Preferred Stock		—		—		180,784
Stock Options		2,094,904		2,313,970		3,249,702

Summary of Significant Revenue [Member]

Summary of Percentage of Customer Concentration

The following table includes those collaborators that represent more than 10% of total revenue earned in the periods indicated:


	Year Ended December 31,
	2014			2013			2012
Servier		36.4	%		51.6	%		17.3	%
Boehringer		28.6	%		24.8	%		18.4	%
Takeda		16.8	%		—			—
Gilead		11.4	%		13.8	%		—
Eli Lilly		0.9	%		1.4	%		48.9	%

Summary of Significant Accounts Receivable[Member]

Summary of Percentage of Customer Concentration

The following table includes those collaborators that represent more than 10% of accounts receivable at the date indicated:


	December 31,
	2014			2013
Servier		33.3	%		6.4	%
Boehringer		21.2	%		12.2	%
Green Cross		17.9	%		—
Gilead		—			53.4	%
Pfizer		—			12.3	%

- Definition

Tabular disclosure of financial instruments measured at fair value, including those classified in shareholders' equity measured on a recurring or nonrecurring basis. Disclosures include, but are not limited to, fair value measurements recorded and the reasons for the measurements, level within the fair value hierarchy in which the fair value measurements are categorized and transfers between levels 1 and 2. Nonrecurring fair value measurements are those that are required or permitted in the statement of financial position in particular circumstances.

+ References+ Details

- Definition

Tabular disclosure of the nature of a concentration, a benchmark to which it is compared, and the percentage that the risk is to the benchmark.

+ References+ Details

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2014

Property, Plant and Equipment [Abstract]

Schedule of Property and Equipment

Property and equipment consists of the following (in thousands):


	December 31,
	2014			2013
Computer equipment	$	2,596		$	2,379
Software		1,683			1,477
Furniture and office equipment		751			651
Lab equipment		13,917			11,166
Leasehold improvements		5,193			4,894

Property and equipment		24,140			20,567
Less accumulated depreciation		(17,355	)		(15,532	)

Property and equipment, net	$	6,785		$	5,035

Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2014

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Stock-Based Compensation Expense

The following stock-based compensation amounts were recognized for the periods indicated (in thousands):


	Year Ended December 31,
	2014		2013		2012
Research and development	$	1,562	$	507	$	472
General and administrative		1,682		355		366

Total stock-based compensation expense	$	3,244	$	862	$	838

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model using the assumptions in the following table:


	Year Ended December 31,
	2014	2013	2012
Expected dividend yield	0%	0%	0%
Expected volatility	67%	53% - 67%	51%
Risk-free interest rate	1.8% - 2.3%	1.2% - 2.2%	1.2%
Expected term.	6.25 years	7 years	7 years

Schedule of Stock Option and Restricted Stock Unit Activity

The following table summarizes stock option and restricted stock unit (RSU) activity for 2014:


	Shares			Weighted- Average Exercise Price		Weighted-Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value (in thousands)
Outstanding, December 31, 2013		3,200,958		$	4.90		6.9
Granted		976,869			27.06
Exercised		(568,906	)		1.31
Forfeited or expired		(36,805	)		9.76

Outstanding, December 31, 2014		3,572,116			11.40		7.3	$	84,515

December 31, 2014:
Exercisable		1,668,962			3.24		5.3		53,122
Vested and expected to vest		3,341,192			11.03		7.2		80,323

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Income Tax Disclosure [Abstract]

Components of the Company's Deferred Income Tax Assets (Liabilities)

The significant components of the Company’s deferred income tax assets (liabilities) were as follows (in thousands):


	December 31,
	2014			2013
Deferred income tax assets:
Federal U.S. net operating loss carryforward	$	55,358		$	36,561
State net operating loss carryforward		3,723			3,316
Research and development credit, net		7,177			3,786
Orphan drug credit, net		19,287			19,883
Deferred rent		4,069			5,132
Deferred revenue		3,989			8,217
Depreciation		1,337			1,438
Other		962			1,439

Gross deferred income tax assets		95,902			79,772
Valuation allowance		(94,297	)		(79,377	)

Net deferred income tax assets		1,605			395
Deferred income tax liabilities:
Prepaid expenditures		(1,605	)		(395	)

Gross deferred income tax liabilities		(1,605	)		(395	)
Net deferred income tax asset/(liability)	$	—		$	—

Reconciliation of Reported Estimated Income Tax Benefit

The reconciliation of the reported estimated income tax benefit to the amount that would result by applying the U.S. federal statutory tax rate to the net income is as follows (in thousands):


