Vitae Pharmaceuticals (VTAE) Inactive 10-K31 Mar 152014 FY Annual reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Mar. 25, 2015
Document and Entity Information
Entity Registrant Name	Vitae Pharmaceuticals, Inc
Entity Central Index Key	1157602
Document Type	10-K
Document Period End Date	31-Dec-14
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float	$90.30
Entity Common Stock, Shares Outstanding		21,829,821
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY

Balance_Sheets

Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$29,494,755	$21,155,247
Marketable securities, available-for-sale	35,823,545	11,299,206
Prepaid expenses and other current assets	1,516,193	968,342
Total current assets	66,834,493	33,422,795
Cash-restricted	200,000	200,000
Property and equipment, net	417,629	377,996
Deferred offering costs	207,743
Other assets		26,963
Total assets	67,659,865	34,027,754
Current liabilities:
Notes payable-current portion	4,804,176	5,281,502
Accounts payable	641,590	458,511
Accrued expenses	3,139,721	1,700,719
Interest payable	278,620	76,687
Deferred revenue		2,000,000
Total current liabilities	8,864,107	9,517,419
Deferred rent and lease incentives	77,707	90,782
Notes payable		4,804,176
Interest payable		162,222
Preferred stock warrant liability		477,375
Total liabilities	8,941,814	15,051,974
Commitments and contingencies
Stockholders' deficit:
Common stock, $0.0001 par value, 150,000,000 and 312,825,000 shares authorized at December 31, 2014 and December 31, 2013, respectively, 18,026,892 and 588,988 shares issued and 16,992,164 and 588,733 shares outstanding at December 31, 2014 and 2013, respectively	1,803	59
Additional paid in capital	188,735,965	3,983,222
Treasury stock		-938
Accumulated other comprehensive income	-38,812	67
Accumulated deficit	-129,980,905	-110,876,561
Total stockholders' deficit	58,718,051	-106,894,151
Total liabilities, convertible preferred stock and stockholders' deficit	67,659,865	34,027,754
Series A-1 preferred stock
Convertible preferred stock:
Convertible preferred stock		675,000
Series A-2 preferred stock
Convertible preferred stock:
Convertible preferred stock		16,379,250
Series B preferred stock
Convertible preferred stock:
Convertible preferred stock		63,964,035
Series C preferred stock
Convertible preferred stock:
Convertible preferred stock		14,936,553
Series D preferred stock
Convertible preferred stock:
Convertible preferred stock		$29,915,093

Balance_Sheets_Parenthetical

Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Sep. 24, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Convertible preferred stock, shares outstanding		9,128,419
Preferred stock, par value (in dollars per share)	0.0001		$0.00
Preferred stock, shares authorized	15,000,000		0
Preferred stock, shares issued	0		0
Preferred stock, shares outstanding	0		0
Common stock, par value (in dollars per share)	0.0001		$0.00
Common stock, shares authorized	150,000,000		312,825,000
Issuance of common stock (in shares)	18,026,892		588,988
Common stock, shares outstanding	18,026,892		588,733
Series A-1 preferred stock
Convertible preferred stock, par value (in dollars per share)			$0.00
Convertible preferred stock, shares authorized	0		675,000
Convertible preferred stock, shares issued	0		29,346
Convertible preferred stock, shares outstanding	0	29,346	29,346	29,346	29,346
Series A-2 preferred stock
Convertible preferred stock, par value (in dollars per share)			$0.00
Convertible preferred stock, shares authorized	0		16,575,000
Convertible preferred stock, shares issued	0		717,379
Convertible preferred stock, shares outstanding	0	717,379	717,379	717,379	717,379
Series B preferred stock
Convertible preferred stock, par value (in dollars per share)			$0.00
Convertible preferred stock, shares authorized	0		151,812,780
Convertible preferred stock, shares issued	0		6,570,106
Convertible preferred stock, shares outstanding	0	6,570,106	6,570,106	6,570,106	6,564,736
Series C preferred stock
Convertible preferred stock, par value (in dollars per share)			$0.00
Convertible preferred stock, shares authorized	0		16,700,007
Convertible preferred stock, shares issued	0		724,632
Convertible preferred stock, shares outstanding	0	724,632	724,632	724,632	724,632
Series D preferred stock
Convertible preferred stock, par value (in dollars per share)			$0.00
Convertible preferred stock, shares authorized	0		26,012,500
Convertible preferred stock, shares issued	0		1,086,956
Convertible preferred stock, shares outstanding	0	1,086,956	1,086,956	1,086,956	1,086,956

Statements_of_Operations

Statements of Operations (USD $)	12 Months Ended
Statements of Operations (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statements of Operations
Collaborative revenues	$8,668,786	$22,512,683	$22,347,827
Operating expenses:
Research and development	19,304,843	14,916,562	15,926,614
General and administrative	7,913,847	5,405,769	4,915,124
Total operating expenses	27,218,690	20,322,331	20,841,738
Operating income	-18,549,904	2,190,352	1,506,089
Other (expenses) income:
Other income	343,318	327,391	243,000
Interest income	63,932	69,497	100,619
Interest expense	-960,752	-1,425,342	-1,626,622
Total other (expenses) income	-553,502	-1,028,454	-1,283,003
Net (loss) income	($19,103,406)	$1,161,898	$223,086
Net income per common share:
Basic (in dollars per share)	($3.61)	$0	$0
Diluted (in dollars per share)	($3.61)	$0	$0
Weighted average number of common shares:
Basic (in shares)	5,290,534	563,136	542,320
Diluted (in shares)	5,290,534	563,136	542,320

Statements_of_Comprehensive_In

Statements of Comprehensive Income (USD $)	12 Months Ended
Statements of Comprehensive Income (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statements of Comprehensive Income
Net (loss) income	($19,103,406)	$1,161,898	$223,086
Other comprehensive income (loss):
Unrealized (losses) gains on marketable securities	-38,879	-2,906	5,859
Comprehensive (loss) income	($19,142,285)	$1,158,992	$228,945

Statement_of_Convertible_Prefe

Statement of Convertible Preferred Stock and Stockholders' Deficit (USD $)	Series A-1 preferred stock	Series A-2 preferred stock	Series B preferred stock	Series C preferred stock	Series D preferred stock	Common stock	Common stock	Additional Paid in Capital	Additional Paid in Capital	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	IPO and over-allotment option	Total
	Series A-1 preferred stock	Series A-2 preferred stock	Series B preferred stock	Series C preferred stock	Series D preferred stock	IPO and over-allotment option	Common stock	IPO and over-allotment option	Additional Paid in Capital	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	IPO and over-allotment option	Total
Balance at Dec. 31, 2011							$54		$3,474,561	($17,917)	($2,886)	($112,200,070)		($108,746,258)
Balance at Dec. 31, 2011	675,000	16,379,250	63,964,023	14,936,553	29,915,093
Balance (in shares) at Dec. 31, 2011							536,882
Balance (in shares) at Dec. 31, 2011	29,346	717,379	6,564,736	724,632	1,086,956
Increase (Decrease) in Convertible Preferred Stock
Cashless exercise of preferred stock warrants (in shares)			5,370
Increase (Decrease) in Stockholders' Equity
Cashless exercise of preferred stock warrants			12						-12					-12
Issuance of common stock							2		52,960					52,962
Issuance of common stock (in shares)							22,959
Repurchase of common stock										-39,605				-39,605
Retirement of common stock							-1		-11	38,605		-38,593
Retirement of common stock (shares)							-5,086
Unrealized gains on marketable securities											5,859			5,859
Stock-based compensation expense									280,210					280,210
Net (loss) income												223,086		223,086
Balance at Dec. 31, 2012							55		3,807,708	-18,917	2,973	-112,015,577		-108,223,758
Balance at Dec. 31, 2012	675,000	16,379,250	63,964,035	14,936,553	29,915,093
Balance (in shares) at Dec. 31, 2012							554,755
Balance (in shares) at Dec. 31, 2012	29,346	717,379	6,570,106	724,632	1,086,956
Increase (Decrease) in Stockholders' Equity
Issuance of common stock							5		75,680					75,685
Issuance of common stock (in shares)							42,823
Repurchase of common stock										-4,923				-4,923
Retirement of common stock							-1		-19	22,902		-22,882
Retirement of common stock (shares)							-8,590
Unrealized gains on marketable securities											-2,906			-2,906
Stock-based compensation expense									99,853					99,853
Net (loss) income												1,161,898		1,161,898
Balance at Dec. 31, 2013							59		3,983,222	-938	67	-110,876,561		-106,894,151
Balance (in shares) at Dec. 31, 2013							588,988
Balance at Dec. 31, 2013	675,000	16,379,250	63,964,035	14,936,553	29,915,093
Balance (in shares) at Dec. 31, 2013	29,346	717,379	6,570,106	724,632	1,086,956
Increase (Decrease) in Convertible Preferred Stock
Conversion of preferred stock into common stock at IPO	-675,000	-16,379,250	-63,964,035	-14,936,553	-29,915,093
Conversion of preferred stock into common stock at IPO (in shares)	-29,346	-717,379	-6,570,106	-724,632	-1,086,956
Increase (Decrease) in Stockholders' Equity
Issuance of common stock						791	4	56,400,651	58,754				56,401,442	58,758
Issuance of common stock (in shares)						7,906,250	40,230
Reclassification of preferred stock warrant liability to equity upon closing of IPO									176,081					176,081
Conversion of preferred stock into common stock on a one-for-one basis at IPO							841		109,489,840					109,490,681
Conversion of preferred stock into common stock on a one-for-one basis at IPO (in shares)							8,411,040
Conversion of preferred stock into common stock on a 1.5064-for-one basis at IPO							108		16,379,142					16,379,250
Conversion of preferred stock into common stock on a 1.5064-for-one basis at IPO (in shares)							1,080,640
Retirement of common stock										938		-938
Retirement of common stock (shares)							-256							-256
Unrealized gains on marketable securities											-38,879			-38,879
Stock-based compensation expense									2,248,275					2,248,275
Net (loss) income												-19,103,406		-19,103,406
Balance at Dec. 31, 2014							$1,803		$188,735,965		($38,812)	($129,980,905)		$58,718,051
Balance (in shares) at Dec. 31, 2014							18,026,892
Balance (in shares) at Dec. 31, 2014	0	0	0	0	0

Statement_of_Convertible_Prefe1

Statement of Convertible Preferred Stock and Stockholders' Deficit (Parenthetical)	Dec. 31, 2014
Convertible preferred stock except Series A-2
Statement of Convertible Preferred Stock and Stockholders' Deficit
Conversion of outstanding shares of preferred stock into shares of common stock	1
Series A-2 preferred stock
Statement of Convertible Preferred Stock and Stockholders' Deficit
Conversion of outstanding shares of preferred stock into shares of common stock	1.5064

Statements_of_Cash_Flows

Statements of Cash Flows (USD $)	12 Months Ended
Statements of Cash Flows (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities:
Net (loss) income	($19,103,406)	$1,161,898	$223,086
Adjustment to reconcile net income to net cash provided by (used in) operating activities:
Depreciation expense	212,690	204,733	531,589
Stock-based compensation expense	2,248,275	99,853	280,210
Deferred rent and lease incentives	1,144	-4,584	-119,580
Amortization of deferred financing fees	218,833	218,834	218,834
Revaluation of preferred stock warrant liability	-301,294	-243,000	-243,000
(Gain) loss on disposal of equipment	-2,500	-5,934
Changes in assets and liabilities:
Accounts receivable		8,740,000	-8,669,708
Prepaid expenses and other current assets	-558,222	-78,219	462,146
Accounts payable and accrued expenses	1,399,017	939,500	-510,260
Deferred revenue	-2,000,000	1,056,307	-2,201,307
Interest payable	39,711	46,062	190,625
Net cash provided by (used in) operating activities	-17,845,752	12,135,450	-9,837,365
Investing activities:
Purchases of property and equipment	-256,219	-185,890	-128,831
Proceeds from disposal of property and equipment	2,500	6,700
Purchases of investments	-50,482,140	-23,009,180	-32,553,054
Sales of investments	25,918,922	28,860,000	29,163,250
Net cash provided by (used in) investing activities	-24,816,937	5,671,630	-3,518,635
Financing activities:
Principal payments under debt facilities	-5,463,002	-4,601,738
Payment of financing costs			-30,808
Payment of deferred offering costs	-2,416,059
Restricted cash		250,000	50,000
Proceeds from the issuance of common stock, net of repurchases	58,881,258	70,762	13,357
Net cash (used in) provided by financing activities	51,002,197	-4,280,976	32,549
Net increase (decrease) in cash and cash equivalents	8,339,508	13,526,104	-13,323,451
Cash and cash equivalents at beginning of period	21,155,247	7,629,143	20,952,594
Cash and cash equivalents at end of period	29,494,755	21,155,247	7,629,143
Supplemental disclosures of cash flow information:
Cash paid for interest	702,208	1,160,446	1,217,163
Noncash Reclassification of Preferred Stock Warrants to Additional Paid in Capital	$176,081

Organization

Organization	12 Months Ended
Organization	Dec. 31, 2014
Organization
Organization	1. Organization
	Vitae Pharmaceuticals, Inc. ("Vitae" or the "Company") is a clinical-stage biotechnology company focused on discovering and developing novel, small molecule drugs for diseases where there are significant unmet medical needs. The Company is developing a robust and growing portfolio of novel product candidates internally generated by Contour®, its proprietary structure-based drug discovery platform. The Company has two partnered product candidates in the clinic and several wholly-owned drug candidates in preclinical development.
	The Company's most advanced product candidate is VTP-34072, which is in a Phase 2 clinical trial for the treatment of type 2 diabetes. The Company was previously developing VTP-37948/BI 1181181, or BI 1181181, for the treatment and prevention of Alzheimer's disease ("Alzheimer's") in collaboration with Boehringer Ingelheim GmbH ("BI"). However, in the first quarter of 2015, BI voluntarily placed BI 1181181 on a temporary clinical hold to further investigate skin reactions observed in some study participants during a Phase 1 multiple rising dose trial. Both the Company's type 2 diabetes and Alzheimer's programs are being developed under separate collaboration with BI. The collaborations with BI has provided the Company with an aggregate of $158 million in funding as of December 31, 2014, including $30 million from sales of the Company's equity securities and $128 million in upfront license fees, research funding and success-based milestones.
	The Company has several wholly-owned product candidates advancing in preclinical development, including VTP-43742 for the treatment of autoimmune disorders, VTP-38543 for the treatment of atopic dermatitis and VTP-38443 for the treatment of acute coronary syndrome. The Company intends to advance and retain rights to these and other programs and product candidates that the Company believes it can develop and commercialize, and to strategically partner where doing so can accelerate the program and generate non-dilutive capital for Vitae.
	Vitae is currently pursuing the following strategies: advance its growing portfolio of product candidates, establish late-stage development and commercialization capabilities for certain of the Company's product candidates in the U.S. and potentially other markets, selectively collaborate with large biotechnology and pharmaceutical companies to maximize the value of the Company's product candidates, leverage Contour to rapidly discover novel small molecule product candidates for additional validated, difficult-to-drug targets, and continue investing in technology, people and intellectual property.
	As of December 31, 2014, the Company had cash, cash equivalents and short-term investments of approximately $65.3 million. In addition, the Company raised $37.8 million, after deducting underwriting discounts and commissions and other offering expenses, on January 28, 2015, through the issuance and sale of 3,450,000 shares of common stock in a public offering. Based on the Company's current operating plan, it believes that the Company's existing cash, cash equivalents and marketable securities, including the net proceeds from its public offering of common stock in January 2015, will be sufficient to fund its projected operating requirements through the end of 2016. However, the Company will need to secure additional funding in the future, from one or more equity or debt financings, collaborations, or other sources, in order to carry out all of the Company's planned research and development activities. The future success of the Company is dependent on its ability to develop its product candidates and ultimately upon its ability to attain profitable operations. The Company is subject to a number of risks similar to other life sciences companies, including, but not limited to, successful discovery and development of its drug candidates, raising additional capital, development by its competitors of new technological innovations, protection of proprietary technology and market acceptance of the Company's products.

