MacroGenics (MGNX) 10-Q 5 Aug 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 30, 2014	Jul. 31, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Jun-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Entity Registrant Name	'MACROGENICS INC	'
Entity Central Index Key	'0001125345	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Non-accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	27,738,557

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$194,014	$116,481
Accounts receivable	2,645	2,004
Prepaid expenses	2,100	972
Total current assets	198,759	119,457
Restricted cash	405	405
Property and equipment, net	5,442	5,035
Other assets	1,114	885
Total assets	205,720	125,782
Current liabilities:	'	'
Accounts payable	3,977	3,169
Accrued expenses	3,310	3,584
Lease exit liability - current	1,538	1,439
Deferred revenue - current	20,684	20,267
Other liabilities - current	363	363
Total current liabilities	29,872	28,822
Lease exit liability, net of current portion	7,204	8,006
Deferred rent liability	2,753	2,904
Deferred revenue, net of current portion	23,912	7,136
Total liabilities	63,741	46,868
Stockholders' equity:	'	'
Common stock, $0.01 par value - 125,000,000 shares authorized, 27,724,454 and 25,177,597 shares outstanding at June 30, 2014 and December 31, 2013, respectively	277	252
Treasury stock, at cost; no shares at June 30, 2014 and 14,381 shares at December 31, 2013	0	-58
Additional paid-in capital	332,802	254,454
Accumulated deficit	-191,100	-175,733
Total stockholders' equity	141,979	78,914
Total liabilities and stockholders' equity	$205,720	$125,782

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 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	27,724,454	25,177,597
Treasury stock, shares	0	14,381

Consolidated_Statements_of_Ope

Consolidated Statements of Operations and Comprehensive Loss (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues:	'	'	'	'
Revenue from collaborative research	$9,202	$11,838	$23,603	$21,905
Grant revenue	18	460	336	991
Total revenues	9,220	12,298	23,939	22,896
Costs and expenses:	'	'	'	'
Research and development	17,335	11,049	31,904	21,146
General and administrative	4,145	1,503	7,403	5,336
Total costs and expenses	21,480	12,552	39,307	26,482
Loss from operations	-12,260	-254	-15,368	-3,586
Other income (expense)	1	-40	1	-74
Net comprehensive loss	($12,259)	($294)	($15,367)	($3,660)
Basic and diluted net loss per common share	($0.44)	($0.24)	($0.57)	($3)
Weighted average common shares outstanding, basic and diluted	27,651,297	1,219,884	26,960,664	1,184,507

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities	'	'
Net loss	($15,367)	($3,660)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:	'	'
Depreciation expense	835	518
Share-based compensation	1,393	257
Fair value adjustment of warrant liabilities	'	72
Changes in operating assets and liabilities:	'	'
Accounts receivable	-641	-2,107
Prepaid expenses	-1,128	67
Other assets	-229	'
Accounts payable	808	-1,620
Accrued expenses	-274	-296
Lease exit liability	-703	-307
Deferred revenue	17,193	-6,772
Deferred rent	-151	53
Net cash provided by (used in) operating activities	1,736	-13,795
Cash flows from investing activities	'	'
Purchases of property and equipment	-1,242	-876
Net cash used in investing activities	-1,242	-876
Cash flows from financing activities	'	'
Proceeds from issuance of common stock, net of offering costs	77,039	709
Net cash provided by financing activities	77,039	709
Net change in cash and cash equivalents	77,533	-13,962
Cash and cash equivalents at beginning of period	116,481	47,743
Cash and cash equivalents at end of period	$194,014	$33,781

Summary_of_Significant_Account

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	1. Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying unaudited interim consolidated financial statements of MacroGenics, Inc. (the “Company”) have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information. The financial statements include all adjustments (consisting only of normal recurring adjustments) that the management of the Company believes are necessary for a fair presentation of the periods presented. These interim financial results are not necessarily indicative of results expected for the full fiscal year or for any subsequent interim period.
	The accompanying unaudited interim consolidated financial statements include the accounts of MacroGenics, Inc. and its wholly owned subsidiary, MacroGenics West, Inc. All intercompany accounts and transactions have been eliminated in consolidation. These consolidated financial statements and related notes should be read in conjunction with the financial statements and notes thereto included in the Company’s 2013 Annual Report on Form 10-K filed with the SEC on March 20, 2014.
	There have been no material changes to the significant accounting policies previously disclosed in the Company’s 2013 Annual Report on Form 10-K.
	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“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 cashflows 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.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	2. 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 June 30, 2014 due to their short-term maturities. The Company accounts for recurring and non-recurring fair value measurements in accordance with 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 June 30, 2014
					Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable Inputs		Unobservable
					Identical Assets				Inputs
			Total		Level 1		Level 2		Level 3
	Assets:
	Cash and cash equivalents		$	167,968	$	167,968	$	—	$	—
	Money market funds			26,046		26,046		—		—
	Restricted cash			405		405		—		—
	Total Assets		$	194,419	$	194,419	$	—	$	—
			Fair Value Measurements at December 31, 2013
					Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable Inputs		Unobservable
					Identical Assets				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	$	—	$	—

Lease_Exit_Liability

Lease Exit Liability	6 Months Ended
	Jun. 30, 2014
Restructuring And Related Activities [Abstract]	'
Lease Exit Liability	'
	3. 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.
	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 acquisitions, 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, 2013	$	9,445
	Principal payments		(703	)
	Accrual balance at June 30, 2014	$	8,742
	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 MacroGenics 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 and if it is deemed probable that the contingencies will be attained. No additional amounts have been recorded during the three and six months ended June 30, 2014 and 2013.