	Year Ended December 31,
	2014			2013			2012
United States federal tax at statutory rate	$	(13,410	)	$	(91	)	$	2,927
State taxes (net of federal benefit)		(1,608	)		609			1,460
Deferred income tax adjustments		—			(855	)		(512	)
Deferred state blended rate adjustments		3,034			(344	)		—
Research credit, net		(2,228	)		(226	)		—
Transaction cost deduction		(379	)		—			—
Transaction cost deduction—prior year adjustment		(564	)		—			—
Orphan drug credit, net		(139	)		(843	)		(4,896	)
Other permanent items		(382	)		3			8
Equity-based compensation		756			241			279
Fair value adjustment of preferred stock warrant liability		—			219			(53	)
Change in valuation allowance		14,920			1,287			787

Income tax expense/(benefit)	$	—		$	—		$	—

Reconciliation of the Beginning and Ending Amount of Gross Unrecognized Tax Benefits

A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows (in thousands):


	Year Ended December 31,
	2014		2013		2012
Beginning balance	$	1,708	$	1,592	$	1,534
Increases/(decreases) for current year tax positions		242		116		58
Increases/(decreases) for prior year tax positions		97		—		—
Decreases as a result of expiration of statute of limitations		—		—		—

Ending balance	$	2,047	$	1,708	$	1,592

Lease Exit Liability (Tables)

12 Months Ended

Dec. 31, 2014

Restructuring and Related Activities [Abstract]

Changes in Lease Exit Liability

Changes in the lease exit liability are as follows (in thousands):


Accrual balance at December 31, 2012.	$	10,074
Principal payments		(629	)

Accrual balance at December 31, 2013		9,445
Principal payments		(1,439	)

Accrual balance at December 31, 2014	$	8,006

Future Principal Payments Under Lease Agreement

Future principal payments to be made under the lease agreement as of December 31, 2014 are as follows (in thousands):


2015	$	1,642
2016		1,866
2017		2,113
2018		2,385

	$	8,006

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2014

Commitments and Contingencies Disclosure [Abstract]

Schedule of Minimum Future Lease Payments

Future minimum lease payments under noncancelable operating leases as of December 31, 2014 are as follows (in thousands):


2015	$	3,945
2016		4,364
2017		4,495
2018		4,396
2019		1,873
Thereafter		116

	$	19,189

- Definition

Tabular disclosure of a lessee's leasing arrangements including: (1) the basis on which contingent rental payments are determined, (2) the existence and terms of renewal or purchase options and escalation clauses, (3) restrictions imposed by lease arrangements, such as those concerning dividends, additional debt, and further leasing, (4) rent holidays, rent concessions, or leasehold improvement incentives and unusual provisions or conditions. Disclosure may also include the specific period used to amortize material leasehold improvements made at the inception of the lease or during the lease term. Additionally, for operating leases having initial or remaining noncancelable lease terms in excess of one year: (a) future minimum rental payments required as of the date of the latest balance sheet presented, in the aggregate and for each of the five succeeding fiscal years, (b) the total of minimum rentals to be received in the future under noncancelable subleases as of the date of the latest balance sheet presented, and (c) for all operating leases, rental expense for each period for which an income statement is presented, with separate amounts for minimum rentals, contingent rentals, and sublease rentals. Rental payments under leases with terms of a month or less that were not renewed need not be included.

+ References+ Details

Quarterly Financial Information (Tables)

12 Months Ended

Dec. 31, 2014

Quarterly Financial Information Disclosure [Abstract]

Company's Consolidated Quarterly Results of Operations


	1^st Quarter			2^nd Quarter			3^rd Quarter			4^th Quarter
	(in thousands, except per share data)
2014
Revenue	$	14,719		$	9,220		$	18,382		$	5,476
Net loss		(3,108	)		(12,259	)		(3,928	)		(19,018	)
Net loss per share, basic and diluted	$	(0.12	)	$	(0.44	)	$	(0.14	)	$	(0.68	)
2013
Revenue	$	10,598		$	12,299		$	20,232		$	14,906
Net income (loss)		(3,366	)		(294	)		6,604			(3,205	)
Net income (loss) per share, basic	$	(2.93	)	$	(0.24	)	$	0.14		$	(0.14	)
Net income (loss) per share, diluted	$	(2.93	)	$	(0.24	)	$	0.01		$	(0.14	)

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014 Segment Assets	Dec. 31, 2013 Assets
Revenue, Major Customer [Line Items]
Effective date of merger	Dec. 22, 2014
Number of operating segments	1
Original maturity of financial instruments	3 months	3 months
Allowance recorded	$ 0	$ 0
Amounts classified as restricted cash	$ 300,000	$ 405,000
Number of impaired assets	0	0
Number of assets held-for-sale	0	0
Minimum [Member] \| Sales Revenue, Net [Member]
Revenue, Major Customer [Line Items]
Percentage of all significant revenue earned	10.00%
Minimum [Member] \| Accounts Receivable [Member]
Revenue, Major Customer [Line Items]
Percentage of all significant revenue earned	10.00%

Summary of Significant Accounting Policies - Summary of Fair Value Measurement Financial Asset and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Assets:
Cash and cash equivalents	$ 131,545	$ 90,434
Money market funds	26,046	26,047
Restricted cash	300	405
Total Assets	157,891	116,886
Quoted Prices in Active Markets for Identical Assets Level 1 [Member]
Assets:
Cash and cash equivalents	131,545	90,434
Money market funds	26,046	26,047
Restricted cash	300	405
Total Assets	$ 157,891	$ 116,886

