Kindred Biosciences (KIN) 10-Q 7 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 01, 2018
Entity [Abstract]
Entity Registrant Name	Kindred Biosciences, Inc.
Entity Central Index Key	1,561,743
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	true
Entity Small Business	false
Entity Ex Transition Period	true
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding (in shares)		33,913,168

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 69,984	$ 34,813
Short-term investments	21,642	46,207
Accounts receivable	242	0
Inventories	2,521	0
Prepaid expenses and other	1,463	797
Total current assets	95,852	81,817
Property and equipment, net	17,483	7,457
Long-term investments	0	1,499
Other assets	53	49
Total assets	113,388	90,822
Current liabilities:
Accounts payable	1,241	1,439
Accrued compensation	2,585	2,688
Accrued liabilities	5,032	1,900
Total current liabilities	8,858	6,027
Long-term liability	99	115
Total liabilities	8,957	6,142
Commitments and contingencies (Note 6)
Stockholders' equity:
Common stock, $0.0001 par value; 100,000,000 shares authorized; 33,815,647 and 28,182,563 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively	3	3
Additional paid-in capital	250,670	196,688
Accumulated other comprehensive loss	(13)	(31)
Accumulated deficit	(146,229)	(111,980)
Total stockholders' equity	104,431	84,680
Total liabilities and stockholders' equity	$ 113,388	$ 90,822

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Common stock, par value (USD per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	33,815,647	28,182,563
Common stock, shares outstanding (in shares)	33,815,647	28,182,563

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net product revenues	$ 640	$ 0	$ 640	$ 0
Operating costs and expenses:
Cost of product revenues	110	0	110	0
Research and development	7,477	4,877	18,643	12,523
Selling, general and administrative	6,608	3,269	17,280	9,168
Total operating costs and expenses	14,195	8,146	36,033	21,691
Loss from operations	(13,555)	(8,146)	(35,393)	(21,691)
Interest and other income, net	518	256	1,144	542
Net loss	(13,037)	(7,890)	(34,249)	(21,149)
Change in unrealized gains or losses on available-for-sale securities	12	13	18	16
Comprehensive loss	$ (13,025)	$ (7,877)	$ (34,231)	$ (21,133)
Net loss per share, basic and diluted (USD per share)	$ (0.39)	$ (0.29)	$ (1.14)	$ (0.88)
Weighted-average number of common shares outstanding, basic and diluted (in shares)	33,601	27,400	30,089	24,130

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash Flows from Operating Activities
Net loss	$ (34,249)	$ (21,149)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	4,572	3,877
Depreciation and amortization expense	527	295
(Gain)/Loss on disposal of property and equipment	(12)	9
Amortization of (discount) premium on marketable securities	(140)	174
Changes in operating assets and liabilities:
Accounts receivable	(242)	0
Inventories	(2,521)	0
Prepaid expenses and other	(670)	368
Accounts payable	(60)	340
Accrued liabilities and accrued compensation	638	(8)
Net cash used in operating activities	(32,157)	(16,094)
Cash Flows from Investing Activities
Purchases of investments	(18,453)	(46,888)
Sales of investments	800	2,896
Maturities of investments	43,875	49,265
Purchases of property and equipment	(8,482)	(4,748)
Proceeds from sale of property and equipment	178	0
Net cash provided by investing activities	17,918	525
Cash Flows from Financing Activities
Exercises of stock options and purchase of ESPP shares	477	348
Payment of restricted stock awards tax liability on net settlement	(247)	0
Net proceeds from sale of common stock	49,180	52,160
Net cash provided by financing activities	49,410	52,508
Net change in cash and cash equivalents	35,171	36,939
Cash and cash equivalents at beginning of period	34,813	6,687
Cash and cash equivalents at end of period	69,984	43,626
Supplemental disclosure of non-cash investing and financing activities:
Purchase of property and equipment included in accounts payable and accrued liabilities	$ 2,388	$ 165

