Aratana Therapeutics (PETX) 10-K 15 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Mar. 10, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Entity Registrant Name	ARATANA THERAPEUTICS, INC.
Entity Central Index Key	1,509,190
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Trading Symbol	petx
Entity Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding		35,355,266
Entity Public Float			$ 405,168,742

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 26,755	$ 9,823
Short-term investments	59,447	88,249
Accounts receivable, net	60	352
Inventories	1,306	427
Prepaid expenses and other current assets	1,451	900
Deferred tax asset		158
Total current assets	89,019	99,909
Property and equipment, net	2,555	620
Long-term marketable securities		2,452
Goodwill	39,781	41,398
Intangible assets, net	15,067	62,323
Restricted cash	350
Other long-term assets	294	1,201
Total assets	147,066	207,903
Current liabilities:
Accounts payable	1,400	1,532
Accrued expenses	4,247	3,229
Current portion-contingent consideration		4,248
Deferred tax liability		413
Other current liabilities	37	46
Total current liabilities	5,684	9,468
Loan payable, net	39,710	14,963
Deferred tax liability		1,610
Other long-term liabilities	122	30
Total liabilities	$ 45,516	$ 26,071
Commitments and contingencies (Notes 12 and 16)
Stockholders' equity:
Common stock, $0.001 par value; 100,000,000 shares authorized at December 31, 2015 and December 31, 2014, 34,563,816 and 34,147,861 issued and outstanding at December 31, 2015 and December 31, 2014, respectively	$ 35	$ 34
Treasury stock	(1,088)	(1,081)
Additional paid-in capital	263,941	254,993
Accumulated deficit	(152,018)	(67,964)
Accumulated other comprehensive loss	(9,320)	(4,150)
Total stockholders' equity	101,550	181,832
Total liabilities and stockholders' equity	$ 147,066	$ 207,903

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014	Jul. 03, 2013	Jul. 02, 2013	Feb. 28, 2013
Consolidated Balance Sheets [Abstract]
Common stock, par value	$ 0.001	$ 0.001		$ 0.001
Common stock, shares authorized	100,000,000	100,000,000	100,000,000	25,041,667	25,041,667
Common stock, shares issued	34,563,816	34,147,861
Common stock, shares outstanding	34,563,816	34,147,861

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues
Licensing and collaboration revenue		$ 500	$ 15
Product sales	$ 678	267	108
Total revenues	678	767	123
Costs and expenses
Cost of product sales	365	333	108
Royalty expense	84	72	1
Research and development	24,964	19,985	10,925
Selling, general and administrative	$ 19,819	17,938	$ 8,572
In-process research and development		2,157
Amortization of acquired intangible assets	$ 1,544	1,891	$ 298
Impairment of acquired intangible assets	43,398
Total costs and expenses	90,174	42,376	19,904
Loss from operations	(89,496)	(41,609)	(19,781)
Other income (expense)
Interest income	189	123	75
Interest expense	(1,585)	(1,060)	(432)
Other income (expense), net	5,140	2,287	478
Total other income (expense)	3,744	1,350	121
Loss before income taxes	(85,752)	(40,259)	(19,660)
Income tax benefit	1,698	1,443	12,722
Net loss	$ (84,054)	$ (38,816)	$ (6,938)
Net loss per share, basic and diluted	$ (2.45)	$ (1.30)	$ (0.63)
Weighted average shares outstanding, basic and diluted	34,355,525	29,767,429	11,059,382

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated Statements Of Comprehensive Loss [Abstract]
Net loss	$ (84,054)	$ (38,816)	$ (6,938)
Other comprehensive loss:
Foreign currency translation adjustments	(3,918)	(5,402)
Unrealized gain on available-for-sale securities	2,622	1,252
Net gain reclassified into income on sale of available-for-sale securities	(3,874)
Other comprehensive loss	(5,170)	(4,150)
Comprehensive loss	$ (89,224)	$ (42,966)	$ (6,938)

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Convertible Preferred Stock And Stockholders' Equity/(Deficit) - USD ($) $ in Thousands	Preferred Stock [Member]Series A-C Convertible Preferred Stock [Member]	Preferred Stock [Member]Series C Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2012	$ 39,197		$ 1	$ 654	$ (22,210)			$ (21,555)
Balance, shares at Dec. 31, 2012	20,241,207		830,823
Issuance of preferred/common stock, net of issuance cost		$ 2,756	$ 6	34,274				34,280
Issuance of preferred/common stock, net of issuance cost, shares		693,571	6,612,500
Compensation expense related to stock options and restricted stock awards				1,025				1,025
Vesting of restricted stock awards, shares			230,298
Vesting of stock awards early exercised				118				118
Vesting of stock awards early exercised, shares			270,419
Issuance of common stock related to stock exercises				57				57
Issuance of common stock related to stock exercises, shares			270,173
Effect of a 1 for 1.662 reverse split on preferred stock	(8,338,699)
Conversion of shares of preferred stock to common stock	$ (41,953)		$ 13	41,940				41,953
Conversion of shares of preferred stock to common stock, shares	(12,596,079)		12,596,079
Dividends for preferred shares issued upon initial public offering			$ 1	(1)
Dividends for preferred shares issued upon initial public offering, shares			755,823
Issuance of common stock relating to Vet Therapeutics, Inc. acquisition			$ 1	14,699				14,700
Issuance of common stock relating to Vet Therapeutics, Inc. acquisition, shares			624,997
Issuance of common stock related to private investment in public entity			$ 1	19,749				19,750
Issuance of common stock related to private investment in public entity, shares			1,234,375
Net loss					(6,938)			(6,938)
Balance at Dec. 31, 2013			$ 23	112,515	(29,148)			83,390
Balance, shares at Dec. 31, 2013			23,425,487
Issuance of preferred/common stock, net of issuance cost			$ 11	135,067				135,078
Issuance of preferred/common stock, net of issuance cost, shares			10,325,000
Compensation expense related to stock options and restricted stock awards				7,130				7,130
Vesting of restricted stock awards, shares			240,528
Vesting of stock awards early exercised				56				56
Vesting of stock awards early exercised, shares			152,272
Issuance of common stock related to stock exercises				225				225
Issuance of common stock related to stock exercises, shares			81,941
Repurchase of common stock							$ (1,081)	(1,081)
Repurchase of common stock, shares			(77,367)
Other comprehensive loss						$ (4,150)		(4,150)
Net loss					(38,816)			(38,816)
Balance at Dec. 31, 2014			$ 34	254,993	(67,964)	(4,150)	(1,081)	181,832
Balance, shares at Dec. 31, 2014			34,147,861
Compensation expense related to stock options and restricted stock awards				8,592				8,592
Vesting of restricted stock awards, shares			205,387
Vesting of stock awards early exercised			$ 1	44				45
Vesting of stock awards early exercised, shares			121,014
Issuance of common stock related to stock exercises				312				312
Issuance of common stock related to stock exercises, shares			90,413
Repurchase of common stock							(7)	(7)
Repurchase of common stock, shares			(859)
Other comprehensive loss						(5,170)		(5,170)
Net loss					(84,054)			(84,054)
Balance at Dec. 31, 2015			$ 35	$ 263,941	$ (152,018)	$ (9,320)	$ (1,088)	$ 101,550
Balance, shares at Dec. 31, 2015			34,563,816

Consolidated Statements Of Cha7

Consolidated Statements Of Changes In Convertible Preferred Stock And Stockholders' Equity/(Deficit) (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Issuance of stock, issuance cost	$ 10,627	$ 5,394
Reverse stock split ratio on shares		1.662
Series C Convertible Preferred Stock [Member]
Issuance of stock, issuance cost		$ 19

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities
Net loss	$ (84,054)	$ (38,816)	$ (6,938)
Adjustments to reconcile net loss to net cash used in operating activities:
Acquired in-process research and development		2,157
Stock-based compensation expense	$ 8,592	7,130	$ 1,025
Depreciation and amortization expense	1,840	2,043	313
Impairment of acquired intangible assets	43,398
Gain on sale of marketable securities	(3,874)
Non-cash interest expense	129	41	23
Creditor fees	(150)
Change in fair value of contingent consideration	(1,248)	(133)	305
Change in fair value of derivative instruments	(1,274)	(465)
Deferred tax benefit	(1,698)	(1,443)	(12,722)
Changes in operating assets and liabilities:
Accounts receivable, net	281	(102)
Inventories	(879)	(372)
Prepaid expenses	(595)	(642)	(249)
Other assets	(31)	(45)	(14)
Accounts payable	(117)	(1,143)	1,527
Accrued expenses and other liabilities	1,185	482	579
Deferred income		(880)
Net cash used in operating activities	(38,495)	(32,188)	(16,151)
Cash flows from investing activities
Purchase of property and equipment, net	(2,245)	(471)	(94)
Cash paid for acquisitions, net of cash received		(12,075)	(30,994)
Proceeds from sales of marketable securities	7,456
Purchase of investments	(2,050,594)	(371,449)	(5,169)
Proceeds from maturities of investments	2,079,396	286,670	6,881
Purchase of derivative instruments		(643)
Purchase of in-process research and development		(2,157)
Change in restricted cash	(350)		141
Net cash provided by (used in) investing activities	33,663	(100,125)	(29,235)
Cash flows from financing activities
Proceeds from the issuance of debt, net of discount	24,779		14,914
Repurchase of common stock	(7)	(1,081)
Proceeds from stock options exercised	312	225	153
Repurchase, early exercised stock			(6)
Proceeds from public offering, net of commission		137,220	36,897
Payments of public offering costs	(189)	(2,153)	(2,617)
Issuance of common stock private investment in public entitiy			19,750
Cash paid for promissory notes		(18,067)
Cash paid for contingent consideration	(3,000)	(15,166)
Net cash provided by financing activities	21,895	100,978	72,497
Effect of exchange rate on cash	(131)	74
Net increase in cash and cash equivalents	16,932	(31,261)	27,111
Cash and cash equivalents, beginning of year	9,823	41,084	13,973
Cash and cash equivalents, end of year	26,755	9,823	41,084
Supplemental disclosure of cash flow information
Cash paid for interest, net of amounts capitalized	$ 1,057	942	357
Supplemental disclosure of noncash investing and financing activities:
Non-cash exercise of warrant	750
Conversion of preferred stock into common stock			41,953
Payment of dividends on preferred stock			4,535
Vet Therapeutics Inc., [Member]
Supplemental disclosure of noncash investing and financing activities:
Issuance of common stock relating to Vet Therapeutics, Inc. acquisition			14,700
Contingent consideration relating to acquisition			4,115
Note payable relating to acquisition			3,000
Okapi Sciences NV [Member]
Cash flows from investing activities
Cash paid for acquisitions, net of cash received		(43,376)
Supplemental disclosure of noncash investing and financing activities:
Contingent consideration relating to acquisition		15,166
Note payable relating to acquisition		$ 15,134
Series C Convertible Preferred Stock [Member]
Cash flows from financing activities
Proceeds from the issuance of Series C convertible preferred stock, net of issuance costs			$ 3,406

The Company And Basis Of Presen

The Company And Basis Of Presentation	12 Months Ended
	Dec. 31, 2015
The Company And Basis Of Presentation [Abstract]
The Company And Basis Of Presentation	1. The Company and Basis of Presentation The Company Aratana Therapeutics, Inc., including its subsidiaries (the “Company,” or “Aratana”) was incorporated on December 1, 2010 under the laws of the State of Delaware. The Company is a pet therapeutics company focused on licensing, developing and commercializing of innovative biopharmaceutical products for companion animals. The Company has one operating segment: pet therapeutics. Since its inception, the Company has devoted substantially all of its efforts to research and development, recruiting management and technical staff, building a commercial infrastructure, acquiring operating assets and raising capital. The Company is subject to risks common to companies in the biotechnology and pharmaceutical industries. There can be no assurance that the Company’s licensing efforts will identify viable product candidates, that the Company’s research and development will be successfully completed, that adequate protection for the Company’s technology will be obtained, that any products developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. The Company operates in an environment of substantial competition from other animal health companies. In addition, the Company is dependent upon the services of its employees and consultants, as well as third-party contract research organizations and manufacturers and collaborators. Basis of Presentation The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and on a basis which assumes that the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the normal course of business. The Company has incurred recurring losses and negative cash flows from operations and has an accumulated deficit of $152,018 as of December 31, 2015. The Company expects to continue to generate operating losses for the foreseeable future. The Company believes that its cash, cash equivalents and short-term investments on hand, will be sufficient to fund operations including, if necessary, the repayment of its long term debt, at least through December 31, 2016. As disclosed in Note 10 to the consolidated financial statements, the Company has a term loan and revolving credit facility with a principal balance of $40,000 as of December 31, 2015. The terms of this agreement require the Company to receive unrestricted net cash proceeds of at least $45,000 from partnering transactions and/or the issuance of equity securities from October 16, 2015 to October 16, 2016 . The loan agreements also require that the Company have at least three products fully USDA-or FDA-approved for commercialization by December 31, 2016. If these conditions are not met, the Company may be required to repay the loan prior to December 31, 2016. The Company expects an increase in investment related to its commercial activities, including expanding commercial operations, milestones related to approval and commencement of commercial sales, and manufacturing activities in preparation for product launches. As a result, the Company may need additional capital to fund its operations beyond December 31, 2016, which the Company may obtain from corporate collaborations and licensing arrangements, or other sources, such as public or private equity and debt financings. The future viability of the Company beyond December 31, 2016 is dependent on its ability to raise additional capital to finance its operations, to fund on-going research and development costs, commercialization of its product candidates and satisfy debt covenants. If the Company is not able to raise additional capital on terms acceptable to it, or at all, as and when needed, it may be required to curtail its operations which could include delaying the commercial launch of its products, discontinuing product development programs, or granting rights to develop and market products or product candidates that it would otherwise prefer to develop and market itself. The Company’s failure to raise capital as and when needed would have a negative impact on its financial condition and its ability to pursue its business strategies as this capital is necessary for it to perform the research and development and commercial activities required to generate future revenue streams.