Summary_of_Significant_Account

Summary of Significant Accounting Policies and Basis of Accounting	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies and Basis of Accounting
Summary of Significant Accounting Policies and Basis of Accounting	2. Summary of Significant Accounting Policies and Basis of Accounting
	Basis of Accounting
	The accompanying financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America ("GAAP"). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification ("ASC") and Accounting Standards Updates ("ASU") of the Financial Accounting Standards Board ("FASB").
	On April 5, 2012, the Jump-Start Our Business Startups Act (the "JOBS Act") was signed into law. The JOBS Act contains provisions that, among other things, reduce certain reporting requirements for an "emerging growth company." The Company is considered an emerging growth company, but has elected to not take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. As a result, the Company will comply with new or revised accounting standards on the relevant dates on which adoption of such standards is required for non-emerging growth companies.
	Use of Estimates
	Management considers many factors in selecting appropriate financial accounting policies and controls, and in developing the estimates and assumptions that are used in the preparation of these financial statements. Management must apply significant judgment in this process. In addition, other factors may affect estimates, including expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates, and whether historical trends are expected to be representative of future trends. The estimation process often may yield a range of potentially reasonable estimates of the ultimate future outcomes and management must select an amount that falls within that range of reasonable estimates. This process may result in actual results differing materially from those estimated amounts used in the preparation of the financial statements if these results differ from historical experience, or other assumptions do not turn out to be substantially accurate, even if such assumptions are reasonable when made. In preparing these financial statements, management used significant estimates in the following areas, among others: stock-based compensation expense, the determination of the fair value of stock-based awards, the fair value of liability-classified preferred stock warrants, the accounting for research and development costs, accrued expenses and the recoverability of the Company's net deferred tax assets and related valuation allowance.
	Segment and Geographic Information
	Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, or decision-making group, in making decisions on how to allocate resources and assess performance. The Company's chief operating decision maker is its chief executive officer. The Company and its chief executive officer view the Company's operations and manage its business as one operating segment. All revenues and long-lived assets of the Company are earned and reside in the United States and the Company's collaboration revenue is generated in the United States.
	Concentrations of Credit Risk and Off-Balance Sheet Risk
	The Company invests cash that is not currently being used for operational purposes in accordance with its investment policy. The policy allows for the purchase of low-risk debt securities issued by U.S. government agencies and very highly rated corporations, subject to certain concentration limits. The weighted-average days to maturity of the Company's portfolio shall not exceed 12 months. The Company believes its established guidelines for investment of its excess cash maintain safety and liquidity through its policies on diversification and investment maturity.
	Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents, and available-for-sale marketable securities.
	The Company is exposed to credit risk in the event of default by the institutions holding the cash and cash equivalents, and that issue available-for-sale securities, to the extent of the amounts recorded on the balance sheets.
	Cash and Cash Equivalents and Restricted Cash
	The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. The Company was required to maintain a cash balance in the amount of $200,000 as collateral for an outstanding letter of credit at December 31, 2014 and 2013, respectively, and has classified this balance as restricted cash in the Balance Sheet. The Company is required to maintain the $200,000 letter of credit through January 2018. No amounts were outstanding under the letter of credit at December 31, 2014 and 2013.
	Marketable Securities, Available-for-Sale
	Marketable securities consist of securities with original maturities greater than three months, and are comprised of securities issued by U.S. government agencies and corporate debt securities. Marketable securities recorded as current assets have maturities of less than one year from the balance sheet date. Marketable securities recorded as noncurrent assets have maturities of one year or greater from the balance sheet date.
	Management determines the appropriate classification of securities at the time of purchase. The Company has classified its investment portfolio as available-for-sale in accordance with ASC 320, Investments—Debt and Equity Securities. The Company's available-for-sale securities are carried at fair value with unrealized gains and losses reported in other comprehensive income (loss). Marketable securities are evaluated periodically for impairment. If it is determined that a decline of any investment is other than temporary, then the carrying amount of the investment is written down to fair value and the write-down is included in the statements of comprehensive income as a loss.
	Deferred Rent and Lease Incentives
	Deferred rent and lease incentives consist of the difference between cash payments made under operating lease agreements and the related rent expense, which is recognized on a straight-line basis over the term of the lease. In August 2011, Vitae amended its facility lease agreement extending the expiration to January 31, 2018 in exchange for reduced rental rates during the extension period. Lease incentives received at the commencement of the lease are amortized on a straight-line basis over the original lease term and recorded as a reduction in rent expense. Recognition of rent expense exceeded actual cash rent payments by $1,144 for the year ended December 31, 2014. Cash rent payments exceeded rent expense by $4,584 and $119,580 for the years ended December 31, 2013 and 2012, respectively. Deferred rent and lease incentives were $90,782 and $89,638 as of December 31, 2014 and 2013, respectively.
	Fair Value of Financial Instruments
	At December 31, 2014 and 2013, the Company's financial instruments included cash and cash equivalents, restricted cash, marketable securities, accounts payable, accrued expenses and notes payable. The carrying amounts reported in the Company's financial statements for cash and cash equivalents, restricted cash, accounts payable and accrued expenses approximates their respective fair values because of the short-term nature of these instruments. The Company's short- and long-term marketable securities are carried at fair value based on quoted market prices and other observable inputs. Notes payable approximates fair value because the interest rate is reflective of the rate the Company could obtain on debt with similar terms and conditions. At December 31, 2013, the Company also reported a preferred stock warrant liability. The carrying amount of the preferred stock warrant liability was the estimated fair value of the liability (Note 6). The Company has determined the estimated fair value of financial instruments using available market information and management's estimates. The use of different market assumptions and/or estimation methodologies could have a significant effect on the estimated fair value amounts.
	Deferred Offering Costs
	Generally, deferred offering costs consist of legal, accounting, and printing fees incurred in connection with offerings of the Company's equity securities, and are capitalized when incurred. In connection with the Company's January 2015 underwritten public offering of common stock, deferred offering costs totaling $0.2 million were recognized in the balance sheet as of December 31, 2014.
	Comprehensive Income
	Comprehensive income (loss) is defined as changes in stockholders' equity (deficit) exclusive of transactions with owners (such as capital contributions and distributions). Comprehensive income (loss) is comprised of net income (loss) and unrealized (losses) gains on marketable securities.
	Property and Equipment
	Property and equipment consist primarily of laboratory equipment, computer equipment and software, office furniture and equipment and leasehold improvements, all of which are stated at cost, less accumulated depreciation. Property and equipment are depreciated using the straight-line method over the estimated useful lives of the assets. Leasehold improvements are amortized over the estimated useful life of the asset or the remaining lease term at the time the asset is placed into service, whichever is shorter. Maintenance and repairs are expensed as incurred. The following estimated useful lives were used to depreciate the Company's assets:

			Estimated Useful Life
	Laboratory equipment		5 years
	Computer equipment and software		2 years
	Office furniture and equipment		5 years
	Leasehold improvements		Various
	Upon retirement or sale, the cost of the disposed asset and the related accumulated depreciation are removed from the balance sheet accounts and any resulting gain or loss is charged to income.
	Revenue Recognition
	Revenue Arrangements with Multiple Deliverables
	The Company's revenues are generated primarily through collaborative arrangements which generally contain multiple elements, or deliverables, including licenses and research and development activities to be performed by the Company on behalf of the licensee. Payments to Vitae under these arrangements typically include one or more of the following: (1) nonrefundable, upfront license fees, (2) funding of discovery research efforts on a full-time equivalent ("FTE") basis, (3) reimbursement of research, development and intellectual property costs, (4) milestone payments, and (5) royalties on future product sales.
	The Company accounts for revenue arrangements with multiple deliverables entered into prior to January 1, 2011 in accordance with ASC 605-25, Revenue Recognition: Multiple-Element Arrangements. The multiple-deliverable items are divided into separate units of accounting if certain criteria are met, including whether the delivered item has stand-alone value to the customer and whether there is objective and reliable evidence of the fair value of the undelivered items. The Company allocates the consideration it receives among the separate units of accounting based on their respective fair value, and applies the applicable revenue recognition criteria to each of the separate units. Where an item in a revenue arrangement with multiple deliverables does not constitute a separate unit of accounting and for which delivery has not occurred, the Company defers revenue until the delivery of the item is completed.
	Effective January 1, 2011, the Company adopted on a prospective basis Accounting Standards Update ("ASU") 2009-13, Multiple-Deliverable Revenue Arrangements, which amends ASC 605-25 and also adopted ASU 2010-17, Revenue Recognition—Milestone Method.
	In accordance with ASU 2009-13, the Company considers whether the deliverables under the arrangement represent separate units of accounting. In determining the units of accounting, management evaluates certain criteria, including whether the deliverables have stand-alone value. The consideration received is allocated to the separate units of accounting using the relative selling price method, and the applicable revenue recognition criteria are applied to each of the separate units.
	The Company determines the estimated selling price for agreement deliverables using the following hierarchy: (1) vendor-specific objective evidence ("VSOE"), (2) third-party evidence ("TPE") or (3) best estimate of selling price if neither VSOE nor TPE is available. Determining the best estimate of selling price for a deliverable requires significant judgment and consideration of various factors including market conditions, items contemplated during agreement negotiation as well as internally developed net present value models.
	The Company typically receives upfront, nonrefundable payments when licensing its intellectual property. For intellectual property licenses that do not have stand-alone value from the other deliverables to be provided, revenue is recognized over the contractual or estimated performance period, which is typically the term of the research and development obligations. The periods over which revenue should be recognized are subject to estimates by management and may change over the course of the research and development agreement. Such a change could have a material impact on the amount of revenue the Company records in future periods.
	Payments or reimbursements resulting from the Company's research and development efforts are recognized as the services are performed and are presented on a gross basis so long as there is persuasive evidence of an arrangement, the fee is fixed or determinable, and collection of the related receivable is reasonably assured. Amounts received prior to satisfying the above revenue recognition criteria are recorded as deferred revenue in the balance sheet.
	In accordance with ASU 2010-17, Vitae recognizes revenue from milestone payments when: (i) the milestone event is substantive and its achievability was not reasonably assured at the inception of the agreement, and (ii) Vitae does not have ongoing performance obligations related to the achievement of the milestone earned. Milestone payments are considered substantive if all of the following conditions are met: the milestone payment (a) is commensurate with either the Company's performance to achieve the milestone or the enhancement of the value of the delivered item or items as a result of a specific outcome resulting from the Company's performance to achieve the milestone, (b) relates solely to past performance, and (c) is reasonable relative to all of the deliverables and payment terms (including other potential milestone consideration) within the arrangement. The Company has concluded that the clinical and development and regulatory milestones pursuant to its research and development arrangements are substantive.
	The following table details the amount of collaborative revenue recognized for the years ended December 31, 2014, 2013 and 2012:

			Year Ended December 31,
			2014			2013			2012
	Amortization of upfront license fees		$	150,000		$	353,693		$	1,921,307
	Collaborative research payments:
	FTE funding			1,850,000			3,108,000			3,436,000
	Research and development costs			—			—			20,055
	Intellectual property costs			668,786			1,050,990			970,465

	Total collaborative research payments			2,518,786			4,158,990			4,426,520

	Milestone revenue			6,000,000			18,000,000			16,000,000

	Total collaborative revenue		$	8,668,786		$	22,512,683		$	22,347,827


	Research and Development Expenses
	Research and development costs are charged to expense as incurred. These costs include, but are not limited to, employee-related expenses, including salaries, benefits and travel and stock-based compensation of the Company's research and development personnel, expenses incurred under agreements with contract research organizations and investigative sites that conduct clinical trials and preclinical studies, the cost of acquiring, developing and manufacturing clinical trial materials, facilities, other supplies, allocated facilities, depreciation and other expenses, which include rent and utilities, insurance, and costs associated with preclinical activities and regulatory operations. Nonrefundable advances for future research and development services are deferred and recognized as expense as the related services are provided.
	Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as subject enrollment, clinical site activations or information provided to the Company by its vendors with respect to their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the financial statements as prepaid or accrued research and development expense, as the case may be.
Accrued Clinical and Preclinical Expenses
As part of the process of preparing the financial statements, the Company is required to estimate its accrued expenses. This process involves reviewing open contracts and purchase orders, communicating with its applicable personnel to identify services that have been performed on its behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of actual cost. The majority of the Company's service providers invoice monthly in arrears for services performed. The Company makes estimates of its accrued expenses as of each balance sheet date in the financial statements based on facts and circumstances known at that time. The Company periodically confirms the accuracy of the estimates with the service providers and makes adjustments if necessary. Examples of estimated accrued clinical expenses include:
•	fees paid to vendors in connection with the preclinical development activities;
•	fees paid to contract manufacturers in connection with the production of preclinical and clinical trial materials;
•	fees paid to contract research organizations in connection with clinical studies; and
•	fees paid to investigative sites in connection with clinical studies.
The Company bases its expenses related to preclinical and clinical studies on its estimates of the services received and efforts expended pursuant to contracts with multiple research institutions and contract research organizations that conduct and manage clinical studies on its behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows. Payments under some of these contracts depend on factors such as the successful enrollment of patients and the completion of clinical trial milestones. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company adjusts the accrual accordingly. Although the Company does not expect its estimates to be materially different from amounts actually incurred, the Company's understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in reporting amounts that are too high or too low in any particular period.
Preferred Stock Warrants
Prior to the Company's IPO, the Company accounted for its preferred stock warrants as liabilities in accordance with the guidance for accounting for certain financial instruments with characteristics of both liabilities and equity as the warrants entitle the holder to purchase preferred stock that was considered contingently redeemable. The fair value of the preferred stock warrant liability was re-measured at the end of each reporting period, and any changes in fair value were recognized in the Statements of Operations as other income or expense. Upon the closing of the IPO, the preferred stock warrant was, in accordance with its terms, automatically converted into a warrant to purchase common stock, which resulted in the reclassification of the preferred stock warrant liability to additional paid-in capital. Upon reclassification, no further changes in fair value will be recognized in other income or expense. The fair value of the preferred stock warrant liability was classified as Level 3 measurements (see Note 6).
Stock-Based Compensation Expense
The Company accounts for stock-based compensation expense in accordance with the provisions of ASC 718, Compensation—Stock Compensation, which addresses the accounting for share-based payment transactions in which an enterprise receives employee services in exchange for (a) equity instruments of the enterprise or (b) liabilities that are based on the fair value of or may be settled by the issuance of the enterprise's equity instruments. ASC 718 requires that an entity measure the cost of equity-based service awards based on the grant-date fair value of the award and recognize the cost of such awards over the period during which the employee is required to provide service in exchange for the award (the vesting period).
For stock options issued to employees and members of the Board for their services on the Board, the Company estimates the grant date fair value of each option using the Black-Scholes option pricing model. The use of the Black-Scholes option pricing model requires management to make assumptions with respect to the expected term of the option, the expected volatility of the common stock over a period consistent with the expected life of the option, risk-free interest rates, the value of the common stock and expected dividend yields of the common stock. For awards subject to service-based vesting conditions, the Company recognizes stock-based compensation expense, net of estimated forfeitures, equal to the grant date fair value of stock options on a straight-line basis over the requisite service period, which is generally the vesting term. For awards subject to both performance and service-based vesting conditions, the Company recognizes stock-based compensation expense using the straight-line recognition method when it is probable that the performance condition will be achieved. Forfeitures are required to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.
The Company utilizes significant estimates and assumptions in determining the fair value of its common stock. The Board determined the estimated fair value of the Company's common stock based on a number of objective and subjective factors, including external market conditions affecting the biotechnology industry and the prices at which the Company sold shares of redeemable convertible preferred stock, the superior rights and preferences of securities senior to the Company's common stock at the time, and the likelihood of achieving a liquidity event, such as an IPO or sale of the Company.
Stock-based compensation expense recognized for the years ended December 31, 2014, 2013 and 2012:

		Year Ended December 31,
		2014			2013			2012
Research and development		$	232,572		$	18,920		$	114,591
General and administrative			2,015,703			80,933			165,619

Total stock-based compensation		$	2,248,275		$	99,853		$	280,210


Income Taxes
Income taxes are recorded in accordance with ASC 740, Income Taxes ("ASC 740"), which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided, if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized.
The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company recognizes interest and penalties accrued on any unrecognized tax benefits in its provision for income taxes in the Statement of Operations. As of December 31, 2014 and 2013, the Company does not have any significant uncertain tax positions.
Net Income (Loss) Per Common Share
Prior to the Company's IPO in September 2014, the Company used the two-class method to compute net income per common share because the Company had outstanding securities, other than common stock, that contractually entitle the holders to participate in dividends and earnings of the Company. The two-class method requires earnings available to common stockholders for the period, after an allocation of earnings to participating securities, to be allocated between common and participating securities based upon their respective rights to receive distributed and undistributed earnings. Each series of the Company's convertible preferred stock were entitled to receive annual non-cumulative dividends that ranged from $0.60 - $1.66 per share, payable prior and in preference to dividends paid to holders of common stock when and if declared by the Company's board of directors. In the event a dividend was paid on common stock, holders of preferred stock were entitled to a proportionate share of any such dividend as if they were holders of common shares (on an as-if converted basis).
For periods with net income prior to the IPO, net income per common share information is computed using the two-class method. Under the two-class method, basic net income per common share is computed by dividing the net income attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period. Basic net income attributable to common stockholders is computed by an adjustment to subtract from net income the portion of current year earnings that the preferred stockholders would have been entitled to receive pursuant to their dividend rights had all of the year's earnings been distributed. No such adjustment to earnings is made during periods with a net loss, as the holders of the convertible preferred shares had no obligation to fund losses.
Diluted net income (loss) per common share is computed by using the weighted-average number of shares of common stock outstanding, plus, for periods with net income attributable to common stock, the dilutive effects of stock options, restricted stock units, and warrants. Potential dilutive shares consist of incremental common stock issuable upon the exercise of stock options and warrants. Basic and dilutive computations are the same in periods with net losses attributable to common stockholders as the dilutive effects of stock options, restricted stock units and warrants would be antidilutive.
Recent Accounting Pronouncements
In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers." ASU 2014-09 will supersede and replace nearly all existing U.S. GAAP revenue recognition guidance, including industry-specific guidance. The guidance is effective for annual reporting periods beginning after December 15, 2016, including interim periods therein. The Company is evaluating ASU 2014-09 and has not yet determined what, if any, effect ASU 2014-09 will have on its results of operations or financial condition.
In August 2014, the FASB issued ASU 2014-15, "Presentation of Financial Statements—Going Concern." ASU 2014-15 requires management of all entities to evaluate whether there are conditions and events that raise substantial doubt about the entity's ability to continue as a going concern within one year after the financial statements are issued, and to make certain disclosures if it concludes that substantial doubt exists or when its plans alleviate substantial doubt about the entity's ability to continue as a going concern. ASU 2014-15 is effective for the Company for annual reporting periods beginning in 2016 and for interim reporting periods starting in the first quarter of 2017. The Company is currently evaluating the impact of the adoption of ASU 2014-15 on its financial statements.