Description of Business, Basis

Description of Business, Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Description of Business, Basis of Presentation and Summary of Significant Accounting Policies	Description of Business, Basis of Presentation and Summary of Significant Accounting Policies Kindred Biosciences, Inc. ("KindredBio", "we", "us" or "our") was incorporated on September 25, 2012 (inception) in the State of Delaware. On April 25, 2016, we filed a Certificate of Incorporation with the State of Delaware for a wholly owned subsidiary, KindredBio Equine, Inc. ("Subsidiary"). The Subsidiary has one class of capital stock which is designated common stock, $0.0001 par value per share. The authorized number of shares of common stock for the Subsidiary is 1,000 . We are a commercial-stage 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 located 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 patent or other intellectual property 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. The accompanying unaudited interim condensed consolidated financial statements (“financial statements”) have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States of America (“U.S. GAAP”) for complete financial statements. These unaudited interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2017 included in our annual report on Form 10-K as filed with the SEC on March 1, 2018. In the opinion of management, all adjustments, consisting of a normal and recurring nature, considered necessary for a fair presentation, have been included in these financial statements. The accompanying financial statements include the accounts of the Company and its wholly owned Subsidiary. All inter-company accounts and transactions have been eliminated in consolidation. Stock Offerings In June 2017, we completed the sale of 4,501,985 shares of common stock under an At Market Issuance Sales Agreement, or ATM. Net proceeds, after deducting commissions, fees and offering costs, were approximately $28,962,000 . In July 2017, we completed an underwritten public offering of 3,000,000 shares of common stock and in August 2017, we completed the closing of the exercise of the underwriter's option to purchase an additional 314,000 shares of common stock, both at an offering price of $7.50 per share for total gross proceeds of $24,855,000 . Net proceeds, after deducting underwriting commission and offering costs, were approximately $23,198,000 . In January 2018, we filed a shelf registration statement on Form S-3 to offer and sell, from time to time, equity securities in one or more offerings up to a total dollar amount of $150.0 million due to the expiration of our January 2015 shelf registration. In May 2018, we entered into an At Market Issuance Sales Agreement, or the Sales Agreement, with B. Riley FBR, Inc., and Oppenheimer & Co. Inc. acting as our distribution agents, relating to the sale of up to $50,000,000 of our common stock from time to time. We terminated the Sales Agreement in June 2018 after having sold 188,100 shares, representing gross proceeds of approximately $1,903,000 . Net proceeds, after deducting commission, fees and offering costs, were approximately $1,758,000 . On June 20, 2018, we entered into an underwriting agreement with Cantor Fitzgerald & Co., as representative of the underwriters, and on June 22, 2018 we completed a public offering of 5,326,314 shares of common stock, which included the underwriter’s option to purchase additional shares, at a public offering price of $9.50 per share for total gross proceeds of approximately $50,600,000 . Net proceeds, after deducting underwriting discounts and commissions and offering expenses were approximately $47,422,000 . Liquidity We have incurred losses and negative cash flows from operations and had an accumulated deficit of $146,229,000 as of September 30, 2018 . 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 our former convertible preferred stock, the sale of our common stock in our initial public offering in December 2013, the sale of our common stock in our April 2014 follow-on public offering, periodic sales of our common stock under an ATM in the first half year of 2017, sale of our common stock in a follow-on public offering in the third quarter of 2017, periodic sales of our common stock under an ATM and sale of our common stock in a follow-on public offering in the second quarter of 2018. We might require additional capital until such time as we can generate operating revenues in excess operating expenses. We believe that our cash, cash equivalents, short-term and long-term investments totaling $91,626,000 as of September 30, 2018 , are sufficient to fund our planned operations through the next 18 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. Revenue Recognition We adopted FASB Accounting Standards Codification Topic 606 (“ASC 606”), Revenue from Contracts with Customers in the first quarter of our fiscal year that began on January 1, 2018. This new standard replaced the previous revenue recognition guidance in U.S. GAAP. No prior period adjustments were needed as our first commercial shipments began in July 2018. Our revenue consists of product revenue resulting from the sale of Mirataz™ (mirtazapine transdermal ointment) for the management of weight loss in cats . We account for a contract with a customer when there is a legally enforceable contract between us and our customer, the rights of the parties are identified, the contract has commercial substance, and collectability of the contract consideration is probable. Our customers could either be distributors who subsequently resell our products to third parties such as veterinarians, clinics or animals hospitals or the third parties themselves. In accordance with ASC 606, we applied the following steps to recognize revenue for the sale of Mirataz that reflects the consideration to which we expect to be entitled to receive in exchange for the promised goods: 1. Identify the contract with a customer A contract with a customer exists when we enter into an enforceable contract with a customer. These contracts define each party's rights, payment terms and other contractual terms and conditions of the sale. We apply judgment in determining the customer’s ability and intention to pay, which is based on published credit and financial information pertaining to the customer. 2. Identify the performance obligations in the contract Our product in a given purchase order is delivered at the same time and we do not separate an individual order into separate performance obligations. We have concluded the sale of finished goods and related shipping and handling are accounted for as a single performance obligation as there are no other promises to deliver goods beyond what is specified in each accepted customer order. 3. Determine the transaction price The transaction price is determined based on the consideration to which we will be entitled to receive in exchange for transferring goods to the customer, typically a fixed consideration in our contractual agreements. 4. Allocate the transaction price to the performance obligations The transaction price is allocated entirely to the performance obligation to provide pharmaceutical products. The nature of the promises/obligations under our contracts is to transfer a distinct good. Accordingly, because a single performance obligation exists, no allocation of the transaction price is necessary. 5. Determine the satisfaction of performance obligation Revenue is recognized when control of the finished goods is transferred to the customer, net of applicable reserves for variable consideration. Control of the finished goods is transferred at a point in time, upon delivery to the customer. Reserves for Variable Consideration Revenues from product sales are recorded at the net sales price, which includes estimates of variable consideration for which reserves are established. Components of variable consideration include product returns, allowances and discounts. These estimates take into consideration a range of possible outcomes for the expected value (probability-weighted estimate) or relevant factors such as current contractual and statutory requirements, specific known market events and trends, industry data, and forecasted customer buying and payment patterns. Overall, these reserves reflect our best estimates of the amount of consideration to which it is entitled based on the terms of the respective underlying contracts. The amount of variable consideration included in the transaction price may be constrained and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized where the contract will not occur in a future period. Actual amounts of consideration ultimately received may differ from our estimates. If actual results in the future vary from our estimates, we will adjust these estimates, which would affect net product revenues and earnings in the period such variances become known. Product Returns Consistent with the industry practice, we generally offer customers a limited right of return of damaged or expired product that has been purchased directly from us. Our return policy generally allows customers to receive credit for expired products within 90 days after the product’s expiration date. We estimate the amount of our product revenues that may be returned by our customers and record these estimates as a reduction of product revenues in the period the related product revenues are recognized, as well as within accrued liabilities, in the consolidated balance sheets. We currently estimate product return liabilities using probability-weighted available industry data and data provided by the our distributors such as the inventories remaining in the distribution channel. To-date, we have no returns and believe that returns of our product in future periods will be minimal. We do not record a return asset associated with the returned damaged or expired goods due to such asset is deemed to be fully impaired at the time of product return. Sales Discounts and Allowances We compensate our distributors for sales order management, data and distribution and other services through sales discounts and allowances. However, such services are not distinct from our sale of products to distributors and, therefore, these discounts and allowances are recorded as a reduction of product revenues in the statements of operations, as well as a reduction to accounts receivable in the consolidated balance sheets. Practical Expedients and Exemptions We generally expense sales commissions when incurred because the amortization period would have been one year or less. These costs are recorded within sales and marketing expenses. Cost of Product Revenues Cost of product revenues c onsists primarily of the cost of direct materials, direct labor and overhead costs associated with manufacturing, inbound shipping and other third-party logistics costs. Inventories We value inventory at the lower of cost or net realizable value. We determine the cost of inventory using the standard-cost method, which approximates actual cost based on a first-in, first-out method. We analyze our inventory levels quarterly and write down inventory subject to expire in excess of expected requirements, or that has a cost basis in excess of its expected net realizable value. These inventory related costs are recognized as cost of product revenues on the accompanying Consolidated Statements of Operations. Currently our inventory consists of finished goods only. Property, Plant and Equipment On June 21, 2017, we entered into a purchase agreement with Strategic Veterinary Pharmaceuticals, Inc. ("SVP") for the purchase of an approximately 180,000 sq. ft. biologics plant ("the Plant") with clean rooms, utility, equipment, and related quality documentation suitable for small molecule and biologics manufacturing, that is located in Elwood, Kansas. The purchase was finalized on August 7, 2017 upon completion of the diligence period and satisfaction of the conditions of escrow. The Plant was purchased for $3,750,000 , which includes approximately eight acres of land located at 1411 Oak Street, Elwood, Kansas, all improvements located at the Plant, and all personal property and intangible property owned by SVP and located at the Plant or used in connection with the operation of the Plant. 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 for furniture, fixtures, lab and computer equipment and software, and fifteen to thirty-nine years for land improvements and real property. Land and assets held within construction in progress are not depreciated. Construction in progress is related to the construction or development of property and equipment that have not yet been placed in service for their intended use. 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 other income/expense. 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 consolidated financial statements, and the reported amounts of revenues and expenses during the reporting periods. Estimates are based historical experiences or on forecasts, including information received from third parties and other assumptions that the Company believes are reasonable under the circumstances. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from those estimates. 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 condensed consolidated balance sheets as accumulated other comprehensive income (loss). Recently Issued Accounting Pronouncements In February 2016, Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, "Leases (Topic 842)", requiring organizations that lease assets—referred to as “lessees”—to recognize on the consolidated balance sheet the assets and liabilities for the rights and obligations created by those leases. Under the new guidance, a lessee will be required to recognize assets and liabilities for leases with lease terms of more than 12 months. The ASU on leases will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. We are currently evaluating the new guidance and have not determined the impact this standard may have on our financial statements. In July 2018, the FASB issued ASU No. 2018-09, "Codification Improvements", and the amendments in this ASU affect a wide variety of Topics in the Codification. It applies to all reporting entities within the scope of the affected accounting guidance. It will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. We are currently evaluating the new guidance and have not determined the impact this standard may have on our financial statements. In July 2018, the FASB issued ASU No. 2018-10, "Codification Improvements to Topic 842, Leases", which affects narrow aspects of the guidance issued in ASU No. 2016-02. The amendments in this ASU related to transition do not include amendments from proposed ASU, Leases (Topic 842): Targeted Improvements, specific to a new and optional transition method to adopt the new lease requirements in Update 2016-02. For entities that have not adopted Topic 842, the effective date and transition requirements will be the same as the effective date and transition requirements in Topic 842. We are currently evaluating the new guidance and have not determined the impact this standard may have on our financial statements. In July 2018, the FASB issued ASU No. 2018-11, "Targeted Improvements to Topic 842, Leases". The Standard provide another transition method in addition to the existing transition method by allowing entities to initially apply the new lease standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. For entities that have not adopted Topic 842, the effective date and transition requirements will be the same as the effective date and transition requirements in Topic 842. We are currently evaluating the new guidance and have not determined the impact this standard may have on our financial statements. In August 2018, the FASB issued ASU No. 2018-13, "Fair Value Measurement (Topic 820)", changes to disclosure requirements for fair value measurement. The amendments of this update modify the disclosure requirements on fair value measurements about Topic 820. It applies to all reporting entities within the scope of the affected accounting guidance. It will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. 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.