Summary Of Significant Accounti

Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Summary Of Significant Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	2 . Summary of Significant Accounting Policies Consolidation The Company’s consolidated financial statements include its financial statements, and those of its wholly-owned subsidiaries and a consolidated variable interest entity. Intercompany balances and transactions are eliminated in consolidation. To determine if the Company holds a controlling financial interest in an entity, the Company first evaluates if it is required to apply the variable interest entity (“VIE”) model to the entity. Where the Company holds current or potential rights that give it the power to direct the activities of a VIE that most significantly impact the VIE’s economic performance combined with a variable interest that gives it the right to receive potentially significant benefits or the obligation to absorb potentially significant losses, the Company is the primary beneficiary of that VIE. When changes occur to the design of an entity, the Company reconsiders whether it is subject to the VIE model. The Company continuously evaluates whether it is the primary beneficiary of a consolidated VIE. Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates, judgments 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 period. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from those estimates. Cash and Cash Equivalents The Company classifies all highly liquid investments with stated maturities of three months or less from the date of purchase as cash equivalents. Cash equivalents consisted of certificates of deposit (“CDs”) at December 31, 2015, and CDs and overnight reverse repurchase agreements a t December 31, 2014 . Restricted Cash Pursuant to the terms of the Loan and Security Agreement, the Company has posted collateral to Square 1 Bank N.A., a division of Pacific Western Bank, to collateralize corporate credit card services. The Company classifies the collateral as restricted cash. Short-term Investments The Company classifies reverse repurchase agreements other than overnight reverse repurchase agreements as short-term investments and as available-for-sale. Short-term investments for both 2015 and 2014 include reverse repurchase agreements and CDs with original maturities greater than three months . Marketable Securities The Company classifies all highly liquid investments with stated maturities of greater than three months from the date of purchase as marketable securities. The Company determines the appropriate classification of investments in marketable securities at the time of purchase and re-evaluates such designation at each consolidated balance sheet date. The Company classifies and accounts for marketable securities as available-for-sale. The Company may or may not hold securities with stated maturities greater than 12 months until maturity. After consideration of the risk versus reward objectives, as well as the Company’s liquidity requirements, the Company may sell these securities prior to their stated maturities. These securities are viewed as being available to support current operations. As a result, the Company classifies securities with maturities beyond 12 months as long-term assets as long-term marketable securities in the consolidated balance sheet. The C ompany reports available-for-sale investments at fair value as of each consolidated balance sheet date and records any unrealized gains and losses as a component of stockholders’ equity (deficit). At December 31, 201 4 , investments in equity securities were classified as long-term marketable securities and were carried at fair value, as determined by quoted market prices, and gains were recorded as a component of other comprehensive loss . No such investments were held as of December 31, 2015. The cost of securities sold is determined on a specific identification basis, and realized gains and losses are included in other income (expense) in the consolidated statements of operations. If any adjustment to fair value reflects a decline in the value of the investment, the Company considers available evidence to evaluate the extent to which the decline is “other than temporary” and recognizes the impairment by releasing other comprehensive income to the consolidated statement of operations. There were no such adjustments necessary during the year s ended December 31, 201 5 and 2014 . Accounts Receivable , net Accounts receivable are uncollateralized customer obligations due under normal trade terms generally requiring payment within 30 days of the invoice date. The Company provides an allowance for doubtful accounts equal to the estimated losses that will be incurred in collection of accounts receivable. This estimate is based on the current review of existing receivables and historical experience in the industry. The allowance and associated accounts receivable are reduced when the receivables are determined to be uncollectible. Inventories The Company states i nventories at the lower of cost or market and consist of raw materials, work-in-process and finished goods. Cost is determined by the average cost method for raw materials and standard cost for work-in-process and finished goods, which approximates actual cost. Market is considered the lower of prevailing replacement cost or net realizable value. Inventories acquired in business combinations are recorded at fair value as of acquisition date. Property and Equipment , net The Company records property and equipment at historical cost or, in the case of a business combination, at fair value on the date of the business combination, less accumulated depreciation and amortization. Depreciation amortization expense is recognized using the straight-line method over the following estimated useful lives: Laboratory and office equipment 3 – 10 years Computer software and equipment 3 – 5 years Furniture 3 – 7 years Vehicles 3 – 5 years Leasehold improvements 3 – 10 years Leasehold improvements are amortized over the shorter of the life of the related asset or the term of the lease. Expenditures for repairs and maintenance of assets are charged to expense as incurred. Costs of major additions and betterments are capitalized and depreciated on a straight-line basis over their useful lives. When property and equipment are disposed of, the cost and respective accumulated depreciation and amortization are removed from the books. Any gain or loss on disposal is recorded in the consolidated statements of operations. Goodwill Goodwill relates to amounts that arose in connection with the Company’s business combinations (Note 17) and represents the difference between the purchase price and the estimated fair value of the identifiable tangible and intangible net assets when accounted for using the acquisition method of accounting. Goodwill is not amortized, but is subject to periodic review for impairment. The Company tests goodwill at the reporting unit level for impairment on an annual basis and between annual tests, if events and circumstances indicate impairment may exist. Events that would indicate impairment and trigger an interim impairment assessment include, but are not limited to, current economic and market conditions, including a decline in market capitalization, a significant adverse change in legal factors, business climate or operational performance of the business and an adverse action or assessment by a regulator. The Company completed its annual goodwill impairment testing during the third quarter of 2015. The Company elected to bypass the qualitative assessment. The Company determined as of the testing date that it consisted of one operating segment which is comprised of one reporting unit. In performing step one of the assessment, the Company determined that its fair value, determined to be its market capitalization, was greater than its carrying value, determined to be stockholders’ equity. Based on this result, step two of the assessment was not required to be performed, and the Company determined there was no impairment of goodwill during the third quarter of 2015. During the fourth quarter of 2015, the Company completed an interim impairment assessment due to a decline in its market capitalization. In performing step one of the assessment, the Company determined that its fair value exceeded its carrying value, by 93% . Based on this result, step two of the assessment was not required to be performed, and the Company determined there was no impairment of goodwill during the fourth quarter of 2015. Subsequent to December 31, 2015, the Company experienced further declines and fluctuations in its market capitalization. The extent and duration of any decline in the Company’s market capitalization will be assessed in future periods against the Company’s carrying value to assess if there is an indication of impairment of the Company’s goodwill which was $39,781 as of December 31, 2015. Intangible Assets, net The Company’s intangible assets consist of intellectual property rights acquired for currently marketed products and intellectual property rights acquired for in-process research and development (“IPR&D”). All of the Company’s intangible assets were recorded in connection with the Company’s business combinations (Note 17). The Company’s intangible assets are recorded at fair value at the time of their acquisition. The Company amortizes intangible assets over their estimated useful lives once the acquired technology is developed into a commercially viable product. The estimated useful lives of the individual categories of intangible assets are based on the nature of the applicable intangible asset and the expected future cash flows to be derived from the intangible asset. Amortization of intangible assets with finite lives is recognized over the time the intangible assets are estimated to contribute to future cash flows. The Company amortizes finite-lived intangible assets using the straight-line method. Indefinite-lived IPR&D intangible assets are assessed for impairment at least annually. In addition, all intangible assets are reviewed for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends, and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset for recoverability, the Company compares forecasts of undiscounted cash flows for definite-lived intangible assets and discounted cash flows for indefinite-lived IPR&D intangible assets expected to result from the use and eventual disposition of the long-lived asset to its carrying value. An impairment loss would be recognized when estimated undiscounted (definite-lived) or discounted (indefinite-lived) future cash flows expected to result from the use of an asset are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset over its fair value, determined based on discounted cash flows. The Company completed its annual indefinite-lived IPR&D intangible assets impairment testing during the fourth quarter of 2015. The Company elected to bypass the qualitative assessment. For purposes of impairment testing, the fair value of the indefinite-lived IPR&D intangible assets was determined by using the framework of ASC 820, Fair Value Measurement. When determining the fair value of the indefinite-lived IPR&D intangible assets, the Company revisited all assumptions used in measuring the indefinite-lived IPR&D intangible assets at the time of acquisition, and evaluated and considered new and updated data and information available. The Company noted the fair values for all indefinite-lived IPR&D intangible assets were greater than the carrying value. As such, no impairment was recognized as of the annual testing date. I n the quarter ended September 30, 2015 and to date, the Company recorded $43,398 of impairment losses on intangible assets (Note 8). Derivative Financial Instruments T he Company accounts for its derivative instruments as either assets or liabilities and carries them at fair value. The Comp any’s sole derivative (Note 9 ) was a warrant t o purchase common stock and was adjusted to fair value through current income as it was not designated as a hedging instrument . In 2015, the Company exercised the warrant and subsequently sold the shares of common stock received upon exercise. Foreign Currency With the acquisition of Okapi Sciences (Note 17 ) in 2014, the Company is exposed to effects of foreign currency from translation. Transactions in foreign currencies are translated into the relevant functional currency at the rate of exchange at the date of the transaction. Transaction gains and losses are recognized in other income (expense) in the consolidated statements of operations. The results of operations for subsidiaries, whose functional currency is not the U.S. Dollar, are translated into the U.S. Dollar at the average rates of exchange during the period, with the subsidiaries’ balance sheets translated at the rates accumulated at the balance sheet date. The cumulative effect of these exchange rate adjustments is included in a separate component of other comprehensive income (loss) in the consolidated balance sheets. Gains and losses arising from intercompany foreign currency transactions are included in loss from operations unless the gains and losses arise from long-term investments in subsidiaries . Gains and losses from long-term investments in subsidiaries are included in a separate component of other comprehensive income (loss). Business Combinations The Company’s business acquisitions were made at a price above the fair value of the assets acquired and liabilities assumed, resulting in goodwill, based on the Company’s expectations of synergies and other benefits of combining the businesses. These synergies and benefits include elimination of redundant facilities, functions and staffing; use of the Company’s existing commercial infrastructure to expand sales of the products of the acquired businesses; and use of the commercial infrastructure of the acquired businesses to expand product sales in a cost-efficient manner. Significant judgment is required in estimating the fair value of intangible assets and in assigning their respective useful lives. The fair value estimates are based on available historical information and on future expectations and assumptions deemed reasonable by management, but which are inherently uncertain. The Company generally employs the income method to estimate the fair value of intangible assets, which is based on forecasts of the expected future cash flows attributable to the respective assets. Significant estimates and assumptions inherent in the valuations reflect a consideration of other marketplace participants, and include the amount and timing of future cash flows (including expected growth rates and profitability), the underlying product life cycles, economic barriers to entry, a brand’s relative market position and the discount rate applied to the cash flows. Unanticipated market or macroeconomic events and circumstances may occur, which could affect the accuracy or validity of the estimates and assumptions. Net assets acquired are recorded at their fair value and are subject to adjustment upon finalization of the fair value analysis. The Company is not aware of any information that indicates the final fair value analysis will differ materially from the preliminary estimates. Contingent consideration is recorded as a liability and measured at fair value using a discounted cash flow model utilizing significant unobservable inputs, including the probability of achieving each of the potential milestones and an estimated discount rate commensurate with the risks of the expected cash flows attributable to the milestones. Significant increases or decreases in any of the probabilities of success would result in a significantly higher or lower fair value, respectively, and commensurate changes to this liability. At each reporting date, we revalue the contingent consideration obligations to the reporting date fair values and record increases and decreases in the fair values as income or expense in the consolidated statements of operations until actual settlement occurs. Increases or decreases in the fair values of the contingent consideration obligations may result from changes in discount periods and rates, changes in the timing and amount of earn-out criteria and changes in probability assumptions with respect to the likelihood of achieving the various earn-out criteria. On January 6, 2014, the Company acquired Okapi Sciences, a Leuven, Belgium based company with a proprietary antiviral platform and three clinical/development stage product candidates. The aggregate purchase price was approximately $44,439 , which consisted of $14,139 in cash, a promissory note in the principal amount of $15,134 with a maturity date of December 31, 2014 , and a contingent consideration of up to $16,308 with an acquisition fair value of $15,166 . The promissory note bore interest at a rate of 7% per annum, payable quarterly in arrears, and was subject to mandatory prepayment in the event of a specified equity financing by the Company. On February 4, 2014, the promissory note and accrued interest was paid in cash in the amount of $15,158 . On March 17, 2014, the contingent consideration was settled in cash in the amount of $15,235 . Deferred Public Offering Costs T he Company capitalizes certain legal, accounting and other third-party fees that are directly associated with in-process equity financings as other assets until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ equity (deficit) as a reduction of additional paid-in capital generated as a result of the offering. Should it no longer be considered probable that the equity financing will be consummated, the deferred offering costs would be expensed immediately as a charge to operating expenses in the consolidated statements of operations. On October 16, 2015, the Company entered into a Sales Agreement with Barclays Capital Inc. (“Barclays”) pursuant to which the Company may sell from time to time, at its option, up to an aggregate of $52,000 of shares of its common stock (the “Shares”) through Barclays, as sales agent. As of the date of this filing, the Company has not sold any shares under the Sales Agreement. The Company recorded $189 and $0 of deferred public offering costs as of December 31, 2015 and 2014, respectively. Income Taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the consolidated financial statements or in the Company’s tax returns. Deferred taxes are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect in the years in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the consolidated financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties. Debt Issuance Costs , net Debt issuance costs, net represent legal and other direct costs related to the Company’s Loan and Security Agreement (Note 10). These costs are recorded as an offset to the carrying value of loans payable on the consolidated balance sheet at the time they are incurred and are amortized to interest expense through the scheduled final principal payment date. During the year ended December 31, 2015, the Company capitalized $360 of debt issuance costs and recognized $129 of amortization expense related to debt issuance costs. During the year ended December 31, 2014, the Company recorded $11 of debt issuance costs and recognized $41 of amortization expense related to debt issuance costs. Revenue Recognition The Company recognizes revenue when all of the following conditions are met: · there is persuasive evidence of an agreement or arrangement; · delivery of products has occurred or services have been rendered; · the seller’s price to the buyer is fixed or determinable; and · collect i bility is reasonably assured. The Company’s principal revenue streams and their respective accounting treatments are discussed below: (i) Product sales - Revenue for the sale of products is recognized when delivery has occurred and substantially all the risks and rewards of ownership have been transferred to the customer. Revenue for the sale of products are recorded net of sales returns, allowances and discounts . (ii) Licensing and collaboration revenues - Revenues derived from product out-licensing arrangements typically consist of an initial up-front payment on inception of the license and subsequent milestone payments contingent on the achievement of certain clinical and sales milestones. Product out licensing arrangements may require the Company to provide multiple deliverables to the licensee which would require the total selling price to be allocated between each of the separable elements in the arrangement based on their relative selling price s . An element is considered separable if it has value to the customer on a stand-alone basis. The selling price used for each separable element will be based on vendor specific objective evidence (“VSOE”) if available, third party evidence if VSOE is not available, or estimated selling price if neither VSOE nor third party evidence is available. Revenue is then recognized as each of the separable elements to which the revenue has been allocated is delivered. Milestone payments which are non-refundable, non-creditable and contingent on achieving certain development, regulatory, or commercial milestones are recognized as revenues either on achievement of such milestones or over the period the Company has continuing substantive performance obligations. Research and Development Costs Research and development costs are expensed as incurred. Included in research and development costs are wages, stock-based compensation and employee benefits, and other operational costs related to the Company’s research and development activities, including facility-related expenses, external costs of outside contractors engaged to conduct both preclinical and clinical studies and allocation of corporate costs. Payments received from external parties to fund the Company’s research and development activities are used to reduce the Company’s research and development expenses. If IPR&D is acquired in an asset purchase then the acquired IPR&D is expensed on its acquisition date. Future costs to develop these assets are recorded to research and development expense as they are incurred. Patent Costs All patent-related costs incurred in connection with filing and prosecuting patent applications are recorded as selling, general and administrative expenses as incurred, as recoverability of such expenditures is uncertain. Shipping Shipping costs are included in cost of product sales. Sales Tax The Company collects and remits taxes assessed by various governmental authorities. These taxes may include sales, use and value added taxes. These taxes are recorded on a net basis and are excluded from sales. Accounting for Stock - Based Compensation The Company’s stock-based compensation program grants awards that may consist of stock options and restricted stock awards. The fair values of stock option grants are determined as of the date of grant using the Black-Scholes option pricing method. This method incorporates the fair value of the Company’s common stock at the date of each grant and various assumptions such as the risk-free interest rate, expected volatility based on the volatility of the Company’s common stock price , expected dividend yield, and expected term of the options. The fair values of restricted stock awards are determined based on the fair value of the Company’s common stock. Prior to the Company’s initial public offering of its common stock in June 2013, the fair value of the common stock was determined by management and the Board of Directors, on the date of grant. Beginning in the first quarter of 2014, the Company began to base expected volatility on the historical volatility of its common stock, as adequate historical data regarding the volatility of its common stock price had become available. The fair values of the stock-based awards, including the effect of estimated forfeitures, are then expensed over the requisite service period, which is generally the award’s vesting period. The Company classifies stock-based compensation expense in the consolidated statements of operations in the same manner in which the respective award recipient’s payroll costs are classified. For stock-based awards granted to consultants and nonemployees, compensation expense is recognized over the period during which services are rendered by such consultants and nonemployees until completed. At the end of each financial reporting period prior to completion of the service, the value of these awards is re-measured using the then-current fair value of the Company’s common stock and updated assumption inputs in the Black-Scholes option pricing model. For stock-based awards granted to employees under the 2010 Equity Incentive Plan (the “2010 Plan”), the Company allows employees to exercise certain awards prior to vesting. However, the employee may not sell or transfer these awards prior to vesting. For most of these awards, the Company has the right, but not the obligation, to repurchase any unvested (but issued) shares of common stock upon termination of employment or service at the lesser of (1) the original purchase price per share or (2) the fair value of the common share on the date of termination. If a stock option is early exercised in this circumstance, the consideration received for an exercise of an option is considered a deposit of the exercise price, and the related dollar amount is recorded as a liability. The unvested shares and liability are reclassified to equity as the award vests. The Company has 90 days from the effective termination of employment or service to repurchase unvested shares that are issued upon the exercise of a stock option prior to its vesting. If, after 90 days, the Company has elected not to repurchase the unvested shares, the shares would become vested in full. The Company would then apply modification accounting and any resulting compensation expense would be immediately recognized related to the award. Upon vesting, these shares would be considered issued and outstanding shares of common stock for accounting purposes. In addition, the Company has granted restricted stock awards subject to repurchase to one employee, under which the Company has the right, but not the obligation, upon termination of the holder’s employment or service, to repurchase unvested shares at the greater of (1) the original purchase price per share or (2) the fair value of the common share on the date of termination (Note 14 ). Comprehensive Loss In addition to the Company’s net loss, comprehensive loss during the years ended December 31, 2015 and 2014 include s foreign currency translation adjustments related to the translation of foreign subsidiaries’ balance s heets and unrealized holding gains and losses on available-for-sale securities . For the year ended December 31, 2013, there was no difference between net loss and comprehensive loss. Net Loss Per Share The Company follows the two-class method when computing net loss per share, as the Company has issued shares that meet the definition of participating securities. The two-class method determines net loss per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. Restricted stock awards granted by the Company entitle the holder of such awards to dividends declared or paid by the Board of Directors, regardless of whether such awards are unvested, as if such shares were outstanding common shares at the time of the dividend. H owever, the unvested restricted stock awards are not entitled to share in the residual net assets (deficit) of the Company. Accordingly, in periods in which the Company reports a net loss or a net loss attributable to common stockholders resulting from preferred stock dividends, accretion or modifications, net losses are not allocated to participating securitie s. The Company reported a net loss in each of the years ended December 31, 2015, 2014 and 2013. Basic net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock outstanding for the period. Diluted net loss is computed by adjusting net loss to reallocate undistributed earnings based on the potential impact of dilutive securities, including outstanding stock options. Diluted net loss per share is computed by dividing the diluted net loss by the weighted average number of shares of common stock, including potential dilutive shares of common stock assuming the dilutive effect of potentially dilutive securities. For periods in which the Company has reported net losses, diluted net loss per share is the same as basic net loss per share, since their impact would be anti-dilutive to the calculation of net loss per share. Diluted net loss per share is the same as basic net loss per share for each of the years ended December 31, 2015, 2014 and 2013. Concentration of Credit Risk and of Significant Suppliers and Customers Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash, cash equivalents, short-term investments and accounts receivable . At December 31, 201 5 , the Company’s short-term investments included reverse repurchase ag reements that are tri-party, have maturities of three months or less at the time of investment and the underlying collateral is U.S. government securities including U.S. treasuries, agency debt and agency mortgage securities . At December 31, 2015 and 201 4 , all of the Company’s fixed income marketable securities were invested in CDs insured by the Federal Deposit Insurance Corporation (“FDIC”). The Company also generally maintains balances in various operating accounts in excess of federally insured limits at two accredited financial institutions. The Company does not believe that it is subjec

