Kindred Biosciences (KIN) 10-K 13 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Mar. 09, 2015	Jun. 30, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	Kindred Biosciences, Inc.
Entity Central Index Key	1561743
Current Fiscal Year End Date	-19
Entity Filer Category	Accelerated Filer
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		19,724,482
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Public Float			$195.50

Balance_Sheets

Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$12,969	$65,329
Short-term investments	88,058	0
Prepaid expenses and other	477	148
Total current assets	101,504	65,477
Property and equipment, net	394	12
Other assets	22	0
Total assets	101,920	65,489
Current liabilities:
Accounts payable	420	689
Accrued compensation	1,457	635
Accrued liabilities	975	886
Total current liabilities	2,852	2,210
Long-term liability	44	0
Total liabilities	2,896	2,210
Commitments and contingencies (Note 10)
Stockholders’ equity:
Common stock; $0.0001 par value; 100,000,000 shares authorized; 19,724,482 shares and 16,214,620 shares issued and outstanding at December 31, 2014 and 2013, respectively	2	2
Additional paid-in capital	130,521	67,610
Accumulated other comprehensive loss	-27	0
Accumulated deficit	-31,472	-4,333
Total stockholders’ equity	99,024	63,279
Total liabilities and stockholders’ equity	$101,920	$65,489

Balance_Sheets_Parenthetical

Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	19,724,482	16,214,620
Common stock, shares outstanding	19,724,482	16,214,620

Statements_of_Operations_and_C

Statements of Operations and Comprehensive Loss (USD $)	3 Months Ended									12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013
Operating expenses:
Research and development	$4,802	$3,755	$5,639	$4,498	$1,746	$953	$300	$141	$75	$18,694	$3,140
General and administrative	2,014	2,342	2,504	1,679	641	259	96	83	45	8,539	1,079
Total operating expenses	6,816	6,097	8,143	6,177	2,387	1,212	396	224	120	27,233	4,219
Loss from operations	-6,816	-6,097	-8,143	-6,177	-2,387	-1,212	-396	-224	-120	-27,233	-4,219
Interest and other income, net	27	25	33	9	4	2	0	0	0	94	6
Net loss	-6,789	-6,072	-8,110	-6,168	-2,383	-1,210	-396	-224	-120	-27,139	-4,213
Change in unrealized losses on investments									0	-27	0
Comprehensive loss									($120)	($27,166)	($4,213)
Net loss per share, basic and diluted	($0.34)	($0.31)	($0.42)	($0.38)	($0.40)	($0.40)	($0.13)	($0.07)	($0.06)	($1.44)	($1.13)
Weighted average common shares outstanding, basic and diluted	19,719	19,713	19,426	16,222	5,899	3,005	3,000	3,000	2,113	18,782	3,732

Statements_of_Changes_in_Conve

Statements of Changes in Convertible Preferred Stock and Stockholders' Equity (Deficit) (USD $)	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Series AA Preferred Stock	Series A-1 Preferred Stock	Series A-1A Preferred Stock
						Preferred Stock	Preferred Stock	Preferred Stock
Beginning balance at Sep. 24, 2012	$0	$0	$0	$0	$0	$0	$0	$0
Beginning balance, shares at Sep. 24, 2012		0				0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock	0					977,000
Issuance of stock, shares		3,000,000				990,000
Exchange of note payable for Series AA convertible preferred stock						10,000
Exchange of note payable for Series AA convertible preferred stock, shares						10,000
Net loss	-120,000				-120,000
Change in unrealized loss on available for sale securities	0
Total comprehensive loss	-120,000
Ending balance at Dec. 31, 2012	-120,000	0	0	0	-120,000	987,000	0	0
Ending balance, shares at Dec. 31, 2012		3,000,000				1,000,000	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock	54,872,000	1,000	54,871,000			15,000	5,843,000	5,144,000
Issuance of stock, shares		8,625,000				15,000	1,850,000	1,650,000
Issuance of stock for services		5,000					10,000	25,000
Issuance of stock for services, shares	12,000		12,000				32,000	78,000
Exercise of common stock options	11,000		11,000
Exercise of common stock options, shares	34,225	34,000
Conversion of Series AA, A-1 and A-1A preferred stock to common stock in connection with initial public offering	12,099,000	1,000	12,098,000			-1,002,000	-5,875,000	-5,222,000
Conversion of Series AA, A-1 and A-1A preferred stock to common stock in connection with initial public offering, shares		4,550,000				-1,015,000	-1,860,000	-1,675,000
Stock-based compensation	618,000		618,000
Net loss	-4,213,000				-4,213,000
Change in unrealized loss on available for sale securities	0
Total comprehensive loss	-4,213,000
Ending balance at Dec. 31, 2013	63,279,000	2,000	67,610,000		-4,333,000	0	0	0
Ending balance, shares at Dec. 31, 2013	16,214,620	16,214,000				0	0	0
Beginning balance at Nov. 30, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock, shares		8,625,000
Ending balance at Dec. 31, 2013	63,279,000	2,000	67,610,000	0	-4,333,000
Ending balance, shares at Dec. 31, 2013	16,214,620	16,214,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock	58,065,000		58,065,000
Issuance of stock, shares		3,450,000
Exercise of common stock options	121,000		121,000
Exercise of common stock options, shares	56,112	56,000
Stock-based compensation	4,725,000		4,725,000
Net loss	-27,139,000				-27,139,000
Change in unrealized loss on available for sale securities	-27,000			-27,000
Total comprehensive loss	-27,166,000
Vesting of restricted stock	0
Vesting of restricted stock, shares		4,000
Ending balance at Dec. 31, 2014	$99,024,000	$2,000	$130,521,000	($27,000)	($31,472,000)	$0	$0	$0
Ending balance, shares at Dec. 31, 2014	19,724,482	19,724,000				0	0	0

Statements_of_Changes_in_Conve1

Statements of Changes in Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) (USD $)	1 Months Ended	3 Months Ended	4 Months Ended	12 Months Ended	2 Months Ended	1 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Nov. 30, 2012	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2013	Apr. 30, 2014	Dec. 31, 2013	Dec. 31, 2014
Preferred Stock | Series AA Preferred Stock
Payments of offering costs	$13	$13
Preferred Stock | Series A-1 Preferred Stock
Payments of offering costs			22	22
Preferred Stock | Series A-1A Preferred Stock
Payments of offering costs				88	88
Common Stock
Payments of offering costs				$5,504		$4,035	$5,504	$4,035

Statements_of_Cash_Flows

Statements of Cash Flows (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013
Cash Flows from Operating Activities
Net loss	($120,000)	($27,139,000)	($4,213,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	11,000	4,422,000	922,000
Depreciation and amortization expense	0	58,000	3,000
Amortization of premium on marketable securities	0	87,000	0
Changes in operating assets and liabilities:
Prepaid expenses and other	0	-329,000	-147,000
Other assets	0	-22,000	0
Accounts payable	6,000	-269,000	683,000
Due to related party	5,000	0	-5,000
Accrued liabilities and accrued compensation	36,000	1,258,000	1,184,000
Net cash used in operating activities	-62,000	-21,934,000	-1,573,000
Cash Flows from Investing Activities
Purchases of short-term investments	0	-145,172,000	0
Sale of short-term investments	0	9,000,000	0
Maturities of short-term investments	0	48,000,000	0
Purchase of property and equipment	0	-440,000	-15,000
Net cash used in investing activities	0	-88,612,000	-15,000
Cash Flows from Financing Activities
Exercise of stock options	0	121,000	11,000
Net proceeds from initial public offering	0	0	54,871,000
Net proceeds from follow-on public offering	0	58,065,000	0
Proceeds from note payable to related party	10,000	0	0
Net cash provided by financing activities	1,000,000	58,186,000	65,979,000
Net change in cash and cash equivalents	938,000	-52,360,000	64,391,000
Cash and cash equivalents at beginning of period	0	65,329,000	938,000
Cash and cash equivalents at end of period	938,000	12,969,000	65,329,000
Supplemental disclosure of non-cash financing activities:
Conversion of note payable into Series AA convertible preferred stock	10,000	0	0
Offering costs in connection with Series AA convertible preferred stock recorded in accrued expenses	13,000	0	0
Issuance of common stock and stock options for accrued consulting expenses			12,000
Conversion of Series AA, Series A-1 and Series A-1A preferred stock into shares of common stock	0	0	12,099,000
Series AA Preferred Stock
Cash Flows from Financing Activities
Proceeds from issuance of convertible preferred stock	990,000	0	0
Supplemental disclosure of non-cash financing activities:
Issuance of convertible stock for settlement of offering costs and other legal fees	0	0	15,000
Series A-1 Preferred Stock
Cash Flows from Financing Activities
Proceeds from issuance of convertible preferred stock	0	0	5,865,000
Supplemental disclosure of non-cash financing activities:
Issuance of convertible stock for settlement of offering costs and other legal fees	0	0	32,000
Series A-1A Preferred Stock
Cash Flows from Financing Activities
Proceeds from issuance of convertible preferred stock	0	0	5,232,000
Supplemental disclosure of non-cash financing activities:
Issuance of convertible stock for settlement of offering costs and other legal fees	0	0	78,000
Common Stock
Supplemental disclosure of non-cash financing activities:
Issuance of common stock and stock options for accrued consulting expenses	$0	$303,000	$535,000