Revenue and Cost of Product Rev

Revenue and Cost of Product Revenues	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue and Cost of Product Revenues	Revenues and Cost of Product Revenues We adopted ASC 606 in the first quarter of our fiscal year that began on January 1, 2018. This new standard replaced the previous revenue recognition guidance in U.S. GAAP. No prior period adjustments were needed as our first commercial shipments began in July 2018. Our revenue consists of product revenue resulting from the sale of Mirataz™ (mirtazapine transdermal ointment) for the management of weight loss in cats . We account for a contract with a customer when there is a legally enforceable contract between us and our customer, the rights of the parties are identified, the contract has commercial substance, and collectability of the contract consideration is probable. Our revenues are measured based on the consideration specified in the contract with each customer, net of product returns, discounts and allowances. The following table presents revenues and cost of product revenues for the quarter ended September 30, 2018 (in thousands): Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Gross product revenues $ 660 $ — $ 660 $ — Less allowance for product returns (20 ) — (20 ) — Net product revenues 640 — 640 — Cost of product revenues 110 — 110 — Gross profit $ 530 $ — $ 530 $ — Concentrations of credit risk Our revenue was generated entirely from sales within the United States. Approximately 80% of our products sold were to four distributors. Product returns Our return policy generally allows customers to receive credit for expired products within 90 days after the product’s expiration date. We currently estimate product return liabilities of 3% of gross revenue using probability-weighted available industry data and data provided by our distributors such as the inventories remaining in the distribution channel. Adjustments will be made in the future if actual results vary from our estimates. Accounts receivable and allowance for doubtful accounts Accounts receivable are stated at their carrying values, net of any allowances for doubtful accounts. Accounts receivable consist primarily of amounts due from distributors, for which collection is probable based on the customer's intent and ability to pay. Receivables are evaluated for collection probability on a regular basis and an allowance for doubtful accounts is recorded, if necessary. We have no allowance for doubtful accounts as of September 30, 2018 as our analysis did not uncover any collection risks.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Certain assets and liabilities are carried at fair value. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. A fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last is considered unobservable, is used to measure fair value: Level 1: Quoted prices in active markets for identical assets or liabilities. Level 2: Observable inputs (other than Level 1 quoted prices) such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. Level 3: Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. 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. Financial assets, which consist of money market funds and available-for-sale securities, are measured at fair value on a recurring basis and are summarized as follows (in thousands): Fair Value Measurements as of September 30, 2018 Description Total Quoted Prices in Significant Other Unobservable Inputs Cash equivalents: Money market funds $ 1,373 $ 1,373 $ — $ — US Treasury bills 1,000 1,000 — — Commercial paper 57,222 — 57,222 — U.S. treasury bonds and notes 9,998 — 9,998 — Short-term investments: U.S. treasury bonds and notes 1,998 1,998 — — U.S. government agency notes 2,998 — 2,998 — Commercial paper 6,369 — 6,369 — Corporate notes 10,277 — 10,277 — $ 91,235 $ 4,371 $ 86,864 $ — Fair Value Measurements as of December 31, 2017 Description Total Quoted Prices in Significant Other Unobservable Inputs Cash equivalents: Money market funds $ 801 $ 801 $ — $ — Commercial paper 31,977 — 31,977 — Corporate notes 1,500 — 1,500 Short-term investments: U.S. treasury bonds and notes 3,482 3,482 — — U.S. government agency notes 6,746 — 6,746 — Commercial paper 22,052 — 22,052 — Corporate notes 13,927 — 13,927 — Long-term investments: Corporate notes 1,499 — 1,499 — $ 81,984 $ 4,283 $ 77,701 $ — During the nine months ended September 30, 2018 , there were no transfers of assets between Level 1, Level 2 or Level 3 of the fair value hierarchy. At September 30, 2018 and December 31, 2017 , we did not have any financial liabilities which were measured at fair value on a recurring basis.

Investments

Investments	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Investments	Investments We classify all highly-liquid investments with stated maturities of greater than three months from the date of purchase and remaining maturities of less than one year as short-term investments. Investments with maturities beyond one year may be classified as short-term based on their highly liquid nature and because such investments are viewed as being available to support current operations. We classify and account for investments as available-for-sale and reflect realized gains and losses using the specific identification method. Changes in market value, if any, excluding other-than-temporary impairments, are reflected in other comprehensive income (loss). The fair value of available-for-sale investments by type of security at September 30, 2018 was as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term investments: Commercial paper $ 6,369 $ — $ — $ 6,369 U.S. government agency notes 2,999 — (1 ) 2,998 U.S. treasury bonds and notes 1,999 — (1 ) 1,998 Corporate notes 10,287 — (10 ) 10,277 Total available-for-sale investments $ 21,654 $ — $ (12 ) $ 21,642 The fair value of available-for-sale investments by type of security at December 31, 2017 was as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term investments: Commercial paper $ 22,052 $ — $ — $ 22,052 U.S. government agency notes 6,750 — (4 ) 6,746 U.S. treasury bonds and notes 3,483 — (1 ) 3,482 Corporate notes 13,946 — (19 ) 13,927 46,231 — (24 ) 46,207 Long-term investments: Corporate notes 1,506 — (7 ) 1,499 Total available-for-sale investments $ 47,737 $ — $ (31 ) $ 47,706

Accrued Liabilities

Accrued Liabilities	9 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities Accrued liabilities consisted of the following (in thousands): September 30, 2018 December 31, 2017 Accrued consulting $ 553 $ 335 Accrued research and development costs 2,274 919 Other expenses 2,188 646 Deferred rent 116 115 5,131 2,015 Less current portion (5,032 ) (1,900 ) Long-term liability (deferred rent) $ 99 $ 115

