Trevena (TRVN) 10-K18 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. 10, 2015	Jun. 30, 2014
Document and Entity Information
Entity Registrant Name	TREVENA INC
Entity Central Index Key	1429560
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	Smaller Reporting Company
Entity Public Float			$47.40
Entity Common Stock, Shares Outstanding		39,241,173
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	$36,205,559	$37,965,198
Marketable securities	70,698,640
Prepaid expenses and other current assets	669,155	1,957,765
Offering costs		1,999,279
Total current assets	107,573,354	41,922,242
Property and equipment, net	553,294	343,059
Restricted cash	112,410	112,000
Other assets	98,401	15,625
Total assets	108,337,459	42,392,926
Current liabilities:
Accounts payable	4,342,480	545,053
Accrued expenses and other current liabilities	2,578,269	2,158,792
Deferred rent	38,359	33,114
Total current liabilities	6,959,108	2,736,959
Loans payable, net of current portion	1,791,285
Capital lease, net of current portion	10,677
Deferred rent, net of current portion	281,885	313,919
Preferred stock warrant liability	82,851	350,519
Other long term liabilities	8,025
Total liabilities	9,133,831	3,401,397
Commitments and contingencies (Note 10)
Redeemable convertible preferred stock:
Total redeemable convertible preferred stock		120,562,138
Stockholders' equity (deficit):
Common stock, $0.001 par value; 100,000,000 and 132,000,000 shares authorized, 39,241,173 and 957,756 shares issued and outstanding at December 31, 2014 and 2013, respectively	39,241	958
Additional paid-in capital	231,152,894	697,283
Accumulated deficit	-131,969,725	-82,268,850
Accumulated other comprehensive loss	-18,782
Total stockholders' deficit	99,203,628	-81,570,609
Total liabilities, redeemable convertible preferred stock and stockholders' deficit	108,337,459	42,392,926
Series A convertible preferred stock
Redeemable convertible preferred stock:
Total redeemable convertible preferred stock		25,024,373
Series B convertible preferred stock
Redeemable convertible preferred stock:
Total redeemable convertible preferred stock		30,778,700
Series B 1 convertible preferred stock
Redeemable convertible preferred stock:
Total redeemable convertible preferred stock		4,823,079
Series C convertible preferred stock
Redeemable convertible preferred stock:
Total redeemable convertible preferred stock		$59,935,986

Balance_Sheets_Parenthetical

Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Redeemable convertible preferred stock, shares outstanding		97,389,703
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, shares authorized	100,000,000	132,000,000
Common stock, shares issued	39,241,173	957,756
Common stock, shares outstanding	39,241,173	957,756
Series A convertible preferred stock
Redeemable convertible preferred stock, par value (in dollars per share)	$0.00	$0.00
Redeemable convertible preferred stock, shares authorized	0	25,074,999
Redeemable convertible preferred stock, shares issued	0	25,074,999
Redeemable convertible preferred stock, shares outstanding	0	25,074,999
Redeemable convertible preferred stock, liquidation preference (in dollars)		$25,074,999
Series B convertible preferred stock
Redeemable convertible preferred stock, par value (in dollars per share)	$0.00	$0.00
Redeemable convertible preferred stock, shares authorized	0	35,500,000
Redeemable convertible preferred stock, shares issued	0	30,800,000
Redeemable convertible preferred stock, shares outstanding	0	30,800,000
Redeemable convertible preferred stock, liquidation preference (in dollars)		30,800,000
Series B 1 convertible preferred stock
Redeemable convertible preferred stock, par value (in dollars per share)	$0.00	$0.00
Redeemable convertible preferred stock, shares authorized	0	6,000,000
Redeemable convertible preferred stock, shares issued	0	4,750,000
Redeemable convertible preferred stock, shares outstanding	0	4,750,000
Redeemable convertible preferred stock, liquidation preference (in dollars)		4,200,000
Series C convertible preferred stock
Redeemable convertible preferred stock, par value (in dollars per share)	$0.00	$0.00
Redeemable convertible preferred stock, shares authorized	0	37,000,000
Redeemable convertible preferred stock, shares issued	0	36,764,704
Redeemable convertible preferred stock, shares outstanding	0	36,764,704
Redeemable convertible preferred stock, liquidation preference (in dollars)		$59,999,997

Statements_of_Operations_and_C

Statements of Operations and Comprehensive Loss (USD $)	12 Months Ended
Statements of Operations and Comprehensive Loss (USD $)	Dec. 31, 2014	Dec. 31, 2013
Revenue:
Grant revenue		$84,980
Collaboration revenue		50,000
Total revenue		134,980
Operating expenses:
General and administrative	9,403,254	4,718,047
Research and development	40,546,666	18,762,219
Total operating expenses	49,949,920	23,480,266
Loss from operations	-49,949,920	-23,345,286
Other income (expense):
Change in fair value of warrant liability	122,412	241,478
Miscellaneous income	184,015	1,245
Loss on asset disposal	-4,104
Interest income	17,372	884
Interest expense	-70,650	-149,756
Total other income	249,045	93,851
Net loss	-49,700,875	-23,251,435
Accretion of redeemable convertible preferred stock	-28,521	-333,710
Net loss attributable to common stockholders	-49,729,396	-23,585,145
Other comprehensive income, net:
Change in unrealized loss	-18,782
Other comprehensive loss	-18,782
Comprehensive loss	($49,748,178)	($23,585,145)
Per share information:
Net loss per share of common stock, basic and diluted (in dollars per share)	($2.02)	($29.71)
Weighted average shares outstanding, basic and diluted (in shares)	24,655,603	793,806

Statements_of_Redeemable_Conve

Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (USD $)	Series A convertible preferred stock	Series A convertible preferred stock	Series A convertible preferred stock	Series B convertible preferred stock	Series B convertible preferred stock	Series B convertible preferred stock	Series B 1 convertible preferred stock	Series B 1 convertible preferred stock	Series B 1 convertible preferred stock	Series C convertible preferred stock	Series C convertible preferred stock	Series C convertible preferred stock	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Total
	Common Stock	Additional Paid-in Capital	Series A convertible preferred stock	Common Stock	Additional Paid-in Capital	Series B convertible preferred stock	Common Stock	Additional Paid-in Capital	Series B 1 convertible preferred stock	Common Stock	Additional Paid-in Capital	Series C convertible preferred stock	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Total
Balance at Dec. 31, 2012													$682	$19,718	($59,017,415)		($58,997,015)
Balance at Dec. 31, 2012			25,004,123			30,770,194			3,183,517								58,957,834
Balance (in shares) at Dec. 31, 2012													682,494
Balance (in shares) at Dec. 31, 2012			25,074,999			30,800,000			4,200,000
Increase (Decrease) in Temporary Equity
Issuance of convertible preferred stock, net of issuance costs												59,918,917					59,918,917
Issuance of convertible preferred stock, net of issuance costs (in shares)												36,764,704
Exercise of Series B-1 preferred stock warrants									1,351,677								1,351,677
Exercise of Series B-1 preferred stock warrants (in shares)									550,000
Accretion of Series A, Series B/B-1 and Series C convertible preferred stock to its redemption value			20,250			8,506			287,885			17,069					333,710
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense														927,996			927,996
Exercise of stock options													276	83,279			83,555
Exercise of stock options (in shares)													275,262
Accretion of Series A, Series B/B-1 and Series C convertible preferred stock to its redemption value														-333,710			-333,710
Net loss															-23,251,435		-23,251,435
Conversion of convertible preferred stock to common stock upon initial public offering (in shares)																	15,708,013
Balance at Dec. 31, 2013													958	697,283	-82,268,850		-81,570,609
Balance at Dec. 31, 2013			25,024,373			30,778,700			4,823,079			59,935,986					120,562,138
Balance (in shares) at Dec. 31, 2013													957,756				957,756
Balance (in shares) at Dec. 31, 2013			25,074,999			30,800,000			4,750,000			36,764,704					97,389,703
Increase (Decrease) in Temporary Equity
Accretion of Series A, Series B/B-1 and Series C convertible preferred stock to its redemption value			1,688			709			23,990			2,134					-28,521
Conversion of Series A convertible preferred stock to common stock upon initial public offering			-25,026,061														-25,026,061
Conversion of Series A convertible preferred stock to common stock upon initial public offering (in shares)			-25,074,999
Conversion of Series B convertible preferred stock to common stock upon initial public offering				4,968	30,774,441	-30,779,409											30,779,409
Conversion of Series B convertible preferred stock to common stock upon initial public offering (in shares)				4,967,741		-30,800,000
Conversion of Series B-1 convertible preferred stock to common stock upon initial public offering									-4,847,069								-4,847,069
Conversion of Series B-1 convertible preferred stock to common stock upon initial public offering (in shares)									-4,750,000
Conversion of Series C convertible preferred stock to common stock upon initial public offering												-59,938,120					-59,938,120
Conversion of Series C convertible preferred stock to common stock upon initial public offering (in shares)												-36,764,704
Increase (Decrease) in Stockholders' Equity
Stock-based compensation expense														2,383,399			2,383,399
Exercise of stock options													186	111,592			111,778
Exercise of stock options (in shares)													186,682
Accretion of Series A, Series B/B-1 and Series C convertible preferred stock to its redemption value														-28,521			-28,521
Change in unrealized investment losses																-18,782	-18,782
Net loss															-49,700,875		-49,700,875
Conversion of convertible preferred stock to common stock upon initial public offering	4,044	25,022,017	-25,026,061			-30,779,409	766	4,846,303	4,847,069	5,930	59,932,190	-59,938,120
Conversion of convertible preferred stock to common stock upon initial public offering (in shares)	4,044,354						766,129			5,929,789
Net conversion of preferred stock warrants common stock upon initial public offering													20	-20
Net conversion of preferred stock warrants common stock upon initial public offering (in shares)													20,273
Reclassification of convertible preferred stock warrant liability														145,256			145,256
Issuance of common stock warrants														1,000			1,000
Issuance of common stock, net of issuance costs													22,369	107,267,954			107,290,323
Issuance of common stock (in shares)													22,368,449
Balance at Dec. 31, 2014													$39,241	$231,152,894	($131,969,725)	($18,782)	$99,203,628
Balance (in shares) at Dec. 31, 2014													39,241,173				39,241,173
Balance (in shares) at Dec. 31, 2014			0			0			0			0

Statements_of_Redeemable_Conve1

Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) (Series C convertible preferred stock, USD $)	1 Months Ended
	31-May-13
Series C convertible preferred stock
Issuance of convertible preferred stock, issuance costs	$81,080

Statements_of_Cash_Flows

Statements of Cash Flows (USD $)	12 Months Ended
Statements of Cash Flows (USD $)	Dec. 31, 2014	Dec. 31, 2013
Operating activities:
Net loss	($49,700,875)	($23,251,435)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	239,390	706,779
Stock-based compensation	2,383,399	927,996
Noncash interest expense on loans	33,442	121,160
Loss on disposal of assets	5,015
Revaluation of warrant liability	-122,412	-241,478
Changes in operating assets and liabilities:
Prepaid expenses, offering costs and other assets	3,196,559	-3,667,605
Accounts payable and other liabilities	4,187,552	1,165,353
Net cash used in operating activities	-39,777,930	-24,239,230
Investing activities:
Purchase of property and equipment	-440,381	-140,036
Purchase of marketable securities	-70,717,422
Net cash used in investing activities	-71,157,803	-140,036
Financing activities:
Proceeds from issuance of redeemable convertible preferred stock and warrants, net		59,918,917
Proceeds from exercise of common stock options	111,778	83,555
Proceeds from exercise of preferred stock warrants		550,000
Proceeds from loans payable	1,775,012
Proceeds from issuance of common stock, net	107,290,323
Repayment of loans payable		-4,946,667
Capital lease payments	-1,019
Net cash provided by financing activities	109,176,094	55,605,805
Net increase (decrease) in cash and cash equivalents	-1,759,639	31,226,539
Cash and cash equivalents, beginning of period	37,965,198	6,738,659
Cash and cash equivalents-end of period	36,205,559	37,965,198
Supplemental disclosure of cash flow information:
Cash paid for interest	37,209	85,422
Capital lease additions	14,259
Common Stock
Supplemental disclosure of cash flow information:
Fair value of stock warrants issued	$1,000

Organization_and_Description_o

Organization and Description of the Business	12 Months Ended
Organization and Description of the Business	Dec. 31, 2014
Organization and Description of the Business
Organization and Description of the Business
	1. Organization and Description of the Business
	Trevena, Inc. (the "Company") was incorporated in Delaware as Parallax Therapeutics, Inc. on November 9, 2007. The Company began operations in December 2007, and its name was changed to Trevena, Inc. on January 3, 2008. The Company is a clinical stage biopharmaceutical company that discovers, develops and intends to commercialize therapeutics that use a novel approach to target G protein coupled receptors. The Company operates in one segment and has its principal office in King of Prussia, Pennsylvania. The Company's revenue has been derived from research grants and a research collaboration with a pharmaceutical company.
	Reverse Stock Split
	During 2013, the Company's Board of Directors and stockholders approved a one-for-6.2 reverse stock split of the company's common stock that became effective on October 30, 2013. All share and per share amounts in the financial statements and notes thereto have been retroactively adjusted for all periods presented to give effect to this reverse stock split.
	Public Offerings
	On February 5, 2014, the Company issued and sold 9,250,000 shares of common stock in an initial public offering (the "IPO") at a price of $7.00 per share, for aggregate gross proceeds of $64.8 million. On March 6, 2014, in connection with the partial exercise of the IPO underwriters' over-allotment option, the Company sold an additional 270,449 shares of common stock at a price of $7.00 per share, for aggregate gross proceeds of approximately $1.9 million. The net offering proceeds to the Company from both sales were approximately $59.5 million, after deducting underwriting discounts and commissions of approximately $4.7 million and offering costs of approximately $2.5 million. In addition, as part of the IPO, all of the Company's outstanding convertible preferred stock was converted and all but 22,580 of its outstanding warrants were net exercised into an aggregate of 15,728,286 shares of common stock.
	On December 10, 2014, the Company issued and sold 11,250,000 shares of common stock in a public offering as well as 1,598,000 shares of common stock pursuant to the partial exercise of the underwriters' over-allotment option for a total of 12,848,000 shares at a price of $4.00 per share, for aggregate gross proceeds of approximately $51.4 million. The net offering proceeds to the Company from the combined sales were approximately $47.7 million, after deducting underwriting discounts and commissions of approximately $3.1 million and offering costs of approximately $0.6 million.
	Liquidity
	At December 31, 2014, the Company had an accumulated deficit of $132.0 million and its net loss was $49.7 million and $23.3 million for the year ended December 31, 2014 and 2013, respectively. The Company expects its cash and cash equivalents of $36.2 million and marketable securities of $70.7 million as of December 31, 2014 and the $16.5 million that the Company currently can draw under the second tranche of our credit facility, together with interest thereon, to be sufficient to fund its operating expenses and capital expenditure requirements through the end of 2016.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2014
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies
	2. Summary of Significant Accounting Policies
	Basis of Presentation
	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 Update ("ASU") of the Financial Accounting Standards Board ("FASB"). The Company considers the U.S. dollar to be its functional currency.

	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 and common stock warrants, and the accounting for research and development costs, accrued expenses and the recoverability of the Company's net deferred tax assets and related valuation allowance.

	Cash and Cash Equivalents
	The Company considers all highly liquid investments that have maturities of three months or less when acquired to be cash equivalents. Cash and cash equivalents subject the Company to concentrations of credit risk. However, the Company has invested in U.S. Treasury Bonds and money market mutual funds that invest substantially all of their assets in U.S. government securities. Cash equivalents are valued at cost, which approximates their fair market value.