Fair Value Of Financial Assets

Fair Value Of Financial Assets And Liabilities	12 Months Ended
	Dec. 31, 2015
Fair Value Of Financial Assets And Liabilities [Abstract]
Fair Value Of Financial Assets And Liabilities	3 . Fair Value of F inancial Assets and Liabilities Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis T he following financial assets and liabilities are measured at fair value on a recurring basis using quoted prices in active markets for identical assets (Level 1); significant other observable inputs (Level 2); and significant unobservable inputs (Level 3). FAIR VALUE MEASUREMENTS AS OF CARRYING DECEMBER 31, 2015 USING: VALUE LEVEL 1 LEVEL 2 LEVEL 3 TOTAL Assets: Cash equivalents: Certificates of deposit $ 6,972 $ — $ 6,972 $ — $ 6,972 Money market fund 35 35 — — 35 Short-term investments: Short-term marketable securities – certificates of deposit 747 — 747 — 747 Reverse repurchase agreements 58,700 — 58,700 — 58,700 $ 66,454 $ 35 $ 66,419 $ — $ 66,454 FAIR VALUE MEASUREMENTS AS OF CARRYING DECEMBER 31, 2014 USING: VALUE LEVEL 1 LEVEL 2 LEVEL 3 TOTAL Assets: Cash equivalents: Certificates of deposit $ 6,972 $ — $ 6,972 $ — $ 6,972 Money market fund 45 — 45 — 45 Short-term investments: Short-term marketable securities – certificate of deposit 249 — 249 — 249 Reverse repurchase agreements 88,000 — 88,000 — 88,000 Long-term marketable securities: Common stock 2,452 2,452 — — 2,452 Derivative financial instruments 1,108 — 1,108 — 1,108 $ 98,826 $ 2,452 $ 96,374 $ — $ 98,826 Liabilities: Contingent consideration $ 4,248 $ — $ — $ 4,248 $ 4,248 $ 4,248 $ — $ — $ 4,248 $ 4,248 Certain estimates and judgments are required to develop the fair value amounts shown above. The fair value amounts shown above are not necessarily indicative of the amounts that the Company would realize upon disposition, nor do they indicate the Company’s intent or ability to dispose of the financial instrument. The following methods and assumptions were used to estimate the fair value of each material class of financial instrument: · Cash equivalents – the fair value of the cash equivalents has been determined to be amortized cost or has been based on the quoted prices in active markets or exchanges for identical assets. · Reverse repurchase agreements – the fair value of reverse repurchase agreements has been determined to be amortized cost given the short duration of the agreements. · Marketable securities (long-term) – the fair value of marketable securities has been based on quoted prices in active markets or exchanges for identical assets. · Marketable securities (short-term) – the fair value of marketable securities has been determined to be amortized cost given the short duration of the agreements. · Derivative financial instruments – the fair value of the derivative instruments has been estimated using a modified Black-Scholes model. Inputs into the Black-Scholes model include interest rates, stock volatilities and dividend data. · Contingent consideration – the fair value of the contingent consideration payable has been estimated using the income approach using a probability weighted discounted cash flow method. Inputs into the discounted cash flow method include the probability of and period in which the relevant milestone event is expected to be achieved and the discount rate to be applied in calculating the present values of the relevant milestones. Transfers Between Levels of the Fair Value Hierarchy Transfers between levels of the fair value hierarchy are reported at the beginning of the reporting period in which they occur. During the year ended December 31, 2014, transfer of investments between Level 1 and Level 2 were $2,452 . In the third quarter of 2014, the Company re-classified its common stock investment in Advaxis (Note 12) to a Level 1 investment from Level 2, because the Company was no longer precluded from selling shares due to restrictions imposed by Rule 144 of the Securities Act of 1933. Previously, the Company calculated a lack of marketability discount on the fair value of the Advaxis common stock because of trading restrictions on the shares. The Company considered the inputs used to calculate the lack of marketability discount Level 2 inputs and, as a result, the Company classified this investment as Level 2. The Company determined the lack of marketability discount by using a Black-Scholes model to value a hypothetical put option to approximate the cost of hedging the stock until the restriction ended. During the years ended December 31, 2015 and 2013, there were no transfers between levels of the fair value hierarchy. Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3) The change in the fair value of the Company’s contingent consideration payable as of December 31, 2015, which is measured at fair value on a recurring basis using significant unobservable inputs (Level 3), was as follows: Contingent consideration 2015 2014 As of January 1, $ 4,248 $ 4,115 Initial recognition of contingent consideration payable — 15,166 Cash settlement of contingent consideration earned (3,000) (15,235) Derecognition of remaining contingent consideration recorded in the consolidated statement of operations (within selling, general and administrative) (1,248) 202 As of December 31, $ — $ 4,248 On January 2, 2015, the Company was granted a full product license for BLONTRESS ® (also known as AT-004). The approval resulted in $3,000 of the contingent consideration being earned and due to the former Vet Therapeutics, Inc. (“Vet Therapeutics”) shareholders per the terms of Vet Therapeutics merger agreement. Further, on February 24, 2015, in connection with the mutual termination of the Elanco Animal Health, Inc. (“Elanco”) Agreement for BLONTRESS (Note 12), the Company obtained consent from the shareholder representative of the former Vet Therapeutics shareholders that the $3,000 payment shall cause the Company to have no further obligation or liability under the merger agreement. The Company paid the $3,000 contingent consideration in March 2015. During the year ended December 31, 2015, the Company recorded a credit of $1,248 to selling, general and administrative expense to reduce the fair value of the contingent consideration to zero as a result of the agreement with the Vet Therapeutics shareholders. Financial Assets and Liabilities that are not Measured at Fair Value on a Recurring Basis The carrying amounts and estimated fair value of the Company’s financial assets and liabilities which are not measured at fair value on a recurring basis was as follows: DECEMBER 31, 2015 CARRYING VALUE FAIR VALUE Financial liabilities: Loan payable (Level 2) $ 39,710 $ 40,569 DECEMBER 31, 2014 CARRYING VALUE FAIR VALUE Financial liabilities: Loan payable (Level 2) $ 14,963 $ 14,933 Certain estimates and judgments were required to develop the fair value amounts. The fair value amount shown above is not necessarily indicative of the amounts that the Company would realize upon disposition, nor do they indicate the Company’s intent or ability to dispose of the financial instrument. T he fair value of l oan payable was estimated using discounted cash flow analysis discounted at current rates . Fair value information about the intangible assets that were impaired during the year ended December 31, 2015 (Note 8) was as follows: FAIR VALUE CARRYING DECEMBER 31, 2015 VALUE LEVEL 1 LEVEL 2 LEVEL 3 IMPAIRMENT Intellectual property rights for currently marketed products $ 6,057 $ — $ — $ 6,057 $ 28,862 Intellectual property rights acquired for in-process research and development 9,010 — — 9,010 14,536 $ 15,067 $ — $ — $ 15,067 $ 43,398 The fair value amount is presented as of the date of impairment, as these assets are not measured at fair value on a recurring basis. (Note 8). The fair value reflects intangible assets written down to fair value during the year ended December 31, 2015. Fair-value was determined using the income approach, specifically the multi-period excess earnings method, a form of a discounted cash flow method. The Company started with a forecast of all the expected net cash flows associated with the asset and then it applied an asset-specific discount rate to arrive at a net present value amount. Some of the more significant estimates and assumptions inherent in this approach include: the amount and timing of the projected net cash flows, which includes the expected impact of competitive legal and/or regulatory forces on the product and the impact of technological risk associated with IPR&D assets; the discount rate, which seeks to reflect the various risks inherent in the projected cash flows; and the tax rate, which seeks to incorporate the geographic diversity of the projected cash flows.

Investments

Investments	12 Months Ended
	Dec. 31, 2015
Investments [Abstract]
Investments	4 . Investments Marketable Securities Marketable securities consisted of the following: DECEMBER 31, 2015 GROSS GROSS AMORTIZED UNREALIZED UNREALIZED FAIR COST GAINS LOSSES VALUE Short-term marketable securities: Certificates of deposit $ 747 $ — $ — $ 747 Total $ 747 $ — $ — $ 747 DECEMBER 31, 2014 GROSS GROSS AMORTIZED UNREALIZED UNREALIZED FAIR COST GAINS LOSSES VALUE Short-term marketable securities: Certificate of deposit $ 249 $ — $ — $ 249 Long-term marketable securities: Common stock 1,200 1,252 — 2,452 Total $ 1,449 $ 1,252 $ — $ 2,701 At December 31, 2015 and 2014, short-term marketable securities consisted of investments that mature within one year. Short-term marketable securities are recorded as short-term-investments in the consolidated balance sheets. At December 31, 2014, unrealized gains in the amount of $1,252 were recorded as a component of other comprehensive loss. Reverse Repurchase Agreements The Company, as part of its cash management strategy, may invest excess cash in reverse repurchase agreements. All reverse repurchase agreements are tri-party and have maturities of three months or less at the time of investment. The underlying collateral is U.S. government securities including U.S. treasuries, agency debt and agency mortgage securities. The underlying collateral posted by each counterparty is required to cover 102% of the principal amount and accrued interest after the application of a discount to fair value.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2015
Inventories [Abstract]
Inventories	5. Inventories Inventories are stated at the lower of cost or market and comprised of the following: DECEMBER 31, DECEMBER 31, 2015 2014 Raw materials $ 120 115 Work-in-process 441 $ 206 Finished goods 745 106 $ 1,306 $ 427

Property And Equipment, Net

Property And Equipment, Net	12 Months Ended
	Dec. 31, 2015
Property And Equipment, Net [Abstract]
Property And Equipment, Net	6. Property and Equipment, Net Property and equipment , net consisted of the following : DECEMBER 31, DECEMBER 31, 2015 2014 Laboratory and office equipment $ 527 $ 478 Computer equipment and software 2,039 68 Furniture 132 71 Vehicles 11 34 Leasehold improvements 91 102 Construction in process 185 49 Total property and equipment 2,985 802 Less: Accumulated depreciation and amortization (430) (182) Property and equipment, net $ 2,555 $ 620 Depreciation expense was $296 , $152 and $16 for the years ended December 31, 201 5 , 201 4 and 201 3 , respectively. No significant gains/losses were recognized d uring the year s ended December 31, 201 5, 2014 and 2013.