Net_Income_Loss_Per_Common_Sha

Net Income (Loss) Per Common Share	12 Months Ended
Net Income (Loss) Per Common Share	Dec. 31, 2014
Net Income (Loss) Per Common Share
Net Income (Loss) Per Common Share
	3. Net Income (Loss) Per Common Share
	The following table sets forth the computation of basic and diluted net income (loss) per common share for the periods indicated:

		Year Ended December 31,
		2014			2013			2012
	Basic and diluted net (loss) income per common share calculation:
	Net (loss) income	$	(19,103,406	)	$	1,161,898		$	223,086
	Less: Undistributed earnings allocated to participating securities		—			(1,161,898	)		(223,086	)

	Net loss attributable to common stockholders		(19,103,406	)		—			—
	Weighted average common shares—basic and diluted		5,290,534			563,136			542,320

	Net (loss) income per common share—basic and diluted	$	(3.61	)	$	0		$	0


	Diluted net income (loss) per share for the years presented do not reflect the following potential common shares, as the effect would be antidilutive:

		Year Ended December 31,
		2014			2013			2012
	Stock options		1,484,696			1,291,917			1,907,568
	Restricted stock units		391,304			391,304			—
	Warrants		45,468			45,468			46,751
	Convertible preferred stock		—			9,491,680			9,491,680

	Total		1,921,468			11,220,369			11,445,999

Property_and_Equipment

Property and Equipment	12 Months Ended
Property and Equipment	Dec. 31, 2014
Property and Equipment
Property and Equipment
	4. Property and Equipment
	Property and equipment, net of accumulated depreciation and amortization consisted of the following:

		December 31,
		2014			2013
	Laboratory equipment	$	3,253,683		$	3,085,736
	Computer equipment and software		1,474,310			1,452,580
	Office furniture and equipment		318,839			311,564
	Leasehold improvements		3,402,330			3,357,312
	Construction in process		—			10,293
	Less accumulated depreciation and amortization		(8,031,533	)		(7,839,489	)

	Property and equipment, net	$	417,629		$	377,996


	Depreciation expense was $212,690, $204,733 and $531,589 for the years ended December 31, 2014, 2013 and 2012, respectively.

Accrued_Expenses

Accrued Expenses	12 Months Ended
Accrued Expenses	Dec. 31, 2014
Accrued Expenses
Accrued Expenses
	5. Accrued Expenses
	Accrued expenses consisted of the following:

		December 31,
		2014		2013
	Payroll and related costs	$	1,710,439	$	1,230,428
	Research and development related costs		760,961		74,260
	Offering costs		207,743		—
	Legal and accounting related costs		264,959		341,901
	Other		195,619		54,130

	Total	$	3,139,721	$	1,700,719

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Dec. 31, 2014
Fair Value Measurements
Fair Value Measurements
	6. Fair Value Measurements
	The Company measures certain assets and liabilities at fair value in accordance with ASC 820, Fair Value Measurements and Disclosures. ASC 820 defines fair value as the price that would be received to sell an asset or paid to transfer a liability (the exit price) in an orderly transaction between market participants at the measurement date. The guidance in ASC 820 outlines a valuation framework and creates a fair value hierarchy in order to increase the consistency and comparability of fair value measurements and the related disclosures. In determining fair value, the Company maximizes the use of quoted prices and observable inputs. Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from independent sources. The fair value hierarchy is broken down into three levels based on the source of inputs as follows:
	•	Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities.
	•	Level 2—Valuations based on observable inputs and quoted prices in active markets for similar assets and liabilities.
	•	Level 3—Valuations based on inputs that are unobservable and models that are significant to the overall fair value measurement.
	The Company's Level 1 assets include money market funds and certificates of deposit ("CD"). Level 2 assets include U.S. government agency securities and corporate debt securities. The following fair value hierarchy tables present information about each major category of financial assets and liabilities measured at fair value on a recurring basis as of December 31, 2014 and 2013:

			Fair Value Measurements as of December 31, 2014 Using
			Level 1			Level 2		Level 3		Balance
										as of
										December 31,
										2014
	Assets
	Money market funds		$	25,664,911		$	—	$	—	$	25,664,911
	Other cash equivalents			—			2,179,290		—		2,179,290
	Cash-restricted, CD			200,000			—		—		200,000
	Marketable securities, available-for-sale			—			35,823,545		—		35,823,545

	Total assets		$	25,864,911		$	38,002,835	$	—	$	63,867,746




			Fair Value Measurements as of December 31, 2013 Using
			Level 1			Level 2		Level 3		Balance
										as of
										December 31,
										2013
	Assets
	Money market funds		$	18,512,463		$	—	$	—	$	18,512,463
	Cash-restricted, CD			200,000			—		—		200,000
	Marketable securities, available-for-sale			—			11,299,206		—		11,299,206

	Total assets		$	18,712,463		$	11,299,206	$	—	$	30,011,669


	Liabilities
	Preferred stock warrant liability		$	—		$	—	$	477,375	$	477,375

	Total liabilities		$	—		$	—	$	477,375	$	477,375


	Prior to the Company's IPO, the Company accounted for its preferred stock warrants as liabilities in accordance with the guidance for accounting for certain financial instruments with characteristics of both liabilities and equity as the warrants entitle the holder to purchase preferred stock that was considered contingently redeemable. The fair value of the preferred stock warrant liability was re-measured at the end of each reporting period, and any changes in fair value were recognized in the Statements of Operations as other income or expense. Upon the closing of the IPO, the preferred stock warrant was, in accordance with its terms, automatically converted into a warrant to purchase common stock, which resulted in the reclassification of the preferred stock warrant liability, measured at its fair value as of the IPO date, to additional paid-in capital. Effective as of the reclassification date, no further changes in fair value will be recognized in other income or expense.
	The fair value of the warrants on the date of issuance and on each re-measurement date of those warrants classified as liabilities was estimated using the Black-Scholes option pricing model using the following assumptions: contractual life according to the remaining terms of the warrants, no dividend yield, weighted average volatility of 83% and weighted average fair value of the underlying instruments of $8.00 and $16.33, and weighted average risk-free interest rate of 2.01% and 2.68%, at September 24, 2014 and December 31, 2013, respectively. For this liability, the Company developed its own assumptions that did not have observable inputs or available market data to support the fair value. This method of valuation involved using inputs such as the fair value of the Company's common stock, stock price volatility, the contractual term of the warrants, risk free interest rates and dividend yields. Due to the nature of these inputs, the valuation of the warrants was considered a Level 3 measurement. For the period January 1, 2014 to September 24, 2014, the date of the Company's IPO, the fair value of the preferred stock warrant liability decreased $301,294 to its then fair value amount of $176,081, which was reclassified to additional paid-in capital. The table below sets forth a summary of changes in fair value of the Company's Level 3 financial instruments measured on a recurring basis:

			Preferred Stock
			Warrant Liability
	Balance as of January 1, 2013		$	720,375
	Changes in estimated fair value			(243,000	)

	Balance as of December 31, 2013		$	477,375
	Changes in estimated fair value			(301,294	)
	Reclassification of warrants to additional paid-in capital			(176,081	)

	Balance as of December 31, 2014		$	—

Investments

Investments	12 Months Ended
Investments	Dec. 31, 2014
Investments
Investments
	7. Investments
	Marketable Securities
	Marketable securities consisted of the following as of December 31, 2014 and 2013:

		Cost		Unrealized		Unrealized			Fair
		Basis		Gains		Losses			Value
	December 31, 2014
	Corporate notes and bonds	$	35,862,357	$	573	$	(39,385	)	$	35,823,545

	Total marketable securities	$	35,862,357	$	573	$	(39,385	)	$	35,823,545


	December 31, 2013
	U.S. government and agency	$	500,066	$	64	$	—		$	500,130
	Corporate notes and bonds		10,799,073		1,964		(1,961	)		10,799,076

	Total marketable securities	$	11,299,139	$	2,028	$	(1,961	)	$	11,299,206


	As of December 31, 2014, the Company's marketable securities had maturities that were less than one year.

Notes_Payable

Notes Payable	12 Months Ended
	Dec. 31, 2014
Notes Payable
Notes Payable
	8. Notes Payable
	Term Notes
	Silicon Valley Bank and Oxford Finance Corp.—2011 Credit Facility
	In December 2011, the Company entered into a $15 million senior secured credit facility with Silicon Valley Bank and Oxford Finance Corp. (together, the Lenders) and drew-down all funds at that time. Pursuant to the terms of the loan and security agreement evidencing the credit facility, the Company made monthly payments of interest only through January 1, 2013 and, thereafter, will make monthly payments of principal and interest over the remaining 33 months of the loan. The credit facility bears interest at the rate of 8.85%. The final payment will include an additional interest payment of $300,000, which is being recognized in interest expense over the term of the note. Therefore, the effective interest rate on the loan is 9.49%. The Company may prepay the debt provided it pays certain prepayment fees.
	The loan is secured by all of the Company's assets other than intellectual property for which the Company has provided a negative pledge. The Company cannot grant a license to its intellectual property without the prior consent of the Lenders except for certain predefined situations. The loan prohibits the Company from paying dividends on its equity securities.
	In connection with the credit facility, the Company issued to Silicon Valley Bank and Oxford Financial Corp. 10-year warrants to purchase an aggregate of 29,889 shares of Series D preferred stock with an exercise price of $27.60 per share. The Series D preferred stock warrants were immediately converted into warrants to purchase common stock upon the closing of the Company's IPO. Upon issuance, the estimated fair value of the preferred stock warrants was $680,625 determined using the Black-Scholes option pricing model and was recorded as a debt discount, with a corresponding credit to the preferred stock warrant liability. The debt discount is being accreted to interest expense over the term of the loan. As of December 31, 2014, the unamortized debt discount was $131,084 and the Company accreted $181,500 to interest expense for the years ended December 31, 2014, 2013 and 2012, respectively. In addition, the Company incurred and capitalized a total of $140,000 in debt issuance costs which are being amortized on a straight-line basis as additional interest expense over the expected 45-month loan term.
	The Company also issued Series D preferred stock warrants in conjunction with a credit facility that is no longer outstanding. All Series D preferred stock warrants were recorded as liabilities in accordance with ASC 480, Distinguishing Liabilities from Equity. Prior to the IPO, the fair value of the preferred stock warrant liability was re-measured at the end of each reporting period, and any changes in fair value was recognized in the Statements of Operations as other income or expense. Upon the closing of the IPO, the preferred stock warrants were, in accordance with its terms, automatically converted into warrants to purchase common stock, which resulted in the reclassification of the preferred stock warrant liability to additional paid-in capital. Upon reclassification, no further changes in fair value will be recognized in other income or expense. See Note 6 for further details.
	The principal balance of the loan was $4,935,260 and $10,398,262 at December 31, 2014 and 2013, respectively. In February 2015, the Company paid the remaining outstanding principal and applicable prepayment penalties in full. See Note 18 for further details.
	Aggregate maturities of all term notes are as follows (amounts exclude unamortized discount at December 31, 2014):

	2015	$	4,935,260

Stockholders_Equity_Deficit

Stockholders' Equity (Deficit)	12 Months Ended
Stockholders' Equity (Deficit)	Dec. 31, 2014
Stockholders' Equity (Deficit)
Stockholders' Equity (Deficit)
	9. Stockholders' Equity (Deficit)
	Common Stock
	On September 29, 2014, the Company closed its IPO, in which it issued and sold 6,875,000 shares of common stock at a price of $8.00 per share, for aggregate gross proceeds of $55.0 million. On October 27, 2014, the underwriters of the Company's IPO exercised in full their over-allotment option and the Company issued and sold an additional 1,031,250 shares of common stock at the IPO price of $8.00 per share, for aggregate gross proceeds of $8.3 million. Total net proceeds for the IPO and the underwriters exercise of their over-allotment option was $56.4 million after deducting underwriting fees and other offerings expenses. As of December 31, 2014, the Company had authorized 150,000,000 shares of common stock at $0.0001 par value. The Company has issued 18,026,892 shares of common stock at prices ranging from $0.0001 to $8.00 including 343,534 and 91,586 shares of common stock issued through the exercise of options in the 2001 Stock Plan and 2004 Stock Plan, respectively. There were 18,026,892 and 588,733 shares of common stock outstanding as of December 31, 2014 and December 31, 2013, respectively. See Note 18 regarding the Company's January 2015 public offering of additional shares of common stock.
	Each holder of common stock is entitled to one vote per share on all matters submitted to a vote of stockholders. The Company has not provided for cumulative voting in the election of directors. Subject to preferences that may apply to shares of preferred stock outstanding at the time, the holders of outstanding shares of the Company's common stock are entitled to receive dividends out of assets legally available at the times and in the amounts that the board of directors may determine from time to time. Upon the Company's liquidation, dissolution or winding-up, the holders of common stock are entitled to share ratably in all assets remaining after payment of all liabilities and the liquidation preferences of any outstanding preferred stock. Holders of common stock have no preemptive or conversion rights or other subscription rights. There are no redemption or sinking fund provisions applicable to the Company's common stock.
	Preferred Stock
	In connection with the IPO, the Company filed an Amended and Restated Certificate of Incorporation that established the preferred stock the Company was authorized to issue. As of December 31, 2014, the Company had authorized 15,000,000 shares of preferred stock at $0.0001 par value. There were no shares of preferred stock issued or outstanding as of December 31, 2014.
	As of December 31, 2013, the Company had authorized 211,775,287 shares of preferred stock at $0.0001 par value. The shares were further designated as 675,000 shares of Series A-1 preferred stock, 16,575,000 shares of Series A-2 preferred stock, 151,812,780 shares of Series B preferred stock, 16,700,007 shares of Series C preferred stock, and 26,012,500 shares of Series D preferred stock. The Company had the following convertible preferred stock outstanding which immediately converted into common shares upon the closing of the Company's IPO on September 29, 2014:

		Preferred to		Preferred		Conversion
		Common		Shares		into Common
		Conversion		Outstanding		Shares upon
		Ratio				Initial Public
						Offering
	Series A		1.00-to-1.00		29,346		29,346
	Series A-2		1.00-to-1.51		717,379		1,080,640
	Series B		1.00-to-1.00		6,570,106		6,570,106
	Series C		1.00-to-1.00		724,632		724,632
	Series D		1.00-to-1.00		1,086,956		1,086,956

	Total				9,128,419		9,491,680


	Treasury Stock
	The Company retired 256 treasury shares during the year ended December 31, 2014. Treasury stock is recorded using the cost method. Treasury stock retirements are recorded by deducting the par value from common stock and charging the remaining excess of cost over par to accumulated deficit.
	Warrants
	Series D preferred stock warrants were immediately converted into common stock warrants upon the closing of the Company's IPO. As of December 31, 2014, the Company had 45,468 warrants outstanding for the purchase of common stock at exercise prices ranging from $20.70 - $27.60. The following table summarizes the warrants outstanding and exercisable as of December 31, 2014:

	Warrants to Purchase	Shares		Exercise		Expiration Date
	Warrants to Purchase	Shares		Price		Expiration Date
	Common stock		1,449	$	20.70		7/12/16
	Common stock		14,130	$	27.60		8/28/18
	Common stock		29,889	$	27.60		12/21/21
	Shares Reserved for Future Issuance
	At December 31, 2014, the Company has reserved the following shares of common stock for issuance:

	Common stock options outstanding		1,484,696
	Restricted stock units outstanding		391,304
	Shares available for future grant under employee compensation plans		1,861,623
	Shares available through employee stock purchase plan		250,000
	Warrants		45,468

			4,033,091

Employee_Compensation_Plans

Employee Compensation Plans	12 Months Ended
Employee Compensation Plans	Dec. 31, 2014
Employee Compensation Plans
Employee Compensation Plans
	10. Employee Compensation Plans
	In July 2014, the Company's Board of Directors approved the 2014 Stock Plan (the 2014 Plan) and reserved to be authorized for issuance under the 2014 Plan the sum of (1) 1,782,500 shares of the Company's common stock, (2) the number of shares of the Company's common stock reserved under the Predecessor Plans (as defined below) that are not issued or subject to outstanding awards under the Predecessor Plans as of the closing of the Company's IPO and (3) any shares of the Company's common stock which are subject to outstanding options under the Predecessor Plans as of the closing of the Company's IPO that subsequently expire or lapse unexercised or are subsequently forfeited to or repurchased by the Company, provided that the shares reserved under clauses (2) and (3) above shall include no more than 1,070,687 shares of the Company's common stock. Under the 2014 Plan, options to purchase common stock, restricted stock and restricted stock units may be granted to the Company's employees, nonemployee directors, and consultants providing services to the Company. As of December 31, 2014, there are 1,861,623 shares available for grant without restriction. The aggregate number of shares of the Company's common stock reserved for issuance under the 2014 Plan shall automatically be increased on the first business day of each of the Company's fiscal years by a number equal to the smallest of (i) 4% of the total number of shares of the Company's common stock actually issued and outstanding on the last business day of the prior fiscal year (excluding any rights to purchase shares of the Company's common stock that may be outstanding, such as options or warrants), (ii) 1,426,000 shares of the Company's common stock or (iii) a number of shares of Common Stock determined by the Company's board of directors. As of January 1, 2015, the number of shares of common stock that may be issued under the 2014 Plan was automatically increased by 721,076 shares, increasing the number of shares of common stock available for issuance under the 2014 Plan to 2,582,699 shares.
	The Company has three additional share-based compensation plans pursuant to which outstanding awards have been made, but from which no further awards can or will be made: (i) the 2001 Stock Plan (the 2001 Plan); (ii) the 2004 Stock Plan (the 2004 Plan); and the 2013 Stock Plan (the 2013 Plan, and collectively with the 2001 Plan and the 2004 Plan (the Predecessor Plans)). In November 2013, the Company's board of directors authorized a decrease in the number of shares available for issuance under the 2001 Plan by 530,674 shares and the automatic transfer of shares to the 2013 Plan from the 2001 and 2004 Plans that become available due to expiry, cancellation, termination or forfeiture. Through December 31, 2014, 402,530 shares became available under the 2001 Plan, due to expiration and forfeiture, which were automatically transferred to the 2013 Plan and subsequently to the 2014 Plan as described in the immediately preceding paragraph.
	Stock Options
	All options granted under the Plans were granted with exercise prices equal to or above the fair market value of the Company's common stock on the date of grant. Options granted under the Plans vest over a time period or based on performance milestones established at the sole discretion of the Company's board of directors or its compensation committee. Vesting for time-based options generally occurs over a period of not greater than four years. All stock options expire no later than ten years from the grant date. As of December 31, 2014, the Company has 117,159 options that will expire during the year ended December 31, 2015, unless exercised. Under the terms of the Plans, employees may use shares to exercise a portion of these options. Shares tendered for this purpose are valued at the fair market value as of the date the options are exercised.
	The following table summarizes stock option activity under the Plans during the year ended December 31, 2014:

			Number of			Weighted-			Weighted-			Aggregate
			Shares			Average			Average			Intrinsic Value
						Exercise			Contractual
						Price			Life (in Years)
	Outstanding, January 1, 2014			1,291,917		$	4.3194
	Granted			463,008		$	5.9434
	Exercised			(40,230	)	$	1.4602
	Expired			(210,043	)	$	4.1992
	Forfeited			(19,956	)	$	7.0579

	Outstanding, December 31, 2014			1,484,696		$	4.884			5.3		$	17,454,021


	Exercisable, December 31, 2014			819,955		$	3.6748			2.79		$	10,630,885


	Vested and Expected to Vest, December 31, 2014			1,454,906		$	4.8411


	The total intrinsic value of options exercised during the years ended December 31, 2014 and 2013 was $166,693 and $112,583, respectively. The cost of each stock-based compensation award is determined based on the grant-date fair value, net of the effects of estimated forfeitures of the awards, and is recognized into expense over the award's requisite service period. The weighted average fair value of options granted during the years ended December 31, 2014, 2013 and 2012 was $4.23, $3.68 and $4.83 per share, respectively.
	The Company granted 303,559 performance-based stock options to employees in March 2011. These performance options have a 10-year life and exercise prices equal to the fair value of the Company's stock at the grant date. Vesting of no more than 60% of these performance options is dependent on (i) meeting certain performance conditions, which relate to the Company's research and development progress, which were established by the Company's board of directors and (ii) the passage of time subsequent to the achievement of such performance conditions. Vesting of no more than 40% of these performance options is dependent on (i) meeting certain performance conditions, which relate to a deemed liquidation of the Company, an IPO or consummation of a strategic transaction, which were established by the Company's board of directors and (ii) the passage of time subsequent to the achievement of such performance conditions. The Company's board of directors determines if the performance conditions have been met. Stock-based compensation expense for these options is recorded when management estimates that the vesting of these options is probable based on the status of the Company's research and development programs and other relevant factors. As of December 31, 2014, 110,701 performance-based stock options have been deemed probable and stock-based compensation expense is recorded ratably over the service period associated with each performance condition. Any change in these estimates will result in a cumulative adjustment in the period in which the estimate is changed, so that as of the end of a period, the cumulative compensation expense recognized for an award or grant equals the amount that would be recognized on a straight-line basis as if the current estimates had been utilized since the beginning of the service period.
	The Company uses the Black-Scholes valuation model to determine the fair value of stock options at the grant date. The Black-Scholes valuation model requires the Company to make certain estimates and assumptions, including assumptions related to the expected price volatility of the Company's stock, the period during which the options will be outstanding, the rate of return on risk-free investments, and the expected dividend yield for the Company's stock.
	The fair values of stock options granted were calculated using the following weighted-average assumptions:

			Year Ended December 31,
			2014			2013			2012
	Weighted-average risk-free interest rate			1.98	%		1.42	%		0.90	%
	Expected term of options (in years)			6.11			6.25			6.25
	Expected stock price volatility			83.00	%		85.00	%		86.16	%
	Expected dividend yield			0	%		0	%		0	%
	The weighted-average valuation assumptions used for each option grant were as follows:
	•	Weighted-average risk-free interest rate: The Company bases the risk-free interest rate on the interest rate payable on U.S. Treasury securities with maturities that are commensurate with the expected term of the option.
	•	Expected term of options: The expected term of options represents the period of time options are expected to be outstanding. The expected term of the options granted is derived using the "simplified" method, as prescribed by the Securities and Exchange Commission Staff Accounting Bulletin No. 107, Share-Based Payment.
	•	Expected stock price volatility: The expected volatility is based on historical stock price volatilities of similar entities within the Company's industry over the period that is commensurate with the expected term of the option.
	•	Expected dividends yield: The dividend yield is assumed to be $0.00, because the Company has not historically paid, and does not expect for the foreseeable future to pay, a dividend.
	The total cash received from employees as a result of employee stock option exercises during the years ended December 31, 2014, 2013 and 2012 was $58,758, $70,762 and $13,357, respectively.
	As of December 31, 2014, excluding performance-based stock options that have not been deemed probable, the aggregate unrecognized stock-based compensation expense related to unvested options granted under the Stock Plans that were expected to vest was $1,731,052. That expense is expected to be recognized as follows:

	Year ending December 31,
	2015		$	616,550
	2016			533,584
	2017			468,723
	2018			112,195

			$	1,731,052


	The aggregate estimated fair value of options for which the satisfaction of the related-performance conditions have not been deemed probable was $827,860 as of December 31, 2014.
	Restricted Stock Units
	During 2013, the Company awarded a performance-based RSU covering 391,304 shares of common stock from the 2013 Plan. An RSU award entitles the holder to receive shares of the Company's common stock as the award vests. The performance-based RSU awarded in 2013 vests contingent upon the achievement of pre-determined performance-based milestones. Stock-based compensation expense is recognized when it is deemed probable that the performance-based goal will be met. The Company's board of directors or its compensation committee determines if the performance conditions have been met. The grant-date fair value of the RSU was $3.68 per share and was based on the fair market value of the Company's common stock on the date of grant.
	During the year ended December 31, 2014, the performance-based milestone on the RSU awarded in 2013 was deemed to be probable and the award was fully vested. The Company recorded $1,440,000 in stock-based compensation which was recorded as a general and administrative operating expense in the Statements of Operations.
	Under settlement procedures applicable to the outstanding RSU award held by the Company's chief executive officer, it is required to deliver the underlying 391,304 shares on March 13, 2015. On the settlement date, the Company withheld and remitted income taxes at applicable minimum statutory rates based on the then current value of the underlying shares. In connection with these net settlements the Company remitted the tax liabilities on behalf of its chief executive officer to the relevant tax authorities in cash.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
Employee Benefit Plans	Dec. 31, 2014
Employee Benefit Plans
Employee Benefit Plans
	11. Employee Benefit Plans
	In July 2014, the Company established an Employee Stock Purchase Plan (the Purchase Plan). Under the Company's Purchase Plan, eligible employees can participate and purchase common stock semi-annually through accumulated payroll deductions at such times as are established by the administrator. The Purchase Plan is administered by the Company's board of directors or a committee appointed by the Company's board of directors. Under the Purchase Plan eligible employees may purchase stock at 85% of the lower of the fair market value of a share of common stock on the exercise date or the offering date. In the offering period that began upon the closing of the Company's IPO, the purchase price was 85% of the lower of the offering price per share on the cover of the Prospectus related to the IPO or the fair market value of a share of common stock on the exercise date. Eligible employees may contribute up to 15% of their eligible compensation. A participant may purchase a maximum of 2,100 shares of common stock per purchase period. The value of the shares purchased in any calendar year may not exceed $25,000.
	The Purchase Plan was effective upon the completion of the Company's IPO, at which time a total of 250,000 shares of the Company's common stock were made available for sale. As of the first business day of each fiscal year, commencing in 2015, the aggregate number of shares that may be issued under the Purchase Plan shall automatically increase by a number equal to the least of (i) 1% of the total number of shares of the Company's common stock actually issued and outstanding on the last business day of the prior fiscal year (excluding any rights to purchase shares of the Company's common stock that may be outstanding, such as options or warrants), (ii) 356,500 shares of the Company's common stock, or (iii) a number of shares of the Company's common stock determined by the Company's board of directors. As of January 1, 2015, the number of shares of common stock that may be issued under the Purchase Plan was automatically increased by 180,269 shares, increasing the number of shares of common stock available for issuance under the Purchase Plan to 430,269 shares. In accordance with ASC 718-50, the ability to purchase stock at 85% of the lower of the fair market value of a share of common stock on the offering date or the exercise date represents an option. The Company estimates the fair value of such options at the inception of each offering period using the Black-Scholes valuation model.

Collaborative_Research_Agreeme

Collaborative Research Agreements	12 Months Ended
Collaborative Research Agreements	Dec. 31, 2014
Collaborative Research Agreements
Collaborative Research Agreements
	12. Collaborative Research Agreements
	Boehringer Ingelheim
	11 HSD1 Inhibitors
	In October 2007, the Company entered into a Research Collaboration and License Agreement with Boehringer Ingelheim International GmbH (BI) pursuant to which BI is responsible for the development and commercialization of 11 HSD1 inhibitors for certain indications, including type 2 diabetes (the 11 Agreement).
	The funded research period under the 11 Agreement for which the Company was required to provide research services ended in December 2009. During the year ended December 31, 2014, 2013 and 2012, the Company earned $6,000,000, $0 and $7,000,000, respectively, for the achievement of substantive development milestones. In 2014, the Company received a $6.0 million milestone payment as a result of the first patient having been dosed in the Phase 2 clinical trial which commenced in July 2014. The Company has earned $43 million in development milestones since the inception of the 11 Agreement and is eligible to receive up to $272 million in additional milestone payments based on the achievement of pre-specified events, including up to $42 million in development milestones, up to $105 million in regulatory milestones and up to $125 million in commercialization milestones. The preceding milestones are payable upon the first occurrence of any product to meet the contractual requirements. The Company is also eligible to receive 50% of the aforementioned milestone payments for any subsequent products and for any additional indications of a product to achieve those milestones.
	The Company has the right, subject to the approval of the joint steering committee established pursuant to the 11 Agreement, to develop and commercialize certain 11 HSD1 inhibitors for indications other than those considered part of metabolic syndrome or reduction of cardiovascular events.
	Beta-site Amyloid Precursor Protein-cleaving Enzyme 1 (BACE) Inhibitors
	In June 2009, the Company entered into a Research Collaboration and License Agreement (the BACE Agreement) with BI pursuant to which BI is responsible for the development and commercialization of BACE inhibitors for the treatment of Alzheimer's disease and other forms of dementia.
	Under the BACE Agreement, the Company was obligated to provide 12 full-time-equivalent employees (FTE's) per month for a period of 36 months to provide research services. Under the terms of the BACE Agreement, the Company received an upfront, license fee of $15 million. This payment was initially recorded to deferred revenue. In addition, under the BACE Agreement, BI was required to make payments for each quarter during the 36-month funded research period of $1,020,000 for a total of $12,240,000. The license fee and the research collaboration fee were being recognized as revenue over the 36-month funded research period commencing June 2009 and continuing through June 2012, which was determined to be the Company's period of substantial involvement under the BACE Agreement. In April 2012, the initial research term was extended for an additional year through June 2013 and BI paid the Company an additional $2,960,000 for the research contributions over the 12 month extension period ($740,000 per quarter). During the extension period the Company was obligated to provide eight FTE's per month. The additional payment of $2,960,000 was recognized ratably over the extension period through June 2013. The revenue recognition period for the nonrefundable license fee was also extended on a prospective basis through June 2013.
	In December 2012, the Company amended the BACE Agreement to expand the core indication definition to include certain other indications, including diabetes and metabolic syndrome. Under the terms of the amendment, Vitae received an upfront fee of $4 million. In accordance with the amendment, the Company was obligated to provide 12 months of research services commencing June 2013 with such services to be completed no later than June 30, 2014. Revenue relating to the upfront payment was recognized over the period in which future research contributions were delivered through June 30, 2014 including $2 million that was recognized in the years ended December 31, 2014 and 2013, respectively.
	For the years ended December 31, 2013 and 2012, the Company earned $18 million and $9 million, respectively, for the achievement of substantive development milestones. The Company has earned $29 million in development milestones since the inception of the BACE Agreement and is eligible to receive up to $326 million in additional milestone payments based on the achievement of pre-specified events, including up to $56 million in development milestones, up to $120 million in regulatory milestones and up to $150 million in commercialization milestones. The preceding milestones are payable upon the first occurrence of any product to meet the contractual requirements. Any subsequent product(s) to achieve the milestone will earn the Company 50% of the milestone amount. In addition, second indications for a product covered by the contract to achieve the regulatory milestones will earn the Company 50% of the milestone amount. The Company also may receive net sales royalties based on total annual future product sales.

Income_Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2014
Income Taxes
Income Taxes
	13. Income Taxes
	Since its inception, the Company has never recorded a provision or benefit for federal or state income taxes.
	The Company sold $45,678 and $91,729 of Pennsylvania research and development tax credits and recorded net proceeds of $42,024 and $84,391 during the years ended December 31, 2014 and 2013, respectively. The net proceeds were recorded in other income in the Statements of Operations.
	As of December 31, 2014 and 2013, the Company has recognized a valuation allowance to the full extent of its deferred tax assets since the likelihood of realization of the benefit cannot be determined. For the years ended December 31, 2014 and 2013, the Company increased the valuation allowance by $8,431,000 and $439,000, respectively. The Company believes that any of its uncertain tax positions would not result in adjustments to its effective income tax rate because likely corresponding adjustments to deferred tax assets would be offset by adjustments to recorded valuation allowances. The Company files U.S. federal and state income tax returns, which are generally subject to tax examinations for the tax years ended December 31, 2011 through December 31, 2014. To the extent the Company utilizes NOL or tax credit attribute carryforwards in the future, the tax years in which the attribute was generated may still be adjusted upon examination by the Internal Revenue Service or state tax authorities of the future period tax return in which the attribute is utilized. The Company's income taxes for 2004 and 2005 were previously audited by the Internal Revenue Service.
	The Company has analyzed tax positions in all jurisdictions where it is required to file an income tax return and has concluded that the Company does not have any material unrecognized tax benefits or interest and penalties thereon as of December 31, 2014 and 2013.
	The reconciliation of the income tax benefit computed at statutory rates to the Company's recorded tax (benefit) expense is as follows:

		Year Ended December 31,
		2014			2013			2012
	Federal income tax (benefit), statutory rates	$	(6,686,192	)	$	406,664		$	78,080
	State income tax, net of federal benefit		(1,025,637	)		109,786			50,876
	Research and development tax credits		(902,502	)		(1,140,768	)		(58,079	)
	Other		183,625			185,519			196,763

	Income tax (benefit) expense		(8,430,706	)		(438,799	)		267,640
	Valuation allowance		8,430,706			438,799			(267,640	)

	Income tax benefit	$	—		$	—		$	—


	The tax effects of temporary differences that give rise to deferred tax assets and deferred tax liabilities are as follows:

		December 31,
		2014			2013
	Long-term deferred tax assets:
	Net operating loss carryforwards (federal and state)	$	34,743,789		$	27,545,207
	Research and development tax credits		6,188,578			5,286,077
	Property and equipment		965,462			989,923
	Other accruals		1,378,237			92,476
	Impairment of cost method investments		1,499,352			1,499,352
	Capitalized research		13,188,718			14,104,291

	Total gross long-term deferred tax assets		57,964,136			49,517,326
	Less valuation allowance		(57,964,136	)		(49,517,326	)

		$	—		$	—


	At December 31, 2014, the Company had net operating loss carryforwards of approximately $84,173,000 and $81,362,000 to offset future federal and state taxable income, respectively. Federal and state net operating loss carryforwards available to offset future taxable income will expire beginning in the year 2024 and through the year 2034. Pennsylvania limits the amount of NOL carryforwards which can be used to offset Pennsylvania taxable income. For taxable years beginning after 2014, the limitation is the greater of $5.0 million or 30% of Pennsylvania taxable income before the NOL deduction. At December 31, 2014 and 2013, the Company had deferred tax assets of approximately $57,964,000 and $49,517,000, respectively, primarily arising from the carryforward of the net operating losses, research and development tax credits and deferred capitalized research expenses. The Company has research and development ("R&D") and investment tax credit carryforwards of approximately $5,956,000 and $359,000 to offset future federal and Pennsylvania state income taxes, respectively. The federal investment tax credits will expire beginning in the year 2021 through the year 2034. The state R&D tax credits will expire beginning in the year 2021 through the year 2029.
	The NOL carry-forwards are subject to review and possible adjustment by the Internal Revenue Service and state tax authorities. NOL and tax credit carry-forwards may become subject to an annual limitation in the event of certain cumulative changes in the ownership interest of significant stockholders over a three-year period in excess of 50%, as defined under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, as well as similar state tax provisions. This could limit the amount of NOLs that the Company can utilize annually to offset future taxable income or tax liabilities. The amount of the annual limitation, if any, will be determined based on the value of our company immediately prior to an ownership change. Subsequent ownership changes may further affect the limitation in future years. Additionally, U.S. tax laws limit the time during which these carry-forwards may be applied against future taxes, therefore, the Company may not be able to take full advantage of these carry-forwards for federal income tax purposes. The Company intends to evaluate the ownership history of our company to determine if there were any ownership changes as defined under Section 382(g) of the Code before utilizing the NOL carry-forwards.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2014
Related Party Transactions
Related Party Transactions
	14. Related Party Transactions
	A member of the Company's Board is a partner/founder of a law firm that provided various legal services to the Company. The Company incurred costs payable to this law firm totaling $1,262,000, $267,000 and $26,000 for the years ended December 31, 2014, 2013 and 2012, respectively.
	Additionally, $129,000 and $209,000 was due to the related party as of December 31, 2014 and 2013, respectively.
	BI, the Company's collaborative research partner (Note 12), is an affiliate of a stockholder in the Company.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2014
Commitments and Contingencies
Commitments and Contingencies
	15. Commitments and Contingencies
	The Company currently leases office space pursuant to a noncancelable operating lease that will expire in January 2018. The Company has the right to extend the lease for one additional period of five years at fixed escalation amounts. In addition, the Company leases certain office equipment under operating leases. Rental expense under these leases was approximately $779,000, $781,000 and $742,000 for the years ended December 31, 2014, 2013 and 2012, respectively. The following is a schedule by year of future minimum rental payments required under the noncancelable leases as of December 31, 2014:

	2015	$	790,433
	2016		805,512
	2017		821,622
	2018		68,581

	Total minimum future rental payments	$	2,486,148

Reverse_Stock_Split

Reverse Stock Split	12 Months Ended
Reverse Stock Split	Dec. 31, 2014
Reverse Stock Split
Reverse Stock Split
	16. Reverse Stock Split
	In connection with preparing for the IPO, the Company's board of directors and stockholders approved a 1-for-23 reverse stock split of the Company's preferred and common stock. The reverse split became effective on September 8, 2014. All preferred share, common share and per share amounts in the financial statements and notes have been retroactively adjusted to give effect to the reverse stock split, including reclassifying an amount equal to the reduction in aggregate par value of common stock to additional paid-in capital.