Common Stock and Stock-Based Aw

Common Stock and Stock-Based Awards	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Common Stock and Stock-Based Awards	Common Stock and Stock-Based Awards Common Stock During the nine months ended September 30, 2018 , we sold 5,326,314 shares of common stock in a follow-on public offering and 188,100 shares of common stock under the Sales Agreement (see Note 1). In addition, we issued 120,834 shares of common stock in connection with the exercise of stock options for gross proceeds of $318,000 and withheld 26,980 shares of restricted common stock to satisfy employee tax withholding obligations arising in conjunction with the vesting of restricted stock (see below). Stock-Based Awards The table below shows the number of shares of common stock underlying options granted to employees, directors and consultants, the assumptions used in the Black-Scholes option pricing model used to value those options and the resulting weighted-average grant date fair value per share: Stock Option Plan Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Shares underlying options granted 101,500 143,500 1,406,193 1,148,200 Weighted-average exercise price $13.34 $7.49 $9.24 $6.57 Weighted average risk- free interest rate 2.82 % 1.97 % 2.56% 1.97% Weighted average expected term (years) 6.1 6.6 5.9 6.0 Weighted average expected volatility 58% 74% 59% 71% Expected dividend yield — — — — Weighted-average grant date fair value per share $7.53 $5.09 $5.28 $4.19 In June 2018, we adopted the 2018 Equity Incentive Plan (the “2018 Plan”), and reserved 3,000,000 shares of our common stock for issuance under the 2018 Plan. The 2018 Plan is the successor to our 2016 Equity Incentive Plan (the “2016 Plan”), which was retired on June 21, 2018 upon stockholders’ approval of our 2018 Plan. The 2016 Plan was the successor to our 2012 Equity Incentive Plan (the "2012 Plan"), which was retired on May 23, 2016 upon stockholders' approval of our 2016 Plan. All awards made under the 2016 and 2012 Plans shall remain subject to the terms of these plans. Options granted under the 2018 Plan may be either incentive stock options or nonstatutory stock options. The 2018 Plan also provides for the grant of stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards, performance cash awards and other stock awards. The exercise price of a stock option may not be less than 100% of the closing price of our common stock on the date of the grant. If, at any time we grant an incentive stock option, and the optionee directly or by attribution owns stock possessing more than 10% of the total combined voting power of all classes of KindredBio stock, the option price shall be at least 110% of the fair value and shall not be exercisable more than five years after the date of grant. Options generally vest over a period of one or four years from the date of grant. Options granted under the 2018 Plan expire no later than 10 years from the date of grant. As of September 30, 2018 , there were 207,993 option shares outstanding, and 2,792,007 shares available for future grants under the 2018 Plan. Our Employee Stock Purchase Plan (the "Stock Purchase Plan" or "ESPP"), adopted in December 2014, permits eligible employees to purchase common stock at a discount through payroll deductions during defined six -month consecutive offering periods beginning December 1 with the exception of our first offering period which commenced on January 1, 2015 for a five month duration. 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. A total of 200,000 shares of common stock are authorized for issuance under the Stock Purchase Plan. At the Annual Meeting of Stockholders of Kindred Biosciences, Inc. held on June 22, 2018, our stockholders approved an amendment to increase the number of shares that may be issued under the ESPP from 200,000 shares to 500,000 shares. A participant may purchase a maximum of 2,000 shares of common stock during each offering period, not to exceed $25,000 worth of common stock on the offering date during each calendar year. We use the Black-Scholes option pricing model, in combination with the discounted employee price, in determining the value of the Stock Purchase Plan expense to be recognized during each offering period. The following assumptions were used in the Black-Scholes option pricing model to calculate employee stock-based compensation: Stock Purchase Plan Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Weighted average risk-free interest rate 2.10% 1.07% 1.78% 0.84% Weighted average expected term (years) 0.5 0.5 0.5 0.5 Weighted average expected volatility 41.6% 54.5% 41.5% 64.4% Expected dividend yield — — — — Weighted-average grant date fair value per share $2.60 $1.96 $2.25 $1.64 Under the Stock Purchase Plan, employees purchased 24,816 shares of common stock for $160,000 as of September 30, 2018 . At September 30, 2018 and December 31, 2017, we had an outstanding liability of $128,000 and $27,000 , respectively, which is included in accrued compensation on the condensed consolidated balance sheets, for employee contributions to the Stock Purchase Plan for shares pending issuance at the end of the next offering period. We recorded stock-based compensation expense as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2018 2017 2,018 2,017 Research and development $416 $410 $1,305 $1,252 General and administrative 1,219 906 3,267 2,625 $1,635 $1,316 $4,572 $3,877 We had an aggregate of approximately $8,944,000 of unrecognized stock-based compensation expense for options outstanding and the Stock Purchase Plan as of September 30, 2018 which is expected to be recognized over a weighted-average period of 2.7 years. Restricted Stock Award and Restricted Stock Units On January 23, 2017, we granted 250,000 shares of restricted stock awards to four employees. Shares will vest 25% on each one year anniversary of the grant date provided that the employee is in the employment of the Company on such vesting date. On January 22, 2018, we granted 315,000 shares of restricted stock units to four employees. Shares will vest 25% on each one year anniversary of the grant date provided that the employee is in the employment of the Company on such vesting date. The total stock-based compensation expense related to these awards and units is $4,356,000 . As of September 30, 2018 , we have an aggregate of approximately $3,207,000 unrecognized stock-based compensation expense for restricted stock awards and units outstanding which is expected to be recognized over a weighted-average period of 3.0 years . Restricted stock activity for the period ended September 30, 2018 was as follows: Restricted Stock Award Shares Weighted Average Grant Date Fair Value Unvested balance at December 31, 2017 250,000 $6.40 Granted — — Vested (62,500) 6.40 Forfeited — — Unvested balance at September 30, 2018 187,500 $6.40 Restricted Stock Units Shares Weighted Average Grant Date Fair Value Unvested balance at December 31, 2017 — — Granted 315,000 $8.75 Vested — — Forfeited — — Unvested balance at September 30, 2018 315,000 $8.75

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies We have non-cancelable operating leases for laboratory space in Burlingame, California with several amendments to expand the facility. Commencing on June 1, 2017, the non-cancelable operating lease for the entire existing laboratory space of a total 10,755 square feet was extended for another 5 years through May 2022. In February 2017, we further amended the operating lease for laboratory space with an additional 721 square feet through May 2022. In April 2017, we renewed our headquarters office lease for 6,900 square feet of office space in Burlingame, California through November 30, 2020 and in June 2017, we amended the lease with an additional 1,190 square feet of office space through November 30, 2020. In addition, we have a non-cancelable operating lease for 3,126 square feet of office space in San Diego, California through September 2019 and three equipment leases expiring through 2020. In October 2018, we signed a short-term lease in Burlingame with Inflammatix, Inc., consisting of 5,613 square feet of space which is part of a larger office project owned by the landlord. The lease will continue through March 31, 2019 and thereafter may continue on a month-to-month basis until December 31, 2019. As of September 30, 2018 , we are obligated to make minimum lease payments under non-cancelable operating leases as follows (in thousands): Year ending December 31, Lease Payments 2018 (remaining of year) $ 223 2019 835 2020 726 2021 459 2022 and after 194 Total $ 2,437 In March 2018, we entered into a standard form of agreement with CRB Builders, LLC (“CRB”) in connection with the renovation of the Plant. Pursuant to the agreement, CRB will provide pre-construction and construction services in connection with constructing and renovating the Plant to provide approximately 16,500 square feet of new production space, and supporting Fill and Finish and Bio Production processes (the “Project”). The date for substantial completion of CRB’s work on the Project is anticipated to be in the first quarter of 2019, which is subject to adjustment in accordance with the terms of the agreement as the renovation progresses, or as agreed and requested by the Company. The agreement is subject to customary undertakings, covenants, obligations, rights and conditions. In June 2018, we entered into a Strategic Supply Agreement (the “Agreement”), with Pall Corporation (“Pall”) for purchase of equipment and consumables to be used in support of our manufacturing requirements, including, but not limited to the Plant. Pursuant to the agreement, we will purchase certain pharmaceutical manufacturing equipment and related services in the aggregate amount of $3.8 million with a seven year consumable purchase obligation in the aggregate amount of approximately $16.5 million . The agreement is subject to customary undertakings, covenants, obligations, rights and conditions. We did not incur any expenditures as of September 30, 2018 .

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share Basic and diluted net loss per share was calculated as follows (in thousands, except per share amounts): Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Basic and diluted net loss per share: Numerator: Net loss $ (13,037 ) $ (7,890 ) $ (34,249 ) $ (21,149 ) Denominator: Weighted-average number of common shares outstanding, basic and diluted 33,601 27,400 30,089 24,130 Net loss per share, basic and diluted $ (0.39 ) $ (0.29 ) $ (1.14 ) $ (0.88 ) There was no difference between the Company’s net loss and the net loss attributable to common stockholders for all periods presented. Stock options to purchase 5,741,001 shares of common stock, 187,500 shares unvested restricted stock awards and 315,000 restricted stock units as of September 30, 2018 , were excluded from the computation of diluted net loss per share attributable to common stockholders for the three and nine months ended September 30, 2018 , because their effect was anti-dilutive. Stock options to purchase 4,538,079 shares of common stock and 250,000 shares unvested restricted stock awards were excluded from the computation of diluted net loss per share attributable to common stockholders for the three and nine months ended September 30, 2017 , because their effect was anti-dilutive.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events We have evaluated subsequent events through the filing date of this quarterly report on Form 10-Q and determined that no subsequent events have occurred that would require recognition in the financial statements or disclosure in the notes thereto.