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill	7 . Goodwill Goodwill is recorded as an indefinite-lived asset and is not amortized for financial reporting purposes but is tested for impairment on an annual basis or when indications of impairment exist. No goodwill impairment losses have been recognized. Goodwill is not expected to be deductible for income tax purposes. The Company performs its annual impairment test of the carrying value of the Company’s goodwill during the third quarter of each year. The Company completed its annual goodwill impairment testing during the third quarter of 2015. The Company elected to bypass the qualitative assessment. The Company determined as of the testing date that it consisted of one operating segment which is comprised of one reporting unit. In performing step one of the assessment, the Company determined that its fair value, determined to be its market capitalization, was greater than its carrying value, determined to be stockholders’ equity. Based on this result, step two of the assessment was not required to be performed, and the Company determined there was no impairment of goodwill during the third quarter of 2015. The Company during the fourth quarter of 2015, completed an interim impairment assessment due to a decline in market capitalization. In performing step one of the assessment, the Company determined that its fair value exceeded its carrying value by 93% . Based on this result, step two of the assessment was not required to be performed, and the Company determined there was no impairment of goodwill during the fourth quarter of 2015. Subsequent to December 31, 2015, the Company experienced further declines and fluctuations in its market capitalization. The extent and duration of any decline in the Company’s market capitalization will be assessed in future periods against the Company’s carrying value to assess if there is an indication of impairment of the Company’s goodwill which was $39,781 as of December 31, 2015. Goodwill as of December 31, 2015, was as follows: GROSS IMPAIRMENT NET CARRYING AMOUNT LOSSES CARRYING VALUE Goodwill $ 39,781 $ — $ 39,781 The change in the net book value of goodwill for the year s ended December 31, 201 5 and 2014, was as follows: 2015 2014 As of January 1, $ 41,398 $ 25,646 Acquisition — 17,909 Effect of foreign currency exchange (1,617) (2,157) As of December 31, $ 39,781 $ 41,398

Intangible Assets, Net

Intangible Assets, Net	12 Months Ended
	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible Assets, Net	8 . Intangible Assets, n et The change in the net book value of intangible assets for the years ended December 31, 2015 and 2014, was as follows: 2015 2014 As of January 1, $ 62,323 $ 38,354 Acquisitions — 29,400 Amortization expense (1,544) (1,891) Effect of foreign currency exchange (2,314) (3,540) Impairment (43,398) — As of December 31, $ 15,067 $ 62,323 The estimated useful lives of the individual categories of intangible assets were based on the nature of the applicable intangible asset and the expected future cash flows to be derived from the intangible asset. Amortization of intangible assets with finite lives is recognized over the shorter of the respective lives of the agreement or the period of time the intangible assets are expected to contribute to future cash flows. The Company amortizes finite-lived intangible assets using the straight-line method. Amortization of intangible assets for the years ended December 31, 2015, 2014 and 2013 amounted to $1,544 , $1,891 and $298 , respectively . I ndefinite-lived IPR&D intangible assets are not amortized until a product reaches its first conditional license or approval, then they are amortized over their estimated useful life. S ummary of estimated aggregate amortization expense of intangible assets for each of the five succeeding years as of December 31, 201 5, was as follows : YEAR ENDING DECEMBER 31, 2016 $ 381 2017 381 2018 381 2019 381 2020 $ 381 Unamortized Intangible Assets In January 2014, the Company completed its acquisition of Okapi Sciences ( Note 17 ). The Company acquired certain identifiable intangible assets which relate to IPR&D. Unamortized intangible assets as of December 31, 2015 and 2014, were as follows: NET CARRYING VALUE AS OF DECEMBER 31, Unamortized intangible assets: 2015 2014 Intellectual property rights acquired for in-process research and development $ 9,010 $ 25,860 Impairment of Unamortized Intangible Assets AT-007 Based on the completed pilot study results for AT-007 received late in the first quarter of 2015, the Company determined additional pilot studies were needed before advancing to a pivotal program. During the third quarter of 2015, the Company met with key opinion leaders to review the pilot study results, determine the relevant treatment population and develop acceptable study protocols. The Company then determined that the best course forward would be to study the product in a more limited clinical setting. The market forecast in the more limited clinical setting required the Company to reassess the target market size and change the treatment regimen assumed at the time of acquisition. Furthermore, the Company concluded that the likely customers for this product would be shelters and non-profits, thereby putting pressure on pricing. Also, while a Minor-Use-Minor-Species (“MUMS”) designation would potentially be available for the more limited indication in the United States, the MUMS pathway would not be available in Europe since other products are available there for this disease. The above factors caused the Company to record an impairment charge of $8,717 , resulting in the net carrying value of $2,202 f or AT-007. The Company intends to explore out-licensing AT-007, and it may consider advancing the program internally at a later time. The Company determined the fair value using a multi-period excess earnings method, a form of the income approach, which incorporates the estimated future cash flows to be generated from this technology. Excess earnings are the earnings remaining after deducting the market rates of return on the estimated values of contributory assets, including debt-free net working capital, tangible, and intangible assets. The excess earnings are thereby calculated for each year of a multi-year projection period and discounted to present value. Accordingly, the primary components of this method consist of the determination of excess earnings and an appropriate rate of return. AT-011 For AT-011, the Company has been conducting early pre-development studies, including lead selection and proof of concept on several molecules. During the third quarter of 2015, the Company completed its evaluation of AT-011. Based on this evaluation, the Company determined that none of the molecules being evaluated were suitable for advancement in development. As such, the Company decided to abandon the development of AT-011, resulting in an impairment charge of $5,819 , the full carrying value of AT-011. Unfavorable outcomes of the Company’s development activities or the Company’s estimates of the market opportunities for the product candidates could result in impairment charges in future periods. Amortized Intangible Assets Amortized intangible assets as of December 31, 2015, were as follows: GROSS NET CARRYING ACCUMULATED CARRYING AVERAGE Amortized intangible assets: VALUE AMORTIZATION VALUE USEFUL LIFE Intellectual property rights for currently marketed products: BLONTRESS $ 28,572 $ 23,103 $ 5,469 20 Years TACTRESS TM(1) $ 10,080 $ 9,492 $ 588 8.25 Years (1) TACTRESS received a conditional license in early 2014 which initiated amortization for this intangible. Accumulated amortization includes both amortization expense and asset impairment charges. Asset impairment charges to date are $20,228 and $8,634 for BLONTRESS and TACTRESS TM (also known as AT-005), respectively. Impairment of Amortized Intangible Assets BLONTRESS and TACTRESS Since the Vet Therapeutics acquisition (October 2013) the Company has been performing various scientific and clinical activities to gain further knowledge around the science and efficacy of BLONTRESS and TACTRESS. The Company’s analysis of the clinical results indicated that TACTRESS did not seem to be adding significant progression free survival in canine T-cell lymphoma. In addition, scientific studies suggested that TACTRESS is not as specific to the target as expected. Given these clinical and scientific results, the Company no longer believes that TACTRESS will capture the desired T-cell lymphoma market opportunity. TACTRESS is commercially available to all oncologists. The Company expects that some oncologists will continue to use TACTRESS in certain, limited settings. Feedback from its oncology advisors and oncologists is that while median progression-free survival would have been important for broad use, there is interest to explore the product in individual dogs especially given the limited effective treatment options in canine T-cell lymphoma. With respect to BLONTRESS, scientific studies suggest that BLONTRESS is not as specific to the target as previously expected. The Company’s market research and interactions with veterinary oncologists indicate that high specificity, including binding and depletion, will likely be necessary to drive wide adoption of monoclonal antibody therapy given that canine B-cell is generally chemotherapy sensitive. Furthermore, the Company is aware of other emerging therapies that will compete in the B-cell lymphoma market, and believes that products with break-through benefit will dominate the market. The first generation products, BLONTRESS and TACTRESS, are expected to continue to be available or become available to oncologists insofar as they are USDA licensed and the Company is manufacturing these products today. The Company believes the revenue and gross margin opportunity for the first generation monoclonal antibodies will be very modest and given that there are not alternative monoclonal antibodies available to veterinarian oncologists, the Company intends to maintain product availability. The Company intends to build awareness of monoclonal antibody therapy with BLONTRESS and TACTRESS and pursue second generation monoclonal antibodies and other product concepts in lymphoma. These second generation products are likely several years away. The Company also intends to improve the gross margins for the second generation products. If the Company determines that it is unlikely to be successful in developing products with sufficient benefits at an economic gross margin, it would consider phasing out BLONTRESS and TACTRESS depending on product volumes. The Company deemed the events and market projections described above to be indicators of potential impairment of its finite-lived intangible assets of BLONTRESS and TACTRESS during the third quarter of 2015. The Company performed impairment testing for intangible assets BLONTRESS and TACTRESS as of September 30, 2015 and recorded an impairment expense of $20,228 and $8,634 , resulting in a net carrying value of $5,546 and $606 for BLONTRESS and TACTRESS, respectively. In conjunction with the Company’s impairment assessment, the Company re-evaluated the useful lives of BLONTRESS and TACTRESS and concluded that the useful life of BLONTRESS will remain at 20 years and the useful life of TACTRESS will be adjusted to 8.25 years. The conclusion of no change in the useful life for BLONTRESS was determined due to the fact that if and when competing therapies come, BLONTRESS for canine B-cell lymphoma is likely to have some demand that can be fulfilled at lower but economically viable production volumes. The new lower useful life for TACTRESS was concluded due to the Company determining that if and when competing therapies come, fulfilling the residual demand for TACTRESS for canine T-cell lymphoma at the lower production volumes would no longer be economically viable. The lower volume assumptions for TACTRESS, reflect the fact that the incidence of canine B-cell lymphoma is three-to-four times the incidence of canine T-cell lymphoma. The Company determined the fair value for both BLONTRESS and TACTRESS using a multi-period excess earnings method, a form of the income approach, which incorporates the estimated future cash flows to be generated from these technologies. Excess earnings are the earnings remaining after deducting the market rates of return on the estimated values of contributory assets, including debt-free net working capital, tangible and intangible assets. The excess earnings are thereby calculated for each year of a multi-year projection period and discounted to present value. Accordingly, the primary components of this method consist of the determination of excess earnings and an appropriate rate of return. Prior to the impairment assessment in the third quarter of 2015 as discussed above, the Company had conducted an impairment assessment in the first quarter of 2015 following the Company and Elanco mutually terminating the Elanco Agreement associated with BLONTRESS (Note 8) and concluded that the BLONTRESS intangible asset was not impaired at that time of the termination. As part of the assessment, the Company considered that the product would be made available in the second half of 2015, as well as manufacturing expenses, technology royalties, post-approval studies, marketing, and selling expenses to commercialize the product. Unfavorable outcomes of the Company’s development activities or the Company’s estimates of the market opportunities for the product candidates could result in impairment charges in future periods.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2015
Derivative Financial Instruments [Abstract]
Derivative Financial Instruments	9. Derivative Financial Instruments The Company records all derivatives in the consolidated balance sheets at fair value in other long-term assets. In 2015, the Company’s derivative financial instrument, the Advaxis warrant, was not designated as a hedging instrument and was adjusted to fair value through earnings in other income (expense). During the year ended December 31, 2015, the Company exercised the Advaxis warrant (Note 12) and subsequently sold the shares of common stock received upon exercise. The Company’s derivative instrument at gross fair value: FAIR VALUE OF DERIVATIVES NOT DESIGNATED AS HEDGING INSTRUMENT DECEMBER 31, 2015 DECEMBER 31, 2014 Derivative assets: Warrant (Notes 3 and 12) $ — $ 1,108 The gain recognized in other income (expense) for the year ended: GAIN RECOGNIZED IN OTHER INCOME (EXPENSE) YEAR ENDED DECEMBER 31, 2015 2014 2013 Derivative assets: Warrant $ 1,274 $ 465 $ NA During the year ended December 31, 2015, the Company exercised the warrant and recognized a gain of $1,274 in other income (expense), and subsequently sold the shares of common stock received upon exercise and recognized a gain of $341 in other income (expense).

Debt

Debt	12 Months Ended
	Dec. 31, 2015
Debt [Abstract]
Debt	10 . Debt Loan and Security Agreement On October 16, 2015, the Company entered into a Loan and Security Agreement with Pacific Western Bank (“Pacific Western Bank”) as collateral agent and a lender and Oxford Finance LLC (“Oxford” and together with Pacific Western Bank, the “Lenders”), pursuant to which the Lenders agreed to make available to the Company, term loans in an aggregate principal amount up to $35,000 (the “Term Loan”) and a revolving credit facility in an aggregate principal amount up to $5,000 (the “Revolving Line” and together with the Term Loan, the “Credit Extensions”) subject to certain conditions to funding. A term loan was made on October 16, 2015 in an aggregate principal amount equal to $35,000 , and an advance under the Revolving Line was made on October 16, 2015 in an aggregate principal amount equal to $5,000 . The Company is required to make interest-only payments on the Term Loan for 18 months, and beginning on May 1, 2017, is required to make payments of principal and accrued interest on the Term Loan in equal monthly installments over a term of 30 months. The interest-only period can be extended by one year to May 1, 2018 if the Company has at least four products fully USDA- or FDA-approved, plus another product conditionally or fully approved, in each case for commercializatio n by December 31, 2016, and agree to certain other financial covenants with the Lenders. The Credit Extensions bear interest per annum at the greater of (i) 6.91% or (ii) 3.66% plus the prime rate, which is customarily defined. All principal and accrued interest on the Term Loan are due on October 16, 2019 (the “Term Loan Maturity Date”), and all principal and accrued interest on the Revolving Line are due on October 16, 2017 (the “Revolving Maturity Date”). The Company used approximately $15,000 of the proceeds from the Credit Extensions to repay all the amounts owed under the Credit Facility, dated as of March 4, 2013, as amended, with Pacific Western Bank (as successor in interest to Square 1 Bank) and the lenders party thereto. The Company’s outstanding debt consisted of term loans under the Credit Facility of $15,000 at a fixed annual rate of 5.50% . The Company was obligated to make interest-only payments on any loans funded under the Credit Facility until June 13, 2016, As security for the obligations under the Loan Agreement, the Company granted a security interest in substantially all of its existing and after-acquired assets except for its intellectual property and certain other customary exclusions. Subject to customary exceptions, the Company is not permitted to encumber its intellectual property. Upon execution of the Loan Agreement, the Company was obligated to pay a facility fee to the Lenders of $150 , and an agency fee to the Collateral Agent of $100 . In addition, the Company is or will be obligated to pay a final payment fee equal to 3.30% of such Term Loan being prepaid or repaid with respect to the Term Loans upon the earliest to occur of the Term Loan Maturity Date, the acceleration of any Term Loan or the prepayment of a Term Loan. The Company will also be obligated to pay a termination fee equal to 3.30% of the highest outstanding amount of the Revolving Line with respect to the Revolving Line upon the earliest to occur of the Revolving Maturity Date, the acceleration of the Revolving Line or the termination of the Revolving Line. The Company will also be obligated to pay an unused-line fee equal to 0.25% per annum of the average unused portion of the Revolving Line. The Loan Agreement contains customary representations and warranties and customary affirmative and negative covenants, including, among others, limits or restrictions on the Company’s ability to incur liens, incur indebtedness, make certain restricted payments, make certain investments, merge, consolidate, make an acquisition, enter into certain licensing arrangements and dispose of certain assets. In addition, the Loan Agreement contains customary events of default that entitle the Lenders to cause the Company’s indebtedness under the Loan Agreement to become immediately due and payable. The events of default, some of which are subject to cure periods, include, among others, a non-payment default, a covenant default, the occurrence of a material adverse change, the occurrence of an insolvency, a material judgment default, defaults regarding other indebtedness and certain actions by governmental authorities. Upon the occurrence and for the duration of an event of default, an additional default interest rate equal to 4% per annum will apply to all obligations owed under the Loan Agreement. The Loan Agreement requires that the Company receive unrestricted net cash proceeds of at least $45,000 from partnering transactions and/or the issuance of equity securities from October 16, 2015 to October 16, 2016. The Loan Agreement also requires that the Company has at least three products fully USDA- or FDA approved for commercializa tion by December 31, 2016. Additionally, the Loan Agreement requires that the Company maintain certain minimum liquidity (approximately $20,000 ) at all times. At December 31, 2015, the Company was in compliance with all financial covenants. If these covenants are not met, the Company may be required to repay the Credit Extensions prior to December 31, 2016. Impairment charges related to goodwill and intangible assets have no impact on the Company’s compliance with financial covenants contained in the Company’s Loan and Security Agreement. On the issuance date of the Credit Extensions, the Company accounted for a portion of the transaction as a debt modification of the Credit Facility dated March 4, 2013 with Pacific Western Bank and a portion as a new financing for the Credit Extensions from Oxford. In conjunction with the refinancing, the Company incurred $556 in lender and legal fees, of which $360 were recorded in the consolidated balance sheet as a reduction in note payable and $196 were expensed as interest expense. Debt issuance fees are amortized throughout the life of Credit Extensions using the straight line method which materially approximates effective interest rate method. Final payment and termination fees related to the Credit Extensions are being accreted to loan payable over the life of the Credit Extensions using the straight line method which materially approximates effective interest rate method. Amortization of debt issuance costs was $129 and $41 for the years ended December 31, 2015 and 2014, respectively. The Company’s loan payable balance as of December 31, 2015 was as follows: Principal amounts Term Loan, due October 16, 2019 $ 35,000 Revolving Line, due October 16, 2017 5,000 Add: accretion of final payment and termination fees 77 Less: unamortized debt issuance costs (367) Loan payable $ 39,710 Estimated future principal payments under the Loan and Security Agreement are as follows: YEARS ENDING DECEMBER 31, 2016 $ — 2017 15,500 2018 14,000 2019 10,500 2020 — Thereafter — Total $ 40,000 During the years ended December 31, 2015 and 2014, the Company recognized $1,579 and $875 of interest expense, respectively.