Interim_Financial_Information_

Interim Financial Information (Unaudited)	12 Months Ended
Interim Financial Information (Unaudited)	Dec. 31, 2014
Interim Financial Information (Unaudited)
Interim Financial Information (Unaudited)
	17. Interim Financial Information (Unaudited)
	(in thousands, except for share data)

			Fiscal 2014 Quarter Ended
			March 31			June 30			September 30			December 31
	Collaborative revenues		$	1,173		$	1,156		$	6,178		$	162
	Net loss			(4,889	)		(5,130	)		(1,809	)		(7,275	)
	Basic and diluted net loss per share(1)			(8.24	)		(8.50	)		(1.06	)		(0.40	)
	Shares used in computation of basic and diluted net loss per share			593,206			603,868			1,711,969			18,113,997


			Fiscal 2013 Quarter Ended
			March 31			June 30			September 30			December 31
	Collaborative revenues		$	1,037		$	925		$	5,353		$	15,198
	Net (loss) income			(4,587	)		(4,136	)		179			9,706
	Basic net (loss) income per share(1)			(8.37	)		(7.44	)		0			0.77
	Diluted net (loss) income per share(1)			(8.37	)		(7.44	)		0			0.74
	Shares used in computation of basic net (loss) income per share			548,051			555,725			564,702			583,653
	Shares used in computation diluted net (loss) income per share			548,051			555,725			564,702			975,795


	-1	Prior to the Company's IPO in September 2014, the Company used the two-class method to compute net income per common share because the Company had outstanding securities, other than common stock, that contractually entitle the holders to participate in dividends and earnings of the Company. The two-class method requires earnings available to common stockholders for the period, after an allocation of earnings to participating securities, to be allocated between common and participating securities based upon their respective rights to receive distributed and undistributed earnings.

Subsequent_Events

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2014
Subsequent Events
Subsequent Events
	18. Subsequent Events
	On January 28, 2015, the Company issued and sold a total of 3,450,000 shares of its common stock at $11.90 per share in an underwritten public offering. The shares include 450,000 shares of common stock sold pursuant to the underwriters' option to purchase additional shares, which was exercised in full. Net proceeds from the offering, including the sale of the additional shares, was approximately $37.8 million, after deducting underwriting discounts and commissions and estimated offering expenses payable by the Company.
	On February 27, 2015, the Company repaid the outstanding balance of the Silicon Valley Bank and Oxford Finance Corporation credit facility. The total payoff was $4,342,855, which included prepayment and other additional fees of $84,453. The Company had $20,852 of deferred financing fees and $101,373 of unamortized debt discount as of the date of payoff. The debt payoff will be accounted for as a debt extinguishment as per ASC 470-50, Debt: Modifications and Extinguishments, therefore, the deferred financing, unamortized debt discount and prepayment and other additional fees will be recorded as a loss on the early extinguishment of debt in the first quarter of 2015.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies and Basis of Accounting (Policies)	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies and Basis of Accounting
Basis of Accounting	Basis of Accounting
	The accompanying financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America ("GAAP"). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification ("ASC") and Accounting Standards Updates ("ASU") of the Financial Accounting Standards Board ("FASB").
	On April 5, 2012, the Jump-Start Our Business Startups Act (the "JOBS Act") was signed into law. The JOBS Act contains provisions that, among other things, reduce certain reporting requirements for an "emerging growth company." The Company is considered an emerging growth company, but has elected to not take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. As a result, the Company will comply with new or revised accounting standards on the relevant dates on which adoption of such standards is required for non-emerging growth companies.

Use of Estimates	Use of Estimates
	Management considers many factors in selecting appropriate financial accounting policies and controls, and in developing the estimates and assumptions that are used in the preparation of these financial statements. Management must apply significant judgment in this process. In addition, other factors may affect estimates, including expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates, and whether historical trends are expected to be representative of future trends. The estimation process often may yield a range of potentially reasonable estimates of the ultimate future outcomes and management must select an amount that falls within that range of reasonable estimates. This process may result in actual results differing materially from those estimated amounts used in the preparation of the financial statements if these results differ from historical experience, or other assumptions do not turn out to be substantially accurate, even if such assumptions are reasonable when made. In preparing these financial statements, management used significant estimates in the following areas, among others: stock-based compensation expense, the determination of the fair value of stock-based awards, the fair value of liability-classified preferred stock warrants, the accounting for research and development costs, accrued expenses and the recoverability of the Company's net deferred tax assets and related valuation allowance.

Segment and Geographic Information	Segment and Geographic Information
	Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, or decision-making group, in making decisions on how to allocate resources and assess performance. The Company's chief operating decision maker is its chief executive officer. The Company and its chief executive officer view the Company's operations and manage its business as one operating segment. All revenues and long-lived assets of the Company are earned and reside in the United States and the Company's collaboration revenue is generated in the United States.

Cash and Cash Equivalents and Restricted Cash	Cash and Cash Equivalents and Restricted Cash
	The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. The Company was required to maintain a cash balance in the amount of $200,000 as collateral for an outstanding letter of credit at December 31, 2014 and 2013, respectively, and has classified this balance as restricted cash in the Balance Sheet. The Company is required to maintain the $200,000 letter of credit through January 2018. No amounts were outstanding under the letter of credit at December 31, 2014 and 2013.

Marketable Securities, Available-for-Sale	Marketable Securities, Available-for-Sale
	Marketable securities consist of securities with original maturities greater than three months, and are comprised of securities issued by U.S. government agencies and corporate debt securities. Marketable securities recorded as current assets have maturities of less than one year from the balance sheet date. Marketable securities recorded as noncurrent assets have maturities of one year or greater from the balance sheet date.
	Management determines the appropriate classification of securities at the time of purchase. The Company has classified its investment portfolio as available-for-sale in accordance with ASC 320, Investments—Debt and Equity Securities. The Company's available-for-sale securities are carried at fair value with unrealized gains and losses reported in other comprehensive income (loss). Marketable securities are evaluated periodically for impairment. If it is determined that a decline of any investment is other than temporary, then the carrying amount of the investment is written down to fair value and the write-down is included in the statements of comprehensive income as a loss.

Deferred Rent and Lease Incentives	Deferred Rent and Lease Incentives
	Deferred rent and lease incentives consist of the difference between cash payments made under operating lease agreements and the related rent expense, which is recognized on a straight-line basis over the term of the lease. In August 2011, Vitae amended its facility lease agreement extending the expiration to January 31, 2018 in exchange for reduced rental rates during the extension period. Lease incentives received at the commencement of the lease are amortized on a straight-line basis over the original lease term and recorded as a reduction in rent expense. Recognition of rent expense exceeded actual cash rent payments by $1,144 for the year ended December 31, 2014. Cash rent payments exceeded rent expense by $4,584 and $119,580 for the years ended December 31, 2013 and 2012, respectively. Deferred rent and lease incentives were $90,782 and $89,638 as of December 31, 2014 and 2013, respectively.

Fair Value of Financial Instruments	Fair Value of Financial Instruments
	At December 31, 2014 and 2013, the Company's financial instruments included cash and cash equivalents, restricted cash, marketable securities, accounts payable, accrued expenses and notes payable. The carrying amounts reported in the Company's financial statements for cash and cash equivalents, restricted cash, accounts payable and accrued expenses approximates their respective fair values because of the short-term nature of these instruments. The Company's short- and long-term marketable securities are carried at fair value based on quoted market prices and other observable inputs. Notes payable approximates fair value because the interest rate is reflective of the rate the Company could obtain on debt with similar terms and conditions. At December 31, 2013, the Company also reported a preferred stock warrant liability. The carrying amount of the preferred stock warrant liability was the estimated fair value of the liability (Note 6). The Company has determined the estimated fair value of financial instruments using available market information and management's estimates. The use of different market assumptions and/or estimation methodologies could have a significant effect on the estimated fair value amounts.

Deferred Offering Costs	Deferred Offering Costs
	Generally, deferred offering costs consist of legal, accounting, and printing fees incurred in connection with offerings of the Company's equity securities, and are capitalized when incurred. In connection with the Company's January 2015 underwritten public offering of common stock, deferred offering costs totaling $0.2 million were recognized in the balance sheet as of December 31, 2014.

Comprehensive Income	Comprehensive Income
	Comprehensive income (loss) is defined as changes in stockholders' equity (deficit) exclusive of transactions with owners (such as capital contributions and distributions). Comprehensive income (loss) is comprised of net income (loss) and unrealized (losses) gains on marketable securities.

Property and Equipment	Property and Equipment
	Property and equipment consist primarily of laboratory equipment, computer equipment and software, office furniture and equipment and leasehold improvements, all of which are stated at cost, less accumulated depreciation. Property and equipment are depreciated using the straight-line method over the estimated useful lives of the assets. Leasehold improvements are amortized over the estimated useful life of the asset or the remaining lease term at the time the asset is placed into service, whichever is shorter. Maintenance and repairs are expensed as incurred. The following estimated useful lives were used to depreciate the Company's assets:

			Estimated Useful Life
	Laboratory equipment		5 years
	Computer equipment and software		2 years
	Office furniture and equipment		5 years
	Leasehold improvements		Various
	Upon retirement or sale, the cost of the disposed asset and the related accumulated depreciation are removed from the balance sheet accounts and any resulting gain or loss is charged to income.

Revenue Recognition	Revenue Recognition
	Revenue Arrangements with Multiple Deliverables
	The Company's revenues are generated primarily through collaborative arrangements which generally contain multiple elements, or deliverables, including licenses and research and development activities to be performed by the Company on behalf of the licensee. Payments to Vitae under these arrangements typically include one or more of the following: (1) nonrefundable, upfront license fees, (2) funding of discovery research efforts on a full-time equivalent ("FTE") basis, (3) reimbursement of research, development and intellectual property costs, (4) milestone payments, and (5) royalties on future product sales.
	The Company accounts for revenue arrangements with multiple deliverables entered into prior to January 1, 2011 in accordance with ASC 605-25, Revenue Recognition: Multiple-Element Arrangements. The multiple-deliverable items are divided into separate units of accounting if certain criteria are met, including whether the delivered item has stand-alone value to the customer and whether there is objective and reliable evidence of the fair value of the undelivered items. The Company allocates the consideration it receives among the separate units of accounting based on their respective fair value, and applies the applicable revenue recognition criteria to each of the separate units. Where an item in a revenue arrangement with multiple deliverables does not constitute a separate unit of accounting and for which delivery has not occurred, the Company defers revenue until the delivery of the item is completed.
	Effective January 1, 2011, the Company adopted on a prospective basis Accounting Standards Update ("ASU") 2009-13, Multiple-Deliverable Revenue Arrangements, which amends ASC 605-25 and also adopted ASU 2010-17, Revenue Recognition—Milestone Method.
	In accordance with ASU 2009-13, the Company considers whether the deliverables under the arrangement represent separate units of accounting. In determining the units of accounting, management evaluates certain criteria, including whether the deliverables have stand-alone value. The consideration received is allocated to the separate units of accounting using the relative selling price method, and the applicable revenue recognition criteria are applied to each of the separate units.
	The Company determines the estimated selling price for agreement deliverables using the following hierarchy: (1) vendor-specific objective evidence ("VSOE"), (2) third-party evidence ("TPE") or (3) best estimate of selling price if neither VSOE nor TPE is available. Determining the best estimate of selling price for a deliverable requires significant judgment and consideration of various factors including market conditions, items contemplated during agreement negotiation as well as internally developed net present value models.
	The Company typically receives upfront, nonrefundable payments when licensing its intellectual property. For intellectual property licenses that do not have stand-alone value from the other deliverables to be provided, revenue is recognized over the contractual or estimated performance period, which is typically the term of the research and development obligations. The periods over which revenue should be recognized are subject to estimates by management and may change over the course of the research and development agreement. Such a change could have a material impact on the amount of revenue the Company records in future periods.
	Payments or reimbursements resulting from the Company's research and development efforts are recognized as the services are performed and are presented on a gross basis so long as there is persuasive evidence of an arrangement, the fee is fixed or determinable, and collection of the related receivable is reasonably assured. Amounts received prior to satisfying the above revenue recognition criteria are recorded as deferred revenue in the balance sheet.
	In accordance with ASU 2010-17, Vitae recognizes revenue from milestone payments when: (i) the milestone event is substantive and its achievability was not reasonably assured at the inception of the agreement, and (ii) Vitae does not have ongoing performance obligations related to the achievement of the milestone earned. Milestone payments are considered substantive if all of the following conditions are met: the milestone payment (a) is commensurate with either the Company's performance to achieve the milestone or the enhancement of the value of the delivered item or items as a result of a specific outcome resulting from the Company's performance to achieve the milestone, (b) relates solely to past performance, and (c) is reasonable relative to all of the deliverables and payment terms (including other potential milestone consideration) within the arrangement. The Company has concluded that the clinical and development and regulatory milestones pursuant to its research and development arrangements are substantive.
	The following table details the amount of collaborative revenue recognized for the years ended December 31, 2014, 2013 and 2012:

			Year Ended December 31,
			2014		2013		2012
	Amortization of upfront license fees		$	150,000	$	353,693	$	1,921,307
	Collaborative research payments:
	FTE funding			1,850,000		3,108,000		3,436,000
	Research and development costs			—		—		20,055
	Intellectual property costs			668,786		1,050,990		970,465

	Total collaborative research payments			2,518,786		4,158,990		4,426,520

	Milestone revenue			6,000,000		18,000,000		16,000,000

	Total collaborative revenue		$	8,668,786	$	22,512,683	$	22,347,827




Research and Development Expenses	Research and Development Expenses
	Research and development costs are charged to expense as incurred. These costs include, but are not limited to, employee-related expenses, including salaries, benefits and travel and stock-based compensation of the Company's research and development personnel, expenses incurred under agreements with contract research organizations and investigative sites that conduct clinical trials and preclinical studies, the cost of acquiring, developing and manufacturing clinical trial materials, facilities, other supplies, allocated facilities, depreciation and other expenses, which include rent and utilities, insurance, and costs associated with preclinical activities and regulatory operations. Nonrefundable advances for future research and development services are deferred and recognized as expense as the related services are provided.
	Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as subject enrollment, clinical site activations or information provided to the Company by its vendors with respect to their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the financial statements as prepaid or accrued research and development expense, as the case may be.

Accrued Clinical and Preclinical Expenses	Accrued Clinical and Preclinical Expenses
	As part of the process of preparing the financial statements, the Company is required to estimate its accrued expenses. This process involves reviewing open contracts and purchase orders, communicating with its applicable personnel to identify services that have been performed on its behalf and estimating the level of service performed and the associated cost incurred for the service when the Company has not yet been invoiced or otherwise notified of actual cost. The majority of the Company's service providers invoice monthly in arrears for services performed. The Company makes estimates of its accrued expenses as of each balance sheet date in the financial statements based on facts and circumstances known at that time. The Company periodically confirms the accuracy of the estimates with the service providers and makes adjustments if necessary. Examples of estimated accrued clinical expenses include:
	•	fees paid to vendors in connection with the preclinical development activities;
	•	fees paid to contract manufacturers in connection with the production of preclinical and clinical trial materials;
	•	fees paid to contract research organizations in connection with clinical studies; and
	•	fees paid to investigative sites in connection with clinical studies.
	The Company bases its expenses related to preclinical and clinical studies on its estimates of the services received and efforts expended pursuant to contracts with multiple research institutions and contract research organizations that conduct and manage clinical studies on its behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows. Payments under some of these contracts depend on factors such as the successful enrollment of patients and the completion of clinical trial milestones. In accruing service fees, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company adjusts the accrual accordingly. Although the Company does not expect its estimates to be materially different from amounts actually incurred, the Company's understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in reporting amounts that are too high or too low in any particular period.