Summary of Significant Accounting Policies - Summary of Collaborators that Represent More Than 10% of Total Revenue Earned (Detail) (Sales Revenue, Net [Member])	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Servier [Member]
Concentration Risk [Line Items]
Percentage of all significant revenue earned	36.40%	51.60%	17.30%
Boehringer [Member]
Concentration Risk [Line Items]
Percentage of all significant revenue earned	28.60%	24.80%	18.40%
Takeda [Member]
Concentration Risk [Line Items]
Percentage of all significant revenue earned	16.80%
Gilead [Member]
Concentration Risk [Line Items]
Percentage of all significant revenue earned	11.40%	13.80%
Eli Lilly [Member]
Concentration Risk [Line Items]
Percentage of all significant revenue earned	0.90%	1.40%	48.90%

Summary of Significant Accounting Policies - Summary of Collaborators that Represent More Than 10% of Accounts Receivable (Detail) (Accounts Receivable [Member])	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Servier [Member]
Concentration Risk [Line Items]
Significant Accounts Receivable	33.30%	6.40%
Boehringer [Member]
Concentration Risk [Line Items]
Significant Accounts Receivable	21.20%	12.20%
Green Cross [Member]
Concentration Risk [Line Items]
Significant Accounts Receivable	17.90%
Gilead [Member]
Concentration Risk [Line Items]
Significant Accounts Receivable		53.40%
Pfizer [Member]
Concentration Risk [Line Items]
Significant Accounts Receivable		12.30%

Summary of Significant Accounting Policies - Estimated Useful Lives (Detail)	12 Months Ended
	Dec. 31, 2014
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	3 years
Software [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	3 years
Furniture [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	10 years
Laboratory and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	5 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Leasehold improvements	Shorter of lease term or useful life

Summary of Significant Accounting Policies - Computation of Basic and Diluted Income (Loss) Per Common Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounting Policies [Abstract]
Net income (loss)	$ (19,018)	$ (3,928)	$ (12,259)	$ (3,108)	$ (3,205)	$ 6,604	$ (294)	$ (3,366)	$ (38,313)	$ (261)	$ 8,362
Less: undistributed earnings allocated to participating securities											(8,362)
Net income (loss) allocable to common shares									(38,313)	(261)
Basic weighted average common shares outstanding									27,384,990	6,847,697	1,083,276
Basic income (loss) per common share					$ (0.14)	$ 0.14	$ (0.24)	$ (2.93)	$ (1.40)	$ (0.04)	$ 0.00
Net income (loss)	(19,018)	(3,928)	(12,259)	(3,108)	(3,205)	6,604	(294)	(3,366)	(38,313)	(261)	8,362
Less: undistributed earnings allocated to participating securities and other add-backs to net income (loss)											(8,362)
Net income (loss) allocable to common shares									$ (38,313)	$ (261)
Basic weighted average common shares outstanding									27,384,990	6,847,697	1,083,276
Effect of dilutive securities									0	0	0
Diluted weighted average common shares outstanding									27,384,990	6,847,697	1,083,276
Diluted income (loss) per common share					$ (0.14)	$ 0.01	$ (0.24)	$ (2.93)	$ (1.40)	$ (0.04)	$ 0.00

Summary of Significant Accounting Policies - Schedule of Antidilutive Securities Excluded from the Calculation of Diluted Income (Loss) Per Share (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Series A-1 Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares			2,156,114
Series A-2 Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares			392,274
Series B Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares			4,336,037
Series C Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares			5,909,906
Series D Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares			769,468
Series D-2 Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares			3,391,991
Effect of Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares		13,189,920
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares			180,784
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, shares	2,094,904	2,313,970	3,249,702

- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References+ Details

Property and Equipment - Schedule of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property and equipment	$ 24,140	$ 20,567
Less accumulated depreciation	(17,355)	(15,532)
Property and equipment, net	6,785	5,035
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	2,596	2,379
Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	1,683	1,477
Furniture and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	751	651
Lab Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	13,917	11,166
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 5,193	$ 4,894