Accrued Expenses, Other Current

Accrued Expenses, Other Current Liabilities And Other Long-Term Liabilities	12 Months Ended
	Dec. 31, 2015
Accrued Expenses, Other Current Liabilities And Other Long-Term Liabilities [Abstract]
Accrued Expenses, Other Current Liabilities And Other Long-Term Liabilities	11 . Accrued Expenses, Other Current Liabilities and Other Long-Term Liabilities Accrued expenses , other current liabilities and other long-term liabilities consisted of the following : DECEMBER 31, DECEMBER 31, 2015 2014 Accrued expenses: Accrued payroll and related expenses $ 1,922 $ 2,017 Accrued professional fees 388 429 Accrued royalty expense 1 72 Accrued interest expense 238 41 Accrued research and development costs 1,111 663 Accrued milestone 500 — Accrued other 87 7 Total accrued expenses $ 4,247 $ 3,229 Other current liabilities: Early exercise of stock-based awards $ 29 46 Other 8 $ — $ 37 $ 46 Other long-term liabilities: Deferred income $ 122 $ 30 $ 122 $ 30

Agreements

Agreements	12 Months Ended
	Dec. 31, 2015
Agreements [Abstract]
Agreements	12 . Agreements RaQualia Pharma Inc. (“RaQualia”) On December 27, 2010, the Company entered into two Exclusive License Agreements with RaQualia (the “RaQualia Agreements”) that granted the Company global rights, subject to certain exceptions for injectables in Japan, Korea, China and Taiwan for development and commercialization of licensed animal health products for compounds RQ-00000005 (ENTYCE ® , also known as AT-002) and RQ-00000007 (GALLIPRANT ® , also known as AT-001). The Company will be required to pay RaQualia milestone payments associated with GALLIPRANT and ENT YCE of up to $10,000 and $8,500 , respec tively, upon the Company’s achievement of certain development, regulatory and commercial milestones, as well as mid-single digit royalties on the Company’s product sales, if any. As of December 31, 2015, the Company had not accrued or paid any milestone or royalty payments since execution of the RaQualia Agreements. It is possible that multiple milestones related to the RaQualia Agreements are achieved within the next twelve months totaling $11,500 . As of the date of this filing, the Company had achieved milestones totaling $3,000 . On July 12, 2012, the Company entered into an API Development Agreement with RaQualia (the “RaQualia API Agreement”) to develop the active pharmaceutical ingredient in relation to compound RQ-00000007 (AT-001). Under the terms of the RaQualia API Agreement, RaQualia was required to pay $800 to the Company upon execution of the agreement. The Company was also eligible to receive another $800 payment for the successful development and delivery of the API to RaQualia. The Company delivered the API to RaQualia during the fourth quarter of 2014. In October 2014, the Company received notice that API delivered to RaQualia was accepted. Per the terms of the RaQualia API Agreement, the Company was entitled to a payment of $800 for the successful development and delivery of the API to RaQualia. The Company recognized $1,600 in other income, consisting of the $800 deferred income related to the payment received at execution and the $800 payment from RaQualia based on the successful delivery, during the fourth quarter of 2014. The RaQualia API Agreement expired by its own terms upon the Company receiving a technical section complete letter for CMC in 2015. Pacira Pharmaceuticals, Inc. (“Pacira”) On December 5, 2012, the Company entered into an Exclusive License, Development, and Commercialization Agreement with Pacira (the “Pacira Agreement”) that granted the Company global rights for development and commercialization of licensed animal health products for NOCITA ® (also known as AT-00 3). The Company will be required to pay Pacira milestone payments of up to $42,000 upon the Company’s achievement of certain development, regulatory $2,000 and commercial $40,000 milestones, as well as tiered royalties on the Company’s product sales, if any. To date the Company had paid $500 in milestone payments and no royalties, and no amounts were accrued at December 31, 2015. It is possible that multiple milestones related to the Pacira Agreement are achieved within the next twelve months totaling $2,000 . Other BLONTRESS and TACTRESS Agreements The Company has entered into agreements with counterparties to utilize technology in the production of BLONTRESS and TACTRESS. These agreements require the Company to pay low to mid-single digit royalties on net product sales of BLONTRESS and TACTRESS, and one of the agreements requires a minimum royalty of $70 that is subject to a yearly inflation index adjustment. The Company may also be required to pay up to $405 in sales milestones, based on future sales of certain products. These agreements would also apply to any other products that would utilize the technology. During the years ended December 31, 2015, 2014 and 2013, the Company had recognized $84 , $72 and $70 in royalty expense, respectively, related to these agreements. Elanco Animal Health, Inc. On December 6, 2012, Vet Therapeutics entered into an Exclusive Commercial License Agreement with Elanco (the “Elanco Agreement”), under which Vet Therapeutics granted a commercial license to Elanco for BLONTRESS for the United States and Canada. On January 2, 2015, the Company was granted a full product license from the USDA for BLONTRESS. The approval resulted in a $3,000 milestone payment being earned and due to the Company per the terms of the Elanco Agreement. During the first quarter of 2015, the Company recognized $3,000 of licensing revenue related to the milestone payment. On February 24, 2015, the Company and Elanco agreed to terminate the Elanco Agreement. In consideration for the return of the commercial license granted to Elanco, the Company paid Elanco $2,500 in March 2015, and will be required to pay an additional $500 upon the first commercial sale by the Company. At that time the Company determined that it is probable that the $500 payment will be paid, and recorded the $500 as a current liability in the first quarter of 2015 . T he Company currently believes the first commercial sale will occur in March 2016. The Company recorded the $3,000 paid to Elanco as a reduction in revenues received from Elanco as the payment was to re-acquire rights that the Company had previously licensed to Elanco. On February 25, 2016, the Company and Elanco agreed to amend the terms related to the $500 payment due upon the first commercial sale by the Company. Under the amended terms, upon the first commercial sale, the Company will be required to pay quarterly, a small royalty per vial sold until $500 in royalties are paid or the end of two years. After two years, the Company will be required to pay Elanco $500 plus 10% interest, compounded annually against the unpaid balance, less any royalties paid during the two years. If during the two years following the first commercial sale, the Company withdraws BLONTRESS from the market and ceases all commercialization the remaining royalty and related interest is no longer payable. Kansas Bioscience Authority (“KBA”) Programs On March 6, 2012, the Company was awarded a research and development grant from KBA, a non-principal owner independent entity of the State of Kansas. The Company received $641 during the life of the agreement which concluded in May 2014. During the years ended December 31, 2015, 2014 and 2013, the Company recognized income of $0 , $62 and $478 , respectively. Pursuant to Kansas law, the Company may be required to repay any financial assistance received from the KBA, which may include an obligation to repurchase the shares of its capital stock purchased by the KBA, subject to the discretion of the KBA, if the Company relocates the operations in which the KBA invested outside of the State of Kansas within ten years after receiving such financial assistance. Further, pursuant to the agreement accompanying the voucher award, the KBA may terminate the agreement and require the Company to repay the grant if it initiates procedures to dissolve and wind up or if it ceases operations within the State of Kansas within 10 years following the final grant payment. The Company has determined these contingencies to be within its control and will only account for the repayment of the equity and grant if it becomes probable that the Company is going to relocate the operations in which the KBA invested outside of the State of Kansas within the ten-year period or for the repayment of only the grant if it becomes probable that the Company is going to initiate procedures to dissolve and wind up or cease operations within the State of Kansas within the ten-year period. Advaxis Inc. (“Advaxis”) On March 19, 2014, the Company entered into an Exclusive License Agreement with Advaxis (the “Advaxis Agreement”) that granted the Company global rights for development and commercialization of licensed animal health products for Advaxis’ ADXS-cHER2 for the treatment of osteosarcoma in dogs (“AT-014”) and three additional cancer immunotherapy products for the treatment of three other types of cancer. Under the terms of the Advaxis Agreement, the Company paid $2,500 in exchange for the license, 306,122 shares of common stock, and a warrant to purchase 153,061 shares of common stock. The consideration was allocated to the common stock and warrant based on their fair values on the date of issuance of $1,200 and $643 , respectively. The remaining consideration of $657 was allocated to the licensed technology. On the date of acquisition, the licensed technology had not reached technological feasibility in animal health indications and had no alternative future use in the field of animal health. Accordingly, in-process research and development of $657 was expensed upon acquisition. The Company will be required to pay Advaxis milestone payments of up to an additional $6,000 in clinical and regulatory milestones for each of the four products, assuming approvals in both cats and dogs, in both the United States and the European Union. In addition, the Company agreed to pay up to $28,500 in commercial milestones, as well as tiered royalties ranging from mid-single digit to 10% on the Company’s product sales, if any. As of December 31, 2015, the Company had not accrued or paid any milestone or royalty payments since execution of the Advaxis Agreement. The Company does not expect to achieve milestones related to the Advaxis Agreement within the next twelve months. Under the terms of the subscription agreement, the Company acquired 306,122 shares of common stock and a warrant to purchase another 153,061 shares of common stock for $1,843 . The warrant is exercisable through March 19, 2024 , at an exercise price of $4.90 per share of common stock and is to be settled through physical share issuance or net share settlement where the total number of issued shares is based on the amount the market price of common stock exceeds the exercise price of $4.90 on date of exercise. Neither the common stock nor warrant have registration rights. The Company allocated the consideration of $1,843 to Advaxis common stock ( $1,200 ) and the Advaxis warrant ( $643 ) based on their respective fair values and recorded the purchase in marketable securities and other long-term assets, respectively. See Note 3 for subsequent fair value matters related to the Advaxis common stock and warrant. In January 2015, Aratana sold 124,971 shares of Advaxis common stock for proceeds of $1,500 and recognized a gain of $1,010 in other income (expense). Further in April 2015, the Company sold the remaining 181,151 shares of Advaxis common stock for proceeds of $3,233 , recognizing a gain of $2,523 in other income (expense) during the second quarter of 2015. In May 2015, the Company, through net share settlement, exercised the Advaxis warrant for a total exercise price equivalent to $750 and received 116,411 net shares of Advaxis common stock. Subsequently, the Company sold this Advaxis common stock for proceeds of $2,724 , a gain of $341 , recorded in other income (expense) during the second quarter of 2015. VetStem BioPharma, Inc. (“VetStem”) On June 12, 2014, the Company entered into an Exclusive License Agreement with VetStem (the “VetStem Agreement”) that granted the Company the exclusive United States rights for commercialization and development of VetStem’s allogeneic stem cells being developed for the treatment of pain and inflammation of canine osteoarthritis (“AT-016”). VetStem is responsible for the development and obtaining regulatory approval of AT-016 and the Company is responsible for the commercialization of licensed products. Under the terms of the VetStem Agreement, the Company paid an initial license fee of $500 . On the date of acquisition, the licensed technology had not reached technological feasibility in animal health indications and had no alternative future use in the field of animal health. Accordingly, in-process research and development of $500 was expensed upon acquisition. The Company will be required to pay VetStem milestone payments of up to $4,200 upon VetStem’s achievement of certain development and regulatory milestones, as well as tiered royalties in the low double digit percentages on the Company’s product sales, if any. The Company could be required to pay to VetStem up to $3,600 in reimbursement for development expenses, unless additional monies are approved by the joint steering committee. In 2015, the Company paid milestones of $300. No royalties or milestone payments were accrued as of December 31, 2015. The Company believes it is possible, but not probable that VetStem might achieve multiple milestones totaling $700 related to the VetStem Agreement within the next twelve months. Atopix Therapeutics Ltd. On October 10, 2014, the Company entered into an Exclusive License Agreement with Atopix (the “Atopix Agreement”) that granted the Company an exclusive global license for development and commercialization of animal health products containing the active pharmaceutical ingredient included in Atopix’s CRTH2 antagonist product for the treatment of atopic dermatitis (“AT-018”). Under the terms of the Atopix Agreement, the Company paid an initial license fee of $1,000 . On the date of acquisition, the licensed technology had not reached technological feasibility in animal health indications and had no alternative future use in the field of animal health. Accordingly, in-process research and development of $1,000 was expensed upon acquisition. The Company will be required to pay Atopix milestone payments of up to an additional $4,000 in clinical and regulatory milestones, assuming approvals in both cats and dogs, in both the United States and the European Union, as well as tiered royalties in the mid-single digits on the Company’s product sales, if any. As of December 31, 2015 and December 31, 2014, the Company had paid $500 and $0 in milestone payments respectively, no royalties, and no milestones or royalty payments had been accrued. The Company does not expect to achieve milestones related to the Atopix Agreement within the next twelve months. Exclusive Option Programs The Company’s business model is to identify innovative proprietary compounds from human biopharmaceutical companies and to develop these product candidates into regulatory-approved therapeutics specifically for use in pets. To this end, the Company has developed a process in which, in exchange for a fee, it enters into a time-limited option agreement (the “Exclusive Option Program”) with a biopharmaceutical company (the “Potential Licensor”). During the option period the Company obtains from the Potential Licensor the data and information necessary to perform studies to evaluate the compound itself or through a cooperative research and development agreement. Once the Company has evaluated the compound, it can choose to either terminate the Exclusive Option Program with no further obligation, or exercise the option to enter into an exclusive, worldwide license agreement (the “License Agreement”) to develop and commercialize products for non-human animal health applications. The fee associated with the Exclusive Option Program is generally non-refundable and non-creditable. The principal terms of any License Agreement entered into by the Company will generally consist of an exclusive, world-wide license to all non-human animal health applications in exchange for an upfront license fee, milestone payments upon the achievement of certain regulatory milestones, as well as royalties on sales. During the years ended December 31, 2015, 2014 and 2013, the Company recognized research and development expenses of $270 , $307 a nd $915 , respectively, due to Exclusive Option Programs.