	Restricted Cash
	At December 31, 2014 and 2013, the Company maintained letters of credit totaling $112,000, as collateral for the Company's facility and laboratory equipment lease obligations in Pennsylvania. In 2014, the Company earned interest of $410 related to these funds.
	Investments
	At the time of purchase, the Company classifies investments in marketable securities as either available-for-sale securities, held to maturity securities, or trading securities, based on the Company's intent at that time.
	As of December 31, 2014, the Company's investments are classified as available-for-sale pursuant to ASC Topic 320, Investments—Debt and Equity Securities ("ASC 320"). The Company classifies investments available to fund current operations as current assets on its balance sheets. The Company considers all investments that have maturities of three months or less when acquired to be cash equivalents. Investments are classified as long-term assets on the balance sheets if (i) the Company has the intent and ability to hold the investments for a period of at least one year and (ii) the contractual maturity date of the investments is greater than one year. As of December 31, 2014, the Company had $70.7 million in available-for-sale investments, all classified as current assets.
	Investments are carried at fair value with unrealized gains and losses included as a component of accumulated other comprehensive loss, until such gains and losses are realized. Fair value is determined based on observable market quotes or valuation models using assessments of counterparty credit worthiness, credit default risk of underlying security and overall capital market liquidity. The company reviews unrealized losses associated with available-for-sale securities to determine the classification as "temporary" or "other-than-temporary" impairment. A temporary impairment results in an unrealized loss being recorded in other comprehensive income. If a decline in the fair value is considered other-than-temporary, based on available evidence, the unrealized loss is transferred from other comprehensive loss to the statement of operations. The Company considers various factors in determining the classification, including the length of time and extent to which the fair value has been less than the Company's cost basis, the financial condition and near-term prospects of the issuer or investee, and the Company's ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value. There were no charges taken for other-than-temporary declines in fair value of short-term or long-term investments during the year ended December 31, 2014. The Company recorded unrealized (gains)/ losses of $18,782 during the year ended December 31, 2014. Realized gains and losses are included in interest income in the statement of operations and comprehensive loss. The Company did not record any realized gains or losses during the year ended December 31, 2014.

	Property and Equipment
	Property and equipment consists of computer and laboratory equipment, software, office equipment, furniture and leasehold improvements and is recorded at cost. Maintenance and repairs that do not improve or extend the lives of the respective assets are expensed to operations as incurred. Upon disposal, retirement or sale the related cost and accumulated depreciation is removed from the accounts and any resulting gain or loss is included in the results of operations. Property and equipment are depreciated on a straight-line basis over their estimated useful lives. The Company uses a life of three years for computer equipment, and five years for laboratory equipment, office equipment, furniture and software. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the asset.
	The Company reviews long-lived assets when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparison of the book values of the assets to future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the book value of the assets exceed their fair value, which is measured based on the projected discounted future net cash flows arising from the assets. No impairment losses have been recorded since inception.

	Preferred Stock and Common Stock Warrants
	Freestanding warrants that are related to the purchase of preferred and common stock are classified as liabilities and recorded at fair value regardless of the timing of the redemption feature or the redemption price or the likelihood of redemption. The warrants are subject to re-measurement at each balance sheet date and any change in fair value is recognized as a component of change in fair value of warrant liability in the statements of operations and comprehensive loss. Pursuant to the terms of the preferred warrants, upon the conversion to common stock of the series of preferred stock underlying the warrant, the warrants automatically became exercisable for shares of common stock based upon the conversion ratio of the underlying preferred stock. The Company will continue to adjust the liability for changes in fair value until the earlier of the exercise or expiration of the warrants. The preferred (at December 31, 2013) and common stock (at December 31, 2014) warrants are classified as Level 3 liabilities (see Fair Value of Financial Instruments).

	Fair Value of Financial Instruments
	The carrying amount of the Company's financial instruments, which include cash and cash equivalents, marketable securities, grants receivable, restricted cash, accounts payable and accrued expenses approximate their fair values, given their short-term nature. The carrying amount of the Company's loans payable at December 31, 2014 approximates fair value because the interest rate is reflective of the rate the Company could obtain on debt with similar terms and conditions. The preferred stock warrants are carried at fair value as disclosed above. The Company has evaluated 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.
	ASC Topic 820, Fair Value Measurement ("ASC 820"), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company's own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company's assumptions about the inputs that market participants would use in pricing the asset or liability, and are developed based on the best information available in the circumstances.
	ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC Topic 820 establishes a three-tier fair value hierarchy that distinguishes among the following:
	•	Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access.
	•	Level 2—Valuations based on quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active and models for which all significant inputs are observable, either directly or indirectly.
	•	Level 3—Valuations based on inputs that are unobservable and significant to the overall fair value measurement.
	To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument's level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement.
	Items measured at fair value on a recurring basis include money market mutual funds, restricted cash and warrants to purchase redeemable convertible preferred stock. During the periods presented, the Company has not changed the manner in which it values assets and liabilities that are measured at fair value using Level 3 inputs. The following fair value hierarchy table presents information about each major category of the Company's financial assets and liabilities measured at fair value on a recurring basis:

			Quoted Prices in			Significant Other			Significant			Total
			Active Markets			Observable Inputs			Unobservable Inputs
			for Identical			(Level 2)			(Level 3)
			Items (Level 1)
	December 31, 2014
	Assets
	Money market mutual funds		$	29,064,011		$	—		$	—		$	29,064,011
	U.S. Treasury Bonds			70,698,640									70,698,640
	Restricted cash			112,410			—			—			112,410

	Total assets		$	99,875,061		$	—		$	—		$	99,875,061


	Liabilities
	Warrants to purchase common stock		$	—		$	—		$	82,851		$	82,851

	Total liabilities		$	—		$	—		$	82,851		$	82,851


	December 31, 2013
	Assets
	U.S. Treasury Bills		$	35,551,000			—			—		$	35,551,000
	Restricted cash			112,000			—			—			112,000

	Total assets		$	35,663,000		$	—		$	—		$	35,663,000


	Liabilities
	Warrants to purchase redeemable preferred stock		$	—		$	—		$	350,519		$	350,519

Total liabilities		$	—		$	—		$	350,519		$	350,519



The following table sets forth a summary of changes in the fair value of the Company's warrant liability, which represents a recurring measurement that is classified within Level 3 of the fair value hierarchy, wherein fair value is estimated using significant unobservable inputs:

		Warrant Liability
Balance as of December 31, 2012		$	1,393,674
Amounts acquired or issued			(801,677	)
Changes in estimated fair value			(241,478	)

Balance as of December 31, 2013			350,519
Amounts acquired or issued			—
Changes in estimated fair value			(122,412	)
Amounts reclassified to additional paid-in capital			(145,256	)

Balance as of December 31, 2014		$	82,851



The money market mutual funds and U.S. Treasury Bills noted above are included in cash and cash equivalents in the accompanying balance sheets. The U.S. Treasury Bonds are included in marketable securities in the accompanying balance sheets. The Company recognizes transfers between levels of the fair value hierarchy as of the end of the reporting period. There were no transfers within the hierarchy during the years ended December 31, 2014 or 2013.
In connection with the issuance of debt, on September 19, 2014, the Company issued to the lenders and the placement agent in the transaction warrants to purchase an aggregate of 7,678 shares of the Company's common stock. These detachable warrant instruments have qualified for equity classification and have been allocated upon the relative fair value of the base instrument and the warrants, according to the guidance of ASC 470-20-25-2. See Note 7 for additional information.
In connection with the issuance and sale of the Company's Series B-1 preferred shares in 2011, the Company issued a warrant to purchase 125,000 shares of Series B preferred stock. Upon the IPO, the warrant to purchase 125,000 shares of Series B preferred stock was converted into a warrant to purchase up to 20,161 shares of the Company's common stock and remains outstanding with a fair value recorded as a liability of $82,851 at December 31, 2014 as it contains a cash settlement feature upon certain strategic transactions. See Note 8 for additional information.
The fair value of the warrants classified as liabilities on each re-measurement date is estimated using the Black-Scholes option pricing model. For this liability, the Company develops its own assumptions that do not have observable inputs or available market data to support the fair value. This method of valuation involves using inputs such as the fair value of the Company's common stock and various classes of preferred 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 is considered a Level 3 measurement. The following assumptions were used at December 31, 2014 and December 31, 2013:

		December 31,			December 31, 2013
		2014			December 31, 2013
		Common stock			Series B-1			Series B
		warrant liability			preferred stock			preferred stock
					warrant liability			warrant liability
Estimated remaining term			7.34 years			0.25 years			8.4 years
Dividend yield			0.00	%		0.00	%		0.00	%
Risk-free interest rate			1.99	%		0.38	%		2.75	%
Fair value of underlying instrument		$	5.98		$	7.00		$	7.00
Volatility			72	%		71	%		70	%

The warrant liability is recorded on its own line item on the Company's Balance Sheet and is marked-to-market at each reporting period with the change in fair value recorded on its own line in the Statement of Operations and Comprehensive Loss.

Concentration of Credit Risk and Off-Balance Sheet Risk
Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash, cash equivalents, marketable securities and restricted cash. The Company maintains its cash, and cash equivalent balances in the form of money market mutual funds that invest substantially all of their assets in U.S. government securities with financial institutions that management believes are creditworthy. The Company maintains its marketable securities balances in the form of U.S. Treasury Bonds. The Company's investment policy includes guidelines on the quality of the institutions and financial instruments and defines allowable investments that the Company believes minimizes the exposure to concentration of credit risk.
The Company routinely assesses the creditworthiness of its collaborators. The Company has not experienced any material losses related to receivables from collaborators. The Company does not require collateral from its collaborators.
The Company has not recognized any losses from credit risks on such accounts since inception. The Company believes it is not exposed to significant credit risk on cash.

Segment 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 the chief executive officer. The Company and the chief executive officer view the Company's operations and manage its business as one operating segment. All long-lived assets of the Company reside in the United States.

Revenue
The Company recognizes grant revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed and determinable, and collectibility is reasonably assured. The Company recognizes revenue under grants in earnings in the period in which the related expenditures are incurred. The Company recognizes collaboration revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed and determinable, and collectibility is reasonably assured.

Research and Development
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 our 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.
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.
As part of the process of preparing its financial statements, the Company is required to estimate its expenses resulting from its obligations under contracts with vendors, clinical research organizations and consultants and under clinical site agreements in connection with conducting clinical trials. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided under such contracts. The Company's objective is to reflect the appropriate trial expenses in its financial statements by matching those expenses with the period in which services are performed and efforts are expended. The Company accounts for these expenses according to the progress of the trial as measured by subject progression and the timing of various aspects of the trial. The Company determines accrual estimates through financial models taking into account discussion with applicable personnel and outside service providers as to the progress or state of consummation of trials, or the services completed. During the course of a clinical trial, the Company adjusts its clinical expense recognition if actual results differ from its estimates. The Company makes estimates of its accrued expenses as of each balance sheet date based on the facts and circumstances known to it at that time. The Company's clinical trial accruals are dependent upon the timely and accurate reporting of contract research organizations and other third-party vendors. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its 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 it reporting amounts that are too high or too low for any particular period. For the years ended December 31, 2014 and 2013, there were no material adjustments to the Company's prior period estimates of accrued expenses for clinical trials.

Stock-Based Compensation
At December 31, 2014, the Company had one stock-based compensation plan, which is more fully described in Note 9. The Company accounts for stock-based compensation in accordance with the provisions of ASC Topic 718, Compensation—Stock Compensation ("ASC 718"), which requires the recognition of expense related to the fair value of stock-based compensation awards in the Statements of Operations and Comprehensive Loss.
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 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 accelerated attribution 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.
Share-based payments issued to non-employees are recorded at their fair values, and are periodically revalued as the equity instruments vest and are recognized as expense over the related service period in accordance with the provisions of ASC 718 and ASC Topic 505, Equity. See Note 9 for a discussion of the assumptions used by the Company in determining the grant date fair value of options granted under the Black-Scholes option pricing model, as well as a summary of the stock option activity under the Company's stock-based compensation plan for the years ended December 31, 2014 and 2013.

Income Taxes
Income taxes are recorded in accordance with ASC Topic 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. As of December 31, 2014 and 2013, the Company does not have any significant uncertain tax positions.

Comprehensive Loss
Comprehensive loss is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Comprehensive loss relates to unrealized investment losses on the Company's marketable securities for the year ended December 31, 2014. Comprehensive loss was equal to net loss for the year ended December 31, 2013.
Basic and Diluted Net Loss Per Share of Common Stock
Basic net loss per share of common stock is computed by dividing net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, excluding the dilutive effects of preferred stock, warrants to purchase preferred stock and stock options. Diluted net loss per share of common stock is computed by dividing the net loss attributable to common stockholders by the sum of the weighted-average number of shares of common stock outstanding during the period plus the potential dilutive effects of preferred stock and warrants to purchase preferred stock, and stock options outstanding during the period calculated in accordance with the treasury stock method, although these shares, options and warrants are excluded if their effect is anti-dilutive. Because the impact of these items is anti-dilutive during periods of net loss, there was no difference between basic and diluted net loss per share of common stock for the years ended December 31, 2014 and 2013.
Recent Accounting Pronouncements
In February 2013, FASB issued ASU No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income (“ASU 2013-02”). ASU 2013-02 requires companies to present either in a single note or parenthetically on the face of the financial statements, the effect of significant amounts reclassified from each component of accumulated other comprehensive income based on its source and the income statement line items affected by the reclassification. This guidance is effective for annual reporting periods beginning January 1, 2013. The adoption of this standard by the Company for the fiscal year beginning January 1, 2013 did not have a significant impact on our financial position, results of operations or cash flows.
On June 10, 2014, FASB issued ASU No. 2014-10, Development Stage Entities (Topic 915): Elimination of Certain Financial Reporting Requirements, Including an Amendment to Variable Interest Entities Guidance in Topic 810, Consolidation ("ASU 2014-10"). ASU 2014-10 eliminates the accounting and reporting differences in U.S. GAAP between development stage entities and other operating entities, including the presentation of inception-to-date financial statement information and the development stage entity financial statement label. FASB guidance related to Risks and Uncertainties and FASB guidance utilized to determine if an entity is a variable interest entity now applies to entities that have not commenced planned principal operations. These changes will provide more consistent consolidation analysis and decisions among reporting entities. While these amendments are retrospectively effective for annual reporting periods beginning after December 15, 2014, early adoption is permitted for any annual reporting period or interim period for which the entity's financial statements have not yet been issued. The Company has elected early adoption in the current period. The Company's adoption of this standard did not have a significant impact on its financial position, results of operations or cash flows.
In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements-Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern, which defines management's responsibility to assess an entity's ability to continue as a going concern, and to provide related footnote disclosures if there is substantial doubt about its ability to continue as a going concern. The pronouncement is effective for annual reporting periods ending after December 15, 2016 with early adoption permitted. The adoption of this guidance is not expected to have a material impact on the Company's financial statements.

Net_Loss_Per_Common_Share

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

		Year Ended December 31,
		2014			2013
	Basic and diluted net loss per common share calculation:
	Net loss	$	(49,700,875	)		(23,251,435	)
	Accretion of redeemable convertible preferred stock		(28,521	)		(333,710	)

	Net loss attributable to common stockholders	$	(49,729,396	)	$	(23,585,145	)


	Weighted average common shares outstanding		24,655,603			793,806


	Net loss per share of common stock—basic and diluted	$	(2.02	)	$	(29.71	)


	The following outstanding securities at December, 31, 2014 and 2013 have been excluded from the computation of diluted weighted shares outstanding, as they would have been anti-dilutive:

		December 31,
		2014			2013
	Redeemable convertible preferred stock		—			15,707,986
	Options outstanding		3,574,450			2,795,746
	Warrants		30,258			199,996

	Total		3,604,708			18,703,728

Comprehensive_Loss

Comprehensive Loss	12 Months Ended
Comprehensive Loss	Dec. 31, 2014
Comprehensive Loss
Comprehensive Loss
	4. Comprehensive Loss
	The following table presents changes in the components of accumulated other comprehensive income or loss, net of tax:

	Balance, January 1, 2014	$	—
	Net unrealized loss arising during the period		18,782

	Balance, December 31, 2014	$	18,782


	There were no reclassifications out of accumulated other comprehensive income or loss during the year ended December 31, 2014. There was no tax effect during the year ended December 31, 2014.

Property_and_Equipment

Property and Equipment	12 Months Ended
Property and Equipment	Dec. 31, 2014
Property and Equipment
Property and Equipment
	5. Property and Equipment
	Property and equipment consisted of the following:

		December 31,
		2014			2013
	Laboratory equipment	$	1,616,420			1,853,685
	Computers and software		554,658			509,109
	Office equipment and furniture		270,845			193,781
	Leasehold improvements		1,986,156			1,718,922
	Leased assets		14,259			—

	Total property and equipment		4,442,338			4,275,497
	Less accumulated depreciation and amortization		(3,889,044	)		(3,932,438	)

	Property and equipment, net	$	553,294		$	343,059


	Depreciation and amortization expense was $239,390 and $706,779 for the years ended December 31, 2014 and 2013, respectively.