Preferred Stock Warrants	Preferred Stock Warrants
	Prior to the Company's IPO, the Company accounted for its preferred stock warrants as liabilities in accordance with the guidance for accounting for certain financial instruments with characteristics of both liabilities and equity as the warrants entitle the holder to purchase preferred stock that was considered contingently redeemable. The fair value of the preferred stock warrant liability was re-measured at the end of each reporting period, and any changes in fair value were recognized in the Statements of Operations as other income or expense. Upon the closing of the IPO, the preferred stock warrant was, in accordance with its terms, automatically converted into a warrant to purchase common stock, which resulted in the reclassification of the preferred stock warrant liability to additional paid-in capital. Upon reclassification, no further changes in fair value will be recognized in other income or expense. The fair value of the preferred stock warrant liability was classified as Level 3 measurements (see Note 6).

Stock-Based Compensation Expense	Stock-Based Compensation Expense
	The Company accounts for stock-based compensation expense in accordance with the provisions of ASC 718, Compensation—Stock Compensation, which addresses the accounting for share-based payment transactions in which an enterprise receives employee services in exchange for (a) equity instruments of the enterprise or (b) liabilities that are based on the fair value of or may be settled by the issuance of the enterprise's equity instruments. ASC 718 requires that an entity measure the cost of equity-based service awards based on the grant-date fair value of the award and recognize the cost of such awards over the period during which the employee is required to provide service in exchange for the award (the vesting period).
	For stock options issued to employees and members of the Board for their services on the Board, the Company estimates the grant date fair value of each option using the Black-Scholes option pricing model. The use of the Black-Scholes option pricing model requires management to make assumptions with respect to the expected term of the option, the expected volatility of the common stock over a period consistent with the expected life of the option, risk-free interest rates, the value of the common stock and expected dividend yields of the common stock. For awards subject to service-based vesting conditions, the Company recognizes stock-based compensation expense, net of estimated forfeitures, equal to the grant date fair value of stock options on a straight-line basis over the requisite service period, which is generally the vesting term. For awards subject to both performance and service-based vesting conditions, the Company recognizes stock-based compensation expense using the straight-line recognition method when it is probable that the performance condition will be achieved. Forfeitures are required to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.
	The Company utilizes significant estimates and assumptions in determining the fair value of its common stock. The Board determined the estimated fair value of the Company's common stock based on a number of objective and subjective factors, including external market conditions affecting the biotechnology industry and the prices at which the Company sold shares of redeemable convertible preferred stock, the superior rights and preferences of securities senior to the Company's common stock at the time, and the likelihood of achieving a liquidity event, such as an IPO or sale of the Company.
	Stock-based compensation expense recognized for the years ended December 31, 2014, 2013 and 2012:

			Year Ended December 31,
			2014		2013		2012
	Research and development		$	232,572	$	18,920	$	114,591
	General and administrative			2,015,703		80,933		165,619

	Total stock-based compensation		$	2,248,275	$	99,853	$	280,210




Income Taxes	Income Taxes
	Income taxes are recorded in accordance with ASC 740, Income Taxes ("ASC 740"), which provides for deferred taxes using an asset and liability approach. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Valuation allowances are provided, if based upon the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized.
	The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740. When uncertain tax positions exist, the Company recognizes the tax benefit of tax positions to the extent that the benefit will more likely than not be realized. The determination as to whether the tax benefit will more likely than not be realized is based upon the technical merits of the tax position as well as consideration of the available facts and circumstances. The Company recognizes interest and penalties accrued on any unrecognized tax benefits in its provision for income taxes in the Statement of Operations. As of December 31, 2014 and 2013, the Company does not have any significant uncertain tax positions.

Net Income (Loss) Per Common Share	Net Income (Loss) Per Common Share
	Prior to the Company's IPO in September 2014, the Company used the two-class method to compute net income per common share because the Company had outstanding securities, other than common stock, that contractually entitle the holders to participate in dividends and earnings of the Company. The two-class method requires earnings available to common stockholders for the period, after an allocation of earnings to participating securities, to be allocated between common and participating securities based upon their respective rights to receive distributed and undistributed earnings. Each series of the Company's convertible preferred stock were entitled to receive annual non-cumulative dividends that ranged from $0.60 - $1.66 per share, payable prior and in preference to dividends paid to holders of common stock when and if declared by the Company's board of directors. In the event a dividend was paid on common stock, holders of preferred stock were entitled to a proportionate share of any such dividend as if they were holders of common shares (on an as-if converted basis).
	For periods with net income prior to the IPO, net income per common share information is computed using the two-class method. Under the two-class method, basic net income per common share is computed by dividing the net income attributable to common stockholders by the weighted average number of shares of common stock outstanding during the period. Basic net income attributable to common stockholders is computed by an adjustment to subtract from net income the portion of current year earnings that the preferred stockholders would have been entitled to receive pursuant to their dividend rights had all of the year's earnings been distributed. No such adjustment to earnings is made during periods with a net loss, as the holders of the convertible preferred shares had no obligation to fund losses.
	Diluted net income (loss) per common share is computed by using the weighted-average number of shares of common stock outstanding, plus, for periods with net income attributable to common stock, the dilutive effects of stock options, restricted stock units, and warrants. Potential dilutive shares consist of incremental common stock issuable upon the exercise of stock options and warrants. Basic and dilutive computations are the same in periods with net losses attributable to common stockholders as the dilutive effects of stock options, restricted stock units and warrants would be antidilutive.

Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers." ASU 2014-09 will supersede and replace nearly all existing U.S. GAAP revenue recognition guidance, including industry-specific guidance. The guidance is effective for annual reporting periods beginning after December 15, 2016, including interim periods therein. The Company is evaluating ASU 2014-09 and has not yet determined what, if any, effect ASU 2014-09 will have on its results of operations or financial condition.
	In August 2014, the FASB issued ASU 2014-15, "Presentation of Financial Statements—Going Concern." ASU 2014-15 requires management of all entities to evaluate whether there are conditions and events that raise substantial doubt about the entity's ability to continue as a going concern within one year after the financial statements are issued, and to make certain disclosures if it concludes that substantial doubt exists or when its plans alleviate substantial doubt about the entity's ability to continue as a going concern. ASU 2014-15 is effective for the Company for annual reporting periods beginning in 2016 and for interim reporting periods starting in the first quarter of 2017. The Company is currently evaluating the impact of the adoption of ASU 2014-15 on its financial statements.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies and Basis of Accounting (Tables)	12 Months Ended
	Dec. 31, 2014
Summary of Significant Accounting Policies and Basis of Accounting
Schedule of estimated useful lives that were used to depreciate the assets

		Estimated Useful Life
	Laboratory equipment	5 years
	Computer equipment and software	2 years
	Office furniture and equipment	5 years
	Leasehold improvements	Various


Schedule of collaborative revenue recognized

		Year Ended December 31,
		2014		2013		2012
	Amortization of upfront license fees	$	150,000	$	353,693	$	1,921,307
	Collaborative research payments:
	FTE funding		1,850,000		3,108,000		3,436,000
	Research and development costs		—		—		20,055
	Intellectual property costs		668,786		1,050,990		970,465

	Total collaborative research payments		2,518,786		4,158,990		4,426,520

	Milestone revenue		6,000,000		18,000,000		16,000,000

	Total collaborative revenue	$	8,668,786	$	22,512,683	$	22,347,827




Schedule of stock-based compensation expense recognized

		Year Ended December 31,
		2014		2013		2012
	Research and development	$	232,572	$	18,920	$	114,591
	General and administrative		2,015,703		80,933		165,619

	Total stock-based compensation	$	2,248,275	$	99,853	$	280,210

Net_Income_Loss_Per_Common_Sha1

Net Income (Loss) Per Common Share (Tables)	12 Months Ended
Net Income (Loss) Per Common Share (Tables)	Dec. 31, 2014
Net Income (Loss) Per Common Share
Schedule of computation of basic and diluted net income(Loss) per common share

		Year Ended December 31,
		2014			2013			2012
	Basic and diluted net (loss) income per common share calculation:
	Net (loss) income	$	(19,103,406	)	$	1,161,898		$	223,086
	Less: Undistributed earnings allocated to participating securities		—			(1,161,898	)		(223,086	)

	Net loss attributable to common stockholders		(19,103,406	)		—			—
	Weighted average common shares—basic and diluted		5,290,534			563,136			542,320

	Net (loss) income per common share—basic and diluted	$	(3.61	)	$	0		$	0




Schedule of potential common shares not reflected in diluted net income (Loss) per share as the effect would be antidilutive

		Year Ended December 31,
		2014			2013			2012
	Stock options		1,484,696			1,291,917			1,907,568
	Restricted stock units		391,304			391,304			—
	Warrants		45,468			45,468			46,751
	Convertible preferred stock		—			9,491,680			9,491,680

	Total		1,921,468			11,220,369			11,445,999

Property_and_Equipment_Tables

Property and Equipment (Tables)	12 Months Ended
Property and Equipment (Tables)	Dec. 31, 2014
Property and Equipment
Schedule of property and equipment and related accumulated depreciation and amortization

		December 31,
		2014			2013
	Laboratory equipment	$	3,253,683		$	3,085,736
	Computer equipment and software		1,474,310			1,452,580
	Office furniture and equipment		318,839			311,564
	Leasehold improvements		3,402,330			3,357,312
	Construction in process		—			10,293
	Less accumulated depreciation and amortization		(8,031,533	)		(7,839,489	)

	Property and equipment, net	$	417,629		$	377,996

Accrued_Expenses_Tables

Accrued Expenses (Tables)	12 Months Ended
Accrued Expenses (Tables)	Dec. 31, 2014
Accrued Expenses
Schedule of accrued expenses

		December 31,
		2014		2013
	Payroll and related costs	$	1,710,439	$	1,230,428
	Research and development related costs		760,961		74,260
	Offering costs		207,743		—
	Legal and accounting related costs		264,959		341,901
	Other		195,619		54,130

	Total	$	3,139,721	$	1,700,719

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
Fair Value Measurements (Tables)	Dec. 31, 2014
Fair Value Measurements
Schedule of major category of financial assets and liabilities measured at fair value on a recurring basis

		Fair Value Measurements as of December 31, 2014 Using
		Level 1			Level 2		Level 3		Balance
									as of
									December 31,
									2014
	Assets
	Money market funds	$	25,664,911		$	—	$	—	$	25,664,911
	Other cash equivalents		—			2,179,290		—		2,179,290
	Cash-restricted, CD		200,000			—		—		200,000
	Marketable securities, available-for-sale		—			35,823,545		—		35,823,545

	Total assets	$	25,864,911		$	38,002,835	$	—	$	63,867,746




		Fair Value Measurements as of December 31, 2013 Using
		Level 1			Level 2		Level 3		Balance
									as of
									December 31,
									2013
	Assets
	Money market funds	$	18,512,463		$	—	$	—	$	18,512,463
	Cash-restricted, CD		200,000			—		—		200,000
	Marketable securities, available-for-sale		—			11,299,206		—		11,299,206

	Total assets	$	18,712,463		$	11,299,206	$	—	$	30,011,669


	Liabilities
	Preferred stock warrant liability	$	—		$	—	$	477,375	$	477,375

	Total liabilities	$	—		$	—	$	477,375	$	477,375




Summary of changes in fair value of the Level 3 financial instruments measured on a recurring basis

		Preferred Stock
		Warrant Liability
	Balance as of January 1, 2013	$	720,375
	Changes in estimated fair value		(243,000	)

	Balance as of December 31, 2013	$	477,375
	Changes in estimated fair value		(301,294	)
	Reclassification of warrants to additional paid-in capital		(176,081	)

	Balance as of December 31, 2014	$	—

Investments_Tables

Investments (Tables)	12 Months Ended
Investments (Tables)	Dec. 31, 2014
Investments
Schedule of maturities of marketable securities

		Cost		Unrealized		Unrealized			Fair
		Basis		Gains		Losses			Value
	December 31, 2014
	Corporate notes and bonds	$	35,862,357	$	573	$	(39,385	)	$	35,823,545

	Total marketable securities	$	35,862,357	$	573	$	(39,385	)	$	35,823,545


	December 31, 2013
	U.S. government and agency	$	500,066	$	64	$	—		$	500,130
	Corporate notes and bonds		10,799,073		1,964		(1,961	)		10,799,076

	Total marketable securities	$	11,299,139	$	2,028	$	(1,961	)	$	11,299,206

Notes_Payable_Tables

Notes Payable (Tables)	12 Months Ended
	Dec. 31, 2014
Notes Payable
Schedule of aggregate maturities of all term notes (amounts exclude unamortized discount)	Aggregate maturities of all term notes are as follows (amounts exclude unamortized discount at December 31, 2014):

	2015	$	4,935,260

Stockholders_Equity_Deficit_Ta

Stockholders' Equity (Deficit) (Tables) (Imported)	12 Months Ended
Stockholders' Equity (Deficit) (Tables) (Imported)	Dec. 31, 2014
Stockholders' Equity (Deficit)
Schedule of convertible preferred stock outstanding which immediately converted into common shares upon the closing of the Company's IPO	The Company had the following convertible preferred stock outstanding which immediately converted into common shares upon the closing of the Company's IPO on September 29, 2014:

		Preferred to		Preferred		Conversion
		Common		Shares		into Common
		Conversion		Outstanding		Shares upon
		Ratio				Initial Public
						Offering
	Series A		1.00-to-1.00		29,346		29,346
	Series A-2		1.00-to-1.51		717,379		1,080,640
	Series B		1.00-to-1.00		6,570,106		6,570,106
	Series C		1.00-to-1.00		724,632		724,632
	Series D		1.00-to-1.00		1,086,956		1,086,956

	Total				9,128,419		9,491,680




Summary of warrants outstanding and exercisable	The following table summarizes the warrants outstanding and exercisable as of December 31, 2014:

	Warrants to Purchase	Shares		Exercise		Expiration Date
	Warrants to Purchase	Shares		Price		Expiration Date
	Common stock		1,449	$	20.70		7/12/16
	Common stock		14,130	$	27.60		8/28/18
	Common stock		29,889	$	27.60		12/21/21


Schedule of shares of common stock reserved for issuance	At December 31, 2014, the Company has reserved the following shares of common stock for issuance:

	Common stock options outstanding		1,484,696
	Restricted stock units outstanding		391,304
	Shares available for future grant under employee compensation plans		1,861,623
	Shares available through employee stock purchase plan		250,000
	Warrants		45,468

			4,033,091

Employee_Compensation_Plans_Ta

Employee Compensation Plans (Tables)	12 Months Ended
Employee Compensation Plans (Tables)	Dec. 31, 2014
Employee Compensation Plans
Summary of stock option activity under the Plans

		Number of			Weighted-			Weighted-			Aggregate
		Shares			Average			Average			Intrinsic Value
					Exercise			Contractual
					Price			Life (in Years)
	Outstanding, January 1, 2014		1,291,917		$	4.3194
	Granted		463,008		$	5.9434
	Exercised		(40,230	)	$	1.4602
	Expired		(210,043	)	$	4.1992
	Forfeited		(19,956	)	$	7.0579

	Outstanding, December 31, 2014		1,484,696		$	4.884			5.3		$	17,454,021


	Exercisable, December 31, 2014		819,955		$	3.6748			2.79		$	10,630,885


	Vested and Expected to Vest, December 31, 2014		1,454,906		$	4.8411




Schedule of weighted-average assumptions used for calculating fair values of stock options granted

		Year Ended December 31,
		2014			2013			2012
	Weighted-average risk-free interest rate		1.98	%		1.42	%		0.90	%
	Expected term of options (in years)		6.11			6.25			6.25
	Expected stock price volatility		83.00	%		85.00	%		86.16	%
	Expected dividend yield		0	%		0	%		0	%


Schedule of total unrecognized compensation expense, excluding performance based stock options that have not been deemed probable, net of estimated forfeitures, related to unvested options granted under the Stock Plans expected to be recognized

	Year ending December 31,
	2015	$	616,550
	2016		533,584
	2017		468,723
	2018		112,195

		$	1,731,052

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2014
Income Taxes
Schedule of reconciliation of the income tax benefit computed at statutory rates to the Company's recorded tax benefit

		Year Ended December 31,
		2014			2013			2012
	Federal income tax (benefit), statutory rates	$	(6,686,192	)	$	406,664		$	78,080
	State income tax, net of federal benefit		(1,025,637	)		109,786			50,876
	Research and development tax credits		(902,502	)		(1,140,768	)		(58,079	)
	Other		183,625			185,519			196,763

	Income tax (benefit) expense		(8,430,706	)		(438,799	)		267,640
	Valuation allowance		8,430,706			438,799			(267,640	)

	Income tax benefit	$	—		$	—		$	—




Schedule of tax effects of temporary differences that give rise to deferred tax assets and deferred tax liabilities