Description of Business, Basi_2

Description of Business, Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Kindred Biosciences, Inc. ("KindredBio", "we", "us" or "our") was incorporated on September 25, 2012 (inception) in the State of Delaware. On April 25, 2016, we filed a Certificate of Incorporation with the State of Delaware for a wholly owned subsidiary, KindredBio Equine, Inc. ("Subsidiary"). The Subsidiary has one class of capital stock which is designated common stock, $0.0001 par value per share. The authorized number of shares of common stock for the Subsidiary is 1,000 . We are a commercial-stage 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 located 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 patent or other intellectual property 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. The accompanying unaudited interim condensed consolidated financial statements (“financial statements”) have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States of America (“U.S. GAAP”) for complete financial statements. These unaudited interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2017 included in our annual report on Form 10-K as filed with the SEC on March 1, 2018. In the opinion of management, all adjustments, consisting of a normal and recurring nature, considered necessary for a fair presentation, have been included in these financial statements. The accompanying financial statements include the accounts of the Company and its wholly owned Subsidiary. All inter-company accounts and transactions have been eliminated in consolidation.
Liquidity	Liquidity We have incurred losses and negative cash flows from operations and had an accumulated deficit of $146,229,000 as of September 30, 2018 . 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 our former convertible preferred stock, the sale of our common stock in our initial public offering in December 2013, the sale of our common stock in our April 2014 follow-on public offering, periodic sales of our common stock under an ATM in the first half year of 2017, sale of our common stock in a follow-on public offering in the third quarter of 2017, periodic sales of our common stock under an ATM and sale of our common stock in a follow-on public offering in the second quarter of 2018. We might require additional capital until such time as we can generate operating revenues in excess operating expenses. We believe that our cash, cash equivalents, short-term and long-term investments totaling $91,626,000 as of September 30, 2018 , are sufficient to fund our planned operations through the next 18 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
Revenue Recognition and Cost of Product Revenues	Revenue Recognition We adopted FASB Accounting Standards Codification Topic 606 (“ASC 606”), Revenue from Contracts with Customers in the first quarter of our fiscal year that began on January 1, 2018. This new standard replaced the previous revenue recognition guidance in U.S. GAAP. No prior period adjustments were needed as our first commercial shipments began in July 2018. Our revenue consists of product revenue resulting from the sale of Mirataz™ (mirtazapine transdermal ointment) for the management of weight loss in cats . We account for a contract with a customer when there is a legally enforceable contract between us and our customer, the rights of the parties are identified, the contract has commercial substance, and collectability of the contract consideration is probable. Our customers could either be distributors who subsequently resell our products to third parties such as veterinarians, clinics or animals hospitals or the third parties themselves. In accordance with ASC 606, we applied the following steps to recognize revenue for the sale of Mirataz that reflects the consideration to which we expect to be entitled to receive in exchange for the promised goods: 1. Identify the contract with a customer A contract with a customer exists when we enter into an enforceable contract with a customer. These contracts define each party's rights, payment terms and other contractual terms and conditions of the sale. We apply judgment in determining the customer’s ability and intention to pay, which is based on published credit and financial information pertaining to the customer. 2. Identify the performance obligations in the contract Our product in a given purchase order is delivered at the same time and we do not separate an individual order into separate performance obligations. We have concluded the sale of finished goods and related shipping and handling are accounted for as a single performance obligation as there are no other promises to deliver goods beyond what is specified in each accepted customer order. 3. Determine the transaction price The transaction price is determined based on the consideration to which we will be entitled to receive in exchange for transferring goods to the customer, typically a fixed consideration in our contractual agreements. 4. Allocate the transaction price to the performance obligations The transaction price is allocated entirely to the performance obligation to provide pharmaceutical products. The nature of the promises/obligations under our contracts is to transfer a distinct good. Accordingly, because a single performance obligation exists, no allocation of the transaction price is necessary. 5. Determine the satisfaction of performance obligation Revenue is recognized when control of the finished goods is transferred to the customer, net of applicable reserves for variable consideration. Control of the finished goods is transferred at a point in time, upon delivery to the customer. Reserves for Variable Consideration Revenues from product sales are recorded at the net sales price, which includes estimates of variable consideration for which reserves are established. Components of variable consideration include product returns, allowances and discounts. These estimates take into consideration a range of possible outcomes for the expected value (probability-weighted estimate) or relevant factors such as current contractual and statutory requirements, specific known market events and trends, industry data, and forecasted customer buying and payment patterns. Overall, these reserves reflect our best estimates of the amount of consideration to which it is entitled based on the terms of the respective underlying contracts. The amount of variable consideration included in the transaction price may be constrained and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized where the contract will not occur in a future period. Actual amounts of consideration ultimately received may differ from our estimates. If actual results in the future vary from our estimates, we will adjust these estimates, which would affect net product revenues and earnings in the period such variances become known. Product Returns Consistent with the industry practice, we generally offer customers a limited right of return of damaged or expired product that has been purchased directly from us. Our return policy generally allows customers to receive credit for expired products within 90 days after the product’s expiration date. We estimate the amount of our product revenues that may be returned by our customers and record these estimates as a reduction of product revenues in the period the related product revenues are recognized, as well as within accrued liabilities, in the consolidated balance sheets. We currently estimate product return liabilities using probability-weighted available industry data and data provided by the our distributors such as the inventories remaining in the distribution channel. To-date, we have no returns and believe that returns of our product in future periods will be minimal. We do not record a return asset associated with the returned damaged or expired goods due to such asset is deemed to be fully impaired at the time of product return. Sales Discounts and Allowances We compensate our distributors for sales order management, data and distribution and other services through sales discounts and allowances. However, such services are not distinct from our sale of products to distributors and, therefore, these discounts and allowances are recorded as a reduction of product revenues in the statements of operations, as well as a reduction to accounts receivable in the consolidated balance sheets. Practical Expedients and Exemptions We generally expense sales commissions when incurred because the amortization period would have been one year or less. These costs are recorded within sales and marketing expenses. Cost of Product Revenues Cost of product revenues c onsists primarily of the cost of direct materials, direct labor and overhead costs associated with manufacturing, inbound shipping and other third-party logistics costs.
Inventories	Inventories We value inventory at the lower of cost or net realizable value. We determine the cost of inventory using the standard-cost method, which approximates actual cost based on a first-in, first-out method. We analyze our inventory levels quarterly and write down inventory subject to expire in excess of expected requirements, or that has a cost basis in excess of its expected net realizable value. These inventory related costs are recognized as cost of product revenues on the accompanying Consolidated Statements of Operations. Currently our inventory consists of finished goods only.
Property, Plant 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 for furniture, fixtures, lab and computer equipment and software, and fifteen to thirty-nine years for land improvements and real property. Land and assets held within construction in progress are not depreciated. Construction in progress is related to the construction or development of property and equipment that have not yet been placed in service for their intended use. 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 other income/expense.
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 consolidated financial statements, and the reported amounts of revenues and expenses during the reporting periods. Estimates are based historical experiences or on forecasts, including information received from third parties and other assumptions that the Company believes are reasonable under the circumstances. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from those estimates.
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 condensed consolidated balance sheets as accumulated other comprehensive income (loss).
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In February 2016, Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, "Leases (Topic 842)", requiring organizations that lease assets—referred to as “lessees”—to recognize on the consolidated balance sheet the assets and liabilities for the rights and obligations created by those leases. Under the new guidance, a lessee will be required to recognize assets and liabilities for leases with lease terms of more than 12 months. The ASU on leases will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. We are currently evaluating the new guidance and have not determined the impact this standard may have on our financial statements. In July 2018, the FASB issued ASU No. 2018-09, "Codification Improvements", and the amendments in this ASU affect a wide variety of Topics in the Codification. It applies to all reporting entities within the scope of the affected accounting guidance. It will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. We are currently evaluating the new guidance and have not determined the impact this standard may have on our financial statements. In July 2018, the FASB issued ASU No. 2018-10, "Codification Improvements to Topic 842, Leases", which affects narrow aspects of the guidance issued in ASU No. 2016-02. The amendments in this ASU related to transition do not include amendments from proposed ASU, Leases (Topic 842): Targeted Improvements, specific to a new and optional transition method to adopt the new lease requirements in Update 2016-02. For entities that have not adopted Topic 842, the effective date and transition requirements will be the same as the effective date and transition requirements in Topic 842. We are currently evaluating the new guidance and have not determined the impact this standard may have on our financial statements. In July 2018, the FASB issued ASU No. 2018-11, "Targeted Improvements to Topic 842, Leases". The Standard provide another transition method in addition to the existing transition method by allowing entities to initially apply the new lease standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. For entities that have not adopted Topic 842, the effective date and transition requirements will be the same as the effective date and transition requirements in Topic 842. We are currently evaluating the new guidance and have not determined the impact this standard may have on our financial statements. In August 2018, the FASB issued ASU No. 2018-13, "Fair Value Measurement (Topic 820)", changes to disclosure requirements for fair value measurement. The amendments of this update modify the disclosure requirements on fair value measurements about Topic 820. It applies to all reporting entities within the scope of the affected accounting guidance. It will take effect for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. 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	Certain assets and liabilities are carried at fair value. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. A fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last is considered unobservable, is used to measure fair value: Level 1: Quoted prices in active markets for identical assets or liabilities. Level 2: Observable inputs (other than Level 1 quoted prices) such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. Level 3: Unobservable inputs that are supported by little or no market activity and that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. 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.