Accrued_Expenses_and_Other_Cur

Accrued Expenses and Other Current Liabilities	12 Months Ended
Accrued Expenses and Other Current Liabilities	Dec. 31, 2014
Accrued Expenses and Other Current Liabilities
Accrued Expenses and Other Current Liabilities
	6. Accrued Expenses and Other Current Liabilities
	Accrued expenses and other current liabilities consisted of the following:

		December 31,
		2014		2013
	Compensation and benefits	$	1,628,102	$	859,444
	Clinical trial fees		846,199		762,687
	Other research and development expenses		96,088		507,845
	Professional services		—		24,005
	Other accrued expenses and other current liabilities		7,880		4,811

	Total accrued expenses and other current liabilities	$	2,578,269	$	2,158,792

Long_Term_Debt

Long Term Debt	12 Months Ended
Long Term Debt	Dec. 31, 2014
Long Term Debt.
Long Term Debt
	7. Long Term Debt
	Debt Outstanding at December 31, 2014
	On September 19, 2014, the Company entered into a loan and security agreement with Oxford Finance LLC, as collateral agent and lender and Square 1 Bank, as lender pursuant to which the lenders have agreed to lend the Company up to $35.0 million in a series of term loans. Upon entering into the agreement, the Company borrowed $2.0 million from the lenders ("Term Loan A"). The Company may, at its sole discretion, borrow from the lenders:
	•	an additional $16.5 million, at any time on or before June 30, 2015 ("Term Loan B") since the Company has satisfied specified conditions precedent related to the results of the Company's ongoing Phase 2 studies of TRV130; and
	•	an additional $16.5 million, at any time on or before March 31, 2016 ("Term Loan C" and together with Term Loan A and Term Loan B, the "Term Loans"), subject to the Company's satisfaction of specified conditions precedent related to the results of the Company's ongoing Phase 2 studies of TRV027.
	The proceeds from Term Loan A and future proceeds, if any, from Term Loan B and/or Term Loan C may be used to satisfy the Company's future working capital needs, potentially including the development of its clinical and preclinical product candidates.
	The Company's obligations under the loan and security agreement are secured by a first priority security interest in substantially all of the assets of the Company, other than intellectual property. The Company has agreed not to pledge or otherwise encumber its intellectual property, other than through grants of certain permitted non-exclusive or exclusive licenses or other conveyances of its intellectual property.
	The term loans will accrue interest at a fixed rate of 6.50% per annum. The Company is required to make payments of interest only on Term Loan A on a monthly basis through and including April 1, 2016—extended from October 1, 2015, since the Company has satisfied specified conditions precedent related to the results of the Company's recently concluded Phase 2 bunionectomy study of TRV130—after which consecutive equal monthly payments of principal, plus accrued interest, will be due until December 1, 2018. Both of these dates may be modified further with respect to the term loans, as applicable, as follows:
	•	If the Company meets the conditions to draw Term Loan C on or before March 31, 2016, then the date until which the Company is required to make payments of interest only will be extended from April 1, 2016 to October 1, 2016.
	•	If the Company meets the condition to draw Term Loan C on or before March 31, 2016, and the Company has received net cash proceeds of at least $50,000,000 from its existing strategic partnership and collaborative license option agreement with Actavis or another strategic partnership in form and substance satisfactory to the lenders, then the date until which consecutive equal monthly payments of principal, plus accrued interest, will be due will be extended from December 1, 2018 to September 1, 2019.
	The Company has paid the lenders a facility fee of $175,000 in connection with the execution of the loan and security agreement. Upon the last payment date of the amounts borrowed under the agreement, the Company will be required to pay the lenders a final payment fee equal to 6.1% of the term loans borrowed—increased from 5.25% since the Company has satisfied specified conditions precedent related to the results of the Company's recently concluded Phase 2 bunionectomy study of TRV130—and subject to further adjustment as follows:
	•	If the Company further meets the condition to draw Term Loan C on or before March 31, 2016, then the Company will be required to pay the lenders a final payment fee equal to 6.6% of the term loans borrowed; and
	•	If the Company further meets the condition to draw Term Loan C on or before March 31, 2016, and the Company has received net cash proceeds of at least $50,000,000 from its existing strategic partnership and collaborative license option agreement with Actavis or another strategic partnership in form and substance satisfactory to the lenders, then the Company will be required to pay the lenders a final payment fee equal to 7.0%.
	In addition, if the Company repays the term loans before the applicable maturity date, it will pay the lenders a prepayment fee of 3.00% of the total amount prepaid if the prepayment occurs prior to the first anniversary of the funding of the applicable term loan, 2.00% percent of the total amount prepaid if the prepayment occurs between the first and second anniversary of the funding of the applicable term loan, and 1.00% percent of the total amount prepaid if the prepayment occurs on or after the second anniversary of the funding of the applicable term loan.
	The loan and security agreement includes affirmative and restrictive covenants, including: (a) financial reporting requirements; (b) limitations on the incurrence of indebtedness; (c) limitations on liens; (d) limitations on certain merger and acquisition transactions; (e) limitations on dispositions of certain assets; (f) limitations on fundamental corporate changes (including changes in control); (g) limitations on investments; (h) limitations on payments and distributions and (i) other covenants. The agreement also contains certain events of default, including for payment defaults, breaches of covenants, a material adverse change in the collateral, the Company's business, operations or condition (financial or otherwise), certain levies, attachments and other restraints on the Company's business, insolvency, defaults under other agreements and misrepresentations.
	Three Point Capital, LLC served as a placement agent in connection with the term loans. The Company paid Three Point $65,000 upon execution of the loan and security agreement and will be obligated to pay up to an additional $175,000 if the Company draws on Term Loan B and Term Loan C.
	In connection with entering into the loan and security agreement, the Company issued to each of Oxford, Square 1 and Three Point warrants to purchase shares of the Company's common stock. The warrants are exercisable, in whole or in part, immediately, and have a per share exercise price of $5.8610, which is the average closing price of the Company's common stock on the NASDAQ Global Market for the ten trading days prior to the effective date of the agreement. The warrants may be exercised on a cashless basis. The warrants will terminate on the earlier of September 19, 2024 or the closing of a merger or consolidation transaction in which the Company is not the surviving entity. If the Company borrows Term Loan B and/or Term Loan C, upon the funding of such Term Loan, the Company will issue additional warrants to purchase shares of the Company's common stock, each with a per share exercise price of $5.8610 and on substantially the same terms as those contained in the warrants. The number of warrants issued or issuable by the Company is as follows:

	Entity		Shares Underlying Warrants			Maximum Number of Shares		Maximum Number of Shares
			Issued on the Effective Date			Underlying Warrants Issuable		Underlying Warrants Issuable
						Assuming Full Draw of Term		Assuming Full Draw of Term
						Loan B		Loan C
	Oxford			4,875			40,217		40,217
	Square 1			1,950			16,087		16,087
	Three Point			853			7,038		7,038

	In connection with the issuance of debt, on September 19, 2014, the Company issued to the lenders and the placement agent in the transaction warrants to purchase an aggregate of 7,678 shares of the Company's common stock. These detachable warrant instruments have qualified for equity classification and have been allocated upon the relative fair value of the base instrument and the warrants, according to the guidance of ASC 470-20-25-2. The maximum aggregate number of shares underlying additional warrants that can be issued by the Company to the lenders under the loan and security agreement and to Three Point under the placement agent arrangement is 126,685.
	As of December 31, 2014, only Term Loan A has been issued, all of which remains outstanding as of such date. The initial maturity date is December 1, 2018 and the loan bears interest at an annual rate of 6.5%. The loan is not convertible and is secured by substantially all of the Company's assets. Interest expense of $36,833 was recorded since inception in September 2014, excluding the amortization of debt discount.
	The Company incurred lender and third party costs of $0.2 million and $0.1 million, respectively, related to the issuance of Term Loan A. The lender costs are classified as a debt discount, a contra-liability on our balance sheet. The third party costs are classified as deferred financing fees, an asset on our balance sheet. Both the debt discount and deferred financing fees will be amortized over the life of the Term Loan using the effective interest method.
	The following table summarizes how the issuance of Term Loan A is reflected on the balance sheet at December 31, 2014:

			December 31,
			2014
	Gross proceeds		$	2,000,000
	Debt discount			(208,715	)

	Carrying value		$	1,791,285



	Debt Outstanding at December 31, 2013
	In December 2011, the Company entered into a loan facility with Comerica Bank (the “Comerica Facility”). Interest expense related to the Comerica Facility was $64,292 for the year ended December 31, 2013. Amortization expense of deferred financing costs was $42,047 for the year ended December 31, 2013. On May 3, 2013, the Company used a portion of the proceeds from the Series C Preferred Stock (Note 8) to repay the remaining Comerica Facility outstanding balance of $4,073,485, including unpaid interest and fees.
	In connection with the borrowings under the Comerica Facility, the Company issued a ten-year warrant to purchase 125,000 shares of Series B preferred stock at $1.00 per share, exercisable through December 2021. The Company recorded a total of $101,707 as debt discount related to the estimated fair value of the preferred stock warrants issued, with a corresponding credit to the warrant liability. The debt discount was being amortized to interest expense over the term of the Comerica Facility. Interest expense related to the amortization of the debt discount was $78,460 for the year ended December 31, 2013.

Stockholders_Equity_Deficit

Stockholders' Equity (Deficit)	12 Months Ended
	Dec. 31, 2014
Stockholders' Equity (Deficit)
Stockholders' Equity (Deficit)
	8. Stockholders' Equity (Deficit)
	Common Stock
	On December 10, 2014, the Company issued and sold 11,250,000 shares of common stock in a public offering of shares as well as 1,598,000 shares of common stock pursuant to the partial exercise of the underwriters' over-allotment option for a total of 12,848,000 shares at a price of $4.00 per share, for aggregate gross proceeds of approximately $51.4 million.
	On February 5, 2014, the Company issued and sold 9,250,000 shares of common stock in an IPO at a price of $7.00 per share, for aggregate gross proceeds of approximately $64.8 million. On March 6, 2014, in connection with the partial exercise of the IPO underwriters' over-allotment option, the Company sold an additional 270,449 shares of common stock at a price of $7.00 per share, for aggregate gross proceeds of approximately $1.9 million.
	As of December 31, 2013, the Company had outstanding the following redeemable convertible preferred stock that converted into common shares on a one-for-6.2 basis upon consummation of the Company's IPO:

		Preferred		Conversion
		Shares		into Common
		Outstanding		Shares upon
				IPO
	Series A		25,074,999		4,044,354
	Series B		30,800,000		4,967,741
	Series B-1		4,750,000		766,129
	Series C		36,764,704		5,929,789

	Total		97,389,703		15,708,013


	In connection with the issuance of the Company's Series B-1 preferred shares in 2011, the Company issued warrants to purchase 1,650,000 shares of the Company's Series B-1 Preferred Stock. Additionally, in connection with a banking facility entered into in 2011, the Company issued a warrant to purchase 125,000 shares of Series B preferred stock. As of December 31, 2013, the fair value of the warrants outstanding of $350,519 was recognized as a liability in the Company's balance sheet. Upon the Company's IPO, 1,100,000 of the outstanding Series B-1 warrants were net exercised into 20,273 shares of common stock and the remaining fair value of $145,256 associated with these particular warrants was reclassified to additional paid-in capital. The warrant to purchase 125,000 shares of Series B preferred stock was converted into a warrant to purchase up to 20,161 shares of the Company's common stock and remains outstanding with a fair value recorded as a liability of $82,851 at December 31, 2014 as it contains a cash settlement feature upon certain strategic transactions.
	Under its certificate of incorporation, the Company was authorized to issue up to 100,000,000 and 132,000,000 shares of common stock as of December 31, 2014 and December 31, 2013, respectively. The Company also was authorized to issue up to 5,000,000 shares of preferred stock as of December 31, 2014. The Company is required, at all times, to reserve and keep available out of its authorized but unissued shares of common stock sufficient shares to effect the conversion of the shares of the preferred stock and all outstanding stock options and warrants.
	Preferred Stock
	As part of the IPO, on February 5, 2014, all of the Company's outstanding convertible preferred stock was converted and all but 22,580 of its outstanding warrants were net exercised into an aggregate of 15,728,286 shares of common stock.
	On January 4, 2008, the Company authorized the sale and issuance of up to 25,000,000 shares of Series A Convertible Preferred Stock (the Series A). On January 7, 2008, the Company completed the first closing of its sale of the Series A and issued 501,562 shares at $1.00 per share generating gross proceeds of $501,562. On January 31, 2008, the Company completed a second closing of its sale of the Series A and issued an additional 4,514,062 shares at $1.00 per share generating gross proceeds of $4,514,062. Costs associated with these offerings were $200,137. In September 2008, the Company completed a third closing of its sale of the Series A and issued an additional 8,025,000 shares at $1.00 per share generating gross proceeds of $8,025,000. Costs associated with this offering were $2,154. On June 30, 2009, the Company completed a fourth closing of its sale of the Series A and issued 11,034,375 shares at $1.00 per share generating gross proceeds of $11,034,375. Costs associated with this offering were $561. On November 16, 2009, the Company amended the stock purchase agreement associated with the Series A financing and issued an additional 1,000,000 shares at $1.00 per share generating gross proceeds of $1,000,000. Costs associated with this offering were $3,398. All offering costs associated with the Series A were being accreted into the carrying value of the Series A until its conversion upon IPO.
	On July 8, 2010, the Company authorized the sale and issuance of up to 35,000,000 shares of Series B Preferred Stock (the Series B) and up to 4,300,000 of Series B-1 Preferred Stock (the Series B-1). In connection with the authorization of the Series B and the Series B-1, the Company also authorized the sale and issuance of warrants to purchase up to 1,700,000 shares of the Series B-1 (the Series B-1 Warrants). On July 8, 2010, the Company completed the first closing of its sale of the Series B and issued 17,500,000 shares at $1.00 per share generating gross proceeds of $17,500,000. Costs associated with this offering were $38,568. On July 8, 2011, the Company completed its second closing, issuing 5,700,000 shares of its Series B at $1.00 per share and 1,800,000 shares of its Series B-1 at $1.00 per share. Costs associated with this offering were $8,229. On December 15, 2011, the Company completed its third closing issuing 7,600,000 shares of its Series B at $1.00 per share and 2,400,000 shares of its Series B-1 at $1.00 per share. Costs associated with this offering were $4,989. All offering costs associated with the Series B and Series B-1 were being accreted into the carrying value of the preferred stock until its conversion upon IPO.
	In connection with the issuance of the Series B-1 shares in the second and third closings, the Series B-1 shareholders received ten-year warrants to purchase a total of 1,650,000 shares of the Company's Series B-1 Preferred Stock at an exercise price of $1.00 per share. The estimated fair value of the preferred stock warrants on the dates of issuance of $1,347,428 was recorded as a reduction to the carrying value of the Series B-1 Preferred stock and was being accreted into the carrying value of the Series B-1 until its conversion upon IPO. The preferred stock warrants were recorded as a liability pursuant to the guidance for accounting for certain financial instruments with characteristics of both liabilities and equity and are revalued at each reporting period to reflect any changes in fair value. In November 2013, one of the Company's warrant holders exercised its warrants to purchase 550,000 shares of the Company's Series B preferred stock. Of the remaining 1,225,000 outstanding warrants to purchase preferred stock at December 31, 2013, 1,100,000 were net exercised immediately prior to the consummation of the Company's initial public offering in February 2014. Upon consummation of the Company's initial public offering, the remaining warrant to purchase up to 125,000 shares of the Company's Series B preferred stock was converted into a warrant to purchase up to 20,161 shares the Company's common stock, and the fair value of the warrant liability at that time was reclassified to additional paid-in capital.
	In May, 2013, the Company authorized the sale and issuance of up to 37,000,000 shares of Series C Preferred Stock (the Series C). On May 3, 2013, the Company completed the closing of its sale of the Series C and issued 36,764,704 shares at $1.632 per share generating gross proceeds of $59,999,997. Costs associated with this offering were $81,080. All offering costs associated with the Series C were recorded as a discount and were being accreted into the carrying value of the Series C until its conversion upon IPO.
	Each share of the Series A, the Series B, the Series B-1 and the Series C preferred stock was convertible into approximately 0.1613 shares of common stock at any time at the option of the holder. The preferred stock was automatically convertible in the event of (i) an initial public offering at a price of at least $4.00 per share of common stock (subject to adjustment to reflect stock splits, stock dividends, stock combinations, recapitalizations and like occurrences) and net proceeds to the Company of at least $40 million; or (ii) the affirmative vote or written consent of the holders of at least 60% of shares of the preferred stock then outstanding. Each share of Series A, B or B-1 preferred stock was also subject to a special mandatory conversion feature. In the event that any holder of shares of Series A, B or B-1 preferred stock did not participate in a Qualified Financing (as defined in the Company's Certificate of Incorporation) by purchasing, in the aggregate, in such Qualified Financing and within the time period specified by the Company, such holder's pro rata amount, then such holder's shares of preferred stock would automatically convert into common stock at the respective Conversion Price (as defined). The Company evaluated each series of its Preferred Stock and determined that each individual series was considered an equity host under ASC 815. As a result of the Company's conclusion that the Preferred Stock represented an equity host, the conversion feature of all series of Preferred Stock was considered to be clearly and closely related to the associated Preferred Stock host instrument. Accordingly, the conversion feature of all series of Preferred Stock was not considered an embedded derivative that required bifurcation. The Company accounted for potential beneficial conversion features under FASB ASC Topic 470-20, Debt with Conversion and Other Options. At the time of each of the issuances of Preferred Stock, the Company's common stock into which each series of the Company's Preferred Stock is convertible had an estimated fair value less than the effective conversion prices of the Preferred Stock. Therefore, there was no intrinsic value on the respective commitment dates.
	Holders of the preferred stock were entitled to receive non-cumulative dividends at the rate of 8% of the applicable purchase price per share per annum if and when declared by the board of directors. No dividends were declared through conversion upon IPO.
	Holders of the preferred stock, voting as a class, were entitled to elect five members of the board of directors.
	Holders of the Series A, the Series B, and the Series B-1 were entitled to a liquidation preference in an amount equal to $1.00 per share plus all declared and unpaid dividends in the event of a liquidation, dissolution, or winding-up of the Company, or in the event the Company merged with or was acquired by another entity. Holders of the Series C were entitled to a liquidation preference in an amount equal to $1.632 per share plus all declared and unpaid dividends in the event of a liquidation, dissolution, or winding-up of the Company, or in the event the Company merged with or ws acquired by another entity.
	At any time on or after July 8, 2016, the holders of at least 60% of the outstanding shares of the preferred stock may have required the Company to redeem, in three annual installments beginning on the date of the initial redemption, all of the outstanding shares of the preferred stock for an amount equal to the original issue price per share plus any declared and unpaid dividends.