Collaboration_and_License_Agre

Collaboration and License Agreements	6 Months Ended
	Jun. 30, 2014
Text Block [Abstract]	'
Collaboration and License Agreements	'
	4. Collaboration and License Agreements
	Takeda Pharmaceutical Company Limited
	In May 2014, the Company entered into a license and option agreement with Takeda Pharmaceutical Company Limited (“Takeda”) for the development and commercialization of MGD010, a product candidate that incorporates the Company’s proprietary Dual-Affinity Re-Targeting (“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 has 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 this license and option agreement include research and development services through the Phase 1a study and delivery of the license for the initial research compound. The Company concluded that the MGD010 option is substantive and that the license fee for this 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.
	Included in this agreement are plans for the parties to enter into good faith negotiations for a separate research agreement related to multiple research compounds. A portion of the $15.0 million upfront payment received upon execution of the MGD010 agreement was allocated to the initial research compound. The portions of the $15.0 million up-front fee allocated to the MGD010 option fee and the license for the initial research compound are reflective of management’s best estimate of selling price had those future licenses been sold separately. Revenue related to the potential license for the initial research compound will be deferred until such time as a research agreement is executed. At such time, revenue will be recognized ratably over the estimated development period. Should a research agreement be executed, the Company will be eligible to receive development, regulatory, and sales milestone payments as well as receive reimbursement for certain research and development expenses.
	The Company’s substantive performance obligations under this agreement include an exclusivity clause to its technology as well as development of MGD010 through completion of a pre-defined Phase 1a study. The Company determined that these performance obligations represent a single unit of accounting, because the license does not have stand-alone value to Takeda without the Company’s technical expertise and development. As such, the portion of the initial upfront payment allocated to MGD010 was deferred and is being recognized ratably over the initial 24-month period, which represents the expected period of development through the completion of a pre-defined Phase 1a study.
	The Company recognized revenues of approximately $0.4 million during the three and six months ended June 30, 2014. At June 30, 2014, $14.6 million of revenue was deferred under this agreement, $5.0 million of which was current and $9.6 million of which was non-current.
	Gilead Sciences, Inc.
	In January 2013, the Company entered into an agreement with Gilead Sciences, Inc. (“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 to $25 million in pre-clinical milestones and up to $240 to $250 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 has determined that the 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 has 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) is being recognized ratably over a period of 21 months, which represents 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 $2.3 million and $2.0 million under this agreement for the three months ended June 30, 2014 and 2013, respectively. The Company recognized revenues of approximately $4.5 million and $3.7 million under this agreement for the six months ended June 30, 2014 and 2013, respectively. No milestones have been achieved under this agreement.
	At June 30, 2014 and December 31, 2013, $0.9 million and $3.6 million of revenue was deferred under this agreement, respectively, all of which was current.
	Les Laboratoires Servier
	In November 2011, the Company entered into a right-to-develop collaboration agreement with Les Laboratoires Servier and Institut de Recherches Servier (collectively, “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 non-refundable payment of $20.0 million to the Company. The Company is eligible to receive up to $30.0 million in license option 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 has 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 during the first year of the agreement 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. In January 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 38-month period.
	During the three months ended June 30, 2014 and 2013, the Company recognized revenue of $0.2 million and $4.4 million, respectively, under this agreement. During the six months ended June 30, 2014 and 2013, the Company recognized revenue of $0.4 million and $6.6 million, respectively, under this agreement.
	At June 30, 2014 and December 31, 2013, $0.4 million and $0.9 million of revenue remained deferred under this agreement, respectively, all of which was included in current liabilities.
	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 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 non-refundable payment of $20.0 million to the Company. In addition, the Company became eligible to receive up to $65.0 million in license option fees, $98.0 million in clinical milestone payments, including $5.0 million upon Investigational New Drug (“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. Through June 30, 2014, the Company has received an additional $15.0 million in license option fees and a $5.0 million milestone payment. In addition to these payments, 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 has 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 up front license payment was deferred and is being recognized ratably over the initial 29-month period, which represents the expected development period.
	During the six months ended June 30, 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 three and six months ended June 30, 2014, the Company recorded approximately $0.3 million and $0.4 million as an offset to research and development costs under this collaboration arrangement, and has recorded a corresponding collaboration receivable, which is included in accounts receivable on the consolidated balance sheet.
	The Company recognized revenue of $2.7 million and $2.2 million during the three months ended June 30, 2014 and 2013, respectively, under this agreement. The Company recognized revenue of $10.0 million and $4.3 million during the six months ended June 30, 2014 and 2013, respectively, under this agreement. Revenue during the six months ended June 30, 2014 includes the $5.0 million payment from Servier upon the achievement of a clinical milestone related to the IND application for MGD006 clearing the 30-day review period by the U.S. Food and Drug Administration (“FDA”). No milestones were recognized under this agreement during the three and six months ended June 30, 2013.
	At June 30, 2014, $19.4 million of revenue was deferred under this agreement, $7.3 million of which was current and $12.1 million of which was non-current. 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 non-current.
	In July 2014, the IND application for MGD007 cleared the 30-day review period by the FDA. This triggered an additional $5.0 million milestone payment due to the Company by Servier.
	Boehringer Ingelheim International GmbH
	In October 2010 the Company entered into a collaboration and license agreement with Boehringer Ingelheim International GmbH (“Boehringer”) to discover, develop and commercialize up to ten DART 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 including one in the fourth quarter of 2013. 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 account 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 $3.0 million and $2.2 million during the three months ended June 30, 2014 and 2013, respectively. The Company recognized revenues of approximately $6.0 million and $4.5 million during the six months ended June 30, 2014 and 2013, respectively. At June 30, 2014, $9.3 million of revenue was deferred under this agreement, $7.0 million of which was current and $2.3 million of which was non-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 non-current.
	There were no material modifications to this agreement since the adoption of ASU 2009-13, Revenue Recognition – Multiple-Deliverable Revenue Arrangements, on January 1, 2011.
	Pfizer, Inc.
	In October 2010, the Company entered into a three year agreement with Pfizer, Inc. (“Pfizer”) to discover, develop and commercialize up to two DART 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 double digit 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 represented 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 $1.0 million during the three months ended June 30, 2013. The Company recognized revenues of approximately $2.2 million during the six months ended June 30, 2013. Revenue recognized related to this agreement was de minimis during the three and six months ended June 30, 2014. As of June 30, 2014, there was no remaining deferred revenue under this agreement.
	Green Cross Corporation
	In June 2010, the Company entered into a collaboration agreement with Green Cross Corp. (“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 the six-month period ended June 30, 2014.
	The Company recognized revenues of approximately $112,500 and $25,000 under this agreement during the three months ended June 30, 2014 and June 30, 2013, respectively. The Company recognized revenues of approximately $1.5 million and $50,000 under this agreement during the six months ended June 30, 2014 and 2013, respectively. No milestones were achieved under this agreement during the three and six months ended June 30, 2014 and 2013.
	At June 30, 2014, there was a $300,000 unbilled receivable balance net of deferred revenue 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.