Organization_and_Description_o

Organization and Description of Business	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business
	Kindred Biosciences, Inc. (“we”, "us" or "our") was incorporated on September 25, 2012 (inception) in the State of Delaware. We are a biopharmaceutical company focused on saving and improving the lives of pets. Our activities since inception have consisted principally of raising capital, establishing facilities, recruiting management and technical staff and performing research and development and advancing our product candidates seeking regulatory approval. Our headquarters are in Burlingame, California.
	We are subject to risks common to companies in the biotechnology and pharmaceutical industries. There can be no assurance that our research and development will be successfully completed, that adequate protection for our technology will be obtained, that any products developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. We operate in an environment of substantial competition from other animal health companies. In addition, we are dependent upon the services of our employees and consultants, as well as third-party contract research organizations and manufacturers.
	Our reference to the year 2012 is defined as the period from September 25, 2012 (inception) to December 31, 2012.
	Liquidity
	We have incurred losses and negative cash flows from operations and have not generated any revenue since our inception and had an accumulated deficit of $31,472,000 as of December 31, 2014. We expect to continue to incur losses and negative cash flows, which will increase significantly from historical levels as we expand our product development activities, seek regulatory approvals for our product candidates, establish a biologics manufacturing capability, and begin to commercialize any approved products. To date, we have been funded primarily through sales of convertible preferred stock, the sale of our common stock in our initial public offering in December 2013 and the sale of our common stock in a follow-on public offering in April 2014. We might require additional capital until such time as we can generate operating revenues in excess of operating expenses. We believe our cash, cash equivalents and short-term investments of $101,027,000 at December 31, 2014 are sufficient to fund our operations for at least the next 24 months.
	If we require additional funding for operations, we may seek such funding through public or private equity or debt financings or other sources, such as corporate collaborations and licensing arrangements. We may not be able to obtain financing on acceptable terms, or at all, and we may not be able to enter into corporate collaborations or licensing arrangements. The terms of any financing may result in dilution or otherwise adversely affect the holdings or the rights of our stockholders. If we are unable to obtain funding, we could be forced to delay, reduce or eliminate our research and development programs or commercialization efforts, which could adversely affect our business prospects.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”).
	Use of Estimates
	The preparation of financial statements and related disclosures in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting periods. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, the valuation of common stock and stock-based awards, the realization of deferred tax assets, the recoverability of long-lived assets and the accrual of research and development expenses. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from those estimates.
	Cash, Cash Equivalents and Short-term Investments
	We consider all highly liquid investments purchased with an original maturity of three months or less at the date of acquisition to be cash equivalents. Debt securities with original maturities greater than three months and remaining maturities less than one year are classified as short-term investments. We classify all investments as available-for-sale. Available-for-sale securities are carried at estimated fair value, with unrealized gains and losses reported as a component of accumulated other comprehensive income (loss) in the accompanying balance sheets.
	Realized gains or losses on the sale of investments are determined on a specific identification method, and such gains and losses are reflected as a component of interest income in the accompanying statements of operations and comprehensive loss.
	Marketable securities investments are evaluated periodically for impairment. We take into account general market conditions, changes in economic environment as well as specific investment attributes, such as credit downgrade or illiquidity for each investment, the expected cash flows from the securities, our intent to sell the securities and whether or not we will be required to sell the securities before the recovery of their amortized cost, to estimate the fair value of our investments and to determine whether impairment is other than temporary. If it is determined that a decline in fair value of any investment is other than temporary, then the unrealized loss related to credit risk would be included in interest and other income, net.
	Concentration of Credit Risk and of Significant Suppliers
	Our financial instrument that potentially subjects us to concentrations of credit risk is cash and cash equivalents. From time to time, we maintain cash balances in excess of amounts insured by the Federal Deposit Insurance Corporation (“FDIC”). Primarily all of our cash and cash equivalents at December 31, 2014 were in excess of amounts insured by the FDIC. We do not believe that we are subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships.
	We are dependent on third-party manufacturers to supply products for research and development activities in our programs. In particular, we rely on a small number of manufacturers to supply us with our requirements for the active pharmaceutical ingredients, or API, and formulated drugs related to some of these programs. These programs would be adversely affected by a significant interruption in the supply of API.
	Fair Value Measurements
	We used the provisions of Accounting Standards Codification ("ASC') 820, “Fair Value Measurements and Disclosure", to determine the fair values of our financial and nonfinancial assets and liabilities where applicable. ASC 820 defines fair value, establishes a framework for measuring fair value in U.S. GAAP and expands disclosure about fair value measurements. The objective of fair value measurement is to determine the price that would be received to sell the asset or paid to transfer the liability (an exit price) in an orderly transaction between market participants at the measurement date. The statement emphasizes that fair value is a market-based measurement, not an entity-specific measurement, and that market participant assumptions include assumptions about risk and effect of a restriction on the sale or use of an asset. To increase consistency and comparability in fair value measurement and related disclosures, this statement establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels: (1) Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date; (2) Level 2 inputs are inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly through corroboration with observable market data; and (3) Level 3 inputs are unobservable inputs for the asset or liability that reflect the reporting entity’s own assumptions about risk and the assumptions market participants would use in pricing the asset or liability developed based on the best information available in the circumstances.
	Government agency securities are recorded at their estimated fair value. Since these government securities generally have market prices from multiple sources and it can be difficult to select the best individual price directly from the quoted prices in the active markets, we use Level 2 inputs for the valuation of these securities. Using the Level 2 inputs, a “consensus price” or a weighted average price for each of these securities can be derived from a distribution-curve-based algorithm which includes market prices obtained from a variety of industrial standard data providers (e.g. Bloomberg), security master files from large financial institutions, and other third-party sources.
	The carrying amount of financial instruments, including cash and cash equivalents, accounts payable and accrued liabilities approximate fair value due to the short maturities of these financial instruments. Financial assets, which consist of money market funds and available-for-sale securities, are measured at fair value on a recurring basis (see Note 3).
	Property and Equipment
	Property and equipment are stated at cost less accumulated depreciation and amortization. We calculate depreciation using the straight-line method over the estimated useful lives of the assets, which range from two to five years. Expenditures for repairs and maintenance of assets are charged to expense as incurred. We amortize leasehold improvements using the straight-line method over the estimated useful lives of the respective assets or the lease term, whichever is shorter. Upon retirement or sale, the cost and related accumulated depreciation and amortization of assets disposed of are removed from the accounts and any resulting gain or loss is included in income (loss) from operations.
	Licenses
	The costs incurred for the rights to use licensed technologies in the research and development process, including licensing fees and milestone payments, are charged to research and development expense as incurred in situations where we have not identified an alternative future use for the acquired rights, and are capitalized in situations where we have identified an alternative future use. No costs associated with the use of licensed technologies have been capitalized to date.
	Impairment of Long-Lived Assets
	We review long-lived assets, including property and equipment, for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that we consider in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends, and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset for recoverability, we compare forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the long-lived asset to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of an asset are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired assets over its fair value, determined based on discounted cash flows. To date, we have not recorded any impairment losses on long-lived assets.
	Revenue Recognition
	We are in the research and development stage and have not generated any revenues since inception.
	Research and Development Costs
	All costs of research and development are expensed in the period incurred. Research and development costs primarily consist of salaries and related expenses for personnel, stock-based compensation expense, fees paid to consultants, outside service providers, professional services, travel costs and materials used in clinical trials and research and development.
	Patent Costs
	All patent-related costs incurred in connection with filing patent applications are recorded in research and development expenses when incurred, as recoverability of such expenditures is uncertain.
	Stock-Based Compensation
	Our stock-based compensation plan (see Note 9) provides for the grant of stock options, restricted common stock and stock appreciation rights. The estimated fair values of stock option grants are determined as of the date of grant using the Black-Scholes option pricing model. This method incorporates the fair value of our common stock at the date of each grant and various assumptions such as the risk-free interest rate, expected volatility based on the historic volatility of publicly-traded peer companies, expected dividend yield, and expected term of the options. The estimated fair values of restricted stock awards are determined based on the fair value of our common stock, as determined by the board of directors, on the date of grant. The estimated fair values of stock-based awards, including the effect of estimated forfeitures, are expensed over the requisite service period, which is generally the awards’ vesting period. We classify stock-based compensation expense in the statement of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified.
	Our accounting policy for equity instruments issued to consultants and vendors in exchange for goods and services follows Financial Accounting Standards Board ("FASB") guidance. All transactions in which goods or services are the consideration received for the issuance of equity instruments are accounted for based on the fair value of the consideration received or the fair value of the equity instrument issued, whichever is more reliably measurable. The measurement date of the fair value of the equity instrument issued is the earlier of the date on which the counterparty’s performance is complete or the date at which a commitment for performance is reached. For transactions in which the fair value of the equity instrument issued to non-employees is the more reliable measurement and a measurement date has not been reached, the fair value is re-measured at each reporting date using the Black-Scholes option pricing model. Compensation expense for these share-based awards is recognized over the term of the consulting agreement or until the award is approved and settled.
	Income Taxes
	We account for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the financial statements or in our tax returns. Deferred taxes are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect in the years in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. We assess the likelihood that our deferred tax assets will be recovered from future taxable income and, to the extent we believe, based upon the weight of available evidence, that it is more likely than not that all or a portion of deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies.
	We account for uncertainty in income taxes recognized in the financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.
	Comprehensive Loss
	Our comprehensive loss includes the change in unrealized gains or losses on available-for-sale securities. The cumulative amount of gains or losses are reflected as a separate component of stockholders' equity in the accompanying balance sheets as accumulated other comprehensive loss.
	Segment Data
	We manage our operations as a single segment for the purposes of assessing performance and making operating decisions. We are a veterinary biotechnology company focusing on developing therapies for pets. Our chief operating decision maker is our Chief Executive Officer. All assets are held in the United States.
	Basic and Diluted Net Loss Per Common Share
	Basic net loss per common share is computed by dividing net loss attributable to common stockholders for the period by the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders for the period by the weighted average number of common shares, including potential dilutive shares of common stock assuming the dilutive effect of potentially dilutive securities. For periods in which we have reported a net loss, diluted net loss per common share is the same as basic net loss per common share, since the impact of the potentially dilutive securities would be anti-dilutive to the calculation of net loss per common share (see Note 13).
	Recently Issued Accounting Pronouncements
	On June 10, 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (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," which eliminates the concept of a development stage entity (DSE) in its entirety from current accounting guidance. A DSE is an entity devoting substantially all of its efforts to establishing a new business and for which either planned principal operations have not yet commenced or have commenced but there has been no significant revenues generated from that business. Under current guidance, DSEs are required to present inception-to-date financial information in their annual statements. We determined we were a DSE and had therefore presented inception-to-date financial information financial statements. As permitted by ASU 2014-10, we have elected to early adopt this standard, and therefore, we have not presented any inception to date financial information and we have removed all references to development stage in these financial statements.
	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 provides guidance regarding management’s responsibility to assess whether substantial doubt exists regarding the ability to continue as a going concern and to provide related footnote disclosures. In connection with preparing financial statements for each annual and interim reporting period, management should evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the company’s ability to continue as a going concern within one year after the date that the financial statements are issued (or within one year after the date that the financial statements are available to be issued when applicable). This ASU is effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. We are currently evaluating the new guidance and have not determined the impact this standard may have on our financial statements.
	We do not believe there are any other recently issued standards not yet effective that will have a material impact on our financial statements when the standards become effective.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements
	We measure certain financial assets at fair value on a recurring basis, including cash equivalents and available-for-sale securities. The fair value of these financial assets was determined based on a three-tier fair value hierarchy as described in Note 2, which prioritizes the inputs used in measuring fair value.
	The following table presents information about our financial assets that are measured at fair value on a recurring basis as of December 31, 2014 and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value:
	(In thousands)	Fair Value Measurements as of December 31, 2014
	Description	Total		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Unobservable Inputs (Level 3)
	Cash equivalents:
	Money market funds	$	834	$	834	$	—	$	—
	Short-term investments:
	U.S. treasury bills	5,998		—		5,998		—
	U.S. treasury bonds and notes	82,060		—		82,060		—
		$	88,892	$	834	$	88,058	$	—
	The following table presents information about our financial assets that are measured at fair value on a recurring basis as of December 31, 2013 and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value:
	(In thousands)	Fair Value Measurements as of December 31, 2013
	Description	Total		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Unobservable Inputs (Level 3)
	Cash equivalents:
	Money market funds	$	65,310	$	65,310	$	—	$	—
		$	65,310	$	65,310	$	—	$	—
	There were no transfers of assets between Level 1, Level 2 or Level 3 of the fair value hierarchy at December 31, 2014 and 2013.
	At December 31, 2014 and 2013, we did not have any financial liabilities which were measured at fair value on a recurring basis.

Shortterm_Investments

Short-term Investments	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Short-term Investments	Short-term Investments
	The fair value of available-for-sale short-term investments by type of security at December 31, 2014 were as follows:
	(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	U.S. treasury bills	$	5,994	$	4	$	—		$	5,998
	U.S. treasury bonds and notes	82,091		—		(31		)	82,060
		$	88,085	$	4	$	(31	)	$	88,058
	We did not hold any short-term investments at December 31, 2013.

Property_and_Equipment_Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment, Net [Abstract]
Property and Equipment, Net	Property and Equipment, Net
	Property and equipment consisted of the following as of December 31, 2014 and 2013:
		Years Ended December 31,
	(in thousands)	2014			2013
	Computer and lab equipment	$	359		$	15
	Furniture & fixtures	24			—
	Leasehold improvements	69			—
	Total	452			15
	Less accumulated depreciation and amortization	(58		)	-3
	Property and equipment, net	$	394		$	12
	Depreciation and amortization expense was $58,000 and $3,000 for the years ended December 31, 2014 and 2013, respectively. We had no capital expenditures or depreciation in 2012.