2008_and_2013_Equity_Incentive

2008 and 2013 Equity Incentive Plans	12 Months Ended
2008 and 2013 Equity Incentive Plans	Dec. 31, 2014
2008 and 2013 Equity Incentive Plans
2008 and 2013 Equity Incentive Plans
	9. 2008 and 2013 Equity Incentive Plans
	In January 2008, the Company adopted the 2008 Equity Incentive Plan, as amended on February 29, 2008, January 7, 2010, July 8, 2010, December 10, 2010, June 23, 2011 and June 17, 2013 (collectively, the “2008 Plan”) that authorized the Company to grant up to 3,310,990 shares of common stock to eligible employees, directors and consultants to the Company, in the form of restricted stock and stock options.
	In 2013, the Company adopted the 2013 Equity Incentive Plan, as amended on May 14, 2014 (collectively, the “2013 Plan”), that reserves for issuance under the plan up to 1,711,290 shares of common stock. The 2013 Plan contains an "evergreen" provision, pursuant to which the number of shares of common stock available for issuance under the plan will automatically increase on January 1 of each year beginning in 2015. The 2013 plan became effective upon the January 2014 IPO and, as of such date, the Company may not make further grants under the 2008 plan. The 2013 plan provides for the grant of incentive stock options, or ISOs, nonstatutory stock options, or NSOs, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance-based stock awards and other forms of equity compensation (collectively, stock awards), all of which may be granted to employees, including officers, non- employee directors and consultants of the Company. Additionally, the 2013 plan provides for the grant of cash and stock based performance awards.
	Under both the 2008 and 2013 Plans, the amount, terms of grants and exercisability provisions are determined by the board of directors or its designee. The term of the options may be up to 10 years, and options are exercisable in cash or as otherwise determined by the board of directors. Vesting generally occurs over a period of not greater than four years.
	The estimated grant-date fair value of the Company's share-based awards is amortized ratably over the awards' service periods. Share-based compensation expense recognized was as follows:

			Year Ended
			December 31,
			2014			2013
	Research and development		$	1,129,244		$	609,483
	General and administrative			1,254,155			318,513

	Total stock-based compensation		$	2,383,399		$	927,996




						Options Outstanding
			Shares			Number			Weighted-		Weighted
			Available			of Shares			Average		Average
			for Grant						Exercise		Remaining
									Price		Contractual
											Term (in years)
	Balance, December 31, 2012			171,803			1,523,156		$	0.56		7.89
	Authorized			1,459,514			—
	Granted			(1,730,156	)		1,730,156			3.73
	Exercised			—			(275,262	)		0.3
	Forfeitures			182,304			(182,304	)		0.95

	Balance, December 31, 2013			83,465			2,795,746		$	2.52		8.45
	Authorized			1,711,290			—
	Granted			(1,095,042	)		1,095,042			6.75
	Exercised			—			(186,687	)		0.6
	Forfeitures			129,651			(129,651	)		7.2

	Balance, December 31, 2014			829,364			3,574,450		$	3.75		8.06


	Vested or expected to vest at December 31, 2014						3,528,809		$	3.71		8.05


	Exercisable at December 31, 2014						1,602,623		$	2.26		7.1


	The intrinsic value of the options exercisable as of December 31, 2014 was $6.4 million, based on the Company's closing stock price of $5.98 per share and a weighted average exercise price of $2.26 per share.
	The Company uses the Black-Scholes option-pricing model to estimate the fair value of stock options at the grant date. The Black-Scholes model requires the Company to make certain estimates and assumptions, including estimating the fair value of the Company's common stock, 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 per-share weighted-average grant date fair value of the options granted to employees and directors during the year ended December 31, 2014 and 2013 was estimated at $4.43 and $2.52 per share, respectively, on the date of grant using the Black-Scholes option-pricing model with the following weighted-average assumptions:

			Year Ended			Year Ended
			December 31,			December 31,
			2014			2013
	Risk-free interest rate			1.80	%		1.52	%
	Expected term of options (in years)			5.8			6.1
	Expected volatility			75.9	%		80.5	%
	Dividend yield			0	%		0	%
	The weighted-average valuation assumptions were determined as follows:
	•	Risk-free interest rate: The Company based the risk-free interest rate on the interest rate payable on U.S. Treasury securities in effect at the time of grant for a period that is commensurate with the assumed expected option term.
	•	Expected term of options: Due to its lack of sufficient historical data, the Company estimates the expected life of its employee stock options using the "simplified" method, as prescribed in Staff Accounting Bulletin (SAB) No. 107, whereby the expected life equals the arithmetic average of the vesting term and the original contractual term of the option.
	•	Expected stock price volatility: The Company estimated the expected volatility based on actual historical volatility of the stock price of similar companies with publicly-traded equity securities. The Company calculated the historical volatility of the selected companies by using daily closing prices over a period of the expected term of the associated award. The companies were selected based on their enterprise value, risk profiles, position within the industry and with historical share price information sufficient to meet the expected term of the associated award. A decrease in the selected volatility would have decreased the fair value of the underlying instrument.
	•	Expected annual dividend yield: The Company estimated the expected dividend yield based on consideration of its historical dividend experience and future dividend expectations. The Company has not historically declared or paid dividends to stockholders. Moreover, it does not intend to pay dividends in the future, but instead expects to retain any earnings to invest in the continued growth of the business. Accordingly, the Company assumed an expected dividend yield of 0.0%.
	•	Estimated forfeiture rate: The Company's estimated annual forfeiture rate on 2014 and 2013 stock option grants was 7% and 5%, respectively, based on the historical forfeiture experience.
	The fair value of the Company's common stock, prior to the Company's initial public offering, was determined by its board of directors with assistance from its management. The board of directors and management considered numerous objective and subjective factors in the assessment of fair value, including the price for the Company's preferred stock that was sold to investors and the rights, preferences and privileges of the preferred stock and common stock, the Company's financial condition and results of operations during the relevant periods and the status of strategic initiatives. These estimates involved a significant level of judgment.
	As of December 31, 2014, there was $6.1 million of total unrecognized compensation expense related to unvested options that will be recognized over the weighted average remaining period of 2.87 years.
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			3,574,450
Common stock options and restricted stock available for future grant (2013 Plan)			829,364
Common stock warrants outstanding			30,258

			4,434,072

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies.
Commitments and Contingencies
	10. Commitments and Contingencies
	Licenses
	On May 3, 2013, the Company entered into an option agreement and a license agreement with Actavis plc (formerly Forest Laboratories Holdings Limited), under which the Company granted to Actavis an exclusive option to license its product candidate, TRV027. If Actavis exercises this option, the license agreement between the Company and Actavis will become effective and Actavis will have an exclusive worldwide license to develop and commercialize TRV027 and specified related compounds. At the Company's request, Actavis will consider in good faith whether to grant the Company the right to co-promote the licensed products in the United States under the terms ot be agreed upon by the parties. Actavis will be responsible for subsequent development, regulatory approval and commercialization of TRV027 at Actavis' sole cost and expense.
	Under the option agreement, the Company is conducting, at its expense, a Phase 2b trial of TRV027 in acute heart failure, or AHF. Actavis may exercise its option during the pendency of the Phase 2b clinical trial or during a specified time period after the Company delivers the data from the Phase 2b clinical trial to Actavis. During the option period, the Company is not permitted to negotiate for or enter into any agreement with a third party for the development and commercialization of TRV027 and its related compounds. Under specified circumstances linked to adverse changes in the market or related to the results from the Phase 2b trial of TRV027, Actavis has the right to renegotiate the terms of the license agreement. If Actavis exercises such right, the Company will be obligated to negotiate in good faith with Actavis for a period of time the terms of any new arrangement. If the Company and Actavis are unable to agree on the terms of any new arrangement, then the option agreement will terminate and for a specified period of time thereafter the Company may not offer a license to any third party on terms better than those last proposed by either the Company or Actavis during the negotiations.
	If Actavis does not exercise its option during the specified period, the option will expire and the license agreement will not become effective. In that case, the Company would be free to enter into a collaboration arrangement with another party for the development and commercialization of TRV027 or to pursue development and commercialization on its own. The Company received no consideration upon the grant of the option to Actavis. If Actavis exercises the option, the Company would receive a $65 million option exercise fee and could potentiall receive up to $365 million depending upon the achievement of future development and commercial milestones. The Company also could receive tiered royalties between 10% and 20% on net sales of licensed products worldwide, with the royalty rates on net sales of licensed products in the United States being somewhat higher than the royalty rates on net sales of licensed products outside the United States. The term of the royalty on sales of TRV027 for a given country would extend until the latest to occur of (i) 10 years from first commercial sale of TRV027 in that country, (ii) the expiration of the last to expire patent claiming TRV027 that is sufficient to block the entrance of a generic version of the product, or (iii) the expiration of any period of exclusivity granted by applicable law or any regulatory authority in such country that confers exclusive marketing rights on the product.
	If the license agreement becomes effective, Actavis has the right to grant sublicenses under the license agreement to affiliates and third parties. Any sublicensing does not act to relieve Actavis of any of its obligations under the license agreement, including Actavis' obligation to make milestone payments to the Company with respect to TRV027 or pay royalties to the Company on sales of TRV027 by such sublicensee. Under the license, both Actavis and the Company have the right to terminate the agreement in the event of an uncured material breach or insolvency of the other party. In addition, Actavis is permitted to terminate the license agreement without cause at any time upon prior written notice or immediately for product safety reasons. Following a termination of the license agreement, all licenses granted to Actavis would terminate, and Actavis would grant the Company an exclusive royalty bearing license under specified patents and know-how to develop and commercialize reverted licensed products. If not terminated, the license agreement would remain in effect until the expiration of the last royalty term for the last licensed product.
	Actavis participated in the Series C Preferred Stock financing and purchased $30 million of Series C Preferred Stock. Because the Series C Preferred Stock was acquired at the same time as the option agreement, management considered whether the Preferred Stock was issued at fair value and if not, whether the consideration received for the Preferred Stock should be allocated in the financial statements in a manner differently than the price stated in the agreement. The Series C Preferred Stock acquired by Actavis was acquired at the same time and at the same price per share as all of the other investors in the Series C Preferred Stock financing and therefore the preferred stock sold to Actavis was deemed to be issued at fair value and no value was allocated to the option agreement. The Series C Preferred Stock held by Actavis was converted into common shares on a one-for-6.2 basis upon consummation of the Company's IPO.
	Operating Leases
	The Company leases office and laboratory space in Pennsylvania. The Company's leases contain escalating rent clauses, which require higher rent payments in future years. The Company expenses rent on a straight-line basis over the term of the lease, including any rent-free periods. In July 2013, the Company extended the lease for the Company's office and laboratory lease in Pennsylvania until September 2020. In March 2014, the Company extended the square footage of the lease. The Company has the option to terminate the lease after May 31, 2018 with a required termination payment of $150,000. In addition, the Company leases vivarium space in Pennsylvania. The vivarium lease can be terminated at any time upon 90 days' written notice by the Company.
	Rent expense under operating leases was $489,810 and $459,288 in 2014 and 2013, respectively.
	Future minimum lease payments, including termination fees, under noncancelable lease agreements as of December 31, 2014, are as follows:

		Operating
		Lease
	2015	$	262,352
	2016		269,631
	2017		276,909
	2018		284,188
	2019 and beyond		514,691

	Total minimum lease payments	$	1,607,771


	The Company had deferred rent of $320,244 and $347,033 at December 31, 2014 and 2013, respectively. This balance related entirely to the Pennsylvania office and laboratory lease.
	Legal Proceedings
	The Company is not involved in any legal proceeding that it expects to have a material effect on its business, financial condition, results of operations and cash flows.