StockBased_Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2014
Disclosure Of Compensation Related Costs Sharebased 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 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. 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 allowed for the grant of awards in respect of an aggregate of 4,336,731 shares of the Company’s common stock. 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. In October 2013 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 was 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. All of the shares available for issuance under the 2013 Plan are eligible for issuance pursuant to the exercise of incentive stock options. 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.
	The following stock-based compensation amounts were recognized for the periods indicated (in thousands):
		Three Months Ended June 30,					Six Months Ended June 30,
		2014			2013		2014				2013
	Research and development	$	365		$	79	$	682			$	172
	General and administrative		416			33		711				85
	Total stock-based compensation expense	$	781		$	112	$	1,393			$	257
	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:
		Six Months Ended June 30,
		2014		2013
	Expected dividend yield	0%		0%
	Expected volatility	67%		58%
	Risk-free interest rate	2.09% - 2.32%		1.80%
	Expected term	6.25 years		7 years
	Expected forfeiture rate	5%		5%
	The following table summarizes stock option activity under the Plan during the six months ended June 30, 2014:
		Shares			Weighted-		Weighted-Average		Aggregate
					Average		Remaining		Intrinsic
					Exercise Price		Contractual Term		Value
							(Years)		(in thousands)
	Outstanding, December 31, 2013		3,200,958		$	4.9	6.9
	Granted		236,294			20.61
	Exercised		(267,573	)		1.03
	Forfeited or expired		(8,452	)		3.32
	Outstanding, June 30, 2014		3,161,227			6.41	6.9		$	49,685
	June 30, 2014:
	Exercisable		1,669,697			2.02	5.1			33,026
	Vested and expected to vest		2,978,791			6.15	6.8			47,529
	The weighted-average grant-date fair value of options granted for the six months ended June 30, 2014 was $14.94. The total intrinsic value of options exercised during the six months ended June 30, 2014 was approximately $7.5 million, and the total cash received for options exercised was approximately $0.3 million. The total fair value of shares vested in the six months ended June 30, 2014 was approximately $1.3 million. As of June 30, 2014 the total unrecognized compensation expense related to non-vested stock options, net of related forfeiture estimates, was approximately $9.6 million, which the Company expects to recognize over a weighted-average period of approximately four years.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	6. Commitments and Contingencies
	Operating Leases
	The Company leases office and laboratory space in Rockville, Maryland, under a lease that expires on June 30, 2018, and leases a manufacturing facility in Rockville under a lease that originally expired on December 31, 2014. The Company has an option under each lease to continue the respective lease for five years under the same terms. During the six months ended June 30, 2014, the Company extended the manufacturing facility lease until December 31, 2019. 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 subleases office and laboratory space in South San Francisco under a lease that expires on December 31, 2018. All of the leases contain rent escalation clauses. For financial reporting purposes, rent expense is charged to operations on a straight-line basis over the term of the lease.
	Future minimum lease payments under noncancelable operating leases as of June 30, 2014 are as follows (in thousands):
	Year Ended December 31,
	2014	$	3,651
	2015		3,832
	2016		4,166
	2017		4,291
	2018		3,348
	Thereafter		507
		$	19,795
	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 believes it is not currently subject to any material matters where there is at least a reasonable possibility that a material loss may be incurred.