Accrued_Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities
	Accrued liabilities consisted of the following as of December 31, 2014 and 2013:
	(In thousands)	December 31, 2014			December 31, 2013
	Accrued consulting	$	—		$	303
	Accrued research and development costs	715			159
	Accrued offering costs	—			381
	Accrued other	247			43
	Deferred rent	57			—
		1,019			886
	Less current portion	(975		)	(886		)
	Long-term liability (deferred rent)	$	44		$	—

Convertible_Preferred_Stock

Convertible Preferred Stock	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Convertible Preferred Stock	Convertible Preferred Stock
	Prior to our initial public offering in December 2013, our Certificate of Incorporation, as amended and restated, authorized us to issue 15,000,000 shares of $0.0001 par value preferred stock. Through December 16, 2013, we had issued 1,015,000 shares of Series AA convertible preferred stock (“Series AA Preferred Stock”), 1,860,204 shares of Series A-1 convertible preferred stock (“Series A-1 Preferred Stock) and 1,675,002 shares of Series A-1A convertible preferred stock (“Series A-1A Preferred Stock) (collectively, the “Preferred Stock”). In connection with our initial public offering in December 2013, all outstanding shares of the Preferred Stock automatically converted into 4,550,195 (net of an adjustment for 11 fractional shares) shares of our common stock.
	During November 2012, we issued 990,000 shares of Series AA Preferred Stock at an issuance price equal to $1.00 per share and received gross proceeds of $990,000. In connection with the Series AA Preferred Stock financing, we incurred offering costs of $13,000, which were recorded as a reduction of the gross proceeds. As of December 31, 2012, the offering costs of $13,000 were included in accrued expenses.
	In November 2012, our co-founder and current President and Chief Executive Officer (“CEO”) exchanged a $10,000 note payable owed to him by us (see Note 11) into 10,000 shares of our Series AA Preferred Stock.
	In November 2013, we issued 15,000 shares of Series AA Preferred Stock for payment of accrued offering costs.
	In connection with the Series AA Preferred Stock offering, each holder of at least 10,000 shares of Series AA Preferred Stock or shares of our common stock issued upon conversion of the Series AA Preferred Stock was granted the right of first refusal to purchase his pro rata share of new securities (any capital stock, including common stock and preferred stock, convertible securities, options or warrants to purchase capital stock) which we may, from time to time, propose to sell and issue. Certain securities transactions were excluded from this right as provided in the Series AA Investors’ Rights Agreement.
	In June 2013, we commenced an offering for the sale and issuance of up to 2,000,000 shares of Series A-1 Preferred Stock at an issuance price equal to $3.17 per share. During June through September 2013, we received gross proceeds of $5,865,000 related to the issuance of 1,850,204 shares of the Series A-1 Preferred Stock. In connection with the Series A-1 Preferred Stock financing, we incurred offering costs of $22,000 which were recorded as a reduction of the gross proceeds. In June 2013, we issued 5,000 shares of the Series A-1 Preferred Stock valued at $16,000 on the date of issuance for partial payment of the Series A-1 Preferred Stock offering costs. In August 2013, we issued an additional 5,000 shares of the Series A-1 Preferred Stock valued at $16,000 on the date of issuance for payment of the remaining Series A-1 Preferred Stock offering costs and other legal fees.
	In connection with the sale and issuance of the Series A-1 Preferred Stock, the holders of the Series AA Preferred Stock waived their right of first refusal under the Series AA Investors’ Rights Agreement with respect to any sale by us of a proposed future series of preferred stock (“Series A-2 Preferred Stock”) on or before June 30, 2014. Additionally, each holder of at least 10,000 shares of Series A-1 Preferred Stock or shares of our common stock issued upon conversion of the Series A-1 Preferred Stock was granted the right of first refusal to purchase his pro rata share of new securities (any capital stock, including common stock and preferred stock, convertible securities, options or warrants to purchase capital stock) which we may, from time to time, propose to sell and issue. Certain securities transactions were excluded from this right as provided in the Series A-1 Investors’ Rights Agreement.
	Pursuant to the terms of the Series A-1 Preferred Stock Purchase Agreement, if shares of the Series A-2 Preferred Stock were issued prior to June 30, 2014, and the rights, preferences, or privileges of the Series A-2 Preferred Stock were more favorable to the holders of those shares than the terms of the Series A-1 Preferred Stock, then the rights, preferences and privileges of the Series A-1 Preferred Stock would be amended to be substantially the same of those of the Series A-2 Preferred Stock. In addition, if shares of the Series A-2 Preferred Stock were issued prior to June 30, 2014 and the purchase price of the Series A-2 Preferred Stock was such that the purchase price of the Series A-1 Preferred Stock was not at least 10% lower than the purchase price of the Series A-2 Preferred Stock, then additional shares of Series A-1 Preferred Stock would be issued to the Series A-1 Preferred Stockholders so that the effective price of the Series A-1 Preferred Stock was at least 10% lower than Series A-2 Preferred Stock. We determined that the value of these embedded derivative features was not significant. Prior to the automatic conversion of the Series A-1 Preferred Stock in December 2013 in connection with our initial public offering, no shares of Series A-2 Preferred Stock were authorized by us.
	In August 2013, we commenced an offering for the sale and issuance of up to 2,000,000 shares of Series A-1A Preferred Stock at an issuance price equal to $3.17 per share. In August and September 2013, we received gross proceeds of $5,232,000 related to the issuance of 1,650,396 shares of the Series A-1A Preferred Stock. In connection with the Series A-1A Preferred Stock financing, we incurred offering costs of $88,000 which were recorded as a reduction of the gross proceeds. In August 2013, we issued 24,606 shares of the Series A-1A Preferred Stock valued at $78,000 on the date of issuance for payment of certain Series A-1A offering costs.
	In connection with the Series A-1A Preferred Stock offering, each holder of at least 10,000 shares of Series A-1A Preferred Stock or shares of our common stock issued upon conversion of the Series A-1A Preferred Stock was granted the right of first refusal to purchase his pro rata share of new securities (any capital stock, including common stock and preferred stock, convertible securities, options or warrants to purchase capital stock) which we may, from time to time, propose to sell and issue. Certain securities transactions were excluded from this right as provided in the Series A-1A Investors’ Rights Agreement. In addition, holders of the Series A-1A Preferred Stock waived their right of first refusal under the Series A-1A Investors’ Rights Agreement with respect to any sale by us of Series A-2 Preferred Stock on or before June 30, 2014.
	Pursuant to the terms of the Series A-1A Preferred Stock Purchase Agreement, if shares of the Series A-2 Preferred Stock were issued prior to June 30, 2014, and the rights, preferences, or privileges of the Series A-2 Preferred Stock were more favorable to the holders of those shares than the terms of the Series A-1A Preferred Stock, then the rights, preferences and privileges of the Series A-1A Preferred Stock would be amended to be substantially the same of those of the Series A-2 Preferred Stock. In addition, if shares of the Series A-2 Preferred Stock were issued prior to June 30, 2014 and the purchase price of the Series A-2 Preferred Stock was such that the purchase price of the Series A-1A Preferred Stock was not at least 10% lower than the purchase price of the Series A-2 Preferred Stock, then additional shares of Series A-1A Preferred Stock would be issued to the Series A-1A Preferred Stockholders so that the effective price of the Series A-1A Preferred Stock was at least 10% lower than Series A-2 Preferred Stock. We determined that the value of these embedded derivative features was not significant. Prior to the automatic conversion of the Series A-1A Preferred Stock in December 2013 in connection with our initial public offering, no shares of Series A-2 Preferred Stock were authorized by us.
	The holders of the Preferred Stock had the following rights and preferences:
	Voting Rights
	Except as otherwise provided in our Certificate of Incorporation, as amended and restated, or as required by law, holders of the Preferred Stock shall vote together and not as a separate class. Each holder of the Preferred Stock shall be entitled to the number of votes equal to the number of shares of common stock into which the shares of the Preferred Stock held by such holder could be converted as of the record date. The holders of shares of the Preferred Stock shall be entitled to vote on all matters on which the common stock shall be entitled to vote.
	Holders of the Preferred Stock shall be entitled to notice of any stockholders’ meeting in accordance with our Bylaws. Fractional votes shall not, however, be permitted and any fractional voting rights resulting from the above formula (after aggregating all shares into which shares of Preferred Stock held by each holder could be converted), shall be disregarded.
	Liquidation Preference
	In the event of any liquidation, dissolution or winding up of our company, either voluntary or involuntary, the holder of the Preferred Stock shall be entitled to receive, prior and in preference to any distribution of any of our assets to the holders of the common stock by reason of their ownership of such stock, an amount per share equal to $1 per share for the Series AA Preferred Stock and $3.17 per share for the Series A-1 Preferred Stock and Series A-1A Preferred Stock, or such lesser amount as may be approved by the holders of the majority of the outstanding shares of the Preferred Stock. If upon liquidation, dissolution or winding up of our company, our assets legally available for distribution to the holders of the Preferred Stock are insufficient to permit the payment in full of the liquidation preference above, then our entire assets legally available for distribution shall be distributed with equal priority and pro rata among the holders of the Preferred Stock in proportion to the full amounts they would otherwise be entitled to receive.
	After the payment or setting aside for payment to the holders of Preferred Stock of the full amounts of the liquidation preferences, our entire remaining assets legally available for distribution shall be distributed pro rata to holders of our common stock in proportion to the number of shares of common stock held by them.
	Conversion Rights
	Optional Conversion
	The shares of Preferred Stock are convertible into shares of common stock, at the option of the holder, at any time after the date of issuance. Each share of Preferred Stock will be converted into shares of common stock at the applicable Series AA, Series A-1 and Series A-1A Preferred Stock conversion rate then in effect, which is calculated by dividing the original issue price by the respective conversion price. The conversion prices for the Series AA, Series A-1 and Series A-1A Preferred Stock are equal to $1.00 per share, $3.17 per share and $3.17 per share, respectively, and are subject to adjustment as set forth in our Certificate of Incorporation, as amended and restated. In connection with our initial public offering in December 2013, all outstanding shares of the Series AA, Series A-1 and Series A-1A Preferred Stock were converted into shares of common stock on a 1-for-1 basis.
	Automatic Conversion
	Each share of Preferred Stock automatically converted into shares of common stock upon us becoming a public company in connection with our initial public offering.
	Redemption Rights
	There were no redemption rights afforded the holders of Preferred Stock. Upon certain change in control events that were outside of our control, including liquidation, sale or transfer of control of our company, holders of the Preferred Stock could cause its redemption. Therefore, prior to the automatic conversion of the Preferred Stock in connection with our initial public offering in December 2013, the Preferred Stock was classified outside of stockholders’ equity (deficit) in accordance with authoritative guidance for the classification and measurement of potentially redeemable securities.
	Reissuance
	All shares of Preferred Stock that were converted into common stock were canceled and will not be reissued by us.
	In December 2013, we amended our Certificate of Incorporation to authorize the issuance of 10,000,000 shares of $0.0001 par value preferred stock. At December 31, 2014, all shares of preferred stock are undesignated and unissued.

Common_Stock

Common Stock	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Common Stock	Common Stock
	Our Certificate of Incorporation, as amended and restated, authorizes us to issue 100,000,000 shares of $0.0001 par value common stock.
	Each share of common stock entitles the holder to one vote on all matters submitted to a vote of our stockholders, provided, however, that, except as otherwise required by law, holders of common stock shall not be entitled to vote on any amendment to the Certificate of Incorporation that relates solely to the terms of one or more outstanding shares of preferred stock if the holders of such affected series are entitled, either separately or together with the holders of one or more other series, to vote thereon pursuant to the Certificate of Incorporation or pursuant to the Delaware General Corporation Law.
	In September and October 2012, we issued an aggregate of 3,000,000 shares of common stock to the co-founder and current President and CEO for total cash consideration of $300.
	In August 2013, we issued 5,200 shares of restricted common stock at a price of $2.27 per share to a consultant for services rendered and recorded stock-based compensation expense of $12,000.
	In 2013, we issued 34,225 shares of common stock upon exercise of stock options at a price of $0.32 per share for total proceeds of $11,000.
	In December 2013, we completed an initial public offering and issued 8,625,000 shares of common stock at $7.00 per share resulting in net proceeds of $54,871,000 after deduction of underwriting commissions and offering expenses of $5,504,000.
	In April 2014, we completed a follow-on public offering and issued 3,450,000 shares of common stock at $18.00 per share resulting in net proceeds of $58,065,000 after deduction of underwriting commissions and offering expenses of $4,035,000.
	In 2014, we issued 56,112 shares of common stock upon exercise of stock options at prices ranging from $0.32 to $15.41 per share for total proceeds of $121,000.
	In 2014, we issued 3,750 shares of restricted common stock to a consultant for services rendered and recorded stock-based compensation expense of $61,000.
	As of December 31, 2014, we had 19,724,482 shares of common stock outstanding.