Common Stock

Common Stock	12 Months Ended
	Dec. 31, 2015
Common Stock [Abstract]
Common Stock	1 3 . Common Stock As of December 31, 2015, there were 34,563,816 shares of the Company’s common stock outstanding, net of 441,800 shares of unvested restricted common stock. As of December 31, 201 4 , there were 34,147,861 shares of the Company’s common stock outstanding, net of 561,651 shares of unvested restricted common stock. Authorized Common Stock In February 2013, the Board of Directors of the Company approved an amendment of the Company’s Certificate of Incorporation and increased the number of authorized shares of common stock to 25,041,667 . On July 2, 2013, the Company increased the number of authorized shares of its common stock from 25,041,667 to 100,000,000 , par value $0.001 per share. Voting Rights Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are entitled to receive dividends, as may be declared by the Board of Directors , if any. As of December 31, 201 5 and 201 4 , the Board of Directors had not declared any dividends in any period. Stock-Based Awards During the year ended December 31, 2013, t he Company issued common stock pursuant to the 2010 Equity Incentive Plan (Note 14) and the 2013 Incentive Award Plan (Note 14) . During the years ended December 31, 2015 and 2014, the Company did not reacquire any unvested shares of common stock from its terminated employees that had been issued upon the exercise of a stock option prior to its vesting. During the years end ed December 31, 201 5 and 2014 , the Company issued common stock pursuant to the 2013 Incentive Award Plan ( Note 14 ). Reverse Stock Split On May 22, 2013, the Company effected a 1-for- 1.662 reverse stock split of its issued and outstanding shares of common stock. No fractional shares were issued in connection with the reverse stock split. Accordingly, all share and per share amounts for all periods presented in these consolidated financial statements and notes thereto have been adjusted retroactively, where applicable, to reflect the reverse stock split. Initial Public Offering In July 2013, the Company completed the initial public offering of its common stock in which the Company issued and sold 6,612,500 shares of common stock at a public offering price of $6.00 per share. The Company received net proceeds of approximately $34,274 after deducting underwriting discounts and commissions of approximately $2,777 and other offering expenses of approximately $2,617 . Preferred Convertible Stock Conversion On June 26, 2013, the holders of at least 75% of the then-outstanding shares of Series A Preferred Stock elected and consented to the automatic conversion of each outstanding share of Preferred Stock into shares of common stock immediately prior to the consummation of the public offering contemplated by the Company’s Registration Statement on Form S-1 (No. 333-187372). Immediately prior to the consummation of the initial public offering, all shares of the Company’s then-outstanding convertible preferred stock and accumulated dividends automatically converted into an aggregate of 13,351,902 shares of common stock. Vet Therapeutics Merger On October 15, 2013, the Company completed the acquisition of Vet Therapeutics, in which the Company issued 624,997 shares of common stock to the former equity and stock option holders of Vet Therapeutics. The fair value of the common stock at time of the acquisition was determined to be $14,700 . Private Placement On October 13, 2013, the Company completed a private placement in which the Company issued and sold 1,234,375 shares of its common stock for $16.00 an aggregate purchase price of $19,750 , or $16.00 per share. Public Offerings On February 3, 2014, the Company completed a public offering of its common stock in which the Company issued and sold 5,150,000 shares of common stock at a public offering price of $19.00 per share. The Company received net proceeds of approximately $90,507 after deducting underwriting discounts and commissions of approximately $5,871 and other offering expenses of approximately $1,472 . On September 22, 2014, the Company completed a public offering of its common stock in which the Company issued and sold 5,175,000 shares of common stock at a public offering price of $9.25 per share. The Company received net proceeds of approximately $44,827 after deducting underwriting discounts and commissions of approximately $2,872 and other offering expenses of approximately $412 . Sales Agreement On October 16, 2015, the Company entered into a Sales Agreement with Barclays Capital Inc. (“Barclays”) pursuant to which the Company may sell from time to time, at its option, up to an aggregate of $52,000 of shares of its common stock (the “Shares”) through Barclays, as sales agent. Sales of the Shares, if any, will be made under the Company’s previously filed and currently effective Registration Statement on Form S-3 (Reg. No. 333-197414), by means of ordinary brokers’ transactions on The NASDAQ Global Market or otherwise. Additionally, under the terms of the Sales Agreement, the Shares may be sold at market prices, at negotiated prices or at prices related to the prevailing market price. The Company will pay Barclays a commission of 2.75% of the gross proceeds from the sale of the Shares, if any. As of the date of this filing the Company has not sold any shares pursuant to the Sales Agreement.

Stock-Based Awards

Stock-Based Awards	12 Months Ended
	Dec. 31, 2015
Stock-Based Awards [Abstract]
Stock-Based Awards	1 4 . Stock-Based Awards 2010 Equity Incentive Plan In 2010, the Company’s Board of Directors adopted the 2010 Equity Incentive Plan (the “2010 Plan”). The 2010 Plan provide d for the Company to sell or issue common stock or restricted common stock and to grant incentive stock options or nonqualified stock options for the purchase of common stock with a maximum term of ten years to employees, members of the Board of Directors and consultants of the Company. With the adoption and approval of the 2013 Incentive Award Plan (the “2013 Plan”) , no further awards will be granted from the 2010 plan. The 2010 Plan permits the exercise of stock options granted under the plan before the options are fully vested. If a stock option is early exercised in this circumstance, the issued common stock is subject to restrictions on the sale or transfer by the holder that lapse according to the vesting terms of the early-exercised stock option. Unvested shares may not be sold or transferred by the holder. In the event of termination of the holder’s employment, any unvested shares received upon early exercise are subject to repurchase by the Company, typically at the lesser of (1) the original purchase price per share or (2) the fair value of the common share on the date of termination. During the year ended December 31, 2012, the Company granted three restricted stock awards under the 2010 Plan that were subject to repurchase at the greater of (1) the original purchase price per share or (2) the fair value of the common share on the date of termination. Only one of these three restricted stock awards remain outstanding as of December 31, 2015. Under the 2010 Plan, the Company has 90 days from the effective termination of the holder’s employment or service to repurchase unvested shares that are issued upon the exercise of a stock award prior to its vesting. If, after 90 days, the Company elects not to repurchase these unvested shares, the shares become vested in full. The Company would then apply modification accounting and any resulting compensation expense would be immediately recognized related to the award. Upon vesting, these shares would be considered issued and out standing shares of common stock for accounting purposes. Stock Options At the year ended December 31, 201 5 , 71,459 shares of restricted common shares issued due to early exercises were unvested and subject to repurchase. Early exercise is not considered an exercise for accounting purposes and, therefore, any payment for unvested shares is recognized as a liability at the original exercise price. As of December 31, 201 5 and 201 4 , the liability related to the early exercise of awards was $30 and $76 , respectively, and was recorded in other current liabilities and other long-term liabilities. During the year ended December 31, 201 3 , the Company repurchased 33,447 unvested shares from terminated employees. No early exercised stock option shares were repurchased by the Company during the year s ended December 31, 201 5 and 2014 . A ctivity related to stock option s for the year ended December 31, 201 5, was as follows : WEIGHTED SHARES WEIGHTED AVERAGE ISSUABLE AVERAGE REMAINING AGGREGATE UNDER EXERCISE CONTRACTUAL INTRINSIC OPTIONS PRICE TERM VALUE (IN YEARS) Outstanding as of December 31, 2014 170,466 $ 1.71 8.05 $ 2,746 Granted — — Exercised (57,652) 0.43 Forfeited (26,324) 0.45 Expired — — Outstanding as of December 31, 2015 86,490 $ 2.95 7.09 $ 228 Options vested and expected to vest as of December 31, 2015 85,385 $ 2.92 7.09 $ 227 Options exercisable as of December 31, 2015 86,213 $ 2.94 7.09 $ 228 No stock options were granted in 2015 and 2014, for the year ended December 31, 2013, the weighted average grant date fair value of stock options granted was $ 2.48 . Fo r the years ended December 31, 201 5 , 201 4 , and 201 3 , the total intrinsic value of options exercised was $786 , $871 and $4,840 , respectively. For the years ended December 31, 201 5 , 201 4 and 201 3 the total fair value of awards vested during the period was $140 , $765 and $98 , respectively. The Company received cash proceeds of $25 , $19 and $153 from the exercise of stock options for the years ended December 31, 201 5, 2014 and 201 3 , respectively, of which $0 , $0 and $97 were from the early exercise of stock options, respectively. During 2014, there were three awards subject to modification accounting under ASC 718-20-35-3 through 35-4. Per terms of separation with a former employee, all unvested shares of restricted stock held by the employee became fully vested upon the employee’s employment termination. In addition, six months of accelerated vesting was granted for the former employee’s two stock option awards. As the employee would have forfeited the unvested awards upon termination according to the awards’ original terms, the awards would not be expected to vest under the original vesting conditions. The accelerated/full vesting of the unvested awards resulted in a Type III modification. The incremental fair value was equal to the fair value of the awards on the modification date. This amount was recognized immediately as the awards did not require further service. The incremental expense for the stock option awards and restricted stock award was $ 327 and $ 649 , respectively. During August 2013, the Company modified two stock option awards granted to the Company’s former President, for the purchase of 269,817 shares of common stock in the aggregate. The modifications included the expiration of options to purchase 9,228 shares of common stock, and extended the expiration date of options from August 9, 2013 to January 31, 2014 . No additional stock - based compensation expense was recognized as a result of this modification. Restricted Common Stock The Company’s 2010 Plan provide d for the award of restricted common stock. The Company has granted restricted common stock with time-based vesting conditions. Unvested shares of restricted common stock may not be sold or transferred by the holder. These restrictions lapse according to the time-based vesting. During the year ended December 31, 201 3 , the Company issued 76,496 shares of restricted common stock for no proceeds. The vesting of these awards is time-based, with terms between two and four years. A ctivity related to restricted stock for the year ended December 31, 201 5, was as follows : WEIGHTED AVERAGE GRANT SHARES DATE FAIR VALUE Unvested restricted common stock as of December 31, 2014 91,334 $ 0.94 Restricted common stock issued — — Restricted common stock vested (54,256) 0.37 Restricted common stock forfeited — — Unvested restricted common stock as of December 31, 2015 37,078 $ 0.36 No restricted stock was granted in 2015 and 2014 . F or the year ended December 31, 2013, the weighted average grant date fair value of restricted stock granted was $2.59 . For the years ended December 31, 2015, 2014 and 2013 , the total fair value of restricted shares vested was $731 , $2,615 and $2,257 , respectively. As of December 31, 2015, 2014 and 2013, 37,078 , 91,334 and 237,740 shares of common stock related to restricted stock awards were unvested and subject to repurchase, respectively. 2013 Incentive Award Plan In 2013, the Company’s Board of Directors adopted and stockholders approve d the 2013 Plan which became effective upon the day prior to the effective date of the Company’s initial public offering. The 2013 Plan currently allows for the issuance of up to 3,222,298 shares of common stock, plus any additional shares represented by the 2010 Plan that are forfeited or lapse unexercised. The number of shares of common stock that may be issued under the plan is also subject to an annual increase on January 1 st of each calendar year beginning in 2014 and ending in 2023, equal to the lesser of (i) 1,203,369 shares, (ii) 4% of the shares of common stock outstanding on the final day of the immediately preceding calendar year and (iii) and amount determined by the Board of Directors. As of December 31, 2015, there were 847,103 shares available for future grant under the 2013 Plan. On January 1, 2016 , the annual increase was determined to be 1,203,369 . The 2013 Plan is administered by the Compensation Committee of the Board of Directors , which selects the individuals eligible to receive awards, determines or modifies the terms and condition of the awards granted, accelerates the vesting schedule of any award and generally administers and interprets the 2013 Plan. The 2013 Plan permits the granting of incentive and nonqualified stock options, with terms of up to ten years and the granting of restricted stock, restricted stock units, performance stock awards, dividend equivalent rights, stock payments (i.e. unrestricted stock), cash bonuses and stock appreciation rights to employees, consultants, and non-employee directors. Stock Options D uring the year ended December 31, 201 5 , the Company granted under the 2013 Plan stock options for the purchase of 523,350 shares of common stock to certain employees and non-employee directors. The vesting conditions for most of these awards are time-based, and the awards typically vest 25% after one year and monthly thereafter for the next 36 months. Awards typically expire after 10 years. Activity related to stock options for the year ended December 31, 2015, was as follows: WEIGHTED SHARES WEIGHTED AVERAGE ISSUABLE AVERAGE REMAINING AGGREGATE UNDER EXERCISE CONTRACTUAL INTRINSIC OPTIONS PRICE TERM VALUE (IN YEARS) Outstanding as of December 31, 2014 1,481,866 $ 17.13 8.96 $ 3,835 Granted 523,350 16.14 Exercised (32,761) 8.76 Forfeited (182,945) 18.96 Expired (61,311) 23.55 Outstanding as of December 31, 2015 1,728,199 $ 16.57 8.31 $ — Options vested and expected to vest as of December 31, 2015 1,642,972 $ 16.59 8.31 $ — Options exercisable as of December 31, 2015 610,406 $ 16.54 7.88 $ — For the years ended December 31, 2015, 2014 and 2013, the weighted average grant date fair value of stock options granted was $10.09 , $ 12.84 and $ 9.16 , respectively . For the years ended December 31, 2015, 2014 and 2013, the total intrinsic value of options exercised was $267 , $ 214 and $0 (no exercises occurred), respectively. For the years ended December 31, 2015, 2014 and 2013, the total fair value of awards vested during the period was $5,660 , $ 1,888 and $ 0 (no awards vested) , respectively. The Company received cash proceeds of $287 , $ 206 and $ 0 (no exercises occurred) from the exercise of stock options for the years ended December 31, 2015, 201 4 and 201 3 , respectively . Restricted Common Stock The Company’s 2013 Plan provides for the award of restricted common stock. The Company has granted restricted common stock typically with time-based vesting conditions, having terms of between several months and four years. The awards granted in 2015 to executives and non-executives typically vest in three annual installments of 33.3% each year for three years. In 2016, the vesting conditions for executive awards changed so that the awards vest in 12 quarterly installments of 8.33% per quarter for three years, similar to the vesting conditions for executive awards in 2014. Awards granted to consultants typically vest in accordance with the expected term length of the consulting arrangement. Unvested shares of restricted common stock may not be sold or transferred by the holder. These restrictions lapse according to the time-based vesting. A ctivity related to restricted stock for the year ended December 31, 201 5, was as follows : WEIGHTED AVERAGE GRANT SHARES DATE FAIR VALUE Unvested restricted common stock as of December 31, 2014 277,844 $ 16.92 Restricted common stock issued 230,400 17.14 Restricted common stock vested (151,131) 15.85 Restricted common stock forfeited (23,850) 14.00 Unvested restricted common stock as of December 31, 2015 333,263 $ 17.77 For the years ended December 31, 2015, 2014 and 2013, the weighted average grant date fair value of restricted common stock granted was $17.14 , $ 16.73 and $18.91 , respectivel y. For the years ended December 31, 2015, 2014 and 2013, the total fair value of restricted common stock vested was $1,893 , $94 and $25 , respectively. The Company received no proceeds for any of the restricted common stock granted during the years ended December 31, 2015, 2014 and 2013. Stock-Based Compensation The fair value of each stock option award is estimated using the Black-Scholes option-pricing model. Prior to 2014, due to the lack of company- specific historical and implied volatility information the Company estimated its expected volatility based on the historical volatility of the Company’s publicly-traded peer companies. Beginning in the first quarter of 2014, the Company began to base expected volatility on historical volatility of the Company’s common stock, as adequate historical data regarding the volatility of the Company’s common stock price had become available . The expected term of the Company’s stock options has been determined utilizing the “simplified” method as the Company has insufficient historical experience for option grants overall, rendering existing historical experience irrelevant to expectations for current grants. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future. The relevant data used to determine the value of the stock option grants, presented on a weighted average basis , was as follows : YEAR ENDED DECEMBER 31, 2015 2014 2013 Risk-free interest rate 1.38 % 1.88 % 1.59 % Expected term (in years) 6.1 6.1 6.1 Expected volatility 70 % 84 % 66 % Expected dividend yield — % — % — % Compensation expense related to restricted stock granted to employees and non-employee directors is equal to the excess, if any, of the fair value of the Company’s common stock on date of grant over the original purchase price per share, multiplied by the number of shares of restricted common stock issued for employees. Compensation expense related to restricted stock granted to non-employee s is equal to the excess, if any, of the fair value of the Company’s common stock on date of vesting over the original purchase price per share, multiplied by the number of shares of restricted common stock vesting. The Company recognizes compensation expense for only the portion of awards that are expected to vest. In developing a forfeiture rate estimate, the Company has considered its historical experience to estimate pre-vesting forfeitures for service-based awards. The impact of a forfeiture rate adjustment will be recognized in full in the period of adjustment, and if the actual forfeiture rate is materially different from the Company’s estimate, the Company may be required to record adjustments to stock-based compensation expense in future periods. The Company recorded stock-based compensation expense related to stoc k options and restricted stock as follows: YEAR ENDED DECEMBER 31, 2015 2014 2013 Research and development $ 1,646 $ 1,611 $ 419 Cost of product sales 118 48 — Selling, general and administrative 6,828 5,471 606 $ 8,592 $ 7,130 $ 1,025 As of December 31, 2015, t he Company had an aggregate of $10,372 and $4,570 of unrecognized stock-based compensation expense for options outstanding and restricted stock awards, respectively, which is expected to be recognized over 2.37 years and 1.68 years, respectively .