Stockholders' Equity - Additional Information (Detail) (USD $)	0 Months Ended	1 Months Ended	12 Months Ended			0 Months Ended		0 Months Ended		0 Months Ended	12 Months Ended	24 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended		1 Months Ended		0 Months Ended	1 Months Ended	12 Months Ended
	Oct. 16, 2013	Feb. 28, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Oct. 16, 2013 IPO [Member]	Oct. 16, 2013 IPO [Member]	Oct. 16, 2013 Over-Allotment Option [Member]	Oct. 16, 2013 Over-Allotment Option [Member]	Jan. 11, 2011 Series D-2 Convertible Preferred Stock [Member]	Dec. 31, 2014 Series A Preferred Stock [Member]	Dec. 31, 2003 Series A Preferred Stock [Member]	Dec. 31, 2014 Series A-1 Preferred Stock [Member]	Dec. 31, 2014 Series A-2 Preferred Stock [Member]	Oct. 31, 2004 Series B Preferred Stock [Member]	Dec. 31, 2014 Series B Preferred Stock [Member]	May 31, 2006 Series B Preferred Stock [Member]	May 31, 2006 Series C Preferred Stock [Member]	Dec. 31, 2014 Series C Preferred Stock [Member]	Dec. 31, 2014 Series D Preferred Stock [Member]	Mar. 31, 2011 Series D Preferred Stock [Member] Raven Biotechnologies Inc. [Member]	Jul. 31, 2008 Series D Preferred Stock [Member] Raven Biotechnologies Inc. [Member]	May 16, 2010 Series D-2 Preferred Stock [Member]	Sep. 30, 2008 Series D-2 Preferred Stock [Member]	Dec. 31, 2014 Series D-2 Preferred Stock [Member]	May 16, 2010 Series D-2 Preferred Stock [Member]	Dec. 31, 2014 Undesignated Preferred Stock [Member]	Dec. 31, 2013 Undesignated Preferred Stock [Member]	Oct. 31, 2004 Series A-1 Preferred Stock [Member]
Class of Stock [Line Items]
Number of shares issued or sold		1,800,000				5,000,000		750,000		18,427,388		34,239,374			71,401,237			110,952,217					6,916,110	38,337,678
Proceeds from issuance of convertible preferred stock												$ 34,000,000			$ 30,300,000			$ 44,900,000						$ 24,800,000
Price per share		$ 36.50					$ 16.00		$ 16.00			$ 1.00
Related offering costs															238,000			101,246						156,788
Shares of common stock allocated																	10,003,300												13,604,016
Shares issued to acquire entity																					14,446,227	12,466,039
Purchased shares																								2,875,327		518,708
Exercise price																									$ 0.65
Proceeds from sale of shares		76,700,000								12,000,000
Accrued noncumulative dividends on preferred stock											$ 0.08					$ 0.0341			$ 0.0324	$ 0.0522					$ 0.0522
Convertible preferred stock series													1.506	1.00		1.14			1.00	1.00					1.00
Conversion price of preferred stock													$ 12.39	$ 18.77		$ 6.95			$ 7.70	$ 12.20					$ 12.20
Proceeds from initial public offering net of expenses	$ 83,800,000
Reverse stock split			1-for-18.7739
Common stock, shares authorized			125,000,000	125,000,000	425,000,000
Undesignated preferred stock, shares authorized																											5,000,000
Undesignated preferred stock, par value																											$ 0.01
Undesignated preferred stock, shares issued																											0	0
Undesignated preferred stock, shares outstanding																											0	0
Additional shares sold under over-allotments option to underwriter		450,000

Stock- based Compensation - Additional Information (Detail) (USD $)	12 Months Ended						60 Months Ended			12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014 Maximum [Member]	Dec. 31, 2014 Stock Option Plan 2000 [Member]	Dec. 31, 2012 Equity Incentive Plan 2003 [Member]	Dec. 31, 2010 Equity Incentive Plan 2003 [Member]	Dec. 31, 2014 Equity Incentive Plan 2003 [Member]	Feb. 28, 2003 Equity Incentive Plan 2003 [Member]	Dec. 31, 2014 Stock Incentive Plan 2013 [Member]	Oct. 31, 2013 Stock Incentive Plan 2013 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, number of shares authorized					130,725				2,051,644		1,960,168
Increased number of shares authorized					150,297	4,336,730	3,790,760			2,967,272
Share-based compensation arrangement by share-based payment award, options, outstanding, number	3,572,116	3,200,958			19,705			2,008,474		1,543,937
Weighted average exercise price	$ 11.40	$ 4.90			$ 0.81			$ 1.64		$ 24.22
Increase in aggregate number of shares authorized						545,970	1,739,116
Stock reserved for future issuance										1,960,168
Percentage of common stock share outstanding										4.00%
Options granted, maximum term				10 years
Expected life of option term	6 years 3 months	7 years	7 years
Common stock, shares issued	568,906	1,268,049	863,176
Cash proceeds from exercise of stock options	$ 744,000	$ 1,100,000	$ 47,000
Weighted-average grant-date fair value of options granted	$ 17.41	$ 6.91	$ 0.94
Share-based compensation arrangement by share-based payment award, options, exercises in period, intrinsic value	14,500,000	5,400,000	271,929
Fair value of shares vested	3,000,000	487,603	879,024
Unrecognized compensation cost related to non-vested stock-based compensation arrangements	$ 19,600,000
Unrecognized compensation expense recognition period	4 years

Stock- based Compensation - Schedule of Stock-Based Compensation Expense (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 3,244	$ 862	$ 838
Research and Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	1,562	507	472
General and Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,682	$ 355	$ 366