StockBased_Awards

Stock-Based Awards	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Awards	Stock-Based Awards
	On November 4, 2012, our board of directors adopted the Kindred Biosciences, Inc. 2012 Equity Incentive Plan (the “2012 Plan”). The 2012 Plan provides for our board of directors to grant incentive stock options or non- qualified stock options for the purchase of common stock, to issue or sell shares of restricted common stock and to grant stock appreciation rights (“SARs”) to our employees, directors, consultants and advisers of the Company. Pursuant to the terms of the 2012 Plan, no options or SARs shall be granted under the 2012 Plan after 10 years from the date of adoption of the 2012 Plan. We have reserved 4,000,000 shares of our common stock for issuance under the 2012 Plan.
	Retrospective Reassessment of the Fair Value of Common Stock
	As required by the 2012 Plan, the exercise price for awards granted is not to be less than the fair market value of our common stock as of the date of grant. We value shares of common stock by taking into consideration our most recently available valuation of common stock performed by management and the board of directors, as well as additional factors which may have changed since the date of the most recent contemporaneous valuations through the date of grant. On February 4, 2013, May 9, 2013, August 29, 2013 and September 12, 2013, the board of directors granted stock options for the purchase of 576,525 shares, 154,793 shares, 412,580 shares, and 29,000 shares, respectively, of our common stock with weighted-average exercise prices of $0.35 per share, $0.32 per share, $0.90 per share and $0.90 per share, respectively. On November 11, 2013, our board of directors, with the consent of the affected employee and director option holders, approved an increase from $0.90 per share to $1.37 per share in the exercise price of 285,092 employee and director options granted in August and September 2013. The fair value of our common stock on the February 4, 2013 and May 9, 2013 grant dates was $0.32 per share, and on the August 29, 2013 and September 12, 2013 grant dates was $1.37 per share, as determined by our board of directors. In connection with the December 2013 initial public offering of our common stock, we reexamined, for financial reporting purposes only, the fair value of our common stock. In connection with the reexamination, we determined that retrospective valuations of the fair value of common stock as of February 4, 2013, May 9, 2013, August 29, 2013 and September 12, 2013 were appropriate due to acceleration of the timeframe to a potential liquidity event and the proposed initial public offering, which had not been contemplated in the determination of the original fair values on these dates. Based on this analysis, the fair value of common stock remained unchanged for the February 4, 2013 and May 9, 2013 grant dates. Based on this analysis, the fair value of the common stock on the August 29, 2013 and September 12, 2013 grant dates was determined to be $2.27 per share, which we used to value the stock-based compensation expense for these awards.
	Stock Options
	Our board of directors determines the exercise price and vesting period of all stock options. The exercise price of the stock options will be no less than 100% of the fair value per share of our common stock on the grant date. If a person owns capital stock representing more than 10% of all classes of our stock, the exercise price will be not less than 110% of the fair market value on the date of grant. Options are vested over variable periods, generally ranging from one to four years, and expire not more than 10 years after the date of grant. As of December 31, 2014, there were 2,329,415 option shares outstanding and 1,571,298 shares available for future grants under the 2012 Plan.
	During the years ended December 31, 2014 and 2013, we granted under the 2012 Plan stock options for the purchase of 1,127,113 and 1,410,139 shares of common stock, respectively, to employees, non-employee consultants and directors. No stock options were granted in 2012.
	2014 Employee Stock Purchase Plan
	In December 2014, our board of directors adopted the Kindred Biosciences, Inc. 2014 Employee Stock Purchase Plan (the “Purchase Plan”). We reserved a total of 200,000 shares of our common stock for issuance under the Purchase Plan. The Purchase Plan permits eligible employees to purchase common stock at a discount through payroll deductions during defined six-month consecutive offering periods beginning on December 1. The price at which the stock is purchased is equal to the lower of 85% of the fair market value of the common stock on the first day of the offering or 85% of the fair market value of our common stock on the purchase date. As of December 31, 2014, there were no issuances under the Purchase Plan.
	Reserved Shares
	At December 31, 2014, shares of common stock reserved for future issuance inclusive of outstanding option shares are as follows:
	2012 Equity Incentive Plan	3,900,713
	2014 Employee Stock Purchase Plan	200,000
		4,100,713
	Stock Option Plan Activity Summary
	A summary of activity under our stock option plans is as follows:
		Shares Available For Grant			Shares Issuable Under Options			Weighted Average Exercise Price				Weighted Average Remaining ContractualTerm (In Years)	Aggregate Intrinsic Value
	Balance, December 31, 2012	4,000,000			—
	Granted	-1,410,139			1,410,139			$	1.31
	Exercised				-34,225			$	0.32
	Restricted stock grants	(10,200	)		—
	Balance, December 31, 2013	2,579,661			1,375,914			$	1.33
	Granted	(1,127,113	)		1,127,113			$	16.23
	Exercised				(56,112	)		$	2.17
	Forfeited - restricted stock and options	118,750			(117,500	)		$	19.57
	Balance, December 31, 2014	1,571,298			2,329,415			$	7.6			8.8	$	8,100,000
	Options vested and expected to vest, December 31, 2014				2,329,415			$	7.6			8.8	$	8,100,000
	Options exercisable, December 31, 2014				953,327			$	3.8			8.6	$	4,930,000
	The aggregate intrinsic value of options is calculated as the difference between the exercise price of options and the fair value of our common stock for those options that had exercise prices lower than the fair value of our common stock on December 31, 2014.
	The aggregate intrinsic value of stock options exercised during the years ended December 31, 2014 and 2013 was $774,000 and $108,000, respectively. No options were exercised during the period ended December 31, 2012.
	We received proceeds of $121,000 and $11,000 from the exercise of common stock options during the years ended December 31, 2014 and 2013, respectively.
	The weighted-average grant date fair value of options granted during the years ended December 31, 2014 and 2013 was $12.09 and $1.50 per share, respectively.
	Restricted Stock
	During the year ended December 31, 2013, we granted 10,200 shares of restricted common stock to consultants. The weighted average fair value of the restricted shares was $6.63. As of December 31, 2014, there were no unvested shares of restricted common stock.
	Stock-Based Compensation
	We recognize stock-based compensation expense for only the portion of awards that are expected to vest. In developing a forfeiture rate estimate, we have considered our historical experience to estimate pre-vesting forfeitures for service-based awards. The impact of a forfeiture rate adjustment will be recognized in full in the period of adjustment, and if the actual forfeiture rate is materially different from our estimate, we may be required to record adjustments to stock-based compensation expense in future periods.
	We value our common stock by taking into consideration its most recently available valuation of common stock performed by management and the board of directors, as well as additional factors which may have changed from the date of the most recent contemporaneous valuation through the grant date.
	The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. We historically have been a private company that lacks company-specific historical and implied volatility information. Therefore, we estimate the expected stock volatility based on the historical volatility of publicly traded peer companies and expect to continue to do so until such time as we have adequate historical data regarding the volatility of our own traded stock price. The expected term of our common stock options has been determined utilizing the “simplified” method as we have insufficient historical experience for options grants overall, rendering existing historical experience irrelevant to expectations for current grants. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that we have never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future.
	Total stock-based compensation expense, related to all of our share-based payment awards, is comprised of the following:
	(In thousands)	Years Ended December 31,
		2014				2013				2012
	Research and development	$	1,453			$	827			$	11
	General and administrative	2,969				95				—
		$	4,422			$	922			$	11
	Total stock-based compensation expense included stock options and restricted stock for the years ended December 31, 2014, 2013 and 2012. We recorded accrued expenses of $303,000 and $11,000 at December 31, 2013 and 2012, respectively, for those options that have been earned but not granted and approved by the board of directors as of these dates. There were no such accruals in 2014.
	We had an aggregate of approximately $8,693,000 of unrecognized stock-based compensation expense for options outstanding as of December 31, 2014, which is expected to be recognized over a weighted average period of 3.1 years.
	Valuation assumptions
	The relevant data used to determine the value of stock options earned or granted is as follows:
		Years Ended December 31,
		2014		2013		2012
	Weighted average risk-free interest rate	1.70%		1.33%		0.62%-0.72%
	Weighted average expected term (in years)	6.4		6.6		10
	Weighted average expected volatility	91.30%		85.20%		90%
	Weighted average expected dividend yield	—		—		—