Net_Loss_Per_Share

Net Loss Per Share	6 Months Ended
	Jun. 30, 2014
Earnings Per Share [Abstract]	'
Net Loss Per Share	'
	7. Net Loss Per Share
	Basic loss per common share is determined by dividing loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration of common stock equivalents. Diluted loss per share is computed by dividing the 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 and the if-converted method is used to determine the dilutive effect of the Company’s preferred stock.
	Prior to the Company’s initial public offering, net 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 were 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.
	Basic and diluted loss per common share is computed as follows:
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
	Net loss	$	(12,259	)	$	(294	)	$	(15,367	)	$	(3,660	)
	Less: undistributed earnings allocated to participating securities		—			—			—			—
	Net loss allocable to common shares	$	(12,259	)	$	(294	)	$	(15,367	)	$	(3,660	)
	Basic weighted average common shares outstanding		27,651,297			1,219,884			26,960,664			1,184,507
	Basic loss per common share	$	(0.44	)	$	(0.24	)	$	(0.57	)	$	(3.00	)
	Net loss	$	(12,259	)	$	(294	)	$	(15,367	)	$	(3,660	)
	Less: undistributed earnings allocated to participating securities and other add-backs to net loss		—			—			—			—
	Net loss allocable to common shares	$	(12,259	)	$	(294	)	$	(15,367	)	$	(3,660	)
	Basic weighted average common shares outstanding		27,651,297			1,219,884			26,960,664			1,184,507
	Effect of dilutive securities		—			—			—			—
	Diluted weighted average common shares outstanding		27,651,297			1,219,884			26,960,664			1,184,507
	Diluted loss per common share	$	(0.44	)	$	(0.24	)	$	(0.57	)	$	(3.00	)
	In October 2013, the Company issued 5,750,000 shares of common stock in connection with its IPO and 16,955,790 shares of common stock in connection with the automatic conversion of its convertible preferred stock upon the closing of the IPO. In February 2014, the Company issued 2,250,000 shares of common stock in a follow-on offering. The issuance of these shares resulted in a significant increase in the Company’s weighted average shares outstanding for the three and six months ended June 30, 2014 when compared to the comparable prior year period and is expected to continue to impact the year-over-year comparability of the Company’s income (loss) per share calculations for the remainder of 2014.
	The following common stock equivalents were excluded from the calculation of diluted loss per share allocable to common stockholders because their inclusion would have been anti-dilutive:
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
	Series A-1 Preferred Stock		—			2,156,114			—			2,156,114
	Series A-2 Preferred Stock		—			392,274			—			392,274
	Series B Preferred Stock		—			4,336,037			—			4,336,037
	Series C Preferred Stock		—			5,909,906			—			5,909,906
	Series D Preferred Stock		—			769,468			—			769,468
	Series D-2 Preferred Stock		—			3,391,991			—			3,391,991
	Warrants to purchase Series D-2 Preferred Stock		—			180,784			—			180,784
	Stock Options		2,270,771			2,441,142			2,376,747			2,763,365

Subsequent_Event

Subsequent Event	6 Months Ended
	Jun. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Event	'
	8. Subsequent Event
	In July 2014, the IND application for MGD007 cleared the 30-day review period by the FDA. This triggered a $5.0 million milestone payment due to the Company by Servier.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accompanying unaudited interim consolidated financial statements of MacroGenics, Inc. (the “Company”) have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information. The financial statements include all adjustments (consisting only of normal recurring adjustments) that the management of the Company believes are necessary for a fair presentation of the periods presented. These interim financial results are not necessarily indicative of results expected for the full fiscal year or for any subsequent interim period.
	The accompanying unaudited interim consolidated financial statements include the accounts of MacroGenics, Inc. and its wholly owned subsidiary, MacroGenics West, Inc. All intercompany accounts and transactions have been eliminated in consolidation. These consolidated financial statements and related notes should be read in conjunction with the financial statements and notes thereto included in the Company’s 2013 Annual Report on Form 10-K filed with the SEC on March 20, 2014.
	There have been no material changes to the significant accounting policies previously disclosed in the Company’s 2013 Annual Report on Form 10-K.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“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 cashflows 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.

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
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 June 30, 2014
				Quoted Prices in		Significant Other		Significant
				Active Markets for		Observable Inputs		Unobservable
				Identical Assets				Inputs
		Total		Level 1		Level 2		Level 3
	Assets:
	Cash and cash equivalents	$	167,968	$	167,968	$	—	$	—
	Money market funds		26,046		26,046		—		—
	Restricted cash		405		405		—		—
	Total Assets	$	194,419	$	194,419	$	—	$	—
		Fair Value Measurements at December 31, 2013
				Quoted Prices in		Significant Other		Significant
				Active Markets for		Observable Inputs		Unobservable
				Identical Assets				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	$	—	$	—

Lease_Exit_Liability_Tables

Lease Exit Liability (Tables)	6 Months Ended
	Jun. 30, 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, 2013	$	9,445
	Principal payments		(703	)
	Accrual balance at June 30, 2014	$	8,742