		December 31,
		2014			2013
	Long-term deferred tax assets:
	Net operating loss carryforwards (federal and state)	$	34,743,789		$	27,545,207
	Research and development tax credits		6,188,578			5,286,077
	Property and equipment		965,462			989,923
	Other accruals		1,378,237			92,476
	Impairment of cost method investments		1,499,352			1,499,352
	Capitalized research		13,188,718			14,104,291

	Total gross long-term deferred tax assets		57,964,136			49,517,326
	Less valuation allowance		(57,964,136	)		(49,517,326	)

		$	—		$	—

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
Commitments and Contingencies (Tables)	Dec. 31, 2014
Commitments and Contingencies
Schedule of future minimum rental payments required under the noncancelable leases	The following is a schedule by year of future minimum rental payments required under the noncancelable leases as of December 31, 2014:

	2015	$	790,433
	2016		805,512
	2017		821,622
	2018		68,581

	Total minimum future rental payments	$	2,486,148

Interim_Financial_Information_1

Interim Financial Information (Unaudited)	12 Months Ended
Interim Financial Information (Unaudited)	Dec. 31, 2014
Interim Financial Information (Unaudited)
Schedule of interim financial information (unaudited)	(in thousands, except for share data)

			Fiscal 2014 Quarter Ended
			March 31			June 30			September 30			December 31
	Collaborative revenues		$	1,173		$	1,156		$	6,178		$	162
	Net loss			(4,889	)		(5,130	)		(1,809	)		(7,275	)
	Basic and diluted net loss per share(1)			(8.24	)		(8.50	)		(1.06	)		(0.40	)
	Shares used in computation of basic and diluted net loss per share			593,206			603,868			1,711,969			18,113,997


			Fiscal 2013 Quarter Ended
			March 31			June 30			September 30			December 31
	Collaborative revenues		$	1,037		$	925		$	5,353		$	15,198
	Net (loss) income			(4,587	)		(4,136	)		179			9,706
	Basic net (loss) income per share(1)			(8.37	)		(7.44	)		0			0.77
	Diluted net (loss) income per share(1)			(8.37	)		(7.44	)		0			0.74
	Shares used in computation of basic net (loss) income per share			548,051			555,725			564,702			583,653
	Shares used in computation diluted net (loss) income per share			548,051			555,725			564,702			975,795


	-1	Prior to the Company's IPO in September 2014, the Company used the two-class method to compute net income per common share because the Company had outstanding securities, other than common stock, that contractually entitle the holders to participate in dividends and earnings of the Company. The two-class method requires earnings available to common stockholders for the period, after an allocation of earnings to participating securities, to be allocated between common and participating securities based upon their respective rights to receive distributed and undistributed earnings.

Organization_Details

Organization (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
	item
Organization
Number of partnered product candidates	2
BI
Organization
Funding provided by counterparty including sale of the Company's equity securities and upfront license fees, research funding and success based milestone payments	158
Funding provided by the counterparty from sale of the Company's equity securities	30
Funding provided by counterparty from upfront license fees, research funding and success based milestone payments	128

Organization_Details_2

Organization (Details 2) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified	Dec. 31, 2014
Organization
Cash, cash equivalents and short-term investments	$65.30

Organization_Details_3

Organization (Details 3) (Subsequent event, Follow-on offering, USD $)	0 Months Ended
In Millions, except Share data, unless otherwise specified	Jan. 28, 2015
Subsequent event \| Follow-on offering
Organization
Net proceeds from issuance	$37.80
Shares issued (in shares)	3,450,000

Summary_of_Significant_Account3

Summary of Significant Accounting Policies and Basis of Accounting (Details)	12 Months Ended
	Dec. 31, 2014
	item
Segment and Geographic Information
Number of operating segments	1
Concentrations of Credit Risk and Off-Balance Sheet Risk
Maximum maturity term for debt security portfolio	12 months

Summary_of_Significant_Account4

Summary of Significant Accounting Policies and Basis of Accounting (Details 2) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Cash and Cash Equivalents and Restricted Cash
Amount required to maintain under the letter of credit	$200,000	$200,000
Letter of credit
Cash and Cash Equivalents and Restricted Cash
Amount required to maintain under the letter of credit	200,000	200,000
Amounts outstanding under the letter of credit	$0	$0

Summary_of_Significant_Account5

Summary of Significant Accounting Policies and Basis of Accounting (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Rent and Lease Incentives
Amount of rent recognized which exceeds the actual cash payments	$1,144
Amount of actual cash rent payments which exceeds the amount of rent recognized		4,584	119,580
Deferred rent and lease incentives	77,707	90,782	89,638
Deferred Offering Costs
Deferred offering costs	$200,000

Summary_of_Significant_Account6

Summary of Significant Accounting Policies and Basis of Accounting (Details 4)	12 Months Ended
	Dec. 31, 2014
Laboratory equipment
Property and equipment
Estimated useful lives	5 years
Computer equipment and software
Property and equipment
Estimated useful lives	2 years
Office furniture and equipment
Property and equipment
Estimated useful lives	5 years

Summary_of_Significant_Account7

Summary of Significant Accounting Policies and Basis of Accounting (Details 5) (USD $)	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
Revenue Recognition
Amortization of upfront license fees									$150,000	$353,693	$1,921,307
Collaborative research payments:
FTE funding									1,850,000	3,108,000	3,436,000
Research and development costs											20,055
Intellectual property costs									668,786	1,050,990	970,465
Total collaborative research payments									2,518,786	4,158,990	4,426,520
Milestone revenue									6,000,000	18,000,000	16,000,000
Total collaborative revenue	$162,000	$6,178,000	$1,156,000	$1,173,000	$15,198,000	$5,353,000	$925,000	$1,037,000	$8,668,786	$22,512,683	$22,347,827

Summary_of_Significant_Account8

Summary of Significant Accounting Policies and Basis of Accounting (Details 6) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock-based compensation expense
Total stock-based compensation	$2,248,275	$99,853	$280,210
Research and development
Stock-based compensation expense
Total stock-based compensation	232,572	18,920	114,591
General and administrative
Stock-based compensation expense
Total stock-based compensation	$2,015,703	$80,933	$165,619

Summary_of_Significant_Account9

Summary of Significant Accounting Policies and Basis of Accounting (Details 7) (Convertible preferred stock, USD $)	12 Months Ended
	Dec. 31, 2014
Minimum
Net Income Per Common Share
Annual rate of noncumulative dividends on preferred stock (in dollars per share)	$0.60
Maximum
Net Income Per Common Share
Annual rate of noncumulative dividends on preferred stock (in dollars per share)	$1.66

Net_Income_Loss_Per_Common_Sha2

Net Income (Loss) Per Common Share (Details) (USD $)	3 Months Ended								12 Months Ended
Net Income (Loss) Per Common Share (Details) (USD $)	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
Net Income (Loss) Per Common Share
Net (loss) income	($7,275,000)	($1,809,000)	($5,130,000)	($4,889,000)	$9,706,000	$179,000	($4,136,000)	($4,587,000)	($19,103,406)	$1,161,898	$223,086
Less: Undistributed earnings allocated to participating securities										-1,161,898	-223,086
Net loss attributable to common stockholders									($19,103,406)
Weighted average common shares-basic and diluted	18,113,997	1,711,969	603,868	593,206					5,290,534	563,136	542,320
Basic and diluted net loss per share	($0.40)	($1.06)	($8.50)	($8.24)					($3.61)	$0	$0

Net_Income_Loss_Per_Common_Sha3

Net Income (Loss) Per Common Share (Details 2)	12 Months Ended
Net Income (Loss) Per Common Share (Details 2)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net income (Loss) per common share
Potential common shares not reflected in diluted net income per share as the effect would be antidilutive	1,921,468	11,220,369	11,445,999
Stock options
Net income (Loss) per common share
Potential common shares not reflected in diluted net income per share as the effect would be antidilutive	1,484,696	1,291,917	1,907,568
Restricted Stock Units
Net income (Loss) per common share
Potential common shares not reflected in diluted net income per share as the effect would be antidilutive	391,304	391,304
Warrants
Net income (Loss) per common share
Potential common shares not reflected in diluted net income per share as the effect would be antidilutive	45,468	45,468	46,751
Convertible preferred stock
Net income (Loss) per common share
Potential common shares not reflected in diluted net income per share as the effect would be antidilutive		9,491,680	9,491,680

Property_and_Equipment_Details

Property and Equipment (Details) (USD $)	12 Months Ended
Property and Equipment (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property and equipment and related accumulated depreciation and amortization
Less accumulated depreciation and amortization	($8,031,533)	($7,839,489)
Property and equipment, net	417,629	377,996
Depreciation expense
Depreciation expense	212,690	204,733	531,589
Laboratory equipment
Property and equipment and related accumulated depreciation and amortization
Property and equipment, gross	3,253,683	3,085,736
Computer equipment and software
Property and equipment and related accumulated depreciation and amortization
Property and equipment, gross	1,474,310	1,452,580
Office furniture and equipment
Property and equipment and related accumulated depreciation and amortization
Property and equipment, gross	318,839	311,564
Leasehold improvements
Property and equipment and related accumulated depreciation and amortization
Property and equipment, gross	3,402,330	3,357,312
Construction in process
Property and equipment and related accumulated depreciation and amortization
Property and equipment, gross		$10,293

Accrued_Expenses_Details

Accrued Expenses (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Accrued Expenses
Payroll and related costs	$1,710,439	$1,230,428
Research and development related costs	760,961	74,260
Offering costs	207,743
Legal and accounting related costs	264,959	341,901
Other	195,619	54,130
Total	$3,139,721	$1,700,719

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	12 Months Ended	0 Months Ended	12 Months Ended
Fair Value Measurements (Details) (USD $)	Dec. 31, 2014	Sep. 24, 2014	Dec. 31, 2013
Preferred stock warrant liability
Assumptions used in estimation of the fair value of the warrants on the date of issuance and on each re measurement date using the Black Scholes option pricing model
Dividend yield (as a percent)	0.00%
Recurring
Fair value measurements
Assets	63,867,746		$30,011,669
Liabilities			477,375
Recurring \| Preferred stock warrant liability
Fair value measurements
Liabilities			477,375
Assumptions used in estimation of the fair value of the warrants on the date of issuance and on each re measurement date using the Black Scholes option pricing model
Weighted average volatility (as a percent)		83.00%	83.00%
Fair value of underlying instrument (in dollars per share)		$16.33	$8
Weighted average risk-free interest rate (as a percent)		2.68%	2.01%
Recurring \| Money market funds
Fair value measurements
Assets	25,664,911		18,512,463
Recurring \| Other cash equivalents
Fair value measurements
Assets	2,179,290
Recurring \| Cash restricted, CD
Fair value measurements
Assets	200,000		200,000
Recurring \| Marketable securities, available-for-sale
Fair value measurements
Assets	35,823,545		11,299,206
Recurring \| Level 1
Fair value measurements
Assets	25,864,911		18,712,463
Recurring \| Level 1 \| Money market funds
Fair value measurements
Assets	25,664,911		18,512,463
Recurring \| Level 1 \| Cash restricted, CD
Fair value measurements
Assets	200,000		200,000
Recurring \| Level 2
Fair value measurements
Assets	38,002,835		11,299,206
Recurring \| Level 2 \| Other cash equivalents
Fair value measurements
Assets	2,179,290
Recurring \| Level 2 \| Marketable securities, available-for-sale
Fair value measurements
Assets	35,823,545		11,299,206
Recurring \| Level 3
Fair value measurements
Liabilities			477,375
Recurring \| Level 3 \| Preferred stock warrant liability
Fair value measurements
Liabilities			$477,375

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (Recurring, Level 3, Preferred stock warrant liability, USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Recurring \| Level 3 \| Preferred stock warrant liability
Changes in the fair value of the Company's Level 3 financial instruments
Balance at the beginning of the period	$477,375	$720,375
Changes in estimated fair value	-301,294	-243,000
Reclassification of warrants to additional paid-in capital	-176,081
Balance at the end of the period		$477,375

Investments_Details

Investments (Details) (USD $)	12 Months Ended
Investments (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Marketable securities
Cost Basis	$35,862,357	$11,299,139
Unrealized Gains	573	2,028
Unrealized Losses	-39,385	-1,961
Total	35,823,545	11,299,206
Maturities for marketable securities, less than	1 year
U.S. government and agency
Marketable securities
Cost Basis		500,066
Unrealized Gains		64
Total		500,130
Corporate notes and bonds
Marketable securities
Cost Basis	35,862,357	10,799,073
Unrealized Gains	573	1,964
Unrealized Losses	-39,385	-1,961
Total	$35,823,545	$10,799,076

Notes_Payable_Details

Notes Payable (Details) (USD $)	12 Months Ended	0 Months Ended	12 Months Ended
Notes Payable (Details) (USD $)	Dec. 31, 2013	Dec. 22, 2011	Dec. 31, 2012	Dec. 31, 2014
Aggregate maturities of all term notes (amounts exclude unamortized discount)
2015				$4,935,260
Total	10,398,262			4,935,260
Series D preferred stock warrants
Notes payable
Estimated fair value of the preferred stock warrants	680,625
Series D preferred stock warrants \| Series D preferred stock
Notes payable
Number of shares of preferred stock that can be purchased by warrants		29,889
Exercise price of warrants (in dollars per share)		$27.60
Senior notes \| Secured debt \| 2011 Credit Facility
Notes payable
Maximum borrowing capacity		15,000,000
Period over which monthly payments of principal and interest of loan will be made		33 months
Interest rate (as a percent)		8.85%
Additional interest payment to be included in final payment		300,000
Effective interest rate (as a percent)		9.49%
Warrants term		10 years
Debt discount accreted to interest expense	131,084		181,500
Debt issuance costs		$140,000
Loan term	45 months

Stockholders_Equity_Deficit_De

Stockholders' Equity (Deficit) (Details) (USD $)	0 Months Ended		1 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 29, 2014	Oct. 27, 2014	Oct. 27, 2014	Dec. 31, 2014	Dec. 31, 2013
Common Stock
Common stock, shares authorized				150,000,000	312,825,000
Common stock, par value (in dollars per share)				$0.00	$0.00
Issuance of common stock (in shares)				18,026,892	588,988
Common stock, shares outstanding				18,026,892	588,733
IPO
Common Stock
Stock issued in an initial public offering (in shares)	6,875,000
Offering price (in dollars per share)	$8
Gross proceeds from issuance	$55
Over-allotment option
Common Stock
Stock issued in an initial public offering (in shares)		1,031,250
Offering price (in dollars per share)		$8	$8
Gross proceeds from issuance		8.3
IPO and over-allotment option
Common Stock
Net proceeds from issuance			$56.40
2001 Stock Plan
Common Stock
Issuance of common stock (in shares)				343,534
2004 Stock Plan
Common Stock
Issuance of common stock (in shares)				91,586
Minimum
Common Stock
Issue price of common stock (in dollars per share)					$0.00
Maximum
Common Stock
Issue price of common stock (in dollars per share)					$8

Stockholders_Equity_Deficit_De1

Stockholders' Equity (Deficit) (Details 2) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Preferred Stock
Preferred stock, shares authorized	15,000,000	0
Preferred stock, par value (in dollars per share)	$0.00	$0.00
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Stockholders_Equity_Deficit_De2

Stockholders' Equity (Deficit) (Details 3) (USD $)	0 Months Ended
Stockholders' Equity (Deficit) (Details 3) (USD $)	Sep. 24, 2014	Dec. 31, 2014	Sep. 24, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Convertible Preferred Stock
Preferred Shares Outstanding	9,128,419		9,128,419
Conversion into Common Shares upon Initial Public Offering	9,491,680
Convertible preferred stock
Convertible Preferred Stock
Convertible preferred stock, shares authorized				211,775,287
Convertible preferred stock, par value (in dollars per share)				$0.00
Series A-1 preferred stock
Convertible Preferred Stock
Convertible preferred stock, shares authorized		0		675,000
Convertible preferred stock, par value (in dollars per share)				$0.00
Convertible preferred stock, shares issued		0		29,346
Conversion of outstanding shares of preferred stock into shares of common stock	1		1
Preferred Shares Outstanding	29,346	0	29,346	29,346	29,346	29,346
Conversion into Common Shares upon Initial Public Offering	29,346
Series A-2 preferred stock
Convertible Preferred Stock
Convertible preferred stock, shares authorized		0		16,575,000
Convertible preferred stock, par value (in dollars per share)				$0.00
Convertible preferred stock, shares issued		0		717,379
Conversion of outstanding shares of preferred stock into shares of common stock	1.51	1.5064	1.51
Preferred Shares Outstanding	717,379	0	717,379	717,379	717,379	717,379
Conversion into Common Shares upon Initial Public Offering	1,080,640
Series B preferred stock
Convertible Preferred Stock
Convertible preferred stock, shares authorized		0		151,812,780
Convertible preferred stock, par value (in dollars per share)				$0.00
Convertible preferred stock, shares issued		0		6,570,106
Conversion of outstanding shares of preferred stock into shares of common stock	1		1
Preferred Shares Outstanding	6,570,106	0	6,570,106	6,570,106	6,570,106	6,564,736
Conversion into Common Shares upon Initial Public Offering	6,570,106
Series C preferred stock
Convertible Preferred Stock
Convertible preferred stock, shares authorized		0		16,700,007
Convertible preferred stock, par value (in dollars per share)				$0.00
Convertible preferred stock, shares issued		0		724,632
Conversion of outstanding shares of preferred stock into shares of common stock	1		1
Preferred Shares Outstanding	724,632	0	724,632	724,632	724,632	724,632
Conversion into Common Shares upon Initial Public Offering	724,632
Series D preferred stock
Convertible Preferred Stock
Convertible preferred stock, shares authorized		0		26,012,500
Convertible preferred stock, par value (in dollars per share)				$0.00
Convertible preferred stock, shares issued		0		1,086,956
Conversion of outstanding shares of preferred stock into shares of common stock	1		1
Preferred Shares Outstanding	1,086,956	0	1,086,956	1,086,956	1,086,956	1,086,956
Conversion into Common Shares upon Initial Public Offering	1,086,956