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	Operating Lease
	In March 2014, we entered into a license agreement under which we made an up-front payment and were obligated to make annual payments and, subject to certain terms and conditions, milestone payments upon achievement of development milestones and a royalty based on sales of products developed under the agreement. In January 2015, we terminated this agreement.
	For the period from September 25, 2012 (inception) through March 2014, we leased our office space on a month-to-month basis. In April 2014, we entered into new non-cancelable operating leases for laboratory space and office space through November 2017. Rent expense for the years ended December 31, 2014 and 2013 were $162,000 and $6,000, respectively. Rent expense for the year ended December 31, 2012 was less than $1,000 . In addition, we have two leases for equipment through 2018.
	As of December 31, 2014, we are obligated to make minimum lease payments under all of our operating leases as follows (in thousands):
	Year ending December 31,	Lease Payments
	2015	$	259
	2016	266
	2017	216
	2018	3
	Total	$	744
	Indemnities and Guarantees
	We have made certain indemnities and guarantees, under which we may be required to make payments to a guaranteed or indemnified party, in relation to certain transactions. We indemnify our officers and directors to the maximum extent permitted under the laws of the State of Delaware. The duration of these indemnities and guarantees varies and, in certain cases, is indefinite. These indemnities and guarantees do not provide for any limitation of the maximum potential future payments we could be obligated to make. Historically, we have not been obligated to make any payments for these obligations and no liabilities have been recorded for these indemnities and guarantees in the accompanying balance sheets.
	Legal Matters
	In the ordinary course of business, we may face various claims brought by third parties and may, from time to time, make claims or take legal actions to assert our rights, including intellectual property disputes, contractual disputes and other commercial disputes. Any of these claims could subject us to litigation. Management believes there are currently no claims that are likely to have a material effect on our financial position and results of operations.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions
	During the period September 25, 2012 (inception) through December 31, 2012, our co-founder and President and Chief Executive Officer paid certain expenses on our behalf totaling $5,000. At December 31, 2013 and 2012, the amounts payable to him for reimbursement of these expenses were $0 and $5,000, respectively.
	In October 2012, our co-founder and President and Chief Executive Officer loaned to us $10,000 for working capital requirements. The note was due on demand and was non-interest bearing. In November 2012, the note payable was exchanged for 10,000 shares of Series AA Preferred Stock (see Note 7).
	We entered into a consulting agreement with S.D. Scientific, a company owned 50% by our co-founder and current Chief Operating Officer. Consulting fees earned by S.D. Scientific during the year ended December 31, 2013 and the period from September 25, 2012 (inception) through December 31, 2012 were $54,000 and $9,000, respectively.
	In connection with our Series AA Preferred Stock financing, our co-founder and current CEO purchased 100,000 shares of Series AA Preferred Stock for $100,000 during the period September 25, 2012 (inception) through December 31, 2012. In addition, our co-founder and Chief Executive Officer purchased 31,546 shares of Series A-1 Preferred Stock for $100,000 during the year ended December 31, 2013.
	In connection with our Series A-1 and Series A-1A Preferred Stock financings in 2013, an entity affiliated with one of our board members purchased 31,546 shares and 15,773 shares of Series A-1 and Series A-1A Preferred Stock, respectively, for $100,000 and $50,000, respectively.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	There is no provision for income taxes because we have historically incurred operating losses and we maintain a full valuation allowance against our net deferred tax assets.
	Differences between the provision (benefit) for income taxes and income taxes at the statutory federal income tax rate are as follows:
	(In thousands, except percentages)	For the years ended December 31,
		2014						2013					2012
	Income tax expense (benefit) at statutory federal rate	$	(9,227	)	34	%		$	(1,432	)	34	%	$	(41	)	34	%
	State income tax, net of federal benefit	(1,663		)	6.1			(245		)	5.8		(6		)	5.2
	Permanent items	14			(0.1	)		2			—		4			(3.7	)
	Research credits	(807		)	3			(188		)	4.5		—			—
	Stock compensation	—			—			6			(0.1	)	—			—
	FIN 48	323			(1.2	)		75			(1.8	)	—			—
	Change in valuation allowance	11,388			(41.9	)		1,782			(42.4	)	43			(35.5	)
	Other individually immaterial items	(28		)	0.1			—			—		—			—
	Provision (benefit) for income taxes	$	—		—	%		$	—		—	%	$	—		—	%
	Deferred tax assets are recognized for temporary differences that will result in deductible amounts in future periods. The components of the deferred tax assets are as follows at December 31, 2014 and 2013:
		December 31,
	(In thousands)	2014			2013
	Deferred tax assets:
	Net operating loss carryforwards	$	10,047		$	479
	Research & development credits	597			113
	Accrued expenses	463			217
	Amortization and depreciation	4			645
	Other	1			—
	Stock-based compensation	2,101			371
		13,213			1,825
	Valuation Allowance	(13,213		)	(1,825		)
	Net current deferred tax assets	$	—		$	—
	At December 31, 2014, we had net deferred tax assets of $13,213,000. Due to uncertainties surrounding our ability to generate future taxable income to realize these assets, a full valuation allowance has been established to offset the net deferred tax asset.
	Additionally, the future utilization of our net operating loss and research and development tax credits carryforwards is subject to annual limitation under Sections 382 and 383 of the internal Revenue Code of 1986, and similar state tax provisions due to ownership change limitations that have occurred previously or that could occur in the future. These ownership changes limit the amount of the net operating loss and research and development tax credit carryforward and other deferred tax assets that can be utilized to offset future taxable income and tax, respectively. In general, an ownership change, as defined by Sections 382 and 383, results from transactions increasing ownership of certain stockholders or public groups in the stock of the corporation by more than 50 percent points over a three-year period. We believe we incurred an ownership change during April 2014, however, we have not completed an analysis yet to determine the impact of our ability to use net operating losses and research and development credits as of December 31, 2014.
	At December 31, 2014, we had federal and California net operating loss carryovers of $25,680,000 and $25,494,000, respectively. The federal and California net loss carryforwards will begin to expire in 2032.
	At December 31, 2014, we had federal and state research tax credit carryovers of approximately $629,000 and $554,000, respectively. The federal research and development tax credit carryforwards will begin to expire in 2033. The California research and development credit carryforwards are available indefinitely.
	The impact of an uncertain income tax position on the income tax return must be recognized at the largest amount that is more likely than not to be sustained upon audit by the relevant taxing authority. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. There were no unrecognized tax benefits recorded by us as of the date of adoption. As a result of the implementation, we did not recognize an increase in the liability for unrecognized tax benefits.
	A rollforward of changes in our unrecognized tax benefits is shown below.
	(In thousands)	December 31,
		2014			2013
	Balance at beginning of year	$	91		$	—
	Additions based on tax positions related to the current year	382			91
	Additions for tax positions of prior years	—			—
	Reductions for tax positions of prior years	—			—
	Settlements	—			—
	Balance at end of year	$	473		$	91
	The amount of unrecognized tax benefits that would impact the effective tax rate if recognized and realized is $398,000.
	Our practice is to recognize interest and/or penalties related to income tax matters as income tax expense. We had no accrual for interest or penalties on our accompanying balance sheets at December 31, 2014 and 2013, and have not recognized interest and/or penalties in our statements of operations and comprehensive loss for the years ended December 31, 2014, 2013 and 2012.
	We do not anticipate a significant change to our unrecognized tax benefits during the next twelve months.
	We file tax returns as prescribed by tax laws of the jurisdictions in which we operate. In the normal course of business, we are subject to examination by federal and state jurisdictions, where applicable. There are currently no pending tax examinations. Our federal and state tax returns are still open under statute from 2012 to present.

Net_Loss_Per_Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share
	Basic and diluted net loss per share was calculated as follows for the years ended December 31, 2014, 2013 and 2012:
	(In thousands, except per share amounts)	Years Ended December 31,
		2014			2013			2012
	Basic and diluted net loss per share attributable to common stockholders:
	Numerator:
	Net loss attributable to common stockholders	$	(27,139	)	$	(4,213	)	$	(120	)
	Denominator:
	Weighted average common shares outstanding, basic and diluted	18,782			3,732			2,113
	Net loss per common share attributable to common shareholders, basic and diluted	$	(1.44	)	$	(1.13	)	$	(0.06	)
	There was no difference between our net loss and the net loss attributable to common stockholders for all periods presented.
	Stock options to purchase 2,329,415 shares of common stock as of December 31, 2014, were excluded from the computation of diluted net loss per share attributable to common stockholders because their effect was anti-dilutive.
	Stock options to purchase 1,375,914 shares of common stock as of December 31, 2013, were excluded from the computation of diluted net loss per share attributable to common stockholders because their effect was anti-dilutive.
	Shares of common stock issuable upon the conversion of preferred stock of 1,000,000 were excluded from the computation of diluted net loss per share attributable to common stockholders for the year ended December 31, 2012, because their effect was anti-dilutive.

Employee_Savings_Plan

Employee Savings Plan	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Employee Savings Plan	Employee Savings Plan
	We have established an employee savings plan pursuant to Section 401(k) of the Internal Revenue Code, effective May 1, 2014. The plan allows participating employees to deposit into tax deferred investment accounts up to 90% of their salary, subject to annual limits. We make contributions to the plan in an amount equal to 50% on the first 6% of the participant’s compensation which is deferred. We contributed approximately $84,000 to the plan during the year ended December 31, 2014.