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Schedule of Stock-Based Compensation Expense	'
	The following stock-based compensation amounts were recognized for the periods indicated (in thousands):
		Three Months Ended June 30,					Six Months Ended June 30,
		2014			2013		2014				2013
	Research and development	$	365		$	79	$	682			$	172
	General and administrative		416			33		711				85
	Total stock-based compensation expense	$	781		$	112	$	1,393			$	257
Schedule of Fair Value Option Award Estimated on the Date of Grant Using the Black-Scholes Option-Pricing Model	'
	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:
		Six Months Ended June 30,
		2014		2013
	Expected dividend yield	0%		0%
	Expected volatility	67%		58%
	Risk-free interest rate	2.09% - 2.32%		1.80%
	Expected term	6.25 years		7 years
	Expected forfeiture rate	5%		5%
Schedule of Stock Option Activity	'
	The following table summarizes stock option activity under the Plan during the six months ended June 30, 2014:
		Shares			Weighted-		Weighted-Average		Aggregate
					Average		Remaining		Intrinsic
					Exercise Price		Contractual Term		Value
							(Years)		(in thousands)
	Outstanding, December 31, 2013		3,200,958		$	4.9	6.9
	Granted		236,294			20.61
	Exercised		(267,573	)		1.03
	Forfeited or expired		(8,452	)		3.32
	Outstanding, June 30, 2014		3,161,227			6.41	6.9		$	49,685
	June 30, 2014:
	Exercisable		1,669,697			2.02	5.1			33,026
	Vested and expected to vest		2,978,791			6.15	6.8			47,529

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2014
Commitments And Contingencies Disclosure [Abstract]	'
Schedule of Minimum Future Lease Payments Payables	'
	Future minimum lease payments under noncancelable operating leases as of June 30, 2014 are as follows (in thousands):
	Year Ended December 31,
	2014	$	3,651
	2015		3,832
	2016		4,166
	2017		4,291
	2018		3,348
	Thereafter		507
		$	19,795

Net_Loss_Per_Share_Tables

Net Loss Per Share (Tables)	6 Months Ended
	Jun. 30, 2014
Earnings Per Share [Abstract]	'
Computation of Basic and Diluted Loss Per Common Share	'
	Basic and diluted loss per common share is computed as follows:
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
	Net loss	$	(12,259	)	$	(294	)	$	(15,367	)	$	(3,660	)
	Less: undistributed earnings allocated to participating securities		—			—			—			—
	Net loss allocable to common shares	$	(12,259	)	$	(294	)	$	(15,367	)	$	(3,660	)
	Basic weighted average common shares outstanding		27,651,297			1,219,884			26,960,664			1,184,507
	Basic loss per common share	$	(0.44	)	$	(0.24	)	$	(0.57	)	$	(3.00	)
	Net loss	$	(12,259	)	$	(294	)	$	(15,367	)	$	(3,660	)
	Less: undistributed earnings allocated to participating securities and other add-backs to net loss		—			—			—			—
	Net loss allocable to common shares	$	(12,259	)	$	(294	)	$	(15,367	)	$	(3,660	)
	Basic weighted average common shares outstanding		27,651,297			1,219,884			26,960,664			1,184,507
	Effect of dilutive securities		—			—			—			—
	Diluted weighted average common shares outstanding		27,651,297			1,219,884			26,960,664			1,184,507
	Diluted loss per common share	$	(0.44	)	$	(0.24	)	$	(0.57	)	$	(3.00	)
Schedule of Antidilutive Securities Excluded From Calculation of Diluted Loss Per Share Allocable to Common Stockholders	'
	The following common stock equivalents were excluded from the calculation of diluted loss per share allocable to common stockholders because their inclusion would have been anti-dilutive:
		Three Months Ended June 30,						Six Months Ended June 30,
		2014			2013			2014			2013
	Series A-1 Preferred Stock		—			2,156,114			—			2,156,114
	Series A-2 Preferred Stock		—			392,274			—			392,274
	Series B Preferred Stock		—			4,336,037			—			4,336,037
	Series C Preferred Stock		—			5,909,906			—			5,909,906
	Series D Preferred Stock		—			769,468			—			769,468
	Series D-2 Preferred Stock		—			3,391,991			—			3,391,991
	Warrants to purchase Series D-2 Preferred Stock		—			180,784			—			180,784
	Stock Options		2,270,771			2,441,142			2,376,747			2,763,365

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Summary of Fair Value Measurement Financial Asset and Liabilities (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets:	'	'
Cash and cash equivalents	$167,968	$90,434
Money market funds	26,046	26,047
Restricted cash	405	405
Total Assets	194,419	116,886
Quoted Prices in Active Markets for Identical Assets Level 1 [Member]	'	'
Assets:	'	'
Cash and cash equivalents	167,968	90,434
Money market funds	26,046	26,047
Restricted cash	405	405
Total Assets	$194,419	$116,886

Lease_Exit_Liability_Additiona

Lease Exit Liability - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jul. 16, 2008
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'
Operating Lease	'	'	'2018	'	'
Onetime purchase payment under purchase agreement	'	'	'	'	$5,000,000
Incremental in-process research and development expense	0	0	0	0	'
Minimum [Member]	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'
Onetime payment paid under license of product	'	'	'	'	8,000,000
Maximum [Member]	'	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'	'
Onetime payment paid under license of product	'	'	'	'	$12,000,000