Income_Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2014
Income Taxes
Income Taxes
	11. Income Taxes
	The Company provides for income taxes under ASC 740. Under ASC 740, the liability method is used in accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities, and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse.
	The Company did not record a current or deferred income tax expense or benefit since its inception.
	The Company's loss before income taxes was $49.7 million and $23.3 million for the years ended December 31, 2014 and 2013, respectively, and was generated entirely in the United States.
	Deferred taxes are recognized for temporary differences between the basis of assets and liabilities for financial statement and income tax purposes. The significant components of the Company's deferred tax assets are the following:

		December 31,
		2014			2013
	Deferred tax assets:
	Net operating losse carryforwards	$	9,245,934		$	5,159,176
	Research and development credits		5,101,755			2,801,924
	Research and development expenses capitalized for tax purposes		43,038,057			26,936,217
	Deferred rent		129,998			140,873
	Depreciation		476,799			652,104
	Other temporary differences		458,413			628,296

	Total deferred tax assets		58,450,956			36,318,590
	Deferred tax liabilities:
	Prepaid expenses		(90,385	)		(80,311	)

	Total deferred tax liabilities		(90,385	)		(80,311	)

	Net deferred tax assets		58,360,571			36,238,279
	Less valuation allowance		(58,360,571	)		(36,238,279	)

	Net deferred tax asset	$	—		$	—



	The Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets. Based on the Company's history of operating losses since inception, the Company has concluded that it is more likely than not that the benefit of its deferred tax assets will not be realized. Accordingly, the Company has provided a full valuation allowance for deferred tax assets as of December 31, 2014 and 2013. The valuation allowance increased by $22.1 million and $10.4 million during the years ended December 31, 2014 and 2013, respectively, due primarily to the generation of net operating losses during the periods.
	A reconciliation of income tax expense computed at the statutory federal income tax rate to income taxes as reflected in the financial statements is as follows:

		December 31,
		2014			2013
	Percent of pre-tax income:
	U.S. federal statutory income tax rate		34.0	%		34.0	%
	Permanent Differences		(0.6	)%		(0.5	)%
	State taxes, net of federal benefit		6.5	%		6.5	%
	Research and development credit		3.9	%		1.9	%
	Change in valuation allowance		(43.8	)%		(41.9	)%

	Effective income tax rate		0.0	%		0.0	%



	As of December 31, 2014 and 2013, the Company had U.S. federal net operating loss carryforwards of $22.8 million and $12.7 million, respectively, which may be available to offset future income tax liabilities and will begin to expire at various dates starting in 2027. As of December 31, 2014 and 2013, the Company also had U.S. state net operating loss carryforwards of $22.8 million and $12.7 million, respectively, which may be available to offset future income tax liabilities and will begin to expire at various dates starting in 2027.
	As of December 31, 2014 and 2013, the Company had federal research and development tax credit carryforwards of $4.7 million and $2.5 million, respectively, available to reduce future tax liabilities which will begin to expire at various dates starting in 2027. As of December 31, 2014 and 2013, the Company had state research and development tax credit carryforwards of approximately $0.7 million and $0.4 million, respectively, available to reduce future tax liabilities which will begin to expire at various dates starting in 2022.
	Under the provisions of the Internal Revenue Code, the net operating loss and tax credit carryforwards are subject to review and possible adjustment by the Internal Revenue Service and state tax authorities. Net operating loss and tax credit carryforwards may become subject to an annual limitation in the event of certain cumulative changes in the ownership interest of significant shareholders over a three-year period in excess of 50 percent, as defined under Sections 382 and 383 of the Internal Revenue Code, respectively, as well as similar state provisions. This could limit the amount of tax attributes that can be utilized annually to offset future taxable income or tax liabilities. The amount of the annual limitation is determined based on the value of the Company immediately prior to the ownership change. Subsequent ownership changes may further affect the limitation in future years. The Company has completed several financings since its inception which may have resulted in a change in control as defined by Sections 382 and 383 of the Internal Revenue Code, or could result in a change in control in the future.
	The Company will recognize interest and penalties related to uncertain tax positions in income tax expense. As of December 31, 2014 and 2013, the Company had no accrued interest or penalties related to uncertain tax positions and no amounts have been recognized in the Company's statements of operations and comprehensive loss.
	For all years through December 31, 2014, the Company generated research credits but has not conducted a study to document the qualified activities. This study may result in an adjustment to the Company's research and development credit carryforwards; however, until a study is completed and any adjustment is known, no amounts are being presented as an uncertain tax position for these years. A full valuation allowance has been provided against the Company's research and development credits and, if an adjustment is required, this adjustment would be offset by an adjustment to the deferred tax asset established for the research and development credit carryforwards and the valuation allowance.
	The Tax Increase Prevention Act of 2014, enacted December 19, 2014, reinstated the research and development credit through December 31, 2014, and the Company recorded a credit of $1.8 million for 2014. In 2013 the Company recorded credits of approximately $1.0 million related to 2012 and 2013 as a result of a previous retroactive reinstatement under the American Tax Relief Act of 2012.
	The Company files income tax returns in the United States, and various state jurisdictions. The federal and state income tax returns are generally subject to tax examinations for the tax years ended December 31, 2010 through December 31, 2013. To the extent the Company has tax attribute carryforwards, the tax years in which the attribute was generated may still be adjusted upon examination by the Internal Revenue Service or state tax authorities to the extent utilized in a future period.

Employee_Benefit_Plan

Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Dec. 31, 2014
Employee Benefit Plan
Employee Benefit Plan
	12. Employee Benefit Plan
	The Company sponsors a 401(k) defined contribution plan for its employees. Employee contributions are voluntary. The Company matches employee contributions in an amount equal to 100% of the first 3% of eligible compensation and 50% of the next 2% of eligible compensation, and such employer contributions are immediately vested. During 2014 and 2013, the Company provided matching contributions of $204,537 and $175,943, respectively.

Subsequent_Events

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2014
Subsequent Events
Subsequent Events
	13. Subsequent Events
	In March 2015, Actavis and the Company signed a letter agreement wherein Actavis agreed to pay the Company $10.0 million to fund the expansion of the Company's ongoing Phase 2b trial of TRV027 from 500 patients to 620 patients. The March 2015 letter agreement does not otherwise amend the terms of the May 2013 option agreement described in Note 10 above.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2014
Summary of Significant Accounting Policies
Basis of Presentation
	Basis of Presentation
	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 Update ("ASU") of the Financial Accounting Standards Board ("FASB"). The Company considers the U.S. dollar to be its functional currency.

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 and common stock warrants, and the accounting for research and development costs, accrued expenses and the recoverability of the Company's net deferred tax assets and related valuation allowance.

Cash and Cash Equivalents
	Cash and Cash Equivalents
	The Company considers all highly liquid investments that have maturities of three months or less when acquired to be cash equivalents. Cash and cash equivalents subject the Company to concentrations of credit risk. However, the Company has invested in U.S. Treasury Bonds and money market mutual funds that invest substantially all of their assets in U.S. government securities. Cash equivalents are valued at cost, which approximates their fair market value.

Restricted Cash
	Restricted Cash
	At December 31, 2014 and 2013, the Company maintained letters of credit totaling $112,000, as collateral for the Company's facility and laboratory equipment lease obligations in Pennsylvania. In 2014, the Company earned interest of $410 related to these funds.

Investments
	Investments
	At the time of purchase, the Company classifies investments in marketable securities as either available-for-sale securities, held to maturity securities, or trading securities, based on the Company's intent at that time.
	As of December 31, 2014, the Company's investments are classified as available-for-sale pursuant to ASC Topic 320, Investments—Debt and Equity Securities ("ASC 320"). The Company classifies investments available to fund current operations as current assets on its balance sheets. The Company considers all investments that have maturities of three months or less when acquired to be cash equivalents. Investments are classified as long-term assets on the balance sheets if (i) the Company has the intent and ability to hold the investments for a period of at least one year and (ii) the contractual maturity date of the investments is greater than one year. As of December 31, 2014, the Company had $70.7 million in available-for-sale investments, all classified as current assets.
	Investments are carried at fair value with unrealized gains and losses included as a component of accumulated other comprehensive loss, until such gains and losses are realized. Fair value is determined based on observable market quotes or valuation models using assessments of counterparty credit worthiness, credit default risk of underlying security and overall capital market liquidity. The company reviews unrealized losses associated with available-for-sale securities to determine the classification as "temporary" or "other-than-temporary" impairment. A temporary impairment results in an unrealized loss being recorded in other comprehensive income. If a decline in the fair value is considered other-than-temporary, based on available evidence, the unrealized loss is transferred from other comprehensive loss to the statement of operations. The Company considers various factors in determining the classification, including the length of time and extent to which the fair value has been less than the Company's cost basis, the financial condition and near-term prospects of the issuer or investee, and the Company's ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value. There were no charges taken for other-than-temporary declines in fair value of short-term or long-term investments during the year ended December 31, 2014. The Company recorded unrealized (gains)/ losses of $18,782 during the year ended December 31, 2014. Realized gains and losses are included in interest income in the statement of operations and comprehensive loss. The Company did not record any realized gains or losses during the year ended December 31, 2014.

Property and Equipment
	Property and Equipment
	Property and equipment consists of computer and laboratory equipment, software, office equipment, furniture and leasehold improvements and is recorded at cost. Maintenance and repairs that do not improve or extend the lives of the respective assets are expensed to operations as incurred. Upon disposal, retirement or sale the related cost and accumulated depreciation is removed from the accounts and any resulting gain or loss is included in the results of operations. Property and equipment are depreciated on a straight-line basis over their estimated useful lives. The Company uses a life of three years for computer equipment, and five years for laboratory equipment, office equipment, furniture and software. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the asset.
	The Company reviews long-lived assets when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparison of the book values of the assets to future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the book value of the assets exceed their fair value, which is measured based on the projected discounted future net cash flows arising from the assets. No impairment losses have been recorded since inception.

Preferred Stock and Common Stock Warrants
	Preferred Stock and Common Stock Warrants
	Freestanding warrants that are related to the purchase of preferred and common stock are classified as liabilities and recorded at fair value regardless of the timing of the redemption feature or the redemption price or the likelihood of redemption. The warrants are subject to re-measurement at each balance sheet date and any change in fair value is recognized as a component of change in fair value of warrant liability in the statements of operations and comprehensive loss. Pursuant to the terms of the preferred warrants, upon the conversion to common stock of the series of preferred stock underlying the warrant, the warrants automatically became exercisable for shares of common stock based upon the conversion ratio of the underlying preferred stock. The Company will continue to adjust the liability for changes in fair value until the earlier of the exercise or expiration of the warrants. The preferred (at December 31, 2013) and common stock (at December 31, 2014) warrants are classified as Level 3 liabilities (see Fair Value of Financial Instruments).

Fair Value of Financial Instruments
	Fair Value of Financial Instruments
	The carrying amount of the Company's financial instruments, which include cash and cash equivalents, marketable securities, grants receivable, restricted cash, accounts payable and accrued expenses approximate their fair values, given their short-term nature. The carrying amount of the Company's loans payable at December 31, 2014 approximates fair value because the interest rate is reflective of the rate the Company could obtain on debt with similar terms and conditions. The preferred stock warrants are carried at fair value as disclosed above. The Company has evaluated 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.
	ASC Topic 820, Fair Value Measurement ("ASC 820"), establishes a fair value hierarchy for instruments measured at fair value that distinguishes between assumptions based on market data (observable inputs) and the Company's own assumptions (unobservable inputs). Observable inputs are inputs that market participants would use in pricing the asset or liability based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company's assumptions about the inputs that market participants would use in pricing the asset or liability, and are developed based on the best information available in the circumstances.
	ASC 820 identifies fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC Topic 820 establishes a three-tier fair value hierarchy that distinguishes among the following:
	•	Level 1—Valuations based on unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access.
	•	Level 2—Valuations based on quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active and models for which all significant inputs are observable, either directly or indirectly.
	•	Level 3—Valuations based on inputs that are unobservable and significant to the overall fair value measurement.
	To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument's level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement.
	Items measured at fair value on a recurring basis include money market mutual funds, restricted cash and warrants to purchase redeemable convertible preferred stock. During the periods presented, the Company has not changed the manner in which it values assets and liabilities that are measured at fair value using Level 3 inputs. The following fair value hierarchy table presents information about each major category of the Company's financial assets and liabilities measured at fair value on a recurring basis:

			Quoted Prices in			Significant Other			Significant		Total
			Active Markets			Observable Inputs			Unobservable Inputs
			for Identical			(Level 2)			(Level 3)
			Items (Level 1)
	December 31, 2014
	Assets
	Money market mutual funds		$	29,064,011		$	—		$	—	$	29,064,011
	U.S. Treasury Bonds			70,698,640								70,698,640
	Restricted cash			112,410			—			—		112,410

	Total assets		$	99,875,061		$	—		$	—	$	99,875,061


	Liabilities
	Warrants to purchase common stock		$	—		$	—		$	82,851	$	82,851

	Total liabilities		$	—		$	—		$	82,851	$	82,851


	December 31, 2013
	Assets
	U.S. Treasury Bills		$	35,551,000			—			—	$	35,551,000
	Restricted cash			112,000			—			—		112,000

	Total assets		$	35,663,000		$	—		$	—	$	35,663,000


	Liabilities
	Warrants to purchase redeemable preferred stock		$	—		$	—		$	350,519	$	350,519

	Total liabilities		$	—		$	—		$	350,519	$	350,519


	The following table sets forth a summary of changes in the fair value of the Company's warrant liability, which represents a recurring measurement that is classified within Level 3 of the fair value hierarchy, wherein fair value is estimated using significant unobservable inputs:

			Warrant Liability
	Balance as of December 31, 2012			1,393,674
	Amounts acquired or issued			(801,677	)
	Changes in estimated fair value			(241,478	)

	Balance as of December 31, 2013			350,519
	Amounts acquired or issued			—
	Changes in estimated fair value			(122,412	)
	Amounts reclassified to additional paid-in capital			(145,256	)

	Balance as of December 31, 2014		$	82,851


	The money market mutual funds and U.S. Treasury Bills noted above are included in cash and cash equivalents in the accompanying balance sheets. The U.S. Treasury Bonds are included in marketable securities in the accompanying balance sheets. The Company recognizes transfers between levels of the fair value hierarchy as of the end of the reporting period. There were no transfers within the hierarchy during the years ended December 31, 2014 or 2013.
	In connection with the issuance of debt, on September 19, 2014, the Company issued to the lenders and the placement agent in the transaction warrants to purchase an aggregate of 7,678 shares of the Company's common stock. These detachable warrant instruments have qualified for equity classification and have been allocated upon the relative fair value of the base instrument and the warrants, according to the guidance of ASC 470-20-25-2. See Note 7 for additional information.
	In connection with the issuance and sale of the Company's Series B-1 preferred shares in 2011, the Company issued a warrant to purchase 125,000 shares of Series B preferred stock. Upon the IPO, the warrant to purchase 125,000 shares of Series B preferred stock was converted into a warrant to purchase up to 20,161 shares of the Company's common stock and remains outstanding with a fair value recorded as a liability of $82,851 at December 31, 2014 as it contains a cash settlement feature upon certain strategic transactions. See Note 8 for additional information.
	The fair value of the warrants classified as liabilities on each re-measurement date is estimated using the Black-Scholes option pricing model. For this liability, the Company develops its own assumptions that do not have observable inputs or available market data to support the fair value. This method of valuation involves using inputs such as the fair value of the Company's common stock and various classes of preferred 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 is considered a Level 3 measurement. The following assumptions were used at December 31, 2014 and December 31, 2013:

		December 31,			December 31, 2013
		2014			December 31, 2013
		Common stock			Series B-1			Series B
		warrant liability			preferred stock			preferred stock
					warrant liability			warrant liability
Estimated remaining term			7.34 years			0.25 years			8.4 years
Dividend yield			0.00	%		0.00	%		0.00	%
Risk-free interest rate			1.99	%		0.38	%		2.75	%
Fair value of underlying instrument		$	5.98		$	7.00		$	7.00
Volatility			72	%		71	%		70	%
The warrant liability is recorded on its own line item on the Company's Balance Sheet and is marked-to-market at each reporting period with the change in fair value recorded on its own line in the Statement of Operations and Comprehensive Loss.

Concentration of Credit Risk and Off-Balance Sheet Risk
	Concentration of Credit Risk and Off-Balance Sheet Risk
	Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash, cash equivalents, marketable securities and restricted cash. The Company maintains its cash, and cash equivalent balances in the form of money market mutual funds that invest substantially all of their assets in U.S. government securities with financial institutions that management believes are creditworthy. The Company maintains its marketable securities balances in the form of U.S. Treasury Bonds. The Company's investment policy includes guidelines on the quality of the institutions and financial instruments and defines allowable investments that the Company believes minimizes the exposure to concentration of credit risk.
	The Company routinely assesses the creditworthiness of its collaborators. The Company has not experienced any material losses related to receivables from collaborators. The Company does not require collateral from its collaborators.
	The Company has not recognized any losses from credit risks on such accounts since inception. The Company believes it is not exposed to significant credit risk on cash.

Segment Information
	Segment 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 the chief executive officer. The Company and the chief executive officer view the Company's operations and manage its business as one operating segment. All long-lived assets of the Company reside in the United States.

Revenue
	Revenue
	The Company recognizes grant revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed and determinable, and collectibility is reasonably assured. The Company recognizes revenue under grants in earnings in the period in which the related expenditures are incurred. The Company recognizes collaboration revenue when persuasive evidence of an arrangement exists, delivery has occurred or services have been rendered, the price is fixed and determinable, and collectibility is reasonably assured.

Research and Development
	Research and Development
	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 our 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.
	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.
	As part of the process of preparing its financial statements, the Company is required to estimate its expenses resulting from its obligations under contracts with vendors, clinical research organizations and consultants and under clinical site agreements in connection with conducting clinical trials. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows that do not match the periods over which materials or services are provided under such contracts. The Company's objective is to reflect the appropriate trial expenses in its financial statements by matching those expenses with the period in which services are performed and efforts are expended. The Company accounts for these expenses according to the progress of the trial as measured by subject progression and the timing of various aspects of the trial. The Company determines accrual estimates through financial models taking into account discussion with applicable personnel and outside service providers as to the progress or state of consummation of trials, or the services completed. During the course of a clinical trial, the Company adjusts its clinical expense recognition if actual results differ from its estimates. The Company makes estimates of its accrued expenses as of each balance sheet date based on the facts and circumstances known to it at that time. The Company's clinical trial accruals are dependent upon the timely and accurate reporting of contract research organizations and other third-party vendors. Although the Company does not expect its estimates to be materially different from amounts actually incurred, its 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 it reporting amounts that are too high or too low for any particular period. For the years ended December 31, 2014 and 2013, there were no material adjustments to the Company's prior period estimates of accrued expenses for clinical trials.