Stock- based Compensation - Schedule of Fair Value Option Award Estimated on the Date of Grant Using the Black-Scholes Option-Pricing Model (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%	0.00%
Expected volatility	67.00%		51.00%
Risk-free interest rate			1.20%
Expected term	6 years 3 months	7 years	7 years
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility		53.00%
Risk-free interest rate	1.80%	1.20%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility		67.00%
Risk-free interest rate	2.30%	2.20%

Stock- based Compensation - Schedule of Stock Option and Restricted Stock Unit Activity (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares, Outstanding, Beginning Balance	3,200,958
Shares, Granted	976,869
Shares, Exercised	(568,906)	(1,268,049)	(863,176)
Shares, Forfeited or expired	(36,805)
Shares, Outstanding, Ending Balance	3,572,116	3,200,958
Shares, Exercisable	1,668,962
Shares, Vested and expected to vest	3,341,192
Weighted-Average Exercise Price, Outstanding, Beginning Balance	$ 4.90
Weighted-Average Exercise Price, Granted	$ 27.06
Weighted-Average Exercise Price, Exercised	$ 1.31
Weighted-Average Exercise Price, Forfeited or expired	$ 9.76
Weighted-Average Exercise Price, Outstanding, Ending Balance	$ 11.40	$ 4.90
Weighted-Average Exercise Price, Exercisable	$ 3.24
Weighted-Average Exercise Price, Vested and expected to vest	$ 11.03
Weighted-Average Remaining Contractual Term, Outstanding	7 years 3 months 18 days	6 years 10 months 24 days
Weighted-Average Remaining Contractual Term, Exercisable	5 years 3 months 18 days
Weighted-Average Remaining Contractual Term, Vested and expected to vest	7 years 2 months 12 days
Aggregate Intrinsic Value, Outstanding, Ending Balance	$ 84,515
Aggregate Intrinsic Value, Exercisable	53,122
Aggregate Intrinsic Value, Vested and expected to vest	$ 80,323

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
Income Taxes - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Line Items]
Provision for federal or state income taxes	$ 0	$ 0	$ 0
Federal Tax credit expiration start year	2020
Federal Tax credit expiration ending year	2034
Net operating loss	7,100,000
Net operating losses limited for year minimum	2015
Net operating losses limited for year maximum	2027
Remaining portion of net operating losses	151,800,000
Net operating losses, recognized as a benefit through additional-paid-in-capital	7,700,000
Current deferred tax liability	1,600,000
Noncurrent deferred tax asset	1,600,000
Net deferred income tax asset/(liability)	0	0
Gross unrecognized tax benefits	1,700,000	1,300,000
Unrecognized interest or penalties	0	0	0
Income tax examination year subject to examination, Range start	2001
Income tax examination year subject to examination, Range End	2014
Minimum [Member]
Income Tax Disclosure [Line Items]
Net operating losses limited for use utilized on an annual basis	200,000
Maximum [Member]
Income Tax Disclosure [Line Items]
Net operating losses limited for use utilized on an annual basis	1,400,000
U.S. Federal Government [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	158,900,000
US Federal Tax credits carry forward	26,300,000
State and Local Jurisdiction [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 103,400,000
Start Year [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards expiration ending year	2020
Ending Year [Member]
Income Tax Disclosure [Line Items]
Net operating loss carryforwards expiration ending year	2034

Income Taxes - Components of the Company's Deferred Tax Assets (Liabilities) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred income tax assets:
Federal U.S. net operating loss carryforward	$ 55,358	$ 36,561
State net operating loss carryforward	3,723	3,316
Research and development credit, net	7,177	3,786
Orphan drug credit, net	19,287	19,883
Deferred rent	4,069	5,132
Deferred revenue	3,989	8,217
Depreciation	1,337	1,438
Other	962	1,439
Gross deferred income tax assets	95,902	79,772
Valuation allowance	(94,297)	(79,377)
Net deferred income tax assets	1,605	395
Deferred income tax liabilities:
Prepaid expenditures	(1,605)	(395)
Gross deferred income tax liabilities	(1,605)	(395)
Net deferred income tax asset/(liability)	$ 0	$ 0

Income Taxes - Reconciliation of Reported Estimated Income Tax Benefit (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Effective Income Tax Rate Reconciliation [Line Items]
United States federal tax at statutory rate	$ (13,410)	$ (91)	$ 2,927
State taxes (net of federal benefit)	(1,608)	609	1,460
Deferred income tax adjustments		(855)	(512)
Deferred state blended rate adjustments	3,034	(344)
Research credit, net	(2,228)	(226)
Transaction cost deduction	(379)
Orphan drug credit, net	(139)	(843)	(4,896)
Other permanent items	(382)	3	8
Equity-based compensation	756	241	279
Fair value adjustment of preferred stock warrant liability		219	(53)
Change in valuation allowance	14,920	1,287	787
Income tax expense/(benefit)	0	0	0
Prior Year Adjustment [Member]
Effective Income Tax Rate Reconciliation [Line Items]
Transaction cost deduction	$ (564)