Selected_Quarterly_Financial_I

Selected Quarterly Financial Information (unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Information (unaudited)	Selected Quarterly Financial Information (unaudited)
	The following table presents selected unaudited quarterly financial data for each of the quarters in the years ended December 31, 2014 and 2013.
	(In thousands, except per share amounts)	2014												2013
	Quarter ended	Dec. 31			Sep. 30			Jun. 30			Mar. 31			Dec. 31			Sep. 30			Jun. 30			Mar. 31
	Operating costs and expenses
	Research and development	$	4,802		$	3,755		$	5,639		$	4,498		$	1,746		$	953		$	300		$	141
	General and administrative	2,014			2,342			2,504			1,679			641			259			96			83
	Total operating cost and expenses	6,816			6,097			8,143			6,177			2,387			1,212			396			224
	Loss from operations	(6,816		)	(6,097		)	(8,143		)	(6,177		)	(2,387		)	(1,212		)	(396		)	(224		)
	Interest and other income, net	27			25			33			9			4			2			—			—
	Net loss	$	(6,789	)	$	(6,072	)	$	(8,110	)	$	(6,168	)	$	(2,383	)	$	(1,210	)	$	(396	)	$	(224	)
	Net loss per share, basic and diluted (1)	$	(0.34	)	$	(0.31	)	$	(0.42	)	$	(0.38	)	$	(0.40	)	$	(0.40	)	$	(0.13	)	$	(0.07	)
	Weighted average shares used in computing net loss per share, basic and diluted	19,719			19,713			19,426			16,222			5,899			3,005			3,000			3,000
	(1) Net loss per share for each quarter are calculated as a discrete period; the sum of four quarters may not equal the calculated full year amount.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events
	We have evaluated subsequent events through the filing date of this annual report on Form 10-K, and determined that no subsequent events have occurred that would require recognition in the financial statements or disclosure in the notes thereto other than as listed below.
	On January 14, 2015, we entered into an agreement to amend our existing operating lease for laboratory space at the Mitten Road facility. The amendment to the original lease calls for an expansion of an additional 2,431 square feet of laboratory space. The term of the lease is March 1, 2015 through November 30, 2017 and total rent payments under this agreement is expected to be $160,000.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
	The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”).
Use of Estimates	Use of Estimates
	The preparation of financial statements and related disclosures in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting periods. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, the valuation of common stock and stock-based awards, the realization of deferred tax assets, the recoverability of long-lived assets and the accrual of research and development expenses. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from those estimates.
Cash, Cash Equivalents and Short-term Investments	Cash, Cash Equivalents and Short-term Investments
	We consider all highly liquid investments purchased with an original maturity of three months or less at the date of acquisition to be cash equivalents. Debt securities with original maturities greater than three months and remaining maturities less than one year are classified as short-term investments. We classify all investments as available-for-sale. Available-for-sale securities are carried at estimated fair value, with unrealized gains and losses reported as a component of accumulated other comprehensive income (loss) in the accompanying balance sheets.
	Realized gains or losses on the sale of investments are determined on a specific identification method, and such gains and losses are reflected as a component of interest income in the accompanying statements of operations and comprehensive loss.
	Marketable securities investments are evaluated periodically for impairment. We take into account general market conditions, changes in economic environment as well as specific investment attributes, such as credit downgrade or illiquidity for each investment, the expected cash flows from the securities, our intent to sell the securities and whether or not we will be required to sell the securities before the recovery of their amortized cost, to estimate the fair value of our investments and to determine whether impairment is other than temporary. If it is determined that a decline in fair value of any investment is other than temporary, then the unrealized loss related to credit risk would be included in interest and other income, net.
Concentration of Credit Risk and of Significant Suppliers	Concentration of Credit Risk and of Significant Suppliers
	Our financial instrument that potentially subjects us to concentrations of credit risk is cash and cash equivalents. From time to time, we maintain cash balances in excess of amounts insured by the Federal Deposit Insurance Corporation (“FDIC”). Primarily all of our cash and cash equivalents at December 31, 2014 were in excess of amounts insured by the FDIC. We do not believe that we are subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships.
	We are dependent on third-party manufacturers to supply products for research and development activities in our programs. In particular, we rely on a small number of manufacturers to supply us with our requirements for the active pharmaceutical ingredients, or API, and formulated drugs related to some of these programs. These programs would be adversely affected by a significant interruption in the supply of API.
Fair Value Measurements	Fair Value Measurements
	We used the provisions of Accounting Standards Codification ("ASC') 820, “Fair Value Measurements and Disclosure", to determine the fair values of our financial and nonfinancial assets and liabilities where applicable. ASC 820 defines fair value, establishes a framework for measuring fair value in U.S. GAAP and expands disclosure about fair value measurements. The objective of fair value measurement is to determine the price that would be received to sell the asset or paid to transfer the liability (an exit price) in an orderly transaction between market participants at the measurement date. The statement emphasizes that fair value is a market-based measurement, not an entity-specific measurement, and that market participant assumptions include assumptions about risk and effect of a restriction on the sale or use of an asset. To increase consistency and comparability in fair value measurement and related disclosures, this statement establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels: (1) Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date; (2) Level 2 inputs are inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly through corroboration with observable market data; and (3) Level 3 inputs are unobservable inputs for the asset or liability that reflect the reporting entity’s own assumptions about risk and the assumptions market participants would use in pricing the asset or liability developed based on the best information available in the circumstances.
	Government agency securities are recorded at their estimated fair value. Since these government securities generally have market prices from multiple sources and it can be difficult to select the best individual price directly from the quoted prices in the active markets, we use Level 2 inputs for the valuation of these securities. Using the Level 2 inputs, a “consensus price” or a weighted average price for each of these securities can be derived from a distribution-curve-based algorithm which includes market prices obtained from a variety of industrial standard data providers (e.g. Bloomberg), security master files from large financial institutions, and other third-party sources.
	The carrying amount of financial instruments, including cash and cash equivalents, accounts payable and accrued liabilities approximate fair value due to the short maturities of these financial instruments. Financial assets, which consist of money market funds and available-for-sale securities, are measured at fair value on a recurring basis (see Note 3).
Property and Equipment	Property and Equipment
	Property and equipment are stated at cost less accumulated depreciation and amortization. We calculate depreciation using the straight-line method over the estimated useful lives of the assets, which range from two to five years. Expenditures for repairs and maintenance of assets are charged to expense as incurred. We amortize leasehold improvements using the straight-line method over the estimated useful lives of the respective assets or the lease term, whichever is shorter. Upon retirement or sale, the cost and related accumulated depreciation and amortization of assets disposed of are removed from the accounts and any resulting gain or loss is included in income (loss) from operations.
Licenses	Licenses
	The costs incurred for the rights to use licensed technologies in the research and development process, including licensing fees and milestone payments, are charged to research and development expense as incurred in situations where we have not identified an alternative future use for the acquired rights, and are capitalized in situations where we have identified an alternative future use. No costs associated with the use of licensed technologies have been capitalized to date.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets
	We review long-lived assets, including property and equipment, for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that we consider in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends, and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset for recoverability, we compare forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the long-lived asset to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of an asset are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired assets over its fair value, determined based on discounted cash flows. To date, we have not recorded any impairment losses on long-lived assets.
Revenue Recognition	Revenue Recognition
	We are in the research and development stage and have not generated any revenues since inception.
Research and Development Costs	Research and Development Costs
	All costs of research and development are expensed in the period incurred. Research and development costs primarily consist of salaries and related expenses for personnel, stock-based compensation expense, fees paid to consultants, outside service providers, professional services, travel costs and materials used in clinical trials and research and development.
Patent Costs	Patent Costs
	All patent-related costs incurred in connection with filing patent applications are recorded in research and development expenses when incurred, as recoverability of such expenditures is uncertain.
Stock-Based Compensation	Stock-Based Compensation
	Our stock-based compensation plan (see Note 9) provides for the grant of stock options, restricted common stock and stock appreciation rights. The estimated fair values of stock option grants are determined as of the date of grant using the Black-Scholes option pricing model. This method incorporates the fair value of our common stock at the date of each grant and various assumptions such as the risk-free interest rate, expected volatility based on the historic volatility of publicly-traded peer companies, expected dividend yield, and expected term of the options. The estimated fair values of restricted stock awards are determined based on the fair value of our common stock, as determined by the board of directors, on the date of grant. The estimated fair values of stock-based awards, including the effect of estimated forfeitures, are expensed over the requisite service period, which is generally the awards’ vesting period. We classify stock-based compensation expense in the statement of operations and comprehensive loss in the same manner in which the award recipient’s payroll costs are classified.
	Our accounting policy for equity instruments issued to consultants and vendors in exchange for goods and services follows Financial Accounting Standards Board ("FASB") guidance. All transactions in which goods or services are the consideration received for the issuance of equity instruments are accounted for based on the fair value of the consideration received or the fair value of the equity instrument issued, whichever is more reliably measurable. The measurement date of the fair value of the equity instrument issued is the earlier of the date on which the counterparty’s performance is complete or the date at which a commitment for performance is reached. For transactions in which the fair value of the equity instrument issued to non-employees is the more reliable measurement and a measurement date has not been reached, the fair value is re-measured at each reporting date using the Black-Scholes option pricing model. Compensation expense for these share-based awards is recognized over the term of the consulting agreement or until the award is approved and settled.
Income Taxes	Income Taxes
	We account for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the financial statements or in our tax returns. Deferred taxes are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect in the years in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. We assess the likelihood that our deferred tax assets will be recovered from future taxable income and, to the extent we believe, based upon the weight of available evidence, that it is more likely than not that all or a portion of deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies.
	We account for uncertainty in income taxes recognized in the financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.
Comprehensive Loss	Comprehensive Loss
	Our comprehensive loss includes the change in unrealized gains or losses on available-for-sale securities. The cumulative amount of gains or losses are reflected as a separate component of stockholders' equity in the accompanying balance sheets as accumulated other comprehensive loss.
Segment Data	Segment Data
	We manage our operations as a single segment for the purposes of assessing performance and making operating decisions. We are a veterinary biotechnology company focusing on developing therapies for pets. Our chief operating decision maker is our Chief Executive Officer. All assets are held in the United States.
Basic and Diluted Net Loss Per Common Share	Basic and Diluted Net Loss Per Common Share
	Basic net loss per common share is computed by dividing net loss attributable to common stockholders for the period by the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders for the period by the weighted average number of common shares, including potential dilutive shares of common stock assuming the dilutive effect of potentially dilutive securities. For periods in which we have reported a net loss, diluted net loss per common share is the same as basic net loss per common share, since the impact of the potentially dilutive securities would be anti-dilutive to the calculation of net loss per common share (see Note 13).
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements
	On June 10, 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (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," which eliminates the concept of a development stage entity (DSE) in its entirety from current accounting guidance. A DSE is an entity devoting substantially all of its efforts to establishing a new business and for which either planned principal operations have not yet commenced or have commenced but there has been no significant revenues generated from that business. Under current guidance, DSEs are required to present inception-to-date financial information in their annual statements. We determined we were a DSE and had therefore presented inception-to-date financial information financial statements. As permitted by ASU 2014-10, we have elected to early adopt this standard, and therefore, we have not presented any inception to date financial information and we have removed all references to development stage in these financial statements.
	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 provides guidance regarding management’s responsibility to assess whether substantial doubt exists regarding the ability to continue as a going concern and to provide related footnote disclosures. In connection with preparing financial statements for each annual and interim reporting period, management should evaluate whether there are conditions or events, considered in the aggregate, that raise substantial doubt about the company’s ability to continue as a going concern within one year after the date that the financial statements are issued (or within one year after the date that the financial statements are available to be issued when applicable). This ASU is effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. We are currently evaluating the new guidance and have not determined the impact this standard may have on our financial statements.
	We do not believe there are any other recently issued standards not yet effective that will have a material impact on our financial statements when the standards become effective.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Schedule of financial assets measured at fair value on a recurring basis	The following table presents information about our financial assets that are measured at fair value on a recurring basis as of December 31, 2014 and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value:
	(In thousands)	Fair Value Measurements as of December 31, 2014
	Description	Total		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Unobservable Inputs (Level 3)
	Cash equivalents:
	Money market funds	$	834	$	834	$	—	$	—
	Short-term investments:
	U.S. treasury bills	5,998		—		5,998		—
	U.S. treasury bonds and notes	82,060		—		82,060		—
		$	88,892	$	834	$	88,058	$	—
	The following table presents information about our financial assets that are measured at fair value on a recurring basis as of December 31, 2013 and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value:
	(In thousands)	Fair Value Measurements as of December 31, 2013
	Description	Total		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Unobservable Inputs (Level 3)
	Cash equivalents:
	Money market funds	$	65,310	$	65,310	$	—	$	—
		$	65,310	$	65,310	$	—	$	—

Shortterm_Investments_Tables

Short-term Investments (Tables)	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Schedule of fair value of available-for-sale short term investments	The fair value of available-for-sale short-term investments by type of security at December 31, 2014 were as follows:
	(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	U.S. treasury bills	$	5,994	$	4	$	—		$	5,998
	U.S. treasury bonds and notes	82,091		—		(31		)	82,060
		$	88,085	$	4	$	(31	)	$	88,058

Property_and_Equipment_Net_Tab

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment, Net [Abstract]
Schedule of property and equipment	Property and equipment consisted of the following as of December 31, 2014 and 2013:
		Years Ended December 31,
	(in thousands)	2014			2013
	Computer and lab equipment	$	359		$	15
	Furniture & fixtures	24			—
	Leasehold improvements	69			—
	Total	452			15
	Less accumulated depreciation and amortization	(58		)	-3
	Property and equipment, net	$	394		$	12

Accrued_Liabilities_Tables

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Schedule of accrued liabilities	Accrued liabilities consisted of the following as of December 31, 2014 and 2013:
	(In thousands)	December 31, 2014			December 31, 2013
	Accrued consulting	$	—		$	303
	Accrued research and development costs	715			159
	Accrued offering costs	—			381
	Accrued other	247			43
	Deferred rent	57			—
		1,019			886
	Less current portion	(975		)	(886		)
	Long-term liability (deferred rent)	$	44		$	—

StockBased_Awards_Tables

Stock-Based Awards (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of shares of common stock reserved for future issuance	At December 31, 2014, shares of common stock reserved for future issuance inclusive of outstanding option shares are as follows:
	2012 Equity Incentive Plan	3,900,713
	2014 Employee Stock Purchase Plan	200,000
		4,100,713
Summary of activity under stock option plans	A summary of activity under our stock option plans is as follows:
		Shares Available For Grant			Shares Issuable Under Options			Weighted Average Exercise Price				Weighted Average Remaining ContractualTerm (In Years)	Aggregate Intrinsic Value
	Balance, December 31, 2012	4,000,000			—
	Granted	-1,410,139			1,410,139			$	1.31
	Exercised				-34,225			$	0.32
	Restricted stock grants	(10,200	)		—
	Balance, December 31, 2013	2,579,661			1,375,914			$	1.33
	Granted	(1,127,113	)		1,127,113			$	16.23
	Exercised				(56,112	)		$	2.17
	Forfeited - restricted stock and options	118,750			(117,500	)		$	19.57
	Balance, December 31, 2014	1,571,298			2,329,415			$	7.6			8.8	$	8,100,000
	Options vested and expected to vest, December 31, 2014				2,329,415			$	7.6			8.8	$	8,100,000
	Options exercisable, December 31, 2014				953,327			$	3.8			8.6	$	4,930,000
Schedule of stock-based compensation expense	Total stock-based compensation expense, related to all of our share-based payment awards, is comprised of the following:
	(In thousands)	Years Ended December 31,
		2014				2013				2012
	Research and development	$	1,453			$	827			$	11
	General and administrative	2,969				95				—
		$	4,422			$	922			$	11
Schedule of valuation assumptions	The relevant data used to determine the value of stock options earned or granted is as follows:
		Years Ended December 31,
		2014		2013		2012
	Weighted average risk-free interest rate	1.70%		1.33%		0.62%-0.72%
	Weighted average expected term (in years)	6.4		6.6		10
	Weighted average expected volatility	91.30%		85.20%		90%
	Weighted average expected dividend yield	—		—		—

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments
	As of December 31, 2014, we are obligated to make minimum lease payments under all of our operating leases as follows (in thousands):
	Year ending December 31,	Lease Payments
	2015	$	259
	2016	266
	2017	216
	2018	3
	Total	$	744

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Differences between provision (benefit) for income taxes and income taxes at the statutory federal income tax rate	Differences between the provision (benefit) for income taxes and income taxes at the statutory federal income tax rate are as follows:
	(In thousands, except percentages)	For the years ended December 31,
		2014						2013					2012
	Income tax expense (benefit) at statutory federal rate	$	(9,227	)	34	%		$	(1,432	)	34	%	$	(41	)	34	%
	State income tax, net of federal benefit	(1,663		)	6.1			(245		)	5.8		(6		)	5.2
	Permanent items	14			(0.1	)		2			—		4			(3.7	)
	Research credits	(807		)	3			(188		)	4.5		—			—
	Stock compensation	—			—			6			(0.1	)	—			—
	FIN 48	323			(1.2	)		75			(1.8	)	—			—
	Change in valuation allowance	11,388			(41.9	)		1,782			(42.4	)	43			(35.5	)
	Other individually immaterial items	(28		)	0.1			—			—		—			—
	Provision (benefit) for income taxes	$	—		—	%		$	—		—	%	$	—		—	%
Components of deferred tax assets	The components of the deferred tax assets are as follows at December 31, 2014 and 2013:
		December 31,
	(In thousands)	2014			2013
	Deferred tax assets:
	Net operating loss carryforwards	$	10,047		$	479
	Research & development credits	597			113
	Accrued expenses	463			217
	Amortization and depreciation	4			645
	Other	1			—
	Stock-based compensation	2,101			371
		13,213			1,825
	Valuation Allowance	(13,213		)	(1,825		)
	Net current deferred tax assets	$	—		$	—
Rollforward of changes in unrecognized tax benefits	A rollforward of changes in our unrecognized tax benefits is shown below.
	(In thousands)	December 31,
		2014			2013
	Balance at beginning of year	$	91		$	—
	Additions based on tax positions related to the current year	382			91
	Additions for tax positions of prior years	—			—
	Reductions for tax positions of prior years	—			—
	Settlements	—			—
	Balance at end of year	$	473		$	91