Stock-Based Compensation
	Stock-Based Compensation
	At December 31, 2014, the Company had one stock-based compensation plan, which is more fully described in Note 9. The Company accounts for stock-based compensation in accordance with the provisions of ASC Topic 718, Compensation—Stock Compensation ("ASC 718"), which requires the recognition of expense related to the fair value of stock-based compensation awards in the Statements of Operations and Comprehensive Loss.
	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 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 accelerated attribution 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.
	Share-based payments issued to non-employees are recorded at their fair values, and are periodically revalued as the equity instruments vest and are recognized as expense over the related service period in accordance with the provisions of ASC 718 and ASC Topic 505, Equity. See Note 9 for a discussion of the assumptions used by the Company in determining the grant date fair value of options granted under the Black-Scholes option pricing model, as well as a summary of the stock option activity under the Company's stock-based compensation plan for the years ended December 31, 2014 and 2013.


Income Taxes
	Income Taxes
	Income taxes are recorded in accordance with ASC Topic 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. As of December 31, 2014 and 2013, the Company does not have any significant uncertain tax positions.

Comprehensive Loss
	Comprehensive Loss
	Comprehensive loss is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources. Comprehensive loss relates to unrealized investment losses on the Company's marketable securities for the year ended December 31, 2014. Comprehensive loss was equal to net loss for the year ended December 31, 2013.

Basic and Diluted Net Loss Per Share of Common Stock
	Basic and Diluted Net Loss Per Share of Common Stock
	Basic net loss per share of common stock is computed by dividing net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, excluding the dilutive effects of preferred stock, warrants to purchase preferred stock and stock options. Diluted net loss per share of common stock is computed by dividing the net loss attributable to common stockholders by the sum of the weighted-average number of shares of common stock outstanding during the period plus the potential dilutive effects of preferred stock and warrants to purchase preferred stock, and stock options outstanding during the period calculated in accordance with the treasury stock method, although these shares, options and warrants are excluded if their effect is anti-dilutive. Because the impact of these items is anti-dilutive during periods of net loss, there was no difference between basic and diluted net loss per share of common stock for the years ended December 31, 2014 and 2013.

Recent Accounting Pronouncements
	Recent Accounting Pronouncements
	In February 2013, FASB issued ASU No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income (“ASU 2013-02”). ASU 2013-02 requires companies to present either in a single note or parenthetically on the face of the financial statements, the effect of significant amounts reclassified from each component of accumulated other comprehensive income based on its source and the income statement line items affected by the reclassification. This guidance is effective for annual reporting periods beginning January 1, 2013. The adoption of this standard by the Company for the fiscal year beginning January 1, 2013 did not have a significant impact on our financial position, results of operations or cash flows.
	On June 10, 2014, FASB issued ASU No. 2014-10, Development Stage Entities (Topic 915): Elimination of Certain Financial Reporting Requirements, Including an Amendment to Variable Interest Entities Guidance in Topic 810, Consolidation ("ASU 2014-10"). ASU 2014-10 eliminates the accounting and reporting differences in U.S. GAAP between development stage entities and other operating entities, including the presentation of inception-to-date financial statement information and the development stage entity financial statement label. FASB guidance related to Risks and Uncertainties and FASB guidance utilized to determine if an entity is a variable interest entity now applies to entities that have not commenced planned principal operations. These changes will provide more consistent consolidation analysis and decisions among reporting entities. While these amendments are retrospectively effective for annual reporting periods beginning after December 15, 2014, early adoption is permitted for any annual reporting period or interim period for which the entity's financial statements have not yet been issued. The Company has elected early adoption in the current period. The Company's adoption of this standard did not have a significant impact on its financial position, results of operations or cash flows.
	In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements-Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern, which defines management's responsibility to assess an entity's ability to continue as a going concern, and to provide related footnote disclosures if there is substantial doubt about its ability to continue as a going concern. The pronouncement is effective for annual reporting periods ending after December 15, 2016 with early adoption permitted. The adoption of this guidance is not expected to have a material impact on the Company's financial statements.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2014
Summary of Significant Accounting Policies
Schedule of major category of financial assets and liabilities measured at fair value on a recurring basis

		Quoted Prices in			Significant Other			Significant			Total
		Active Markets			Observable Inputs			Unobservable Inputs
		for Identical			(Level 2)			(Level 3)
		Items (Level 1)
	December 31, 2014
	Assets
	Money market mutual funds	$	29,064,011		$	—		$	—		$	29,064,011
	U.S. Treasury Bonds		70,698,640									70,698,640
	Restricted cash		112,410			—			—			112,410

	Total assets	$	99,875,061		$	—		$	—		$	99,875,061


	Liabilities
	Warrants to purchase common stock	$	—		$	—		$	82,851		$	82,851

	Total liabilities	$	—		$	—		$	82,851		$	82,851


	December 31, 2013
	Assets
	U.S. Treasury Bills	$	35,551,000			—			—		$	35,551,000
	Restricted cash		112,000			—			—			112,000

	Total assets	$	35,663,000		$	—		$	—		$	35,663,000


	Liabilities
	Warrants to purchase redeemable preferred stock	$	—		$	—		$	350,519		$	350,519

	Total liabilities	$	—		$	—		$	350,519		$	350,519




Schedule of changes in the fair value of the Company's preferred warrant liability representing a recurring measurement classified within Level 3, wherein fair value is estimated using significant unobservable inputs

		Warrant Liability
	Balance as of December 31, 2012	$	1,393,674
	Amounts acquired or issued		(801,677	)
	Changes in estimated fair value		(241,478	)

	Balance as of December 31, 2013		350,519
	Amounts acquired or issued		—
	Changes in estimated fair value		(122,412	)
	Amounts reclassified to additional paid-in capital		(145,256	)

	Balance as of December 31, 2014	$	82,851




Schedule of assumptions used for valuation of warrants

		December 31,			December 31, 2013
		2014			December 31, 2013
		Common stock			Series B-1			Series B
		warrant liability			preferred stock			preferred stock
					warrant liability			warrant liability
	Estimated remaining term		7.34 years			0.25 years			8.4 years
	Dividend yield		0.00	%		0.00	%		0.00	%
	Risk-free interest rate		1.99	%		0.38	%		2.75	%
	Fair value of underlying instrument	$	5.98		$	7.00		$	7.00
	Volatility		72	%		71	%		70	%

Net_Loss_Per_Common_Share_Tabl

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

		Year Ended December 31,
		2014			2013
	Basic and diluted net loss per common share calculation:
	Net loss	$	(49,700,875	)		(23,251,435	)
	Accretion of redeemable convertible preferred stock		(28,521	)		(333,710	)

	Net loss attributable to common stockholders	$	(49,729,396	)	$	(23,585,145	)


	Weighted average common shares outstanding		24,655,603			793,806


	Net loss per share of common stock—basic and diluted	$	(2.02	)	$	(29.71	)




Schedule of outstanding securities excluded from the computation of diluted weighted shares outstanding as they would have been anti dilutive

		December 31,
		2014			2013
	Redeemable convertible preferred stock		—			15,707,986
	Options outstanding		3,574,450			2,795,746
	Warrants		30,258			199,996

	Total		3,604,708			18,703,728

Comprehensive_Loss_Tables

Comprehensive Loss (Tables)	12 Months Ended
Comprehensive Loss (Tables)	Dec. 31, 2014
Comprehensive Income Loss
Schedule of Accumulated Other Comprehensive Income (Loss)

	Balance, January 1, 2014	$	—
	Net unrealized loss arising during the period		18,782

	Balance, December 31, 2014	$	18,782

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

		December 31,
		2014			2013
	Laboratory equipment	$	1,616,420			1,853,685
	Computers and software		554,658			509,109
	Office equipment and furniture		270,845			193,781
	Leasehold improvements		1,986,156			1,718,922
	Leased assets		14,259			—

	Total property and equipment		4,442,338			4,275,497
	Less accumulated depreciation and amortization		(3,889,044	)		(3,932,438	)

	Property and equipment, net	$	553,294		$	343,059

Accrued_Expenses_and_Other_Cur1

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
Accrued Expenses and Other Current Liabilities (Tables)	Dec. 31, 2014
Accrued Expenses and Other Current Liabilities
Schedule of accrued expenses and other current liabilities

		December 31,
		2014		2013
	Compensation and benefits	$	1,628,102	$	859,444
	Clinical trial fees		846,199		762,687
	Other research and development expenses		96,088		507,845
	Professional services		—		24,005
	Other accrued expenses and other current liabilities		7,880		4,811

	Total accrued expenses and other current liabilities	$	2,578,269	$	2,158,792

Long_Term_Debt_Tables

Long Term Debt (Tables)	12 Months Ended
Long Term Debt (Tables)	Dec. 31, 2014
Long Term Debt
Schedule of number of warrants issued or issuable by the Company

	Entity	Shares Underlying Warrants			Maximum Number of Shares		Maximum Number of Shares
		Issued on the Effective Date			Underlying Warrants Issuable		Underlying Warrants Issuable
					Assuming Full Draw of Term		Assuming Full Draw of Term
					Loan B		Loan C
	Oxford		4,875			40,217		40,217
	Square 1		1,950			16,087		16,087
	Three Point		853			7,038		7,038


Term Loan A
Long Term Debt
Schedule of loan reflected on Balance Sheet

		December 31,
		2014
	Gross proceeds	$	2,000,000
	Debt discount		(208,715	)

	Carrying value	$	1,791,285

Stockholders_Equity_Deficit_Ta

Stockholders' Equity (Deficit) (Tables)	12 Months Ended
Stockholders' Equity (Deficit) (Tables)	Dec. 31, 2014
Stockholders' Equity (Deficit)
Schedule of redeemable convertible preferred stock outstanding which converted into common shares

		Preferred		Conversion
		Shares		into Common
		Outstanding		Shares upon
				IPO
	Series A		25,074,999		4,044,354
	Series B		30,800,000		4,967,741
	Series B-1		4,750,000		766,129
	Series C		36,764,704		5,929,789

	Total		97,389,703		15,708,013

2008_and_2013_Equity_Incentive1

2008 and 2013 Equity Incentive Plans (Tables)	12 Months Ended
2008 and 2013 Equity Incentive Plans (Tables)	Dec. 31, 2014
2008 and 2013 Equity Incentive Plans
Schedule of share-based compensation expense recognized

		Year Ended
		December 31,
		2014			2013
	Research and development	$	1,129,244		$	609,483
	General and administrative		1,254,155			318,513

	Total stock-based compensation	$	2,383,399		$	927,996




Schedule of options outstanding

					Options Outstanding
		Shares			Number			Weighted-		Weighted
		Available			of Shares			Average		Average
		for Grant						Exercise		Remaining
								Price		Contractual
										Term (in years)
	Balance, December 31, 2012		171,803			1,523,156		$	0.56		7.89
	Authorized		1,459,514			—
	Granted		(1,730,156	)		1,730,156			3.73
	Exercised		—			(275,262	)		0.3
	Forfeitures		182,304			(182,304	)		0.95

	Balance, December 31, 2013		83,465			2,795,746		$	2.52		8.45
	Authorized		1,711,290			—
	Granted		(1,095,042	)		1,095,042			6.75
	Exercised		—			(186,687	)		0.6
	Forfeitures		129,651			(129,651	)		7.2

	Balance, December 31, 2014		829,364			3,574,450		$	3.75		8.06


	Vested or expected to vest at December 31, 2014					3,528,809		$	3.71		8.05


	Exercisable at December 31, 2014					1,602,623		$	2.26		7.1




Schedule of weighted-average assumptions:

		Year Ended			Year Ended
		December 31,			December 31,
		2014			2013
	Risk-free interest rate		1.80	%		1.52	%
	Expected term of options (in years)		5.8			6.1
	Expected volatility		75.9	%		80.5	%
	Dividend yield		0	%		0	%


Schedule of shares of common stock reserved for issuance

	Common stock options outstanding		3,574,450
	Common stock options and restricted stock available for future grant (2013 Plan)		829,364
	Common stock warrants outstanding		30,258

			4,434,072

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
Commitments and Contingencies (Tables)	Dec. 31, 2014
Commitments and Contingencies.
Schedule of future minimum lease payments, including termination fees, under non cancelable lease agreements

		Operating
		Lease
	2015	$	262,352
	2016		269,631
	2017		276,909
	2018		284,188
	2019 and beyond		514,691

	Total minimum lease payments	$	1,607,771

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2014
Income Taxes
Schedule of significant components of the Company's deferred tax assets

		December 31,
		2014			2013
	Deferred tax assets:
	Net operating losse carryforwards	$	9,245,934		$	5,159,176
	Research and development credits		5,101,755			2,801,924
	Research and development expenses capitalized for tax purposes		43,038,057			26,936,217
	Deferred rent		129,998			140,873
	Depreciation		476,799			652,104
	Other temporary differences		458,413			628,296

	Total deferred tax assets		58,450,956			36,318,590
	Deferred tax liabilities:
	Prepaid expenses		(90,385	)		(80,311	)

	Total deferred tax liabilities		(90,385	)		(80,311	)

	Net deferred tax assets		58,360,571			36,238,279
	Less valuation allowance		(58,360,571	)		(36,238,279	)

	Net deferred tax asset	$	—		$	—




Schedule of reconciliation of income tax expense computed at the statutory federal income tax rate to income taxes as reflected in the financial statements

		December 31,
		2014			2013
	Percent of pre-tax income:
	U.S. federal statutory income tax rate		34.0	%		34.0	%
	Permanent Differences		(0.6	)%		(0.5	)%
	State taxes, net of federal benefit		6.5	%		6.5	%
	Research and development credit		3.9	%		1.9	%
	Change in valuation allowance		(43.8	)%		(41.9	)%

	Effective income tax rate		0.0	%		0.0	%

Organization_and_Description_o1

Organization and Description of the Business (Details) (USD $)	0 Months Ended				1 Months Ended	12 Months Ended
	Dec. 10, 2014	Mar. 06, 2014	Feb. 05, 2014	Oct. 30, 2013	Mar. 06, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Dec. 10, 2014	Mar. 06, 2014	Feb. 05, 2014	Oct. 30, 2013	Mar. 06, 2014	item	Dec. 31, 2013	Dec. 31, 2012
Organization and Description of the Business
Number of operating segments						1
Reverse stock split ratio				0.1613
Public Offering
Issuance of common stock in public offering (in shares)	11,250,000
Issuance of common stock underwriters allotment option (in shares)	1,598,000
Issuance of common stock (in shares)	12,848,000	270,449	9,250,000
Public offering price (in dollars per share)	$4	$7	$7
Aggregate gross proceeds from shares sold	$51,400,000	$1,900,000	$64,800,000
Number of outstanding warrants not exercised as part of the IPO					22,580
Shares of common stock issued upon conversion of outstanding convertible preferred stock and net exercise of a portion of warrants					15,728,286
Payment of underwriting discounts and commissions	3,100,000				4,700,000
Offering expense	600,000				2,500,000
Net offering proceeds after deducting underwriting discounts and commissions and offering expenses					59,534,984
Proceeds from issuance of common stock, net	47,700,000					107,290,323
Liquidity
Accumulated deficit						-131,969,725	-82,268,850
Net loss						-49,700,875	-23,251,435
Cash and cash equivalents						36,205,559	37,965,198	6,738,659
Marketable securities						70,698,640
Amount available for withdrawal under credit facility						$16,500,000

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended	86 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Restricted Cash
Letters of credit	$112,000	$112,000	$112,000
Interest on restricted cash	410
Investments
Marketable Securities	70,698,640	70,698,640
Change in unrealized loss	-18,782
Property and Equipment
Impairment losses		$0
Computer Equipment
Property and Equipment
Estimated useful life	P3Y
Laboratory Equipment Office Equipment Furniture and Software
Property and Equipment
Estimated useful life	P5Y