Income Taxes - Reconciliation of the Beginning and Ending Amount of Gross Unrecognized Tax Benefits (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Beginning balance	$ 1,708	$ 1,592	$ 1,534
Increases/(decreases) for current year tax positions	242	116	58
Increases/(decreases) for prior year tax positions	97
Decreases as a result of expiration of statute of limitations	0	0	0
Ending balance	$ 2,047	$ 1,708	$ 1,592

Lease Exit Liability - Additional Information (Detail) (USD $)	12 Months Ended						0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 16, 2008	Jul. 16, 2008 Minimum [Member]	Jul. 16, 2008 Maximum [Member]	Jul. 16, 2014 Series D Convertible Preferred Stock [Member]
Restructuring Cost and Reserve [Line Items]
Shares issued in connection with acquisition							12,466,039
Operating Lease	2018
Onetime purchase payment under purchase agreement				$ 5,000,000
Onetime payment paid under license of product					8,000,000	12,000,000
Additional amounts recorded	$ 0	$ 0	$ 0

Lease Exit Liability - Changes in Lease Exit Liability (Detail) (Contract Termination [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Accrual Beginning Balance	$ 9,445	$ 10,074
Principal payments	(1,439)	(629)
Accrual Ending Balance	$ 8,006	$ 9,445

Lease Exit Liability - Future Principal Payments Under Lease Agreement (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014
Operating Leased Assets [Line Items]
2015	$ 3,945
2016	4,364
2017	4,495
2018	4,396
Total	19,189
Raven Biotechnologies Inc. [Member]
Operating Leased Assets [Line Items]
2015	1,642
2016	1,866
2017	2,113
2018	2,385
Total	$ 8,006

Collaboration and License Agreements - Additional Information 1 (Detail) (USD $)	1 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended
	Feb. 28, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014 Janssen Biotech Inc. [Member]	May 31, 2014 Takeda [Member]	Dec. 31, 2014 Takeda [Member]	Dec. 31, 2014 Takeda [Member] Research Collaboration And License Option Agreement [Member]
License And Collaboration Agreements [Line Items]
Collaboration agreement date				December 2014		May 2014	September 2014
Stock issued during period value, new issues		$ 76,716,000	$ 83,623,000	$ 75,000,000
Stock issued during the period for new issue	1,800,000			1,923,077
Common stock price per share				$ 39.00
Nonrefundable upfront payment receivable				50,000,000
Clinical, regulatory and commercialization milestone payments				575,000,000
Recognized revenue under agreement				0		3,000,000	5,000,000
Deferred revenue				0		7,100,000
Nonrefundable upfront payment					15,000,000
License option fee and early development milestone						18,000,000
Development, regulatory and sales milestone payments						468,500,000
Amount allocated to agreement						10,000,000	5,000,000
Expected period of development						24 months
Deferred revenue current		14,248,000	20,267,000			5,000,000
Deferred revenue non-current		$ 16,472,000	$ 7,136,000			$ 2,100,000

Collaboration and License Agreements - Additional Information 2 (Detail) (USD $)	1 Months Ended	12 Months Ended
	Jan. 31, 2013 Molecule	Dec. 31, 2014	Dec. 31, 2013
License And Collaboration Agreements [Line Items]
Deferred revenue, Current		$ 14,248,000	$ 20,267,000
Gilead [Member]
License And Collaboration Agreements [Line Items]
Collaboration agreement date		January 2013
Commercialization of molecules	4
License grant fees		7,500,000
Expected period of development		21 months
Recognized revenue under agreement		5,500,000	8,000,000
Milestone achieved		0	0
Deferred revenue, Current		0	3,600,000
Gilead [Member] \| Minimum [Member]
License And Collaboration Agreements [Line Items]
Regulatory and sales milestone		240,000,000
Gilead [Member] \| Maximum [Member]
License And Collaboration Agreements [Line Items]
Regulatory and sales milestone		250,000,000
Gilead [Member] \| Pre-Clinical Milestones [Member] \| Minimum [Member]
License And Collaboration Agreements [Line Items]
Clinical milestone payments		20,000,000
Gilead [Member] \| Pre-Clinical Milestones [Member] \| Maximum [Member]
License And Collaboration Agreements [Line Items]
Clinical milestone payments		$ 25,000,000