Net_Loss_Per_Share_Tables

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Calculation of basic and diluted net loss per share	Basic and diluted net loss per share was calculated as follows for the years ended December 31, 2014, 2013 and 2012:
	(In thousands, except per share amounts)	Years Ended December 31,
		2014			2013			2012
	Basic and diluted net loss per share attributable to common stockholders:
	Numerator:
	Net loss attributable to common stockholders	$	(27,139	)	$	(4,213	)	$	(120	)
	Denominator:
	Weighted average common shares outstanding, basic and diluted	18,782			3,732			2,113
	Net loss per common share attributable to common shareholders, basic and diluted	$	(1.44	)	$	(1.13	)	$	(0.06	)

Selected_Quarterly_Financial_I1

Selected Quarterly Financial Information (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Unaudited quarterly financial data	The following table presents selected unaudited quarterly financial data for each of the quarters in the years ended December 31, 2014 and 2013.
	(In thousands, except per share amounts)	2014												2013
	Quarter ended	Dec. 31			Sep. 30			Jun. 30			Mar. 31			Dec. 31			Sep. 30			Jun. 30			Mar. 31
	Operating costs and expenses
	Research and development	$	4,802		$	3,755		$	5,639		$	4,498		$	1,746		$	953		$	300		$	141
	General and administrative	2,014			2,342			2,504			1,679			641			259			96			83
	Total operating cost and expenses	6,816			6,097			8,143			6,177			2,387			1,212			396			224
	Loss from operations	(6,816		)	(6,097		)	(8,143		)	(6,177		)	(2,387		)	(1,212		)	(396		)	(224		)
	Interest and other income, net	27			25			33			9			4			2			—			—
	Net loss	$	(6,789	)	$	(6,072	)	$	(8,110	)	$	(6,168	)	$	(2,383	)	$	(1,210	)	$	(396	)	$	(224	)
	Net loss per share, basic and diluted (1)	$	(0.34	)	$	(0.31	)	$	(0.42	)	$	(0.38	)	$	(0.40	)	$	(0.40	)	$	(0.13	)	$	(0.07	)
	Weighted average shares used in computing net loss per share, basic and diluted	19,719			19,713			19,426			16,222			5,899			3,005			3,000			3,000
	(1) Net loss per share for each quarter are calculated as a discrete period; the sum of four quarters may not equal the calculated full year amount.

Organization_and_Description_o1

Organization and Description of Business (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit	$31,472	$4,333
Cash, cash equivalents and short-term investments	$101,027

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value Measurements
Short-term investments	$88,058
U.S. treasury bills
Fair Value Measurements
Short-term investments	5,998
U.S. treasury bonds and notes
Fair Value Measurements
Short-term investments	82,060
Financial assets measured at fair value on a recurring basis
Fair Value Measurements
Cash equivalents	834	65,310
Total assets	88,892	65,310
Financial assets measured at fair value on a recurring basis | U.S. treasury bills
Fair Value Measurements
Short-term investments	5,998
Financial assets measured at fair value on a recurring basis | U.S. treasury bonds and notes
Fair Value Measurements
Short-term investments	82,060
Financial assets measured at fair value on a recurring basis | Quoted Prices in Active Markets (Level 1)
Fair Value Measurements
Cash equivalents	834	65,310
Total assets	834	65,310
Financial assets measured at fair value on a recurring basis | Quoted Prices in Active Markets (Level 1) | U.S. treasury bills
Fair Value Measurements
Short-term investments	0
Financial assets measured at fair value on a recurring basis | Quoted Prices in Active Markets (Level 1) | U.S. treasury bonds and notes
Fair Value Measurements
Short-term investments	0
Financial assets measured at fair value on a recurring basis | Significant Other Observable Inputs (Level 2)
Fair Value Measurements
Cash equivalents	0	0
Total assets	88,058	0
Financial assets measured at fair value on a recurring basis | Significant Other Observable Inputs (Level 2) | U.S. treasury bills
Fair Value Measurements
Short-term investments	5,998
Financial assets measured at fair value on a recurring basis | Significant Other Observable Inputs (Level 2) | U.S. treasury bonds and notes
Fair Value Measurements
Short-term investments	82,060
Financial assets measured at fair value on a recurring basis | Unobservable Inputs (Level 3)
Fair Value Measurements
Cash equivalents	0	0
Total assets	0	0
Financial assets measured at fair value on a recurring basis | Unobservable Inputs (Level 3) | U.S. treasury bills
Fair Value Measurements
Short-term investments	0
Financial assets measured at fair value on a recurring basis | Unobservable Inputs (Level 3) | U.S. treasury bonds and notes
Fair Value Measurements
Short-term investments	$0

Shortterm_Investments_Details

Short-term Investments (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$88,085
Gross Unrealized Gains	4
Gross Unrealized Losses	-31
Fair Value	88,058
U.S. treasury bills
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,994
Gross Unrealized Gains	4
Gross Unrealized Losses	0
Fair Value	5,998
U.S. treasury bonds and notes
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	82,091
Gross Unrealized Gains	0
Gross Unrealized Losses	-31
Fair Value	$82,060

Property_and_Equipment_Net_Det

Property and Equipment, Net (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property and equipment, gross		$452	$15
Less accumulated depreciation and amortization		-58	-3
Property and equipment, net		394	12
Depreciation and amortization expense	0	58	3
Computer and lab equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross		359	15
Furniture & fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross		24	0
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross		$69	$0

Accrued_Liabilities_Details

Accrued Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Payables and Accruals [Abstract]
Accrued consulting	$0	$303
Accrued research and development costs	715	159
Accrued offering costs	0	381
Accrued other	247	43
Deferred rent	57	0
Accrued liabilities	1,019	886
Less current portion	-975	-886
Long-term liability (deferred rent)	$44	$0

Convertible_Preferred_Stock_De

Convertible Preferred Stock (Details) (USD $)	12 Months Ended	3 Months Ended	12 Months Ended	27 Months Ended	1 Months Ended	0 Months Ended	1 Months Ended			4 Months Ended	6 Months Ended	2 Months Ended	1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2014	Nov. 30, 2012	Dec. 31, 2013	Nov. 30, 2013	Aug. 31, 2013	Jun. 30, 2013	Sep. 30, 2013	Jun. 30, 2014	Sep. 30, 2013	Apr. 30, 2014	Dec. 31, 2013	Dec. 16, 2013
Class of Stock [Line Items]
Preferred stock, shares authorized	10,000,000					10,000,000								10,000,000
Preferred stock, par value	$0.00					$0.00								$0.00
Issuance of common stock and stock options for accrued consulting expenses	$12,000
Series AA Preferred Stock
Class of Stock [Line Items]
Proceeds from issuance of convertible preferred stock	0	990,000	0
Series AA Preferred Stock | Co-Founder and CEO
Class of Stock [Line Items]
Number of shares issued during period				100,000
Series A-1 Preferred Stock
Class of Stock [Line Items]
Proceeds from issuance of convertible preferred stock	5,865,000	0	0
Series A-1 Preferred Stock | Co-Founder and CEO
Class of Stock [Line Items]
Number of shares issued during period	31,546
Series A-1A Preferred Stock
Class of Stock [Line Items]
Proceeds from issuance of convertible preferred stock	5,232,000	0	0
Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized															15,000,000
Preferred stock, par value															$0.00
Preferred Stock | Co-Founder and CEO
Class of Stock [Line Items]
Exchange of note payable for Series AA convertible preferred stock					10,000
Preferred Stock | Series AA Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued															1,015,000
Conversion of Series AA, A-1 and A-1A preferred stock to common stock in connection with initial public offering, shares	-1,015,000
Number of shares issued during period	15,000	990,000			990,000		15,000
Share price					$1
Benchmark of ownership that allows a unitholder to purchase new shares under the IPO						10,000
Proceeds from issuance of convertible preferred stock					990,000
Exchange of note payable for Series AA convertible preferred stock		10,000
Exchange of note payable for Series AA convertible preferred stock, shares		10,000
Payments of offering costs		13,000			13,000
Liquidation preference per share			$1	1
Conversion price per share	$1					$1								$1
Conversion ratio						1
Preferred Stock | Series AA Preferred Stock | Co-Founder and CEO
Class of Stock [Line Items]
Exchange of note payable for Series AA convertible preferred stock, shares					10,000
Preferred Stock | Series A-1 Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized									2,000,000
Preferred stock, shares issued															1,860,204
Conversion of Series AA, A-1 and A-1A preferred stock to common stock in connection with initial public offering, shares	-1,860,000
Number of shares issued during period	1,850,000							5,000	5,000	1,850,204
Share price									$3.17
Benchmark of ownership that allows a unitholder to purchase new shares under the IPO						10,000
Issuance of common stock and stock options for accrued consulting expenses	32,000							16,000	16,000
Proceeds from issuance of convertible preferred stock										5,865,000
Payments of offering costs	22,000									22,000
Percentage of purchase price											10.00%
Liquidation preference per share			$3.17	3.17
Conversion price per share	$3.17					$3.17								$3.17
Conversion ratio	1
Preferred Stock | Series A-1A Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized								2,000,000
Preferred stock, shares issued															1,675,002
Conversion of Series AA, A-1 and A-1A preferred stock to common stock in connection with initial public offering, shares	-1,675,000
Number of shares issued during period	1,650,000							24,606				1,650,396
Share price								$3.17
Benchmark of ownership that allows a unitholder to purchase new shares under the IPO						10,000
Issuance of common stock and stock options for accrued consulting expenses	78,000							78,000
Proceeds from issuance of convertible preferred stock												5,232,000
Payments of offering costs	88,000											88,000
Percentage of purchase price											10.00%
Liquidation preference per share	$3.17					$3.17								$3.17
Conversion price per share	$3.17					$3.17								$3.17
Conversion ratio	1
Common Stock
Class of Stock [Line Items]
Conversion of Series AA, A-1 and A-1A preferred stock to common stock in connection with initial public offering, shares	4,550,000
Number of shares issued during period	8,625,000	3,000,000	3,450,000										3,450,000	8,625,000
Payments of offering costs	$5,504,000		$4,035,000										$4,035,000	$5,504,000
Common Stock | Conversion of Preferred Stock
Class of Stock [Line Items]
Conversion of Series AA, A-1 and A-1A preferred stock to common stock in connection with initial public offering, shares						4,550,195

Common_Stock_Details

Common Stock (Details) (USD $)	1 Months Ended		3 Months Ended	12 Months Ended		1 Months Ended
	Apr. 30, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Oct. 31, 2012	Aug. 31, 2013	Sep. 24, 2012
Class of Stock [Line Items]
Number of common shares authorized		100,000,000		100,000,000	100,000,000
Par value of common shares		$0.00		$0.00	$0.00
Net proceeds from initial public offering	$58,065,000		$0	$58,065,000	$0
Stock-based compensation expense			11,000	4,422,000	922,000
Number of shares of common stock issued upon exercise of stock options				1,127,113	1,410,139
Net proceeds from initial public offering		54,871,000	0	0	54,871,000
Common stock, shares outstanding		16,214,620		19,724,482	16,214,620
Common Stock
Class of Stock [Line Items]
Number of voting rights				1
Number of shares issued during period	3,450,000	8,625,000	3,000,000	3,450,000	8,625,000
Restricted stock issued				4,000
Share price	$18	$7			$7
Payments of underwriting commissions and offering expenses	4,035,000	5,504,000		4,035,000	5,504,000
Common stock, shares outstanding		16,214,000	3,000,000	19,724,000	16,214,000			0
Common Stock | Co-Founder and CEO
Class of Stock [Line Items]
Number of shares issued during period						3,000,000
Net proceeds from initial public offering						300
Common Stock | Consultants | Restricted Common Stock
Class of Stock [Line Items]
Restricted stock issued				3,750			5,200
Share price							$2.27
Stock-based compensation expense				61,000			12,000
Common Stock | Employee | Employee Stock Option
Class of Stock [Line Items]
Net proceeds from initial public offering				$121,000	$11,000
Share price		$0.32			$0.32
Number of shares of common stock issued upon exercise of stock options				56,112	34,225
Common Stock | Employee | Employee Stock Option | Minimum
Class of Stock [Line Items]
Share price				$0.32
Common Stock | Employee | Employee Stock Option | Maximum
Class of Stock [Line Items]
Share price				$15.41