Summary_of_Significant_Account4

Summary of Significant Accounting Policies (Details 2) (Recurring basis, USD $)	Dec. 31, 2014	Dec. 31, 2013
Quoted Prices in Active Markets for Identical Items (Level 1)
Financial assets and liabilities measured at fair value on a recurring basis
Assets	$99,875,061	$35,663,000
Quoted Prices in Active Markets for Identical Items (Level 1) \| Money market mutual funds
Financial assets and liabilities measured at fair value on a recurring basis
Assets	29,064,011
Quoted Prices in Active Markets for Identical Items (Level 1) \| U.S. Treasury Bonds
Financial assets and liabilities measured at fair value on a recurring basis
Assets	70,698,640
Quoted Prices in Active Markets for Identical Items (Level 1) \| U.S. Treasury Bills
Financial assets and liabilities measured at fair value on a recurring basis
Assets		35,551,000
Quoted Prices in Active Markets for Identical Items (Level 1) \| Restricted cash
Financial assets and liabilities measured at fair value on a recurring basis
Assets	112,410	112,000
Significant Unobservable Inputs (Level 3)
Financial assets and liabilities measured at fair value on a recurring basis
Liabilities	82,851	350,519
Significant Unobservable Inputs (Level 3) \| Warrants
Financial assets and liabilities measured at fair value on a recurring basis
Liabilities	82,851
Significant Unobservable Inputs (Level 3) \| Warrants \| Redeemable convertible preferred stock
Financial assets and liabilities measured at fair value on a recurring basis
Liabilities		350,519
Total
Financial assets and liabilities measured at fair value on a recurring basis
Assets	99,875,061	35,663,000
Liabilities	82,851	350,519
Total \| Warrants
Financial assets and liabilities measured at fair value on a recurring basis
Liabilities	82,851
Total \| Warrants \| Redeemable convertible preferred stock
Financial assets and liabilities measured at fair value on a recurring basis
Liabilities		350,519
Total \| Money market mutual funds
Financial assets and liabilities measured at fair value on a recurring basis
Assets	29,064,011
Total \| U.S. Treasury Bonds
Financial assets and liabilities measured at fair value on a recurring basis
Assets	70,698,640
Total \| U.S. Treasury Bills
Financial assets and liabilities measured at fair value on a recurring basis
Assets		35,551,000
Total \| Restricted cash
Financial assets and liabilities measured at fair value on a recurring basis
Assets	$112,410	$112,000

Summary_of_Significant_Account5

Summary of Significant Accounting Policies (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Changes in the fair value of warrant liability
Changes in estimated fair value	$122,412	$241,478
Warrants
Changes in the fair value of warrant liability
Balance at the beginning of the period	350,519	1,393,674
Amounts acquired or issued		-801,677
Changes in estimated fair value	-122,412	-241,478
Amounts reclassified to additional paid-in capital	-145,256
Balance at the end of the period	$82,851	$350,519

Summary_of_Significant_Account6

Summary of Significant Accounting Policies (Details 4) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Jul. 08, 2010	Sep. 19, 2014	Dec. 31, 2011
Fair value, warrant liability
Transfers between levels within the fair value hierarchy	$0	$0
Fair value of the warrants outstanding		350,519
Warrants
Fair value, warrant liability
Fair value of the warrants outstanding	$82,851
Series B-1 warrants
Fair value, warrant liability
Number of shares called upon exercise of warrants (in shares)			1,700,000
Maximum \| Lenders and Placement Agent \| Warrants
Fair value, warrant liability
Number of shares called upon exercise of warrants (in shares)				126,685
Common Stock \| Series B-1 warrants
Fair value, warrant liability
Number of shares called upon exercise of warrants (in shares)	20,273
Common Stock \| Lenders and Placement Agent \| Warrants
Fair value, warrant liability
Number of shares called upon exercise of warrants (in shares)				7,678
Common Stock \| Maximum \| Warrants
Fair value, warrant liability
Number of shares called upon exercise of warrants (in shares)	20,161
Series B preferred stock \| Warrants
Fair value, warrant liability
Number of shares called upon exercise of warrants (in shares)					125,000
Series B 1 convertible preferred stock
Fair value, warrant liability
Number of shares called upon exercise of warrants (in shares)	1,650,000
Series B 1 convertible preferred stock \| Warrants
Fair value, warrant liability
Number of shares called upon exercise of warrants (in shares)					1,650,000

Summary_of_Significant_Account7

Summary of Significant Accounting Policies (Details 5) (USD $)	12 Months Ended	24 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 15, 2011	Jul. 08, 2011	Jul. 08, 2010
	item	item	Dec. 31, 2013	Dec. 15, 2011	Jul. 08, 2011	Jul. 08, 2010
Fair value assumptions
Fair value of underlying instrument (in dollar per share)	$1	$1
Segment Information
Number of operating segments	1
Stock-Based Compensation
Number of stock-based compensation plans	1	1
Basic and diluted net loss per common share calculation:
Difference between basic and diluted net loss per share of Common Stock		$0
Series B 1 convertible preferred stock
Fair value assumptions
Fair value of underlying instrument (in dollar per share)				$1	$1
Series B convertible preferred stock
Fair value assumptions
Fair value of underlying instrument (in dollar per share)				$1	$1	$1
Significant Unobservable Inputs (Level 3) \| Warrants \| Series B 1 convertible preferred stock
Fair value assumptions
Estimated remaining term			3 months
Dividend yield (as a percent)			0.00%
Risk-free interest rate (as a percent)			0.38%
Fair value of underlying instrument (in dollar per share)			$7
Volatility (as a percent)			71.00%
Significant Unobservable Inputs (Level 3) \| Warrants \| Series B convertible preferred stock
Fair value assumptions
Estimated remaining term			8 years 4 months 24 days
Dividend yield (as a percent)			0.00%
Risk-free interest rate (as a percent)			2.75%
Fair value of underlying instrument (in dollar per share)			$7
Volatility (as a percent)			70.00%
Significant Unobservable Inputs (Level 3) \| Warrants \| Common Stock
Fair value assumptions
Estimated remaining term	7 years 4 months 2 days
Dividend yield (as a percent)	0.00%
Risk-free interest rate (as a percent)	1.99%
Fair value of underlying instrument (in dollar per share)	$5.98	$5.98
Volatility (as a percent)	72.00%

Net_Loss_Per_Common_Share_Deta

Net Loss Per Common Share (Details) (USD $)	12 Months Ended
Net Loss Per Common Share (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Basic and diluted net loss per common share calculation:
Net loss	($49,700,875)	($23,251,435)
Accretion of redeemable convertible preferred stock	-28,521	-333,710
Net loss attributable to common stockholders	($49,729,396)	($23,585,145)
Weighted average common shares outstanding	24,655,603	793,806
Net loss per share of common stock-basic and diluted	($2.02)	($29.71)
Outstanding securities excluded from computation of diluted weighted shares outstanding as they would have been anti dilutive:
Outstanding securities excluded from computation of diluted weighted shares outstanding (in shares)	3,604,708	18,703,728
Redeemable convertible preferred stock
Outstanding securities excluded from computation of diluted weighted shares outstanding as they would have been anti dilutive:
Outstanding securities excluded from computation of diluted weighted shares outstanding (in shares)		15,707,986
Stock options
Outstanding securities excluded from computation of diluted weighted shares outstanding as they would have been anti dilutive:
Outstanding securities excluded from computation of diluted weighted shares outstanding (in shares)	3,574,450	2,795,746
Warrants
Outstanding securities excluded from computation of diluted weighted shares outstanding as they would have been anti dilutive:
Outstanding securities excluded from computation of diluted weighted shares outstanding (in shares)	30,258	199,996

Comprehensive_Loss_Details

Comprehensive Loss (Details) (USD $)	12 Months Ended
Comprehensive Loss (Details) (USD $)	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net unrealized loss arising during the period	$18,782
Accumulated other comprehensive income (loss), net of tax, ending balance	18,782
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0
Tax affect	$0

Property_and_Equipment_Details

Property and Equipment (Details) (USD $)	12 Months Ended
Property and Equipment (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Property and Equipment
Property and equipment, gross	$4,442,338	$4,275,497
Less accumulated depreciation and amortization	-3,889,044	-3,932,438
Property, plant and equipment, net, total	553,294	343,059
Depreciation and amortization expense	239,390	706,779
Laboratory Equipment
Property and Equipment
Property and equipment, gross	1,616,420	1,853,685
Computers and Software
Property and Equipment
Property and equipment, gross	554,658	509,109
Furniture and Fixtures
Property and Equipment
Property and equipment, gross	270,845	193,781
Leasehold Improvements
Property and Equipment
Property and equipment, gross	1,986,156	1,718,922
Leased Assets
Property and Equipment
Property and equipment, gross	$14,259

Accrued_Expenses_and_Other_Cur2

Accrued Expenses and Other Current Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Accrued Expenses and Other Current Liabilities
Compensation and benefits	$1,628,102	$859,444
Clinical trial fees	846,199	762,687
Other research and development expenses	96,088	507,845
Professional services		24,005
Other accrued expenses and other current liabilities	7,880	4,811
Total accrued expenses and other current liabilities	$2,578,269	$2,158,792

Long_Term_Debt_Details

Long Term Debt (Details) (USD $)	12 Months Ended		4 Months Ended	0 Months Ended
Long Term Debt (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Sep. 19, 2014
Long Term Debt
Gross proceeds	$1,775,012
Interest expense	70,650	149,756
Loan and security agreement
Long Term Debt
Face amount				35,000,000
Term Loan A
Long Term Debt
Face amount				2,000,000
Interest rate (as a percent)	6.50%		6.50%	6.50%
Deferred financing fees				100,000
Gross proceeds	2,000,000
Debt discount	208,715		208,715	200,000
Carrying value	1,791,285		1,791,285
Interest expense			36,833
Term Loan B
Long Term Debt
Face amount				16,500,000
Term Loan C
Long Term Debt
Face amount				16,500,000
Term Loans B And C
Long Term Debt
Minimum net cash proceeds from strategic partnerships as a condition to extend the date for payments	50,000,000
Lenders \| Loan and security agreement
Fees
Final payment fee due upon that last payment date of the amounts borrowed under the agreement subject to adjustment (as a percent)				6.10%
Final payment fee due upon that last payment date of the amounts borrowed under the agreement, scenario 1 (as a percent)				5.25%
Final payment fee due upon that last payment date of the amounts borrowed under the agreement, scenario 2 (as a percent)				6.60%
Final payment fee due upon that last payment date of the amounts borrowed under the agreement, scenario 3 (as a percent)				7.00%
Prepayment fee as a percent of total amount prepaid if prepayment occurs prior to the first anniversary of the funding				3.00%
Prepayment fee as a percent of total amount prepaid if prepayment occurs between the first and second anniversary of the funding				2.00%
Prepayment fee as a percent of total amount prepaid if prepayment occurs on or after the second anniversary of the funding				1.00%
Three Point
Fees
Facility fee				65,000
Additional fee if draws are made on term loans				175,000
Warrants
Warrants
Exercise price (in dollars per share)				5.861
Number of trading days prior to the effective date of the agreement that are used to determine the exercise price of warrants				10 days
Warrants \| Lenders and Placement Agent \| Maximum
Warrants
Number of shares called upon exercise of warrants (in shares)				126,685
Warrants \| Three Point
Warrants
Number of shares called upon exercise of warrants (in shares)				853
Maximum Number of Shares Underlying Warrants Issuable Assuming Full Draw of Term Loan B				7,038
Maximum Number of Shares Underlying Warrants Issuable Assuming Full Draw of Term Loan C				7,038
Warrants \| Oxford
Warrants
Number of shares called upon exercise of warrants (in shares)				4,875
Maximum Number of Shares Underlying Warrants Issuable Assuming Full Draw of Term Loan B				40,217
Maximum Number of Shares Underlying Warrants Issuable Assuming Full Draw of Term Loan C				40,217
Warrants \| Square I
Warrants
Number of shares called upon exercise of warrants (in shares)				1,950
Maximum Number of Shares Underlying Warrants Issuable Assuming Full Draw of Term Loan B				16,087
Maximum Number of Shares Underlying Warrants Issuable Assuming Full Draw of Term Loan C				16,087
Warrants \| Common Stock \| Maximum
Warrants
Number of shares called upon exercise of warrants (in shares)	20,161		20,161
Warrants \| Common Stock \| Lenders and Placement Agent
Warrants
Number of shares called upon exercise of warrants (in shares)				7,678

Long_Term_Debt_Details_2

Long Term Debt (Details 2) (USD $)	12 Months Ended	0 Months Ended	1 Months Ended
Long Term Debt (Details 2) (USD $)	Dec. 31, 2013	3-May-13	Dec. 31, 2011	Sep. 19, 2014	Dec. 31, 2014
Long Term Debt
Repayments of outstanding amount of loan, including unpaid interest and fees	$4,946,667
Warrants
Long Term Debt
Exercise price of warrants (in dollars per share)				$5.86
Warrants \| Series B preferred stock
Long Term Debt
Number of shares that can be purchased			125,000
Maximum \| Warrants \| Common Stock
Long Term Debt
Number of shares that can be purchased					20,161
Loan Facility with Comerica Bank
Long Term Debt
Interest expense	42,047
Repayments of outstanding amount of loan, including unpaid interest and fees		4,073,485
Debt discount			101,707
Amortization of debt discount	78,460
Loan Facility with Comerica Bank \| Warrants \| Series B preferred stock
Long Term Debt
Warrant exercise period			10 years
Number of shares that can be purchased			125,000
Exercise price of warrants (in dollars per share)			$1
Loan Facility with Comerica Bank \| Maximum
Long Term Debt
Face amount	$64,292

Stockholders_Equity_Deficit_De

Stockholders' Equity (Deficit) (Details) (USD $)	0 Months Ended			1 Months Ended	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 10, 2014	Mar. 06, 2014	Feb. 05, 2014	Mar. 06, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stockholders' (deficit) equity
Issuance of common stock in public offering (in shares)	11,250,000
Issuance of common stock underwriters allotment option (in shares)	1,598,000
Shares of common stock sold	12,848,000	270,449	9,250,000
Public offering price (in dollars per share)	$4	$7	$7
Aggregate gross proceeds from shares sold	$51.40	$1.90	$64.80
Redeemable convertible preferred stock, conversion ratio					0.1613	0.1613
Number of outstanding warrants not exercised as part of the IPO				22,580
Shares of common stock issued upon conversion of outstanding convertible preferred stock and net exercise of a portion of warrants				15,728,286
Redeemable convertible preferred stock outstanding which converted into common shares
Preferred Shares Outstanding						97,389,703
Conversion into common shares upon initial public offering (in shares)						15,708,013
Series A convertible preferred stock
Redeemable convertible preferred stock outstanding which converted into common shares
Preferred Shares Outstanding					0	25,074,999	25,074,999
Conversion into common shares upon initial public offering (in shares)				4,044,354
Series B convertible preferred stock
Stockholders' (deficit) equity
Number of shares in warrant issued in connection with a banking facility						125,000
Redeemable convertible preferred stock outstanding which converted into common shares
Preferred Shares Outstanding					0	30,800,000	30,800,000
Conversion into common shares upon initial public offering (in shares)				4,967,741
Series B 1 convertible preferred stock
Redeemable convertible preferred stock outstanding which converted into common shares
Preferred Shares Outstanding					0	4,750,000	4,200,000
Conversion into common shares upon initial public offering (in shares)				766,129
Series C convertible preferred stock
Redeemable convertible preferred stock outstanding which converted into common shares
Preferred Shares Outstanding					0	36,764,704
Conversion into common shares upon initial public offering (in shares)				5,929,789