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2015
Net Loss Per Share [Abstract]
Net Loss Per Share	15 . Net Loss Per Share Basic and diluted net loss per share attributable to common stockholders was calculated as follows: YEAR ENDED DECEMBER 31, 2015 2014 2013 Numerator: Net loss attributable to common stockholders $ (84,054) $ (38,816) $ (6,938) Denominator: Weighted average shares outstanding – basic and diluted 34,355,525 29,767,429 11,059,382 Net loss per share attributable to common stockholders – basic and diluted (1) $ (2.45) $ (1.30) $ (0.63) __________________ (1) All per share amounts and shares outstanding for all periods reflect the 1-for- 1.662 reverse stock split, which was effective May 22, 2013. Stock options for the purchase of 1,814,689 , 1,789,305 , and 1,294,146 shares of common stock were excluded from the computation of diluted net loss per share attributable to common stockholders for the years ended December 31, 201 5 , 201 4 and 201 3 , respectively, because those options had an anti-dilutive impact due to the net loss attributable to common stockholders incurred for the period.

Commitments And Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies [Abstract]
Commitments And Contingencies	1 6 . Commitments and Contingencies Operating Leases Future minimum lease payments for operating leases as of December 31, 201 5, were as follows: YEAR ENDING DECEMBER 31, 2016 598 2017 605 2018 590 2019 466 2020 and thereafter 526 Total $ 2,785 The Company leases facilities and certain operating equipment under operating leases expiring through 20 21 . The Company incurred rent expense of $678 , $565 and $177 for the years ended December 31, 2015, 2014 and 2013, respectively. Contingent Consideration Obligations The Company determines the acquisition date fair value of the contingent consideration obligation based on a probability-weighted approach derived from the overall likelihood of achi eving certain specified future milestones, such as certain regulatory and manufacturing milestones. The fair value measurement is based on significant inputs not observable in the market and thus represents a Level 3 measurement ( Note 3 ), as defined in fair value measurement accounting. The resultant probability-weighted earn-out payments are discounted using a discount rate based upon the Company’s current borrowing rate. At each reporting date, the Company revalues the contingent consideration obligations to the reporting date fair values and record increases and decreases in the fair values as income or expense in the consolidated statements of operations. Increases or decreases in the fair values of the contingent consideration obligations may result from changes in discount periods and rates, changes in the timing and amount of earn-out criteria and changes in probability assumptions with respect to the likelihood of achieving the various earn-out criteria. The Company ha d a contractual contingent purchase price consideration obligation related to acquisitions, as follows (in thousands): Maximum Remaining Remaining Earn-out Earn-out Estimated Potential Period Fair Value Payments Acquisition as of as of as of made Date Fair December 31, December 31, December 31, during Acquisition Acquisition Date Value 2015 2015 2015 2015 Vet Therapeutics October 15, 2013 $ 3,810 $ — — $ — $ 3,000 $ — — $ — $ 3,000 On January 2, 2015 the Company was granted a full product license for BLONTRESS. The approval resulted in $3,000 of the contingent consideration being earned and due to the former Vet Therapeutics shareholders per the terms of Vet Therapeutics merger. Further, on February 24, 2015 in connection with the mutual termination of the NAH Agreement for BLONTRESS, the Company’s obligation to pay additional consideration to the Vet Therapeutics shareholders upon achievement of certain manufacturing milestones ended. The Company paid the $3,000 contingent consideration in March 2015. During the first quarter of 2015, the Company recorded a credit of $1,248 to reduce the fair value of the contingent consideration to zero as a result of the agreement the Vet Therapeutics shareholders. Litigation and Contingencies Related to Use of Intellectual Property From time to time, the Company may become subject to legal proceedings, claims and litigation arising in the ordinary course of business. The Company currently is not a party to any threatened or pending litigation. However, third parties might allege that the Company or its licensors are infringing their patent rights or that the Company is otherwise violating their intellectual property rights. Such third parties may resort to litigation against the Company or its licensors, which the Company has agreed to indemnify. With respect to some of these patents, the Company expects that it will be required to obtain licenses and could be required to pay license fees or royalties, or both. These licenses may not be available on acceptable terms, or at all. A costly license, or inability to obtain a necessary license, could have a material adverse effect on the Company’s financial condition, results of operations or cash flows. The Company accrues contingent liabilities when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. Indemnification Agreements In the ordinary course of business, the Company may provide indemnifications of varying scope and terms to customers, vendors, lessors, business partners, and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements, from services to be provided by the Company, or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with certain of its officers and members of its Board of Directors that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, not readily quantifiable. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company does not believe that the outcome of any claims under indemnification arrangements will have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its consolidated financial statements as of December 31, 201 5 or 201 4 .