StockBased_Awards_Narrative_De

Stock-Based Awards - Narrative (Details) (USD $)	3 Months Ended	12 Months Ended		0 Months Ended						2 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Nov. 11, 2013	Nov. 10, 2013	Sep. 12, 2013	Aug. 29, 2013	9-May-13	Feb. 04, 2013	Sep. 30, 2013	Nov. 04, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period of stock option plan		10 years
Shares reserved for future issuance		4,100,713
Number of shares of common stock issued upon exercise of stock options		1,127,113	1,410,139
Weighted-average exercise price per share		$16.23	$1.31
Fair value of common stock per share		$12.09	$1.50
Number of shares issuable under options	0	2,329,415	1,375,914
Number of shares available for grant	4,000,000	1,571,298	2,579,661
Aggregate intrinsic value of stock options exercised		$774	$108
Proceeds from exercise of common stock options	0	121	11
Accrued expenses for options earned but not granted and approved	11		303
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of fair value per share of common stock		100.00%
Benchmark ownership percentage of all classes of stock		10.00%
Percent of fair value per share of common stock, if person owns 10% of all classes		110.00%
Unrecognized stock-based compensation expense		$8,693
Weighted average period for recognition		3 years 1 month 12 days
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards granted			10,200
Restricted stock awards granted, weighted average fair value			$6.63
Minimum | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of options		1 year
Maximum | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of options		4 years
2012 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period of stock option plan		10 years
Shares reserved for future issuance		3,900,713									4,000,000
Number of shares of common stock issued upon exercise of stock options		1,127,113	1,410,139			29,000	412,580	154,793	576,525	285,092
Weighted-average exercise price per share				$1.37	$0.90	$0.90	$0.90	$0.32	$0.35
Fair value of common stock per share						$1.37	$2.27	$0.32	$0.32
Number of shares issuable under options		2,329,415
Number of shares available for grant		1,571,298
2012 Equity Incentive Plan | Previously Reported
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of common stock per share						$2.27	$1.37
2014 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance		200,000
2014 Employee Stock Purchase Plan | Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance		200,000
Purchase price of common stock, percent of fair market value		85.00%

StockBased_Awards_Reserved_Sha

Stock-Based Awards - Reserved Shares (Details)	Dec. 31, 2014	Nov. 04, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for future issuance	4,100,713
2012 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for future issuance	3,900,713	4,000,000
2014 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for future issuance	200,000

StockBased_Awards_Stock_Option

Stock-Based Awards - Stock Option Plan Activity Summary (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Shares
Number of shares available for grant, beginning balance	2,579,661	4,000,000
Number of shares issuable under options, beginning balance	1,375,914	0
Granted	-1,127,113	-1,410,139
Exercised	-56,112	-34,225
Restricted stock grants		-10,200
Forfeited restricted stock	118,750
Forfeited options	-117,500
Number of shares available for grant, ending balance	1,571,298	2,579,661
Number of shares issuable under options, ending balance	2,329,415	1,375,914
Weighted Average Exercise Price
Granted	$16.23	$1.31
Exercised	$2.17	$0.32
Forfeited - restricted stock and options	$19.57
Outstanding	$7.60	$1.33
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Term (In Years)	8 years 9 months 18 days
Aggregate Intrinsic Value	$8,100
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest [Abstract]
Options vested and expected to vest, shares issuable under options	2,329,415
Options vested and expected to vest, weighted average exercise price	$7.60
Options vested and expected to vest, weighted average remaining contractual term (in years)	8 years 9 months 18 days
Options vested and expected to vest, aggregate intrinsic value	8,100
Options exercisable, shares issuable under options	953,327
Options exercisable, weighted average exercise price	$3.80
Options exercisable, weighted average remaining contractual term (in years)	8 years 7 months 6 days
Options exercisable, aggregate intrinsic value	$4,930

StockBased_Awards_StockBased_C

Stock-Based Awards - Stock-Based Compensation Expense (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$11	$4,422	$922
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	11	1,453	827
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$0	$2,969	$95

StockBased_Awards_Valuation_As

Stock-Based Awards - Valuation Assumptions (Details) (Employee Stock Option)	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average risk-free interest rate		1.70%	1.33%
Weighted average expected term (in years)	10 years	6 years 4 months 24 days	6 years 7 months 6 days
Weighted average expected volatility	90.00%	91.30%	85.20%
Weighted average expected dividend yield	0.00%	0.00%	0.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average risk-free interest rate	0.62%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average risk-free interest rate	0.72%

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$1	$162	$6
Lease Payments
2015		259
2016		266
2017		216
2018		3
Total		$744

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	3 Months Ended	12 Months Ended		27 Months Ended	1 Months Ended
	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Nov. 30, 2012	Oct. 31, 2012
Related Party Transaction [Line Items]
Value of stock issued	$0	$58,065,000	$54,872,000
Co-Founder and CEO
Related Party Transaction [Line Items]
Expenses paid on behalf of Company				5,000
Amount payable to affiliates	5,000		0
Notes payable to affiliates						10,000
Co-Founder and CEO | Series AA Preferred Stock
Related Party Transaction [Line Items]
Shares issued on conversion of debt instrument					10,000
Number of shares issued during period				100,000
Value of stock issued				100,000
Co-Founder and CEO | Series A-1 Preferred Stock
Related Party Transaction [Line Items]
Number of shares issued during period			31,546
Value of stock issued			100,000
Co-Founder and CEO | S.D. Scientific
Related Party Transaction [Line Items]
Ownership percentage		50.00%		50.00%
Affiliated Entity | Series A-1 Preferred Stock
Related Party Transaction [Line Items]
Number of shares issued during period			31,546
Value of stock issued			100,000
Affiliated Entity | Series A-1A Preferred Stock
Related Party Transaction [Line Items]
Number of shares issued during period			15,773
Value of stock issued			50,000
Affiliated Entity | S.D. Scientific | Consulting Fees
Related Party Transaction [Line Items]
Expenses paid on behalf of Company	$9,000		$54,000

Income_Taxes_Narrative_Details

Income Taxes - Narrative (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Operating Loss Carryforwards [Line Items]
Net deferred tax assets	$13,213	$1,825
Unrecognized tax benefits that would impact the effective tax rate	398
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryovers	25,680
Federal | Research tax credit carryover
Operating Loss Carryforwards [Line Items]
Tax credit carryovers	629
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryovers	25,494
State | Research tax credit carryover
Operating Loss Carryforwards [Line Items]
Tax credit carryovers	$554

Income_Taxes_Reconciliation_St

Income Taxes - Reconciliation Statutory Federal Income Tax to Effective Tax (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax expense (benefit) at statutory federal rate	($41)	($9,227)	($1,432)
State income tax, net of federal benefit	-6	-1,663	-245
Permanent items	4	14	2
Research credits	0	-807	-188
Stock compensation	0	0	6
FIN 48	0	323	75
Change in valuation allowance	43	11,388	1,782
Other individually immaterial items	0	-28	0
Provision (benefit) for income taxes	$0	$0	$0
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income tax expense (benefit) at statutory federal rate	34.00%	34.00%	34.00%
State income tax, net of federal benefit	5.20%	6.10%	5.80%
Permanent items	-3.70%	-0.10%	0.00%
Research credits	0.00%	3.00%	4.50%
Stock compensation	0.00%	0.00%	-0.10%
FIN 48	0.00%	-1.20%	-1.80%
Change in valuation allowance	-35.50%	-41.90%	-42.40%
Other individually immaterial items	0.00%	0.10%	0.00%
Provision (benefit) for income taxes	0.00%	0.00%	0.00%

Income_Taxes_Components_of_Def

Income Taxes - Components of Deferred Tax Assets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred tax assets:
Net operating loss carryforwards	$10,047	$479
Research & development credits	597	113
Accrued expenses	463	217
Amortization and depreciation	4	645
Other	1	0
Stock-based compensation	2,101	371
Deferred tax assets, gross	13,213	1,825
Valuation Allowance	-13,213	-1,825
Net current deferred tax assets	$0	$0

Income_Taxes_Rollforward_of_Ch

Income Taxes - Rollforward of Changes in Unrecognized Tax Benefits (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$91	$0
Additions based on tax positions related to the current year	382	91
Additions for tax positions of prior years	0	0
Reductions for tax positions of prior years	0	0
Settlements	0	0
Balance at end of year	$473	$91

Net_Loss_Per_Share_Details

Net Loss Per Share (Details) (USD $)	3 Months Ended									12 Months Ended		27 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014
Numerator:
Net loss attributable to common stockholders	($6,789)	($6,072)	($8,110)	($6,168)	($2,383)	($1,210)	($396)	($224)	($120)	($27,139)	($4,213)
Denominator:
Weighted average common shares outstanding, basic and diluted	19,719,000	19,713,000	19,426,000	16,222,000	5,899,000	3,005,000	3,000,000	3,000,000	2,113,000	18,782,000	3,732,000
Net loss per common share attributable to common shareholders, basic and diluted	($0.34)	($0.31)	($0.42)	($0.38)	($0.40)	($0.40)	($0.13)	($0.07)	($0.06)	($1.44)	($1.13)
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from EPS computation											1,375,914	2,329,415
Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from EPS computation									1,000,000

Employee_Savings_Plan_Details

Employee Savings Plan (Details) (Employee savings plan, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Employee savings plan
Defined Contribution Plan Disclosure [Line Items]
Maximum contributions per employee, percent of salary	90.00%
Employer matching contribution, percent of match	50.00%
Employer matching contribution, percent of participant's compensation	6.00%
Contributions during the year	$84

Selected_Quarterly_Financial_I2

Selected Quarterly Financial Information (unaudited) (Details) (USD $)	3 Months Ended									12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013
Selected Quarterly Financial Information [Abstract]
Research and development	$4,802	$3,755	$5,639	$4,498	$1,746	$953	$300	$141	$75	$18,694	$3,140
General and administrative	2,014	2,342	2,504	1,679	641	259	96	83	45	8,539	1,079
Total operating cost and expenses	6,816	6,097	8,143	6,177	2,387	1,212	396	224	120	27,233	4,219
Loss from operations	-6,816	-6,097	-8,143	-6,177	-2,387	-1,212	-396	-224	-120	-27,233	-4,219
Interest and other income, net	27	25	33	9	4	2	0	0	0	94	6
Net loss	($6,789)	($6,072)	($8,110)	($6,168)	($2,383)	($1,210)	($396)	($224)	($120)	($27,139)	($4,213)
Net loss per share, basic and diluted	($0.34)	($0.31)	($0.42)	($0.38)	($0.40)	($0.40)	($0.13)	($0.07)	($0.06)	($1.44)	($1.13)
Weighted average common shares outstanding, basic and diluted	19,719	19,713	19,426	16,222	5,899	3,005	3,000	3,000	2,113	18,782	3,732

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	Dec. 31, 2014	Jan. 14, 2015
In Thousands, unless otherwise specified
Subsequent Event [Line Items]
Total expected rent payments	$744
Subsequent Event
Subsequent Event [Line Items]
Total expected rent payments		$160
Subsequent Event | Operating Lease | Laboratory space
Subsequent Event [Line Items]
Square footage of laboratory space		2,431