Stockholders_Equity_Deficit_De3

Stockholders' Equity (Deficit) (Details 4)	12 Months Ended
Stockholders' Equity (Deficit) (Details 4)	Dec. 31, 2014
Treasury Stock
Treasury shares retired	256

Stockholders_Equity_Deficit_De4

Stockholders' Equity (Deficit) (Details 5) (USD $)	Dec. 31, 2014
Warrants
Warrants Outstanding (in shares)	45,468
Warrant to purchase common stock, expiring on 07/12/2016
Warrants
Warrants Outstanding (in shares)	1,449
Exercise Price (in dollars per share)	20.7
Warrant to purchase common stock, expiring on 08/28/2018
Warrants
Warrants Outstanding (in shares)	14,130
Exercise Price (in dollars per share)	27.6
Warrant to purchase common stock, expiring on 12/21/2021
Warrants
Warrants Outstanding (in shares)	29,889
Exercise Price (in dollars per share)	27.6
Minimum
Warrants
Exercise Price (in dollars per share)	20.7
Maximum
Warrants
Exercise Price (in dollars per share)	27.6

Stockholders_Equity_Deficit_De5

Stockholders' Equity (Deficit) (Details 6)	Dec. 31, 2014
Stockholders' Equity (Deficit)
Common stock options outstanding	1,484,696
Restricted stock units outstanding	391,304
Shares available for future grant	1,861,623
Shares available through employee stock purchase plan	250,000
Warrants	45,468
Common stock reserved for issuance	4,033,091

Employee_Compensation_Plans_De

Employee Compensation Plans (Detail) (USD $)	1 Months Ended	12 Months Ended			1 Months Ended	0 Months Ended
Employee Compensation Plans (Detail) (USD $)	Jul. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 30, 2013	Jan. 01, 2015
Employee compensation plans
Shares available for grant		1,861,623
Automatic increase in shares reserved for issuance on first business day of each of fiscal year	1,426,000
Additional disclosures
Intrinsic value of options exercised		$166,693	$112,583
Stock options
Employee compensation plans
Number of additional share-based compensation plans		3
Awards expiring during the year ending December 31, 2014, unless exercised		117,159
Number of Shares
Balance at the beginning of the period (in shares)		1,291,917
Granted (in shares)		463,008
Exercised (in shares)		-40,230
Expired (in shares)		-210,043
Forfeited (in shares)		-19,956
Balance at the end of the period (in shares)		1,484,696	1,291,917
Exercisable, at the end of the period (in shares)		819,955
Vested and Expected to Vest, at the end of the period (in shares)		1,454,906
Weighted-Average Exercise Price
Balance at the beginning of the period (in dollars per share)		$4.32
Granted (in dollars per share)		$5.94
Exercised (in dollars per share)		$1.46
Expired (in dollars per share)		$4.20
Forfeited (in dollars per share)		$7.06
Balance at the end of the period (in dollars per share)		$4.88	$4.32
Exercisable, at the end of the period (in dollars per share)		$3.67
Vested and Expected to Vest, at the end of the period (in dollars per share)		$4.84
Weighted-Average Remaining Contractual Term (Years)
Balance at the end of the period		5 years 3 months 18 days
Exercisable, at the end of the period		2 years 9 months 15 days
Aggregate intrinsic value
Balance at the end of the period		17,454,021
Exercisable, at the end of the period		$10,630,885
Additional disclosures
Weighted average fair value of options granted (in dollars per share)		$4.23	$3.68	$4.83
Stock options \| Maximum
Employee compensation plans
Vesting period		4 years
Expiration period		10 years
2013 Plan \| Stock options
Employee compensation plans
Shares available for grant		1,861,623
2001 Stock Plan \| Stock options
Employee compensation plans
Common stock authorized for issuance (in shares)		402,530
Decrease in shares available for issuance under the Plan					530,674
2014 Stock Plan
Employee compensation plans
Common stock authorized for issuance (in shares)	1,782,500					2,582,699
Automatic increase in shares reserved for issuance on first business day of each of fiscal year as a percentage of shares actually issued and outstanding on last business day of prior fiscal year	4.00%
Automatic increase in shares reserved for issuance on first business day of each of fiscal year						721,076
2014 Stock Plan \| Maximum
Employee compensation plans
Number of shares reserved under clauses (2) and (3)	1,070,687

Employee_Compensation_Plans_De1

Employee Compensation Plans (Details 2) (USD $)	12 Months Ended			1 Months Ended
Employee Compensation Plans (Details 2) (USD $)	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2011	Jul. 31, 2007
Weighted average fair value assumptions used to calculate fair values of stock options granted
Weighted average risk free interest rate (as a percent)	0.90%
Expected term of options	6 years 3 months
Expected stock price volatility (as a percent)	86.16%
Expected dividend yield (as a percent)	0.00%
Total unrecognized compensation expense, excluding performance based stock options that have not been deemed probable, net of estimated forfeitures, related to unvested options granted under the Stock Plans expected to be recognized
2014		$616,550
2015		533,584
2016		468,723
2017		112,195
Total unrecognized compensation expense		1,731,052
Stock options
Employee compensation plans
Awards granted (in shares)		463,008
Weighted average fair value assumptions used to calculate fair values of stock options granted
Weighted average risk free interest rate (as a percent)		1.98%	1.42%
Expected term of options		6 years 1 month 10 days	6 years 3 months
Expected stock price volatility (as a percent)		83.00%	85.00%
Expected dividend yield (as a percent)		0.00%	0.00%
Estimate for annual dividends (in dollars per share)		0
Total cash received from employees as a result of employee stock option exercises	13,357	58,758	70,762
Total unrecognized compensation expense, excluding performance based stock options that have not been deemed probable, net of estimated forfeitures, related to unvested options granted under the Stock Plans expected to be recognized
Exercise price (in dollars per share)		$4.88	$4.32
Stock options \| Maximum
Employee compensation plans
Expiration period		10 years
Performance-based stock options granted to employees
Employee compensation plans
Awards granted (in shares)				303,559
Expiration period				10 years	10 years
Total unrecognized compensation expense, excluding performance based stock options that have not been deemed probable, net of estimated forfeitures, related to unvested options granted under the Stock Plans expected to be recognized
Stock options deemed probable (in shares)		110,701
Aggregate estimated fair value of options for which the satisfaction of the related performance conditions have not been deemed probable		$827,860
Share-based Compensation Award, Tranche One [Member] \| Performance-based stock options granted to employees \| Maximum
Employee compensation plans
Vesting percentage		60.00%
Share-based Compensation Award, Tranche Two [Member] \| Performance-based stock options granted to employees \| Maximum
Employee compensation plans
Vesting percentage		40.00%

Employee_Compensation_Plans_De2

Employee Compensation Plans (Details 3) (Restricted Stock Units, 2013 Plan, USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2014
Restricted Stock Units \| 2013 Plan
Employee compensation plans
RSUs awarded (in shares)	391,304
Total unrecognized compensation expense		$1,440,000
Grant date fair value (in dollars per share)	$3.68

Employee_Benefit_Plans_Details

Employee Benefit Plans (Details) (USD $)	0 Months Ended	1 Months Ended	12 Months Ended
Employee Benefit Plans (Details) (USD $)	Jan. 01, 2015	Jul. 31, 2014	Dec. 31, 2014	Jan. 01, 2015
Employee compensation plans
Automatic increase in shares reserved for issuance on first business day of each of fiscal year		1,426,000
Employee Stock Purchase Plan
Employee compensation plans
Purchase price of common stock (as a percent)		85.00%
Purchase price of common stock in an offering period beginning upon the closing of the Company's IPO (as a percent)		85.00%
Maximum percentage of eligible compensation that eligible employee may contribute		15.00%
Maximum number of shares of common stock that participants may purchase		2,100
The maximum value a participant can purchase in any calendar year		$25,000
Number of shares of common stock made available for sale	430,269	250,000		430,269
Minimum percentage of total number of shares of the Company's common stock actually issued and outstanding on the last business day of the prior fiscal year that may automatically increase under the plan			1.00%
Minimum number of shares of Company's common stock that may automatically increase under the plan			356,500
Automatic increase in shares reserved for issuance on first business day of each of fiscal year	180,269
Common stock authorized for issuance (in shares)	430,269	250,000		430,269

Collaborative_Research_Agreeme1

Collaborative Research Agreements (Details) (USD $)	12 Months Ended			1 Months Ended					14 Months Ended	36 Months Ended	67 Months Ended	3 Months Ended	87 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2013	Dec. 31, 2012	Apr. 30, 2012	Sep. 30, 2009	Jun. 30, 2009	Jun. 30, 2013	31-May-12	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2007
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2013	Dec. 31, 2012	Apr. 30, 2012	item	Jun. 30, 2009	item	31-May-12	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2007
Collaborative research agreements
Development milestones earned	$6,000,000	$18,000,000	$16,000,000
11-Beta HSD1 Inhibitors \| BI \| Commercialization milestones
Collaborative research agreements
Maximum milestone payments that may be received based on the achievement of pre specified events	125,000,000										125,000,000	125,000,000	125,000,000
Research Collaboration and License Agreement \| BACE Inhibitors \| BI
Collaborative research agreements
Period for which company is obligated to provide full time equivalent employees for research services							36 months	36 months
Upfront license fee received					4,000,000		15,000,000
Payments the counterparty required to make each quarter during the funded research period									740,000	1,020,000
Total payments the counterparty required to make during the funded research period									2,960,000	12,240,000
Extended research period						12 months
Number of FTE's per month which company is obligated to provide during the extended research period							12		8
Development milestones earned		18,000,000	9,000,000								29,000,000
Maximum milestone payments that may be received based on the achievement of pre specified events	326,000,000										326,000,000	326,000,000	326,000,000
Percentage of milestone amount to be earned by any subsequent product(s) achieving the milestone	50.00%										50.00%	50.00%	50.00%
Percentage of milestone amount to be earned for second indications for a product covered by the contract to achieve the regulatory milestones	50.00%										50.00%	50.00%	50.00%
Research services period				12 months
Revenue recognized relating to the upfront payment	2,000,000
Research Collaboration and License Agreement \| BACE Inhibitors \| BI \| Development milestones
Collaborative research agreements
Maximum milestone payments that may be received based on the achievement of pre specified events	56,000,000										56,000,000	56,000,000	56,000,000
Research Collaboration and License Agreement \| BACE Inhibitors \| BI \| Regulatory milestones
Collaborative research agreements
Maximum milestone payments that may be received based on the achievement of pre specified events	120,000,000										120,000,000	120,000,000	120,000,000
Research Collaboration and License Agreement \| BACE Inhibitors \| BI \| Commercialization milestones
Collaborative research agreements
Maximum milestone payments that may be received based on the achievement of pre specified events	150,000,000										150,000,000	150,000,000	150,000,000
Research Collaboration and License Agreement \| 11-Beta HSD1 Inhibitors \| BI
Collaborative research agreements
Milestone payments received	6,000,000	0	7,000,000									6,000,000
Development milestones earned													43,000,000
Maximum milestone payments that may be received based on the achievement of pre specified events	272,000,000										272,000,000	272,000,000	272,000,000	272,000,000
Percentage of milestone amount to be earned by any subsequent product(s) achieving the milestone	50.00%										50.00%	50.00%	50.00%
Research Collaboration and License Agreement \| 11-Beta HSD1 Inhibitors \| BI \| Development milestones
Collaborative research agreements
Maximum milestone payments that may be received based on the achievement of pre specified events	42,000,000										42,000,000	42,000,000	42,000,000
Research Collaboration and License Agreement \| 11-Beta HSD1 Inhibitors \| BI \| Regulatory milestones
Collaborative research agreements
Maximum milestone payments that may be received based on the achievement of pre specified events	$105,000,000										$105,000,000	$105,000,000	$105,000,000

Income_Taxes_Details

Income Taxes (Details) (USD $)	1 Months Ended	12 Months Ended
Income Taxes (Details) (USD $)	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Research and development tax credits
Amount of Pennsylvania research and development tax credits sold	$91,729	$45,678
Net proceeds from sale of Pennsylvania research and development tax credits recorded in other income		42,024	84,391
Reconciliation of the income tax benefit computed at statutory rates to the Company's recorded tax benefit
Federal income tax (benefit), statutory rates		-6,686,192	406,664	78,080
State income tax, net of federal benefit		-1,025,637	109,786	50,876
Research and development tax credits		-902,502	-1,140,768	-58,079
Other		183,625	185,519	196,763
Income tax (benefit) expense		-8,430,706	-438,799	267,640
Valuation allowance		8,430,706	438,799	-267,640
Increase in valuation allowance		8,431,000	439,000
Long-term deferred tax assets:
Net operating loss carryforwards (federal and state)		34,743,789	27,545,207
Research and development tax credits		6,188,578	5,286,077
Property and equipment		965,462	989,923
Other accruals		1,378,237	92,476
Impairment of cost method investments		1,499,352	1,499,352
Capitalized research		13,188,718	14,104,291
Total gross long-term deferred tax assets		57,964,136	49,517,326
Less valuation allowance		($57,964,136)	($49,517,326)

Income_Taxes_Details_2

Income Taxes (Details 2) (USD $)	Dec. 31, 2014
Federal
Net operating loss carryforward
Net operating loss carryforward	$84,173,000
State
Net operating loss carryforward
Net operating loss carryforward	81,362,000
State \| Pennsylvania Department of Revenue
Net operating loss carryforward
Net operating loss carryforward limitation	$5,000,000
Net operating loss carryforward limitation (as a percent)	30.00%

Income_Taxes_Details_3

Income Taxes (Details 3) (USD $)	12 Months Ended
Income Taxes (Details 3) (USD $)	Dec. 31, 2014
Research and development tax credit carryforwards
Tax credit carryforward
Reduction in tax credits	$5,956,000
Investment Tax Credit Carryforward
Tax credit carryforward
Reduction in tax credits	$359,000

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	12 Months Ended
Related Party Transactions (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Related Party Transactions
Costs incurred for related party	$1,262,000	$267,000	$26,000
Due to the related party	$129,000	$209,000

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	item	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies
Number of additional lease periods	1
Period of additional lease term at fixed escalation amounts	5 years
Rental expense	$779,000	$781,000	$742,000
Future minimum payments under operating leases
2015	790,433
2016	805,512
2017	821,622
2018	68,581
Total minimum future rental payments	$2,486,148

Reverse_Stock_Split_Details

Reverse Stock Split (Details)	0 Months Ended
Reverse Stock Split (Details)	Sep. 08, 2014
Convertible preferred stock
Reverse Stock Split
Reverse stock split conversion ratio	0.04347826
Common stock
Reverse Stock Split
Reverse stock split conversion ratio	0.04347826

Interim_Financial_Information_2

Interim Financial Information (Unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
Interim Financial Information (Unaudited) (Details) (USD $)	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
Interim Financial Information (Unaudited)
Collaborative revenues	$162,000	$6,178,000	$1,156,000	$1,173,000	$15,198,000	$5,353,000	$925,000	$1,037,000	$8,668,786	$22,512,683	$22,347,827
Net loss	($7,275,000)	($1,809,000)	($5,130,000)	($4,889,000)	$9,706,000	$179,000	($4,136,000)	($4,587,000)	($19,103,406)	$1,161,898	$223,086
Basic and diluted net loss per share	($0.40)	($1.06)	($8.50)	($8.24)					($3.61)	$0	$0
Shares used in computation of basic and diluted net loss per share	18,113,997	1,711,969	603,868	593,206					5,290,534	563,136	542,320
Basic net (loss) income per share					$0.77	$0	($7.44)	($8.37)	($3.61)	$0	$0
Diluted net (loss) income per share					$0.74	$0	($7.44)	($8.37)	($3.61)	$0	$0
Shares used in computation of basic net (loss) income per share					583,653	564,702	555,725	548,051	5,290,534	563,136	542,320
Shares used in computation diluted net (loss) income per share					975,795	564,702	555,725	548,051	5,290,534	563,136	542,320

Subsequent_Event_Details

Subsequent Event (Details) (Subsequent event, USD $)	0 Months Ended
In Millions, except Share data, unless otherwise specified	Jan. 28, 2015	Jan. 28, 2015
Follow-on offering
Subsequent Events
Shares issued (in shares)	3,450,000
Offering price (in dollars per share)	$11.90	$11.90
Net proceeds from issuance	$37.80
Option to purchase additional shares
Subsequent Events
Shares issued (in shares)	450,000

Subsequent_Event_Details_2

Subsequent Event (Details 2) (2011 Credit Facility, Secured debt, Senior notes, USD $)	0 Months Ended
	Feb. 27, 2015
Subsequent Events
Deferred financing fees	$20,852
Unamortized debt discount	101,373
Subsequent event
Subsequent Events
Total payoff	4,342,855
Prepayment and other additional fees	$84,453