Revenue and Cost of Product R_2

Revenue and Cost of Product Revenues (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue and Cost of Product Revenues	The following table presents revenues and cost of product revenues for the quarter ended September 30, 2018 (in thousands): Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Gross product revenues $ 660 $ — $ 660 $ — Less allowance for product returns (20 ) — (20 ) — Net product revenues 640 — 640 — Cost of product revenues 110 — 110 — Gross profit $ 530 $ — $ 530 $ —

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Financial Assets Measured at Fair Value on a Recurring Basis	Financial assets, which consist of money market funds and available-for-sale securities, are measured at fair value on a recurring basis and are summarized as follows (in thousands): Fair Value Measurements as of September 30, 2018 Description Total Quoted Prices in Significant Other Unobservable Inputs Cash equivalents: Money market funds $ 1,373 $ 1,373 $ — $ — US Treasury bills 1,000 1,000 — — Commercial paper 57,222 — 57,222 — U.S. treasury bonds and notes 9,998 — 9,998 — Short-term investments: U.S. treasury bonds and notes 1,998 1,998 — — U.S. government agency notes 2,998 — 2,998 — Commercial paper 6,369 — 6,369 — Corporate notes 10,277 — 10,277 — $ 91,235 $ 4,371 $ 86,864 $ — Fair Value Measurements as of December 31, 2017 Description Total Quoted Prices in Significant Other Unobservable Inputs Cash equivalents: Money market funds $ 801 $ 801 $ — $ — Commercial paper 31,977 — 31,977 — Corporate notes 1,500 — 1,500 Short-term investments: U.S. treasury bonds and notes 3,482 3,482 — — U.S. government agency notes 6,746 — 6,746 — Commercial paper 22,052 — 22,052 — Corporate notes 13,927 — 13,927 — Long-term investments: Corporate notes 1,499 — 1,499 — $ 81,984 $ 4,283 $ 77,701 $ —

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of Fair Value of Available-for-Sale Short Term Investments	The fair value of available-for-sale investments by type of security at September 30, 2018 was as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term investments: Commercial paper $ 6,369 $ — $ — $ 6,369 U.S. government agency notes 2,999 — (1 ) 2,998 U.S. treasury bonds and notes 1,999 — (1 ) 1,998 Corporate notes 10,287 — (10 ) 10,277 Total available-for-sale investments $ 21,654 $ — $ (12 ) $ 21,642 The fair value of available-for-sale investments by type of security at December 31, 2017 was as follows (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Short-term investments: Commercial paper $ 22,052 $ — $ — $ 22,052 U.S. government agency notes 6,750 — (4 ) 6,746 U.S. treasury bonds and notes 3,483 — (1 ) 3,482 Corporate notes 13,946 — (19 ) 13,927 46,231 — (24 ) 46,207 Long-term investments: Corporate notes 1,506 — (7 ) 1,499 Total available-for-sale investments $ 47,737 $ — $ (31 ) $ 47,706

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	9 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): September 30, 2018 December 31, 2017 Accrued consulting $ 553 $ 335 Accrued research and development costs 2,274 919 Other expenses 2,188 646 Deferred rent 116 115 5,131 2,015 Less current portion (5,032 ) (1,900 ) Long-term liability (deferred rent) $ 99 $ 115

Common Stock and Stock-Based _2

Common Stock and Stock-Based Awards (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Stock Option Plan Valuation Assumptions	The table below shows the number of shares of common stock underlying options granted to employees, directors and consultants, the assumptions used in the Black-Scholes option pricing model used to value those options and the resulting weighted-average grant date fair value per share: Stock Option Plan Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Shares underlying options granted 101,500 143,500 1,406,193 1,148,200 Weighted-average exercise price $13.34 $7.49 $9.24 $6.57 Weighted average risk- free interest rate 2.82 % 1.97 % 2.56% 1.97% Weighted average expected term (years) 6.1 6.6 5.9 6.0 Weighted average expected volatility 58% 74% 59% 71% Expected dividend yield — — — — Weighted-average grant date fair value per share $7.53 $5.09 $5.28 $4.19
Schedule of Stock Purchase Plan Valuation Assumptions	The following assumptions were used in the Black-Scholes option pricing model to calculate employee stock-based compensation: Stock Purchase Plan Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Weighted average risk-free interest rate 2.10% 1.07% 1.78% 0.84% Weighted average expected term (years) 0.5 0.5 0.5 0.5 Weighted average expected volatility 41.6% 54.5% 41.5% 64.4% Expected dividend yield — — — — Weighted-average grant date fair value per share $2.60 $1.96 $2.25 $1.64
Schedule of Stock-Based Compensation Expense	We recorded stock-based compensation expense as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2018 2017 2,018 2,017 Research and development $416 $410 $1,305 $1,252 General and administrative 1,219 906 3,267 2,625 $1,635 $1,316 $4,572 $3,877
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	Restricted stock activity for the period ended September 30, 2018 was as follows: Restricted Stock Award Shares Weighted Average Grant Date Fair Value Unvested balance at December 31, 2017 250,000 $6.40 Granted — — Vested (62,500) 6.40 Forfeited — — Unvested balance at September 30, 2018 187,500 $6.40 Restricted Stock Units Shares Weighted Average Grant Date Fair Value Unvested balance at December 31, 2017 — — Granted 315,000 $8.75 Vested — — Forfeited — — Unvested balance at September 30, 2018 315,000 $8.75

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments Under Noncancelable Operating Leases	As of September 30, 2018 , we are obligated to make minimum lease payments under non-cancelable operating leases as follows (in thousands): Year ending December 31, Lease Payments 2018 (remaining of year) $ 223 2019 835 2020 726 2021 459 2022 and after 194 Total $ 2,437

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Calculation of Basic and Diluted Net Loss per Share	Basic and diluted net loss per share was calculated as follows (in thousands, except per share amounts): Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Basic and diluted net loss per share: Numerator: Net loss $ (13,037 ) $ (7,890 ) $ (34,249 ) $ (21,149 ) Denominator: Weighted-average number of common shares outstanding, basic and diluted 33,601 27,400 30,089 24,130 Net loss per share, basic and diluted $ (0.39 ) $ (0.29 ) $ (1.14 ) $ (0.88 )