Lease_Exit_Liability_Changes_i

Lease Exit Liability - Changes in Lease Exit Liability (Detail) (Contract Termination [Member], USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014
Contract Termination [Member]	'
Restructuring Cost and Reserve [Line Items]	'
Accrual beginning balance	$9,445
Principal payments	-703
Accrual ending balance	$8,742

Collaboration_and_License_Agre1

Collaboration and License Agreements - Additional Information 1 (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014	Jun. 30, 2014
			Takeda Pharmaceutical Company Limited [Member]	Takeda Pharmaceutical Company Limited [Member]
License And Collaboration Agreements [Line Items]	'	'	'	'
Non-refundable payment for development and commercialization	'	'	'	$15,000,000
Collaboration agreement date	'	'	'	'May 2014
license option fee and early development milestone	'	'	18,000,000	18,000,000
Development, regulatory and sales milestone payments	'	'	468,500,000	468,500,000
Expected period of development	'	'	'	'24 months
Recognized revenue under agreement	'	'	400,000	400,000
Deferred revenue	'	'	14,600,000	14,600,000
Deferred revenue current	20,684,000	20,267,000	5,000,000	5,000,000
Deferred revenue non-current	$23,912,000	$7,136,000	$9,600,000	$9,600,000

Collaboration_and_License_Agre2

Collaboration and License Agreements - Additional Information 2 (Detail) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 31, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
	Molecule
License And Collaboration Agreements [Line Items]	'	'	'	'	'	'
License grant fees	'	$15,000,000	'	$15,000,000	'	'
Clinical milestone payments	'	5,000,000	'	5,000,000	'	'
Deferred revenue under agreement	'	20,684,000	'	20,684,000	'	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	'	2,300,000	2,000,000	4,500,000	3,700,000	'
Deferred revenue under agreement	'	900,000	'	900,000	'	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_Agre3

Collaboration and License Agreements - Additional Information 3 (Detail) (USD $)

3 Months Ended

6 Months Ended

1 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

1 Months Ended

Jun. 30, 2014

Jun. 30, 2014

Dec. 31, 2013

Jan. 31, 2014

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Dec. 31, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Dec. 31, 2013

Jul. 31, 2014

Jun. 30, 2014

Jun. 30, 2014

Servier [Member]

Servier [Member]

Servier [Member]

Servier [Member]

Servier [Member]

Servier [Member]

Servier [Member]

Servier [Member]

Servier [Member]

Servier [Member]

Servier [Member]

Servier [Member]

Servier [Member]

Servier [Member]

Second Right to Develop Collaboration [Member]

Second Right to Develop Collaboration [Member]

Second Right to Develop Collaboration [Member]

Second Right to Develop Collaboration [Member]

Second Right to Develop Collaboration [Member]

Subsequent Event [Member]

Maximum [Member]

Maximum [Member]

Second Right to Develop Collaboration [Member]

License And Collaboration Agreements [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Collaboration agreement date

'

'

'

'

'

'

'November 2011

'

'

'

'

'September 2012

'

'

'

'

'

Non-refundable payment

'

'

'

'

'

'

$20,000,000

'

'

'

'

$20,000,000

'

'

'

'

'

Additional license grant fees

15,000,000

15,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

30,000,000

65,000,000

Clinical milestone payments

5,000,000

5,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

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

'

'

'

'38 months

'

'

'27 months

'

'

'

'

'29 months

'

'

'

'

'

Recognized revenue under agreement

'

'

'

'

200,000

4,400,000

400,000

6,600,000

'

2,700,000

2,200,000

10,000,000

4,300,000

'

'

'

'

Deferred revenue

'

'

'

'

400,000

'

400,000

'

900,000

19,400,000

'

19,400,000

'

9,400,000

'

'

'

License option fees received

'

'

'

'

'

'

'

'

'

'

'

15,000,000

'

'

'

'

'

Clinical milestone payments received

'

'

'

'

'

'

'

'

'

5,000,000

'

5,000,000

'

'

'

'

'

Clinical milestone payments under agreement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,000,000

Offset to research and development costs under collaboration arrangement

300,000

400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expected development period

'

'82 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Review period

'

'30 days

'

'

'

'

'

'

'

'

'

'

'

'

'30 days

'

'

Milestones under agreement

'

'

'

'

'

0

'

0

'

'

'

'

'

'

'

'

'

Deferred revenue included in current liabilities

20,684,000

20,684,000

20,267,000

'

'

'

'

'

'

7,300,000

'

7,300,000

'

8,600,000

'

'

'

Deferred revenue included in long-term liabilities

23,912,000

23,912,000

7,136,000

'

'

'

'

'

'

12,100,000

'

12,100,000

'

800,000

'

'

'

Additional milestone payment due

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$5,000,000

'

'