Collaboration and License Agreements - Additional Information 3 (Detail) (USD $)	12 Months Ended		1 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Nov. 30, 2011 Servier [Member]	Dec. 31, 2014 Servier [Member]	Dec. 31, 2013 Servier [Member]	Dec. 31, 2012 Servier [Member]	Sep. 30, 2012 Servier [Member] Second Right to Develop Collaboration [Member]	Dec. 31, 2014 Servier [Member] Second Right to Develop Collaboration [Member] Milestone	Dec. 31, 2013 Servier [Member] Second Right to Develop Collaboration [Member]	Dec. 31, 2012 Servier [Member] Second Right to Develop Collaboration [Member]	Dec. 31, 2014 Servier [Member] Scenario, Adjustment [Member]	Dec. 31, 2014 Servier [Member] Scenario, Adjustment [Member] Second Right to Develop Collaboration [Member]	Dec. 31, 2014 Servier [Member] Maximum [Member]	Dec. 31, 2014 Servier [Member] Maximum [Member] Second Right to Develop Collaboration [Member]
License And Collaboration Agreements [Line Items]
Collaboration agreement date				November 2011				September 2012
Nonrefundable upfront payment			$ 20,000,000				$ 20,000,000
Additional license grant fees													30,000,000	65,000,000
Clinical milestone payments													47,000,000	98,000,000
Regulatory milestone payments													140,000,000	300,000,000
Sales milestone payments													208,000,000	630,000,000
Expected period of development				27 months				29 months			42 months	75 months
Recognized revenue under agreement				700,000	21,300,000	9,100,000		16,700,000	8,600,000	2,000,000
Milestone payment					10,000,000			5,000,000	0	0
Deferred revenue, Current	14,248,000	20,267,000		100,000	900,000			3,300,000	8,600,000
Clinical milestone payments under agreement														5,000,000
Change in accounting estimate, current year impact	3,700,000
Option exercise fee								15,000,000
Offset to research and development costs under collaboration arrangement								1,000,000	0	0
Option exercise fee recognition period								82 months
Collaboration receivable, included in accounts receivable								800,000
Number of milestones achieved								2
Review period								30 days
Deferred revenue								17,700,000	9,400,000
Deferred revenue, Long-term liabilities	$ 16,472,000	$ 7,136,000						$ 14,400,000	$ 800,000

Collaboration and License Agreements - Additional Information 4 (Detail) (USD $)	1 Months Ended	12 Months Ended
	Oct. 31, 2010 Molecule	Dec. 31, 2014 Payments	Dec. 31, 2013	Dec. 31, 2012
License And Collaboration Agreements [Line Items]
Deferred revenue, Current		$ 14,248,000	$ 20,267,000
Deferred revenue, Long-term liabilities		16,472,000	7,136,000
Boehringer [Member]
License And Collaboration Agreements [Line Items]
Collaboration agreement date		October 2010
Commercialization of molecules	10
Nonrefundable upfront payment	15,000,000
Number of annual maintenance payments received		3
Clinical milestone payments		41,000,000
Regulatory milestone payments		89,000,000
Sales milestone payments		83,000,000
Research obligation completion date		2015-09
Recognized revenue under agreement		13,700,000	14,400,000	11,700,000
Deferred revenue			12,800,000
Deferred revenue, Current		5,800,000	7,000,000
Deferred revenue, Long-term liabilities			5,800,000
Milestone payment		$ 2,000,000	$ 5,000,000	$ 2,000,000

Collaboration and License Agreements - Additional Information 5 (Detail) (USD $)	1 Months Ended	12 Months Ended
	Oct. 31, 2010 Molecule	Dec. 31, 2014 Program	Dec. 31, 2013	Dec. 31, 2012
License And Collaboration Agreements [Line Items]
Deferred revenue		$ 14,248,000	$ 20,267,000
Pfizer [Member]
License And Collaboration Agreements [Line Items]
Collaboration agreement date		October 2010
Period of agreement		3 years
Commercialization of molecules	2
Nonrefundable upfront payment	5,000,000	5,000,000
Clinical milestone payments		17,000,000
Commercialization and sales milestones		195,000,000
DART program		1
Research obligation completion date		2014-01
Term of the agreement		2014-01
Recognized revenue under agreement		100,000	3,500,000	5,500,000
Milestones achieved		0		500,000
Deferred revenue		$ 0	$ 7,000

Collaboration and License Agreements - Additional Information 6 (Detail) (USD $)	1 Months Ended	12 Months Ended
	Jun. 30, 2010	Dec. 31, 2014	Dec. 31, 2013
License And Collaboration Agreements [Line Items]
Deferred revenue, Current		$ 14,248,000	$ 20,267,000
Deferred revenue, Long-term liabilities		16,472,000	7,136,000
Green Cross [Member]
License And Collaboration Agreements [Line Items]
Collaboration agreement date		June 2010
Term of the agreement		2020-06
Nonrefundable upfront payment	1,000,000
Adjustment to revenue from contract material modification		1,300,000
Recognized revenue under agreement		1,700,000	100,000.0
Milestones achieved		0	0
Deferred revenue			650,000
Unbilled receivable balance		525,000
Deferred revenue, Current			100,000
Deferred revenue, Long-term liabilities			550,000
Green Cross [Member] \| Maximum [Member]
License And Collaboration Agreements [Line Items]
Aggregate potential future cost reimbursement		5,500,000
Clinical and commercial milestone payments		$ 2,500,000