Description of Business, Basi_3

Description of Business, Basis of Presentation and Summary of Significant Accounting Policies - Stock Offerings and Liquidity (Details)	Jun. 22, 2018USD ($)$ / sharesshares	Apr. 25, 2016class_of_stock$ / sharesshares	Jun. 30, 2018USD ($)shares	May 31, 2018USD ($)	Jan. 31, 2018USD ($)	Aug. 31, 2017$ / sharesshares	Jul. 31, 2017$ / sharesshares	Jun. 30, 2017USD ($)shares	Aug. 31, 2017USD ($)$ / shares	Sep. 30, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares
Subsidiary or Equity Method Investee [Line Items]
Common stock, par value (USD per share) | $ / shares										$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares) | shares										100,000,000	100,000,000
Number of shares issued in transaction (in shares) | shares	5,326,314		188,100				3,000,000
Net proceeds received in sale of stock	$ 47,422,000		$ 1,758,000						$ 23,198,000
Shares issued (USD per share) | $ / shares	$ 9.50					$ 7.50	$ 7.50		$ 7.50
Gross proceeds received in sale of stock	$ 50,600,000		$ 1,903,000						$ 24,855,000
Maximum dollar amount of equity and debt securities offered					$ 150,000,000
Maximum aggregate offering price of common stock sold under agreement				$ 50,000,000
Accumulated deficit										$ 146,229,000	$ 111,980,000
Cash, cash equivalents, and short-term investments										$ 91,626,000
FBR Capital Markets & Co.
Subsidiary or Equity Method Investee [Line Items]
Number of shares issued in transaction (in shares) | shares								4,501,985
Net proceeds received in sale of stock								$ 28,962,000
Over-allotment option
Subsidiary or Equity Method Investee [Line Items]
Number of shares issued in transaction (in shares) | shares						314,000
KindredBio Equine, Inc
Subsidiary or Equity Method Investee [Line Items]
Number of classes of stock | class_of_stock		1
Common stock, par value (USD per share) | $ / shares		$ 0.0001
Common stock, shares authorized (in shares) | shares		1,000

Description of Business, Basi_4

Description of Business, Basis of Presentation and Summary of Significant Accounting Policies - Revenue Recognition (Details)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Product return period after expiration	90 days
Amortization period (one year or less)	1 year

Description of Business, Basi_5

Description of Business, Basis of Presentation and Summary of Significant Accounting Policies - Property, Plant and Equipment (Details) ft² in Thousands, $ in Thousands	Aug. 07, 2017USD ($)ft²a	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)
Property, Plant and Equipment [Line Items]
Payment to acquire plant		$ 8,482	$ 4,748
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)		2 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)		5 years
Lab and computer equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)		2 years
Lab and computer equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)		5 years
Software | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)		2 years
Software | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)		5 years
Land improvements and real property | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)		15 years
Land improvements and real property | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)		39 years
Strategic Veterinary Pharmaceuticals, Inc.
Property, Plant and Equipment [Line Items]
Square footage of plant (in sqft) | ft²	180
Payment to acquire plant	$ 3,750
Area of land (in acres) | a	8

Revenue and Cost of Product R_3

Revenue and Cost of Product Revenues - Disaggregation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue from Contract with Customer [Abstract]
Gross product revenues	$ 660	$ 0	$ 660	$ 0
Less allowance for product returns	(20)	0	(20)	0
Net product revenues	640	0	640	0
Cost of product revenues	110	0	110	0
Gross profit	$ 530	$ 0	$ 530	$ 0

Revenue and Cost of Product R_4

Revenue and Cost of Product Revenues - Narrative (Details)	9 Months Ended
	Sep. 30, 2018USD ($)
Concentration Risk [Line Items]
Product return period after expiration	90 days
Product return liability percentage	3.00%
Allowance for doubtful accounts	$ 0
Customer Concentration Risk | Revenue | Four distributors
Concentration Risk [Line Items]
Concentration risk percentage	80.00%

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 21,642,000	$ 46,207,000
Long-term investments	0	1,499,000
Recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	91,235,000	81,984,000
Financial liabilities	0	0
Recurring basis | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	4,371,000	4,283,000
Recurring basis | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	86,864,000	77,701,000
Recurring basis | Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Recurring basis | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	1,373,000	801,000
Recurring basis | Money market funds | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	1,373,000	801,000
Recurring basis | Money market funds | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Recurring basis | Money market funds | Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Recurring basis | US Treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	1,000,000
Recurring basis | US Treasury bills | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	1,000,000
Recurring basis | US Treasury bills | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Recurring basis | US Treasury bills | Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Recurring basis | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	57,222,000	31,977,000
Short-term investments	6,369,000	22,052,000
Recurring basis | Commercial paper | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Short-term investments	0	0
Recurring basis | Commercial paper | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	57,222,000	31,977,000
Short-term investments	6,369,000	22,052,000
Recurring basis | Commercial paper | Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Short-term investments	0	0
Recurring basis | U.S. treasury bonds and notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	9,998,000
Short-term investments	1,998,000	3,482,000
Recurring basis | U.S. treasury bonds and notes | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Short-term investments	1,998,000	3,482,000
Recurring basis | U.S. treasury bonds and notes | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	9,998,000
Short-term investments	0	0
Recurring basis | U.S. treasury bonds and notes | Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Short-term investments	0	0
Recurring basis | U.S. government agency notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	2,998,000	6,746,000
Recurring basis | U.S. government agency notes | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0	0
Recurring basis | U.S. government agency notes | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	2,998,000	6,746,000
Recurring basis | U.S. government agency notes | Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0	0
Recurring basis | Corporate notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		1,500,000
Short-term investments	10,277,000	13,927,000
Long-term investments		1,499,000
Recurring basis | Corporate notes | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		0
Short-term investments	0	0
Long-term investments		0
Recurring basis | Corporate notes | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents		1,500,000
Short-term investments	10,277,000	13,927,000
Long-term investments		1,499,000
Recurring basis | Corporate notes | Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 0	0
Long-term investments		$ 0

Investments (Details)

Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Gain (Loss) on Securities [Line Items]
Amortized Cost	$ 21,654	$ 47,737
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(12)	(31)
Fair Value	21,642	47,706
Short-term investments
Gain (Loss) on Securities [Line Items]
Amortized Cost		46,231
Gross Unrealized Gains		0
Gross Unrealized Losses		(24)
Fair Value		46,207
Short-term investments | Commercial paper
Gain (Loss) on Securities [Line Items]
Amortized Cost	6,369	22,052
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	6,369	22,052
Short-term investments | U.S. government agency notes
Gain (Loss) on Securities [Line Items]
Amortized Cost	2,999	6,750
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	(4)
Fair Value	2,998	6,746
Short-term investments | U.S. treasury bonds and notes
Gain (Loss) on Securities [Line Items]
Amortized Cost	1,999	3,483
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	(1)
Fair Value	1,998	3,482
Short-term investments | Corporate notes
Gain (Loss) on Securities [Line Items]
Amortized Cost	10,287	13,946
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(10)	(19)
Fair Value	$ 10,277	13,927
Long-term investments | Corporate notes
Gain (Loss) on Securities [Line Items]
Amortized Cost		1,506
Gross Unrealized Gains		0
Gross Unrealized Losses		(7)
Fair Value		$ 1,499

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued consulting	$ 553	$ 335
Accrued research and development costs	2,274	919
Other expenses	2,188	646
Deferred rent	116	115
Accrued liabilities	5,131	2,015
Less current portion	(5,032)	(1,900)
Long-term liability (deferred rent)	$ 99	$ 115

Common Stock and Stock-Based _3

Common Stock and Stock-Based Awards - Narrative (Details)