Collaboration_and_License_Agre4

Collaboration and License Agreements - Additional Information 4 (Detail) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended
	Oct. 31, 2010	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
	Molecule			Payments
License And Collaboration Agreements [Line Items]	'	'	'	'	'	'
Clinical milestone payments	'	$5,000,000	'	$5,000,000	'	'
Deferred revenue included in current liabilities	'	20,684,000	'	20,684,000	'	20,267,000
Deferred revenue included in long-term liabilities	'	23,912,000	'	23,912,000	'	7,136,000
Boehringer [Member]	'	'	'	'	'	'
License And Collaboration Agreements [Line Items]	'	'	'	'	'	'
Collaboration agreement date	'	'	'	'October 2010	'	'
Commercialization of molecules	10	'	'	'	'	'
Non-refundable upfront payment	'	'	'	15,000,000	'	'
Number of annual maintenance payments received	'	'	'	3	'	'
Clinical milestone payments	'	41,000,000	'	41,000,000	'	'
Regulatory milestone payments	'	89,000,000	'	89,000,000	'	'
Sales milestone payments	'	83,000,000	'	83,000,000	'	'
Research obligation completion date	'	'	'	'2015-09	'	'
Recognized revenue under agreement	'	3,000,000	2,200,000	6,000,000	4,500,000	'
Deferred revenue	'	9,300,000	'	9,300,000	'	12,800,000
Deferred revenue included in current liabilities	'	7,000,000	'	7,000,000	'	7,000,000
Deferred revenue included in long-term liabilities	'	$2,300,000	'	$2,300,000	'	$5,800,000

Collaboration_and_License_Agre5

Collaboration and License Agreements - Additional Information 5 (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013	Oct. 31, 2010	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
			Pfizer [Member]	Pfizer [Member]	Pfizer [Member]	Pfizer [Member]
			Molecule		Program
License And Collaboration Agreements [Line Items]	'	'	'	'	'	'
Collaboration agreement date	'	'	'	'	'October 2010	'
Period of agreement	'	'	'	'	'3 years	'
Commercialization of molecules	'	'	2	'	'	'
Non-refundable upfront payment	'	'	$5,000,000	'	'	'
Clinical milestone payments	5,000,000	'	'	'	17,000,000	'
Sales milestone payments	'	'	'	'	195,000,000	'
DART program	'	'	'	'	1	'
Research obligation completion date	'	'	'	'	'2014-01	'
Recognized revenue under agreement	'	'	'	1,000,000	'	2,200,000
Deferred revenue	$20,684,000	$20,267,000	'	'	$0	'

Collaboration_and_License_Agre6

Collaboration and License Agreements - Additional Information 6 (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
License And Collaboration Agreements [Line Items]	'	'	'	'	'
Clinical milestone payments	$5,000,000	'	$5,000,000	'	'
Additional clinical, regulatory and sales milestone payments	'	'	1,300,000	'	'
Deferred revenue included in current liabilities	20,684,000	'	20,684,000	'	20,267,000
Deferred revenue included in long-term liabilities	23,912,000	'	23,912,000	'	7,136,000
Green Cross [Member]	'	'	'	'	'
License And Collaboration Agreements [Line Items]	'	'	'	'	'
Collaboration agreement date	'	'	'June 2010	'	'
Term of the agreement	'	'	'2020-06	'	'
Non-refundable upfront payment	'	'	1,000,000	'	'
Recognized revenue under agreement	112,500	25,000	1,500,000	50,000	'
Milestones under agreement	0	0	0	0	'
Deferred revenue	300,000	'	300,000	'	650,000
Deferred revenue included in current liabilities	'	'	'	'	100,000
Deferred revenue included in 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 milestone payments	$2,500,000	'	$2,500,000	'	'

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	6 Months Ended	12 Months Ended
In Millions, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Oct. 31, 2013	Jun. 30, 2014	Feb. 28, 2003
		2013 Stock Incentive Plan [Member]	2013 Stock Incentive Plan [Member]	Stock Option Plan 2000 [Member]	Equity Incentive Plan 2003 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Share-based compensation, Number of shares authorized	'	'	1,960,168	150,297	4,336,731
Stock reserved for future issuance	'	'	1,960,168	'	'
Percentage of Common stock share outstanding	'	4.00%	'	'	'
Weighted-average grant-date fair value of options granted	$14.94	'	'	'	'
Intrinsic value of options exercised	$7.50	'	'	'	'
Fair value of shares vested	1.3	'	'	'	'
Unrecognized compensation cost related to non-vested stock-based compensation arrangements	9.6	'	'	'	'
Unrecognized compensation expense recognition period	'4 years	'	'	'	'
Cash received option exercises	$0.30	'	'	'	'

StockBased_Compensation_Schedu

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation expense	$781	$112	$1,393	$257
Research and Development [Member]	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation expense	365	79	682	172
General and Administrative [Member]	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Stock-based compensation expense	$416	$33	$711	$85

StockBased_Compensation_Schedu1

Stock-Based Compensation - Schedule of Fair Value Option Award Estimated on the Date of Grant Using the Black-Scholes Option-Pricing Model (Detail)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Expected dividend yield	0.00%	0.00%
Expected volatility	67.00%	58.00%
Risk-free interest rate	'	1.80%
Expected term	'6 years 3 months	'7 years
Expected forfeiture rate	5.00%	5.00%
Minimum [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Risk-free interest rate	2.09%	'
Maximum [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Risk-free interest rate	2.32%	'