Stockholders_Equity_Deficit_De1

Stockholders' Equity (Deficit) (Details 2) (USD $)	12 Months Ended
Stockholders' Equity (Deficit) (Details 2) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011	Jul. 08, 2010
Warrants liability
Outstanding warrants (in shares)	30,258
Reclassification of warrant to additional paid-in capital	$145,256
Fair value of the warrants outstanding		350,519
Common stock, shares authorized	100,000,000	132,000,000
Preferred Stock, shares authorized	5,000,000
Fair value of the warrants outstanding	82,851	350,519
Series B convertible preferred stock
Warrants liability
Number of shares called upon exercise of warrants (in shares)	125,000
Outstanding warrants (in shares)	1,225,000
Series B 1 convertible preferred stock
Warrants liability
Number of shares called upon exercise of warrants (in shares)	1,650,000
Warrants
Warrants liability
Fair value of the warrants outstanding	82,851
Warrants \| Series B 1 convertible preferred stock
Warrants liability
Number of shares called upon exercise of warrants (in shares)			1,650,000
Warrants \| Common Stock \| Maximum
Warrants liability
Number of shares called upon exercise of warrants (in shares)	20,161
Series B-1 warrants
Warrants liability
Number of shares called upon exercise of warrants (in shares)				1,700,000
Outstanding warrants (in shares)	1,100,000
Reclassification of warrant to additional paid-in capital	$145,256
Series B-1 warrants \| Common Stock
Warrants liability
Number of shares called upon exercise of warrants (in shares)	20,273

Stockholders_Equity_Deficit_De2

Stockholder's Equity (Deficit) (Details 3) (USD $)	0 Months Ended	1 Months Ended	12 Months Ended		0 Months Ended				1 Months Ended	0 Months Ended	1 Months Ended		0 Months Ended
	Dec. 10, 2014	Mar. 06, 2014	Dec. 31, 2014	Dec. 31, 2013	Nov. 16, 2009	Jun. 30, 2009	Jan. 31, 2008	Jan. 07, 2008	Sep. 30, 2008	Jul. 08, 2010	Jan. 31, 2014	Nov. 30, 2013	3-May-13	Dec. 15, 2011	Jul. 08, 2011	Jan. 04, 2008	31-May-13
	Dec. 10, 2014	Mar. 06, 2014	Dec. 31, 2014	Dec. 31, 2013	Nov. 16, 2009	Jun. 30, 2009	Jan. 31, 2008	Jan. 07, 2008	Sep. 30, 2008	Jul. 08, 2010	Jan. 31, 2014	item	3-May-13	Dec. 15, 2011	Jul. 08, 2011	Jan. 04, 2008	31-May-13
Redeemable convertible preferred stock and stockholder's equity
Par value (in dollars per share)			$1
Proceeds from issuance of redeemable convertible preferred stock				$59,918,917
Outstanding warrants (in shares)			30,258
Redeemable convertible preferred stock, conversion ratio			0.1613	0.1613
Annual rate of noncumulative dividends on preferred stock (as a percent)				8.00%
Dividend declared (in dollars per share)				$0
Liquidation preference (in dollars per share)			$1.63
Common Stock
Common stock, shares authorized			100,000,000	132,000,000
Restricted Stock Agreements
Share price (in dollars per share)			$1
Payment of recorded expense	3,100,000	4,700,000
Initial public offering
Redeemable convertible preferred stock and stockholder's equity
Minimum initial public offering price required to automatically convert preferred stock into common stock (in dollars per share)			$4
Minimum net proceed from initial public offering required to automatically convert preferred stock into common stock			40,000,000
Minimum percentage of stockholders whose affirmative vote or written consent is required to automatically convert preferred stock into common stock			60.00%
Common Stock
Redeemable convertible preferred stock and stockholder's equity
Shares of common stock that may be purchased by warrant			20,161
Intrinsic value			0
Series B-1 warrants
Redeemable convertible preferred stock and stockholder's equity
Shares of common stock that may be purchased by warrant										1,700,000
Warrants term			10 years
Outstanding warrants (in shares)			1,100,000
Redeemable convertible preferred stock
Redeemable convertible preferred stock and stockholder's equity
Number of board of directors that stockholders are entitled to elect			5
Minimum percentage of stockholders required to redeem stock			60.00%
Number of annual installments to redeem stock			3
Series A convertible preferred stock
Redeemable convertible preferred stock and stockholder's equity
Shares authorized			0	25,074,999												25,000,000
Shares issued			0	25,074,999	1,000,000	11,034,375	4,514,062	501,562	8,025,000
Par value (in dollars per share)					$1	$1	$1	$1	$1
Proceeds from issuance of redeemable convertible preferred stock					1,000,000	11,034,375	4,514,062	501,562	8,025,000
Offering costs					3,398	561	200,137		2,154
Restricted Stock Agreements
Share price (in dollars per share)					$1	$1	$1	$1	$1
Series B convertible preferred stock
Redeemable convertible preferred stock and stockholder's equity
Shares authorized			0	35,500,000						35,000,000
Shares issued			0	30,800,000						17,500,000				7,600,000	5,700,000
Par value (in dollars per share)										$1				$1	$1
Proceeds from issuance of redeemable convertible preferred stock										17,500,000
Offering costs										38,568
Shares of common stock that may be purchased by warrant			125,000
Number of warrant holders exercising the right												1
Number of shares issued on exercise of warrants											1,100,000	550,000
Outstanding warrants (in shares)			1,225,000
Restricted Stock Agreements
Share price (in dollars per share)										$1				$1	$1
Series B 1 convertible preferred stock
Redeemable convertible preferred stock and stockholder's equity
Shares authorized			0	6,000,000						4,300,000
Shares issued			0	4,750,000										2,400,000	1,800,000
Par value (in dollars per share)														$1	$1
Shares of common stock that may be purchased by warrant			1,650,000
Exercise price of warrants (in dollars per share)			$1
Estimated fair value of the preferred stock warrants			1,347,428
Restricted Stock Agreements
Share price (in dollars per share)														$1	$1
Series C convertible preferred stock
Redeemable convertible preferred stock and stockholder's equity
Shares authorized			0	37,000,000													37,000,000
Shares issued			0	36,764,704									36,764,704
Par value (in dollars per share)													$1.63
Proceeds from issuance of redeemable convertible preferred stock													59,999,997
Offering costs													81,080
Restricted Stock Agreements
Share price (in dollars per share)													$1.63
Series B and B 1 convertible preferred stock
Redeemable convertible preferred stock and stockholder's equity
Offering costs														$4,989	$8,229

2008_and_2013_Equity_Incentive2

2008 and 2013 Equity Incentive Plans (Details) (USD $)	12 Months Ended
2008 and 2013 Equity Incentive Plans (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
2008 and 2013 Equity Incentive Plans
Number of shares may further be granted under the plan	829,364
Stock-based compensation	$2,383,399	$927,996
Stock options
2008 and 2013 Equity Incentive Plans
Number of shares authorized to grant	1,711,290	1,459,514
Number of shares may further be granted under the plan	829,364	83,465	171,803
Stock options \| Research and development
2008 and 2013 Equity Incentive Plans
Stock-based compensation	1,129,244	609,483
Stock options \| General and administrative
2008 and 2013 Equity Incentive Plans
Stock-based compensation	$1,254,155	$318,513
2008 Plan
2008 and 2013 Equity Incentive Plans
Number of shares authorized to grant	3,310,990
2008 Plan \| Stock options \| Maximum
2008 and 2013 Equity Incentive Plans
Term of award	10 years	10 years
Vesting period	4 years	4 years
2013 plan
2008 and 2013 Equity Incentive Plans
Number of shares authorized to grant	1,711,290
2013 plan \| Stock options \| Maximum
2008 and 2013 Equity Incentive Plans
Term of award	10 years	10 years
Vesting period	4 years	4 years

2008_and_2013_Equity_Incentive3

2008 and 2013 Equity Incentive Plans (Details 2) (USD $)	12 Months Ended
2008 and 2013 Equity Incentive Plans (Details 2) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Shares Available for Grant
Balance at the end of the period (in shares)	829,364
Number of Shares
Balance at the end of the period (in shares)	3,574,450
Stock options
Shares Available for Grant
Balance at the beginning of the period (in shares)	83,465	171,803
Authorized (in shares)	1,711,290	1,459,514
Granted (in shares)	-1,095,042	-1,730,156
Forfeitures (in shares)	129,651	182,304
Balance at the end of the period (in shares)	829,364	83,465	171,803
Number of Shares
Balance at the beginning of the period (in shares)	2,795,746	1,523,156
Granted (in shares)	1,095,042	1,730,156
Exercised (in shares)	-186,687	-275,262
Forfeitures (in shares)	-129,651	-182,304
Balance at the end of the period (in shares)	3,574,450	2,795,746	1,523,156
Vested or expected to vest at the end of the period (in shares)	3,528,809
Exercisable at the end of the period (in shares)	1,602,623
Weighted-Average Exercise Price
Balance at the beginning of the period (in dollars per share)	$2.52	$0.56
Granted (in dollars per share)	$6.75	$3.73
Exercised (in dollars per share)	$0.60	$0.30
Forfeitures (in dollars per share)	$7.20	$0.95
Balance at the end of the period (in dollars per share)	$3.75	$2.52	$0.56
Vested or expected to vest at the end of the period (in dollars per share)	$3.71
Exercisable at the end of the period (in dollars per share)	$2.26
Weighted Average Remaining Contractual Term
Options Outstanding at the end of the period	8 years 22 days	8 years 5 months 12 days	7 years 10 months 21 days
Vested or expected to vest at the end of the period	8 years 18 days
Exercisable at the end of the period	7 years 1 month 6 days

2008_and_2013_Equity_Incentive4

2008 and 2013 Equity Incentive Plans (Details 3) (USD $)

12 Months Ended

In Millions, except Share data, unless otherwise specified

Dec. 31, 2014

Dec. 31, 2013

Nov. 16, 2009

Jun. 30, 2009

Sep. 30, 2008

Jan. 31, 2008

Jan. 07, 2008

Dec. 15, 2011

Jul. 08, 2011

Jul. 08, 2010

3-May-13

Dec. 31, 2012

2008 and 2013 Equity Incentive Plans

Per share price of Company's closing stock price (in dollars per share)

Shares of common stock reserved for issuance

Common stock options outstanding (in shares)

3,574,450

Common stock options and restricted stock available for future grant (2013 Plan) (in shares)

829,364

Common stock warrants outstanding (in shares)

30,258

Total shares of common stock reserved for issuance

4,434,072

Estimated

Weighted-average assumptions:

Estimated annual forfeiture rate (as a percent)

7.00%

5.00%

Series A convertible preferred stock

2008 and 2013 Equity Incentive Plans

Per share price of Company's closing stock price (in dollars per share)

Series B 1 convertible preferred stock

2008 and 2013 Equity Incentive Plans

Per share price of Company's closing stock price (in dollars per share)

Series B convertible preferred stock

2008 and 2013 Equity Incentive Plans

Per share price of Company's closing stock price (in dollars per share)

Shares of common stock reserved for issuance

Common stock warrants outstanding (in shares)

1,225,000

Series C convertible preferred stock

2008 and 2013 Equity Incentive Plans

Per share price of Company's closing stock price (in dollars per share)

$1.63

Stock options

2008 and 2013 Equity Incentive Plans

Intrinsic value of options exercisable

6.4

Per share price of Company's closing stock price (in dollars per share)

5.98

Weighted average exercise price (in dollars per share)

2.26

Per-share weighted-average grant date fair value of options granted (in dollars per share)

4.43

2.52

Weighted-average assumptions:

Unrecognized compensation expense

6.1

Weighted average remaining period for recognition of unrecognized compensation expense

2 years 10 months 13 days

Shares of common stock reserved for issuance

Common stock options outstanding (in shares)

3,574,450

2,795,746

1,523,156

Common stock options and restricted stock available for future grant (2013 Plan) (in shares)

829,364

83,465

171,803

Stock options | Weighted-average

Weighted-average assumptions:

Risk-free interest rate (as a percent)

1.80%

1.52%

Expected term of options (in years)

5 years 9 months 18 days

6 years 1 month 6 days

Expected volatility (as a percent)

75.90%

80.50%

Dividend yield (as a percent)

0.00%

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	0 Months Ended	12 Months Ended
Commitments and Contingencies (Details) (USD $)	Oct. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Licenses
Value of temporary equity purchased by licensee			120,562,138	$58,957,834
Reverse stock split ratio	0.1613
Series C convertible preferred stock
Licenses
Value of temporary equity purchased by licensee			59,935,986
Actavis plc (formerly Forest Laboratories Holdings Limited) \| Series C convertible preferred stock
Licenses
Value of temporary equity purchased by licensee		30,000,000
Option agreement and a license agreement \| Minimum
Licenses
Tiered royalties that could be received, as a percentage of net sales of licensed products		10.00%
Option agreement and a license agreement \| Maximum
Licenses
Tiered royalties that could be received, as a percentage of net sales of licensed products			20.00%
Option agreement and a license agreement \| Actavis plc (formerly Forest Laboratories Holdings Limited)
Licenses
Consideration received upon the grant of the option		0
Aggregate potential consideration		365,000,000
Option exercise fee		65,000,000
Term of royalty on sales from the first commercial sale of product		10 years
Option agreement and a license agreement \| Actavis plc (formerly Forest Laboratories Holdings Limited) \| Series C convertible preferred stock
Licenses
Value of temporary equity allocated to the option agreement		0
Reverse stock split ratio		0.1613

Commitments_and_Contingencies_2

Commitments and Contingencies (Details 2) (USD $)	12 Months Ended
Commitments and Contingencies (Details 2) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies
Rent expense	$489,810	$459,288
Future minimum payments under operating leases
2015	262,352
2016	269,631
2017	276,909
2018	284,188
2019 and thereafter	514,691
Total minimum lease payments	1,607,771
Office and Laboratory Space
Commitments and Contingencies
Termination payment if the Company opts to terminate the lease	150,000
Future minimum payments under operating leases
Deferred rent	$320,244	$347,033
Vivarium Space
Commitments and Contingencies
Notice period	90 days

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
Income Taxes (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Income Taxes
Net loss before income taxes	$49,700,875	$23,251,435
Deferred tax assets:
Net operating loss carryforwards	9,245,934	5,159,176
Research and development credits	5,101,755	2,801,924
Research and development expenses capitalized for tax purposes	43,038,057	26,936,217
Deferred rent	129,998	140,873
Depreciation	476,799	652,104
Other temporary differences	458,413	628,296
Total deferred tax assets	58,450,956	36,318,590
Deferred tax liabilities:
Prepaid expenses	-90,385	-80,311
Total deferred tax liabilities	-90,385	-80,311
Net deferred tax assets	58,360,571	36,238,279
Less valuation allowance	-58,360,571	-36,238,279
Increase in valuation allowance	$22,100,000	$10,400,000

Income_Taxes_Details_2

Income Taxes (Details 2) (USD $)	12 Months Ended
Income Taxes (Details 2) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Percent of pre-tax income:
U.S. federal statutory income tax rate (as a percent)	34.00%	34.00%
Permanent Differences (as a percent)	-0.60%	-0.50%
State taxes, net of federal benefit (as a percent)	6.50%	6.50%
Research and development credit (as a percent)	3.90%	1.90%
Change in valuation allowance (as a percent)	-43.80%	-41.90%
Effective income tax rate (as a percent)	0.00%	0.00%
Operating loss carryforwards
Interest and penalties related to uncertain tax positions	$0
Research and development credit retroactively reinstated	1,800,000	1,000,000	1,000,000
Research and development.
Operating loss carryforwards
Uncertain tax positions	0
U.S. federal
Operating loss carryforwards
Net operating loss carryforwards	22,800,000	12,700,000
U.S. federal \| Research and development.
Operating loss carryforwards
Tax credit carryforwards	4,700,000	2,500,000
U.S. State
Operating loss carryforwards
Net operating loss carryforwards	22,800,000	12,700,000
U.S. State \| Research and development.
Operating loss carryforwards
Tax credit carryforwards	$700,000	$400,000

Employee_Benefit_Plan_Details

Employee Benefit Plan (Details) (USD $)	12 Months Ended
Employee Benefit Plan (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Defined contribution plan
Employer matching contribution for employee's contributions of the first 3% of eligible compensation (as a percent)	100.00%
Percentage of eligible compensation, matched 100% by employer	3.00%
Employer matching contribution for employee's contributions of the next 2% of eligible compensation (as a percent)	50.00%
Percentage of eligible compensation, matched 50% by employer	2.00%
Company's matching contributions to the plan	$204,537	$175,943

Subsequent_Events_Details

Subsequent Events (Details) (Subsequent event, Actavis plc (formerly Forest Laboratories Holdings Limited), USD $)	1 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015
	person
Subsequent event \| Actavis plc (formerly Forest Laboratories Holdings Limited)
Subsequent events
Payment received to fund expansion of clinical trial	$10
Number of patients before expansion of the trial	500
Number of patients after expansion of the trial	620