Jun. 22, 2018shares

Jan. 22, 2018employeeshares

Jan. 23, 2017employeeshares

Jan. 01, 2015

Jun. 30, 2018shares

Jul. 31, 2017shares

Dec. 31, 2014USD ($)shares

Sep. 30, 2018USD ($)shares

Sep. 30, 2017USD ($)

Sep. 30, 2018USD ($)shares

Sep. 30, 2017USD ($)

Jan. 22, 2018USD ($)employee

Dec. 31, 2017USD ($)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Number of shares issued in transaction (in shares)

5,326,314

188,100

3,000,000

Stock issued in connection with the exercise of common stock (in shares)

120,834

Stock issued in connection with the exercise of common stock | $

$ 318,000

Restricted common stock withheld for tax obligations (in shares)

26,980

Outstanding liability included in accrued compensation | $

$ 128,000

$ 128,000

$ 27,000

Stock-based compensation expense | $

1,635,000

$ 1,316,000

$ 4,572,000

$ 3,877,000

Employee Stock Purchase Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Stock issued to employee stock purchase plans (in shares)

24,816

Value of stock issued, employee stock purchase plans | $

$ 160,000

Unrecognized stock-based compensation | $

8,944,000

$ 8,944,000

Weighted-average period for recognition (in years)

2 years 8 months 16 days

Restricted Stock

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Vesting period

1 year

Number of awards issued in the period (in shares)

250,000

0

Number of employees granted stock options | employee

4

Vesting rights percentage

25.00%

Restricted Stock Units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Vesting period

1 year

Number of awards issued in the period (in shares)

315,000

315,000

Number of employees granted stock options | employee

4

4

Vesting rights percentage

25.00%

Restricted Stock Awards and Units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Unrecognized stock-based compensation | $

$ 3,207,000

$ 3,207,000

Weighted-average period for recognition (in years)

3 years

Stock-based compensation expense | $

$ 4,356,000

2018 Equity Incentive Plan | Stock Option Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Shares reserved for future issuance (in shares)

3,000,000

Purchase price of common stock, percent of fair market value

100.00%

Ownership percentage

10.00%

Purchase price of common stock if ownership threshold is reached, percent

110.00%

Expected term

10 years

Option shares outstanding (in shares)

207,993

207,993

Number of shares available for grant (in shares)

2,792,007

2,792,007

Stock Purchase Plan | Employee Stock Purchase Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Shares reserved for future issuance (in shares)

500,000

200,000

Purchase price of common stock, percent of fair market value

85.00%

Initial offering period

6 months

Consecutive offering period

5 months

Maximum number of shares participant may purchase during each offering period (in shares)

2,000

Maximum value of shares participant may purchase during each offering period | $

$ 25,000

Minimum | 2018 Equity Incentive Plan | Stock Option Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Vesting period

1 year

Maximum | 2018 Equity Incentive Plan | Stock Option Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Exercise period

5 years

Vesting period

4 years

Public stock offering

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Number of shares issued in transaction (in shares)

5,326,314

Common stock offering under sales agreement

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Number of shares issued in transaction (in shares)

188,100

Common Stock and Stock-Based _4

Common Stock and Stock-Based Awards - Stock Option Plan (Details) - Stock Option Plan - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares underlying options granted (in shares)	101,500	143,500	1,406,193	1,148,200
Weighted-average exercise price (USD per share)	$ 13.34	$ 7.49	$ 9.24	$ 6.57
Weighted average risk- free interest rate	2.82%	1.97%	2.56%	1.97%
Weighted average expected term (years)	6 years 1 month 6 days	6 years 7 months 6 days	5 years 10 months 24 days	6 years
Weighted average expected volatility	58.00%	74.00%	59.00%	71.00%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Weighted-average grant date fair value per share (USD per share)	$ 7.53	$ 5.09	$ 5.28	$ 4.19

Common Stock and Stock-Based _5

Common Stock and Stock-Based Awards - Stock Purchase Plan (Details) - Stock Purchase Plan - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average risk- free interest rate	2.10%	1.07%	1.78%	0.84%
Weighted average expected term (years)	6 months	6 months	6 months	6 months
Weighted average expected volatility	41.60%	54.50%	41.50%	64.40%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Weighted-average grant date fair value per share (USD per share)	$ 2.60	$ 1.96	$ 2.25	$ 1.64

Common Stock and Stock-Based _6

Common Stock and Stock-Based Awards - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,635	$ 1,316	$ 4,572	$ 3,877
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	416	410	1,305	1,252
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,219	$ 906	$ 3,267	$ 2,625

Common Stock and Stock-Based _7

Common Stock and Stock-Based Awards - Restricted Stock and Restricted Stock Units (Details) - $ / shares	Jan. 22, 2018	Jan. 23, 2017	Sep. 30, 2018
Restricted Stock Award
Shares
Unvested balance, beginning (in shares)			250,000
Granted (in shares)		250,000	0
Vested (in shares)			(62,500)
Forfeited (in shares)			0
Unvested balance, ending (in shares)			187,500
Weighted Average Grant Date Fair Value
Unvested balance, beginning (USD per share)			$ 6.40
Granted (USD per share)			0
Vested (USD per share)			6.40
Forfeited (USD per share)			0
Unvested balance, ending (USD per share)			$ 6.40
Restricted Stock Units
Shares
Unvested balance, beginning (in shares)			0
Granted (in shares)	315,000		315,000
Vested (in shares)			0
Forfeited (in shares)			0
Unvested balance, ending (in shares)			315,000
Weighted Average Grant Date Fair Value
Unvested balance, beginning (USD per share)			$ 0
Granted (USD per share)			8.75
Vested (USD per share)			0
Forfeited (USD per share)			0
Unvested balance, ending (USD per share)			$ 8.75

Commitments and Contingencies_2

Commitments and Contingencies (Details) $ in Thousands	Jun. 01, 2017ft²	Jun. 30, 2018USD ($)	Sep. 30, 2018USD ($)ft²equipment_lease	Oct. 31, 2018ft²	Mar. 31, 2018ft²	Jun. 30, 2017ft²	Apr. 30, 2017ft²	Feb. 28, 2017ft²
Property, Plant and Equipment [Line Items]
Number of equipment leases (in equipment leases) | equipment_lease			3
Year ending December 31,
2018 (remaining of year)			$ 223
2,019			835
2,020			726
2,021			459
2022 and after			194
Total			2,437
Purchase commitment, amount		$ 3,800
Purchase commitment, period		7 years
Purchase obligation			$ 16,500
Laboratory space | Operating lease
Property, Plant and Equipment [Line Items]
Area of real estate property (in sqft) | ft²	10,755
Operating leases, extension term	5 years
Additional area of real estate property (in sqft) | ft²								721
Office space | Operating lease
Property, Plant and Equipment [Line Items]
Area of real estate property (in sqft) | ft²			3,126				6,900
Additional area of real estate property (in sqft) | ft²						1,190
New production space
Property, Plant and Equipment [Line Items]
Area of real estate property (in sqft) | ft²					16,500
Subsequent Event | Office space | Operating lease
Property, Plant and Equipment [Line Items]
Area of real estate property (in sqft) | ft²				5,600

Net Loss Per Share (Details)

Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Numerator:
Net loss	$ (13,037)	$ (7,890)	$ (34,249)	$ (21,149)
Denominator:
Weighted-average number of common shares outstanding, basic and diluted (in shares)	33,601,000	27,400,000	30,089,000	24,130,000
Net loss per share, basic and diluted (USD per share)	$ (0.39)	$ (0.29)	$ (1.14)	$ (0.88)
Stock Option Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from EPS computation (in shares)	5,741,001	4,538,079	5,741,001	4,538,079
Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from EPS computation (in shares)	187,500	250,000	187,500	250,000
Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from EPS computation (in shares)	315,000		315,000