StockBased_Compensation_Schedu2

Stock-Based Compensation - Schedule of Stock Option Activity (Detail) (USD $)	6 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'	'
Shares, Outstanding, Beginning Balance	3,200,958	'
Shares, Granted	236,294	'
Shares, Exercised	-267,573	'
Shares, Forfeited or expired	-8,452	'
Shares, Outstanding, Ending Balance	3,161,227	3,200,958
Shares, Exercisable	1,669,697	'
Shares, Vested and expected to vest	2,978,791	'
Weighted- Average Exercise Price, Outstanding, Beginning Balance	$4.90	'
Weighted- Average Exercise Price, Granted	$20.61	'
Weighted- Average Exercise Price, Exercised	$1.03	'
Weighted- Average Exercise Price, Forfeited or expired	$3.32	'
Weighted- Average Exercise Price, Outstanding, Ending Balance	$6.41	$4.90
Weighted- Average Exercise Price, Exercisable	$2.02	'
Weighted- Average Exercise Price, Vested and expected to vest	$6.15	'
Weighted- Average Remaining Contractual Term, Outstanding	'6 years 10 months 24 days	'6 years 10 months 24 days
Weighted- Average Remaining Contractual Term, Exercisable	'5 years 1 month 6 days	'
Weighted- Average Remaining Contractual Term, Vested and expected to vest	'6 years 9 months 18 days	'
Aggregate Intrinsic Value, Outstanding, Ending Balance	$49,685	'
Aggregate Intrinsic Value, Exercisable	33,026	'
Aggregate Intrinsic Value, Vested and expected to vest	$47,529	'

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2014
Operating Leased Assets [Line Items]	'
Lessee leasing arrangements, operating leases, renewal term	'5 years
Manufacturing Facilities [Member]	'
Operating Leased Assets [Line Items]	'
Term of additional space lease	'4 years
Amended lease expiration date	31-Dec-19
Origination date for additional space in manufacturing facility	1-Apr-14
Lease [Member] | Office and Laboratory Space [Member]	'
Operating Leased Assets [Line Items]	'
Lease expiration date	30-Jun-18
Lease [Member] | Manufacturing Facilities [Member]	'
Operating Leased Assets [Line Items]	'
Lease expiration date	31-Dec-14
Sublease [Member] | Office and Laboratory Space [Member]	'
Operating Leased Assets [Line Items]	'
Lease expiration date	31-Dec-18

Commitments_and_Contingencies_2

Commitments and Contingencies - Schedule of Minimum Future Lease Payments (Detail) (USD $)	Jun. 30, 2014
In Thousands, unless otherwise specified
Commitments And Contingencies Disclosure [Abstract]	'
2014	$3,651
2015	3,832
2016	4,166
2017	4,291
2018	3,348
Thereafter	507
Total	$19,795

Net_Loss_Per_Share_Computation

Net Loss Per Share - Computation of Basic and Diluted Loss Per Common Share (Detail) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share [Abstract]	'	'	'	'
Net loss	($12,259)	($294)	($15,367)	($3,660)
Less: undistributed earnings allocated to participating securities	0	0	0	0
Net loss allocable to common shares	-12,259	-294	-15,367	-3,660
Basic weighted average common shares outstanding	27,651,297	1,219,884	26,960,664	1,184,507
Basic loss per common share	($0.44)	($0.24)	($0.57)	($3)
Net loss	-12,259	-294	-15,367	-3,660
Less: undistributed earnings allocated to participating securities and other add-backs to net loss	0	0	0	0
Net loss allocable to common shares	($12,259)	($294)	($15,367)	($3,660)
Basic weighted average common shares outstanding	27,651,297	1,219,884	26,960,664	1,184,507
Effect of dilutive securities	0	0	0	0
Diluted weighted average common shares outstanding	27,651,297	1,219,884	26,960,664	1,184,507
Diluted loss per common share	($0.44)	($0.24)	($0.57)	($3)

Net_Loss_Per_Share_Additional_

Net Loss Per Share - Additional Information (Detail)	1 Months Ended
	Feb. 28, 2014	Oct. 31, 2013
Earnings Per Share [Abstract]	'	'
Shares of common stock issued	2,250,000	5,750,000
Convertible preferred stock, shares issued upon conversion	'	16,955,790

Net_Loss_Per_Share_Schedule_of

Net Loss Per Share - Schedule of Diluted Loss Per Share Allocable to Common Stockholders (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Series A-1 Convertible Preferred Stock [Member]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Preferred Stock	'	2,156,114	'	2,156,114
Series A-2 Convertible Preferred Stock [Member]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Preferred Stock	'	392,274	'	392,274
Series B Convertible Preferred Stock [Member]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Preferred Stock	'	4,336,037	'	4,336,037
Series C Convertible Preferred Stock [Member]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Preferred Stock	'	5,909,906	'	5,909,906
Series D Convertible Preferred Stock [Member]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Preferred Stock	'	769,468	'	769,468
Series D-2 Convertible Preferred Stock [Member]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Preferred Stock	'	3,391,991	'	3,391,991
Warrant [Member]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Preferred Stock	'	180,784	'	180,784
Equity Option [Member]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Preferred Stock	2,270,771	2,441,142	2,376,747	2,763,365

Subsequent_Event_Additional_In

Subsequent Event - Additional Information (Detail) (USD $)	6 Months Ended	1 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jul. 31, 2014
		Subsequent Event [Member]
		Servier [Member]
Subsequent Event [Line Items]	'	'
Review period	'30 days	'30 days
Milestone payment due	'	$5