Collaboration and License Agreements - Additional Information 7 (Detail) (Eli Lilly [Member], USD $)	1 Months Ended		12 Months Ended
	May 31, 2010	May 31, 2008	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Eli Lilly [Member]
License And Collaboration Agreements [Line Items]
Collaboration agreement date			October 2007
Nonrefundable upfront payment			$ 41,000,000
Milestone payment	5,000,000	50,000,000	0
Recognized revenue under agreement			$ 400,000	$ 800,000	$ 31,200,000

Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Leased Assets [Line Items]
Lease agreement description	During 2014, the Company exercised its 5-year renewal option on the manufacturing facility. The Company also entered into a new four-year lease for additional space in the manufacturing facility effective April 1, 2014. This lease also has an option to continue the lease for five years under the same terms.
Deferred rent liability	$ 2.7	$ 2.9
Rent expense	$ 2.0	$ 2.7	$ 2.7
Office and Laboratory Space [Member] \| Rockville, Maryland [Member]
Operating Leased Assets [Line Items]
Lease expiration date	Mar. 31, 2018
Amended lease expiration date	Jan. 31, 2020
Office and Laboratory Space [Member] \| South San Francisco [Member]
Operating Leased Assets [Line Items]
Lease expiration date	Feb. 28, 2018
Manufacturing Space [Member]
Operating Leased Assets [Line Items]
Lease expiration date	Dec. 31, 2014
Lessee leasing arrangements, operating leases, renewal term	5 years
Additional Manufacturing Space [Member]
Operating Leased Assets [Line Items]
Term of additional space lease	4 years
Origination date for additional space in manufacturing facility	Apr. 01, 2014

Commitments and Contingencies - Schedule of Minimum Future Lease Payments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
2015	$ 3,945
2016	4,364
2017	4,495
2018	4,396
2019	1,873
Thereafter	116
Total	$ 19,189

Product Milestone Payments and Royalty Agreements - Additional Information (Detail) (USD $)	12 Months Ended	36 Months Ended		1 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Jun. 30, 2005	Jun. 30, 2005 Minimum [Member]	Jun. 30, 2005 Maximum [Member]
Royalty Agreement [Line Items]
Additional consideration of asset purchase agreement			$ 10,950,000
Common stock shares			36,135
Maximum royalty payments percentage				1.75%	4.00%
Payments related to the additional considerations		0
Revenue from product sales	$ 0

Employee Benefit Plan - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended
	Sep. 25, 2002	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Eligibility of employee participation Plan	21 years
Percentage of employee contribution to salary	100.00%
Percentage of employee vested contribution		100.00%
Defined contribution plan, employer discretionary contribution amount		$ 318,390	$ 252,930	$ 225,195

Quarterly Financial Information - Company's Consolidated Quarterly Results of Operations (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 5,476	$ 18,382	$ 9,220	$ 14,719	$ 14,906	$ 20,232	$ 12,299	$ 10,598	$ 47,797	$ 58,035	$ 63,826
Net income (loss)	$ (19,018)	$ (3,928)	$ (12,259)	$ (3,108)	$ (3,205)	$ 6,604	$ (294)	$ (3,366)	$ (38,313)	$ (261)	$ 8,362
Net income (loss) per share, basic					$ (0.14)	$ 0.14	$ (0.24)	$ (2.93)	$ (1.40)	$ (0.04)	$ 0.00
Net income (loss) per share, basic and diluted	$ (0.68)	$ (0.14)	$ (0.44)	$ (0.12)					$ (1.40)	$ (0.04)	$ 0.00
Net income (loss) per share, diluted					$ (0.14)	$ 0.01	$ (0.24)	$ (2.93)	$ (1.40)	$ (0.04)	$ 0.00

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References+ Details

Subsequent Event - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended			1 Months Ended
	Feb. 28, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014 Janssen Biotech Inc. [Member]	Jan. 31, 2015 Subsequent Event [Member] Johnson & Johnson Innovation JJDC, Inc, [Member]	Jan. 31, 2015 Subsequent Event [Member] Janssen Biotech Inc. [Member]
Subsequent Event [Line Items]
Stock issued during the period for new issue	1,800,000			1,923,077	1,923,077
Stock issued during period value, new issues		$ 76,716,000	$ 83,623,000	$ 75,000,000	$ 75,000,000
Nonrefundable upfront payment receivable				$ 50,000,000		$ 50,000,000

Subsequent Event	12 Months Ended
Subsequent Event	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Event	13. Subsequent Event In January 2015, the Federal Trade Commission granted early termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 with respect to the collaboration and license agreement with Janssen and the stock purchase agreement and investor agreement with JJDC (as described in Note 8). Accordingly, the Company issued 1,923,077 shares of common stock to JJDC and received $75.0 million from JJDC under the stock purchase agreement and received the $50.0 million upfront payment from Janssen under the collaboration and license agreement.

Organization and Nature of Operations - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
MacroGenics incorporated date	Aug. 14, 2000