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Business Combinations	17 . Business Combinations Acquisition of Okapi Sciences On January 6, 2014 , the Company acquired Okapi Sciences, a Leuven, Belgium based company with a proprietary antiviral platform and three clinical/development stage product candidates. This acquisition further expanded the existing Company pipeline. The aggregate purchase price was approximately $ 44,439 , which consisted of $ 14,139 in cash, a promissory note in the principal amount of $ 15,134 with a maturity date of December 31, 2014 , and a contingent consideration of up to $16,308 with an acquisition fair value of $ 15,166 . The promissory note bore interest at a rate of 7% per annum, payable quarterly in arrears, and was subject to mandatory prepayment in the event of a specified equity financing by the Company. On February 4, 2014, the promissory note and accrued interest was paid in cash in the amount of $15,158 . On March 17, 2014, the contingent consideration was settled in cash in the amount of $15,235 . Included in the Company’s consolidated statements of operations for the year ended December 31, 2014 is revenue totaling approximately $452 related to Okapi Sciences. The acquisition-date fair value of the consideration transferred to the sellers of Okapi Sciences, less cash acquired, was $ 43,376 , which consisted of the following: Cash consideration $ 14,139 Fair value of promissory note 15,134 Fair value of contingent consideration 15,166 Fair value of total consideration 44,439 Less cash acquired (1,063) Total consideration transferred, net of cash acquired $ 43,376 Fair Value of Contingent Consideration : The Company agreed to pay up to $ 16,308 on or prior to April 7, 2014, subject to mandatory prepayment in cash in the event of a specified future equity financing, provided that if not paid in cash by April 7, 2014, payment was to be made in the form of shares of the Company’s common stock - based on the average closing price of the Company’s common stock during the 10-trading day period ending April 4, 2014, subject to a maximum of 1,060,740 shares and a minimum of 707,160 shares. This contingent consideration was recorded as a liability and measured at fair value using a probability-weighted model utilizing significant observable and unobservable inputs, including the volatility in the market price of the Company’s common stock, the expected probability of settling the contingent consideration in either cash or shares and an estimated discount rate commensurate with the risks of these outcomes. The analysis resulted in an estimated fair value of contingent consideration of $ 15,166 . The contingent consideration was settled March 17, 2014 for $ 15,235 and the difference between the initial fair value amount and settlement amount was $69 which is reflected as a charge to selling, general and administrative expenses in the consolidated statement of operations. The acquisition of Okapi Sciences was accounted for as a business combination under the acquisition method of accounting. Accordingly, the assets acquired and liabilities assumed were recorded at fair value with the remaining purchase price recorded as goodwill. The assets acquired and the liabilities assumed from Okapi Sciences have been recorded at their fair values at the date of acquisition, being January 6, 2014. The Company’s consolidated financial statements and results of operations include the results of Okapi Sciences from January 6, 2014. The Company’s allocation of the purchase price to the assets acquired and liabilities assumed was as follows: Cash $ 1,063 Accounts receivable 149 Other receivables 60 Prepaid expenses and other current assets 82 Property and equipment 217 Other long-term assets 18 Identifiable intangible assets 29,400 Accounts payable and accrued expenses (586) Deferred revenue (83) Deferred tax liabilities, net (3,786) Long-term debt (4) Total identifiable net assets 26,530 Goodwill 17,909 Total net assets acquired 44,439 Less: Promissory note 15,134 Contingent consideration 15,166 Cash paid $ 14,139 The following are the intangible assets acquired by drug program and their estimated useful lives as of the date of the acquisition: FAIR VALUE USEFUL LIFE AT-006 $ 3,400 13 years AT-007 13,500 15 years AT-008 5,300 13 years AT-011 7,200 14 years Total intangible assets $ 29,400 The identifiable intangible assets recognized by the Company as a result of the Okapi Sciences acquisition relate to Okapi Sciences technology, and consist primarily of its intellectual property related to Okapi Sciences AT-006, AT-007, AT-008 and AT-011 programs, and the estimated net present value of future cash flows from commercial agreements related to the AT-006 program. All Okapi Sciences programs, which were considered IPR&D at the acquisition date, were valued using a multi-period excess earnings method, a form of the income approach, which incorporates the estimated future cash flows to be generated from this technology. Excess earnings are the earnings remaining after deducting the market rates of return on the estimated values of contributory assets, including debt-free net working capital, tangible, and intangible assets. The excess earnings are thereby calculated for each year of a multi-year projection period and discounted to present value. Accordingly, the primary components of this method consist of the determination of excess earnings and an appropriate rate of return. The Company will not amortize the assets related to the Okapi Sciences programs until commercialization has been achieved. The valuation analysis conducted by the Company determined that the aggregate fair value of identifiable assets acquired less the aggregate fair value of identifiable liabilities assumed by the Company is less than the purchase price. As the purchase price exceeds the fair value of assets and liabilities acquired or assumed, goodwill will be recognized. Goodwill is calculated as the difference between the Okapi Sciences acquisition date fair value of the consideration transferred and the fair values of the assets acquired and liabilities assumed. The goodwill is not expected to be deductible for income tax purposes. Goodwill is recorded as an indefinite-lived asset and is not amortized but tested for impairment on an annual basis or when indications of impairment exist. The difference between the total consideration and the fair value of the net assets acquired of $ 17,909 was recorded as Goodwill in the consolidated balance sheet. This goodwill represents the excess of the purchase price over the fair value of the tangible and identifiable intangible assets acquired and liabilities assumed, principally representing the tax attributes of the acquisition and certain operational and strategic synergies such as advancement toward becoming a commercial company and acquiring a proprietary antiviral platform. Acquisition of Vet Therapeutics, Inc. On October 15, 2013 , the Company acquired Vet Therapeutics, a San Diego, California based company with a proprietary antibody-based biologics platform. This acquisition further expanded the existing Company pipeline . The aggregate purchase price was approximately $51,515 , which consisted of $30,005 in cash, 624,997 shares of Aratana’s common stock with an acquisition date fair value of $14,700 , a promissory note in the principal amount of $3,000 with a maturity date of December 31, 2014 , and contingent consideration of up to $5,000 with an acquisition -date fair value of $3,810 . The promissory note b ore interest at a rate of 7% per annum, payable quarterly in arrears, and was subject to prepayment in the event of a specified equity financing by the Company. The Company could have paid up to $5,000 in contingent cash consideration in connection with the achievement of certain regulatory and manufacturing milestones for BLONTRES S. On February 4, 2014 the promissory note and accrued interest was paid in cash in the amount of $3,020 . On March 5, 2015 the contingent consideration was settled in the amount of $3,000 . Included in the Company’s consolidated statements of operations for the year s ended December 31, 201 4 and 2013, is revenue totaling approximately $273 and $123 , respectively, related to Vet Therapeutics. The amount of goodwill from this acquisition is not deductible for tax purposes. The acquisition-date fair value of the consideration transferred to the sellers of Vet Therapeutics, less cash acquired, was $51,503 , which consisted of the following: Cash consideration $ 30,005 Fair value of promissory note 3,000 Fair value of merger shares 14,700 Fair value of contingent consideration 3,810 Fair value of total consideration 51,515 Less cash acquired (12) Total consideration transferred, net of cash acquired $ 51,503 Fair Value of Merger Shares : The Company agreed to transfer 624,997 unregistered shares of its common stock without registration rights to former Vet Therapeutics stock and option holders. On October 15, 2013, the closing date of the Vet Merger, the fair market value of Aratana’s publicly traded common stock was $27.67 per share. In order to determine the fair value of consideration transferred to Vet Therapeutics stock and option holders related to the Merger Shares, the Company applied a discount for the lack of marketability of 15% to the Company’s closing stock price on the closing date of the Vet Merger to account for the lack of access to an active public market for these shares. This resulted in aggregate purchase consideration related to the Merger Shares of $14,700 . Fair Value of Contingent Consideration : The Company agreed to pay up to $5,000 in contingent cash consideration in connection with the achievement of certain regulatory and manufacturing milestones for BLONTRESS . Contingent consideration is recorded as a liability and measured at fair value using a discounted cash flow model utilizing significant unobservable inputs, including the probability of achieving each of the potential milestones and an estimated discount rate commensurate with the risks of the expected cash flows attributable to the milestones. This resulted in aggregate contingent purchase consideration of $3,810 . Significant increases or decreases in any of the probabilities of success would result in a significantly higher or lower fair value, respectively, and commensurate changes to this liability. The fair value of contingent consideration and the associated liability was adjusted to fair value at each reporting date until actual settlement occur red , with the changes in fair value reflected in earnings. The acquisition of Vet Therapeutics was accounted for as a business combination under the acquisition method of accounting. Accordingly, the assets acquired and liabilities assumed were recorded at fair value with the remaining purchase price recorded as goodwill. The assets acquired and the liabilities assumed from Vet Therapeutics have been recorded at their fair values at the date of acquisition, being October 15, 2013. The Company’s consolidated financial statements and results of operations include the results of Vet Therapeutics from October 16, 2013. In the year ended December 31, 2013 , the Company incurred expenses totaling $1,369 relating to the Vet Therapeutics acquisition, which were recorded within selling, general and administrative expenses in the Company’s consolidated statement of operations. The Company’s allocation of the purchase price to the assets acquired and liabilities assumed was as follows: Cash $ 12 Inventories 173 Other current assets 5 Property and equipment 73 Other long-term assets 3 Identifiable intangible assets 38,652 Accounts payable and accrued expenses (273) Deferred revenue (55) Deferred tax liabilities, net (12,722) Total identifiable net assets $ 25,868 Goodwill 25,646 Total net assets acquired $ 51,514 Less: Merger shares 14,700 Promissory note 3,000 Contingent consideration 3,810 Cash paid $ 30,005 The following are the intangible assets acquired by drug program and their estimated useful lives as of the date of the acquisition : FAIR VALUE USEFUL LIFE AT-004 (Antibody for B-cell lymphoma) $ 28,572 20 years AT-005 (Antibody for T-cell lymphoma) 10,080 20 years Total intangible assets subject to amortization $ 38,652 The identifiable intangible assets recognized by the Company as a result of the Vet Therapeutics acquisition relate to Vet Therapeutics’ technology, and consist primarily of its intellectual property related to Vet Therapeutics’ B-cell and T-cell antibodies, and the estimated net present value of future cash flows from commercial agreements related to the B-cell technology. The Vet Therapeutics B-cell technology, which is now referred to as BLONTRESS , was valued using the discounted cash flow method, a form of the income approach, which incorporates the estimated royalty income and milestone payments to be generated from this technology. The estimated cash flows are then discounted to present value. Accordingly, the primary components of this method consist of the determination of cash flows, the probability of achieving and the anticipated timing of the milestone payments, and an appropriate rate of return. The Vet Therapeutics T-cell technology, which was considered in-process research and development at the acquisition date and which is now referred to as TACTRESS , was valued using a multi-period excess earnings method, a form of the income approach, which incorporates the estimated future cash flows to be generated from this technology. Excess earnings are the earnings remaining after deducting the market rates of return on the estimated values of contributory assets, including debt-free net working capital, tangible, and intangible assets. The excess earnings are thereby calculated for each year of a multi-year projection period and discounted to present value. Accordingly, the primary components of this method consist of the determination of excess earnings and an appropriate rate of return. For the B-cell technology, the Company will recognize straight-line amortization expense over the estimated useful life of the asset. The Company began amor tizing the asset related to the T-cell technology when the conditional license was issued during January of 2014. The difference between the total consideration and the fair value of the net assets acquired of $25,646 was recorded to Goodwill in the consolidated balance sheet. This goodwill represents the excess of the purchase price over the fair value of the tangible and identifiable intangible assets acquired and liabilities assumed, principally representing the tax attributes of the acquisition and certain operational and strategic synergies such as advancement toward becoming a commercial company and acquiring a proprietary antibody-based biologics platform focused on the treatment of lymphoma. Pro Forma Financial Information The following pro forma financial information summarizes the combined results of operations for the Company as though the acquisition of Okapi Sciences occurred on January 1, 2013 and acquisition of Vet Therapeutics occurred on January 1, 2012 . The unaudited pro forma financial information was as follows: YEAR ENDED DECEMBER 31, 2014 2013 (Unaudited) (Unaudited) Revenue $ 767 $ 2,570 Loss from operations (41,314) (22,977) Loss before income taxes $ (39,979) $ (24,448) Net loss per share before income taxes – basic and diluted $ (1.34) $ (1.95) Pro forma results include non-recurring pro forma adjustments that were directly attributable to the business combinations. The following material non-recurring pro forma adjustments relating to charges recorded in 2014 have been assumed to have occurred in 2013 for pro forma purposes: · Pre-tax increase in income of $440 in 2014, relating to acquisition-related transaction costs incurred by the Company and Okapi Sciences. Additionally, the following material non-recurring pro forma adjustments relating to charges recorded in 2013 have been assumed to have occurred in 2012 for pro forma purposes: · Pre-tax increase in income of $ 1,639 for 2013, relating to acquisition-related transaction costs incurred by the Company and Vet Therapeutics. The pro forma financial information for all periods presented has been calculated after adjusting the results of the Company and Okapi Sciences and Vet Therapeutics to reflect the business combination accounting effects resulting from these acquisitions including the amortization expenses from acquired intangible assets, the depreciation expenses from acquired tangible assets, the stock-based compensation expense for unvested stock options and restricted stock units assumed and the related tax effects as though the acquisition occurred as of January 1, 2013 for Okapi Sciences and January 1, 2012 for Vet Therapeutics . The pro forma financial information is for informational purposes only and is not indicative of the results of operations that would have been achieved if the acquisition had taken place at the beginning of the Company’s 2013 fiscal year.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Taxes [Abstract]
Income Taxes	18 . Income Taxes The components of income from continuing operations before income taxes benefit were as follows: YEAR ENDED DECEMBER 31, 2015 2014 2013 U.S. $ (65,481) $ (34,256) $ (19,660) Non-U.S. (20,271) (6,003) — Income from continuing operations $ (85,752) $ (40,259) $ (19,660) The components of the income tax benefit were as follows: YEAR ENDED DECEMBER 31, 2015 2014 2013 Current: Federal $ — $ — $ State — — Deferred: Federal — — 10,782 State — — 1,940 Foreign 1,698 1,443 — Total $ 1,698 $ 1,443 $ 12,722 A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate was as follows: YEAR ENDED DECEMBER 31, 2015 2014 2013 Federal statutory income tax rate 34.0 % 34.0 % 34.0 % State income taxes, net of federal tax benefit 2.5 1.1 7.2 Non-deductible expenses (1.1) (3.0) (2.5) Research credits 0.4 0.8 0.9 Losses benefitted/(not benefitted) (33.8) (29.3) 25.3 Total 2.0 % 3.6 % 64.9 % Net deferred tax assets consisted of the following: YEAR ENDED DECEMBER 31, 2015 2014 2013 Net operating loss carry forwards $ 26,670 $ 12,196 $ 3,180 Capitalized start-up costs 6,645 7,151 3,751 Tax credit carry forwards 1,308 1,062 784 Other temporary differences 3,451 1,469 1,421 Capitalized research and development, net 11,911 10,378 5,788 Total deferred tax assets 49,985 32,256 14,924 Valuation allowance (46,885) (14,747) (3,118) Net deferred tax assets 3,100 17,509 11,806 Intangibles, net (3,041) (19,356) (11,790) Depreciation (59) (18) (16) Total deferred tax liabilities (3,100) (19,374) (11,806) Net deferred tax liability $ — $ (1,865) $ — As of December 31, 201 5 , the Company had net operating loss carryforwards for federal and state income tax purposes of $44,247 and $42,381 , respectively, which begin to expire in fiscal year 2031 and 2020 , re spectively. Approximately $1,209 of the federal and state net operating loss carryforwards relate to excess tax deductions from share-based payments, the tax benefits of which would be credited to additional paid-in capital when the deductions reduce cash taxes payable. As of December 31, 2015, the Company had federal and state research and development tax credit carryforwards of $935 and $567 , respectively, which begin to expire in fiscal year 2031 and until utilized, respectively. Additionally, $4,038 of excess tax deductions from share-based payments were capitalized in 2014 and are being amortized over 15 years for tax purposes. The tax benefits of these items would be credited to additional paid-in capital when the deductions reduce cash taxes payable. The Company has approximately $31,546 of foreign net operating loss carryforward, which may be carried forward indefinitely. Management of the Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets, which are comprised principally of net operating loss carryforwards and research and development credits. Under the applicable accounting standards, management has considered the Company’s history of losses and concluded that it is more likely than not that the Company will not recognize the benefits of net federal and state deferred tax assets. Accordingly, a full valuation allowance of the net U . S . deferred tax asset had been established at December 31, 201 5 and 201 4 . The Company recognized a deferred tax benefit of approximately $1,698 during 2015 for losses incurred in Belgium. On January 6, 2014, we acquired Okapi Sciences. As a result of the acquisition, we recorded approximately $3,786 of net deferred tax liability primarily related to the step-up of intangible assets for book purposes. The taxable temporary difference from the acquisition is considered a source of future taxable income in determining the realizability of our deferred tax assets. During 2014, we recognized approximately $1,443 of income tax benefit for losses incurred in Aratana NV. During 2013, as a result of the acquisition of Vet Therapeutics, the Company recorded approximately $12,722 of net deferred tax liability, primarily related to the step-up of intangible assets for book purposes. The taxable temporary difference from the acquisition is considered as a source of future taxable income in determining the realizability of the Company’s deferred tax assets. The Company recognized a deferred tax benefit of approximately $12,722 due to a release of the valuation allowance against the Company’s federal deferred tax assets of $10,782 and a change in the valuation allowance against our state deferred tax assets of $1,940 . Utilization of the net operating loss and research and development credit carryforwards may be subject to a substantial annual limitation under Section 382 of the Internal Revenue Code of 1986 due to ownership change limitations that have occurred previously or that could occur in the future. These ownership changes may limit the amount of net operating loss and research and development credit carryforwards that can be utilized annually to offset future taxable income and tax, respectively. The Company has not completed a study to assess whether an ownership change has occurred, or whether there have been multiple ownership changes since its formation, due to significant complexity and related costs associated with such a study. Changes in the valuation allowance for deferred tax assets during the years ended December 31, 201 5 , 2014 and 201 3, were as follows: YEAR ENDED DECEMBER 31, 2015 2014 2013 Valuation allowance as of beginning of year $ 14,747 $ 3,118 $ 8,065 Decreases recorded as income tax benefit — — (4,947) Increases due to acquisitions — 271 — Increases due to operations 32,138 11,358 — Valuation allowance as of end of year $ 46,885 $ 14,747 $ 3,118 The Company has not recorded any amounts for unrecognized tax benefits as of December 31, 201 5 and 201 4 . The Company will recognize interest and penalties related to uncertain tax positions in income tax expense. As of December 31, 201 5 and 201 4 , the Company had no accrued interest or penalties related to uncertain tax positions and no amounts have been recognized in the Company’s consolidated statements of operations. The Company files tax returns as prescribed by the tax laws of the jurisdictions in which it operates. The Company’s major taxing jurisdictions include the U.S. federal and states, and Belgium. In the normal course of business, the Company is subject to examination by federal and state jurisdictions, where applicable. The Company’s federal income tax return for 2013 is currently under e xamination by the Internal Revenue Service. The Company does not expect that the examination would result in any significant adjustments to the taxable loss previously reported. The Company’s tax years are still open under statute from 2012 to the present. The Company’s policy is to record interest and penalties related to income taxes as part of its income tax expense in the consolidated statements of operations . On December 18, 2015, the Consolidated Appropriations Act, 2016 (Pub. L. 114-113)("the 2015 Act") was signed into law, retroactively reinstated research credit for qualified research expenses ("QREs") paid or incurred in 2015, and made the credit permanent. Under the accounting guidance on this topic, the effects are recognized as a component of income tax expense or benefit from continuing operations in the consolidated financial statements for the interim or annual period that includes the enactment date.

Variable Interest Entity

Variable Interest Entity	12 Months Ended
	Dec. 31, 2015
Variable Interest Entity [Abstract]
Variable Interest Entity	19. Variable Interest Entity ViroVet BVBA During the third quarter of 2015, the Company reviewed certain operations of its wholly owned subsidiary, Aratana NV. As a result, the Company made the strategic decision to wind down pre-clinical discovery efforts being performed at Aratana NV and focus future efforts of Aratana NV on clinical assets, the development of core legacy programs, i.e. AT-001, AT-002 and AT-003 for EU approval, business development and monetization of production animal assets and know-how obtained in the acquisition of Okapi Sciences . To facilitate this reorganization, the Company via Aratana NV, along with the former General Manager of Aratana NV, the current General Manager of Aratana NV and a consultant to the Company formed ViroVet BVBA (“ViroVet”) during the third quarter . During the third quarter of 2015 , the Company began to transition employees from Aratana NV to ViroVet. The Company plans to transition selected Aratana NV employees, assets and liabilities over the next six months to ViroVet to further pursue the research and development of production animal products. These employees will be focused on the advancement of production animal a ssets/know-how and the securing of additional funding for future operations. Except for the financing matters described below, the Company will have little to no involvement in the operations of ViroVet. Equity Investment In July 2015, the Company paid $2 a nd committed another $4 for 28% ownership interest in ViroVet. The Company has no further obligation to provide any further capital. Convertible Loan Agreement On September 11, 2015, Aratana NV and ViroVet executed a convertible loan agreement in which Aratana NV agreed to loan ViroVet $335 ( €300 ) on September 15, 2015. The proceeds from the loan require ViroVet to use the monies towards the development and operations of ViroVet in accordance with the budget prepared by ViroVet. The loan bears interest at 7% and is unsecured. Primary Beneficiary The Company determined ViroVet is a VIE and it had a controlling financial interest in ViroVet due to the Company having the power to direct the activities of ViroVet that most significantly impact ViroVet’s economic performance and having the obligation to absorb losses or receive benefits . The Company will continue to consolidate ViroVet unless a reconsideration event occurs, for example, an equity financing. Total assets and liabilities of the Company’s consolidated VIE were not material as of December 31, 2015. For the year ended December 31, 2015, ViroVet’s net loss and non-controlling interest was not material and is included in the Company’s consolidated statement of operations. Creditors in ViroVet only have recourse to the assets owned by the VIE and not to the Company’s general credit. The Company currently does not have implicit support arrangements with ViroVet.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2015
Related Party Transactions [Abstract]
Related Party Transactions	2 0 . Related Party Transactions MPM Asset Management, LLC The Company sublease d office space (Heartland House in Kansas City, Kansas) and receive d office related services from MPM Asset Management, LLC, formerly an affiliate of two of the Company’s principal stockholders. Rent paid in each of the years ended December 31, 201 5, 2014 and 2013, was $50 , $67 and $67 , respectively. This sublease ended December 31, 2015. The Company leased office space (Boston) and received certain office-related services. The term of the agreement was from February 9, 2013 through December 31, 2013 . The Company then leased this space month-to-month through June 2014. Rent and services paid in the years ended December 31, 2014 and 2 013 , was $60 and $52 , respectively. MPM Heartland House, LLC The Company lease d its former corporate headquarters office space in Kansas City, Kansas from MPM Heartland House, LLC, a company in which the current Chief Executive Officer and President of the Company, also a director of the Company, is the principal owner . R ent paid for the years ended December 31, 201 5, 2014 and 2013, were $131 , $113 and $60 , respectively. The most recent lease period was from May 1, 2013 to December 31, 2015 . The Company believes the terms of the lease agreement with MPM Heartland House were no less favorable than those that the Company could have obtained from an unaffiliated third party. Also, the Company ha d a services agreement with MPM Heartland House, LLC which include d the lease of the furniture, janitorial and other services to care for the property. Service charges for the years ended December 31, 201 5, 2014 and 2013, were $33 , $33 and $5 , respectively. Indemnification Agreements The Company has entered into indemnification agreements with each of its directors and executive officers. These agreements, among other things, require the Company or will require the Company to indemnify each director (and in certain cases their related venture capital funds) and executive officer to the fullest extent permitted by Delaware law, including indemnification of expenses such as attorneys’ fees, judgments, fines and settlement amounts incurred by the director or executive officer in any action or proceeding, including any action or proceeding by or in right of the Company, arising out of the person’s services as a director or executive officer.

Selected Quarterly Financial Da

Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2015
Selected Quarterly Financial Data [Abstract]
Selected Quarterly Financial Data	2 1. Selected Quarterly Financial Data (unaudited) S elected unaudited quarterly financial data for each of the quarters in the years ended December 31, 2015 and 2014 (in thousands, except per share data) , was as follows : 2015 First Second Third Fourth Quarter Quarter Quarter Quarter Net revenue $ 156 $ 230 $ 229 $ 63 Gross profit 46 121 91 55 Net loss (8,774) (7,983) (54,442) (12,855) Basic and diluted– loss per common share: Net loss per common share (1) $ (0.26) $ (0.23) $ (1.58) $ (0.37) Weighted average number of common shares outstanding, basic and diluted 34,193,994 34,278,105 34,405,646 34,540,001 2014 First Second Third Fourth Quarter Quarter Quarter Quarter Net revenue $ 176 $ 300 $ 43 $ 248 Gross profit 176 300 43 (85) Net loss (9,152) (9,278) (10,130) (10,256) Basic and diluted– loss per common share: Net loss per common share (1) $ (0.34) $ (0.32) $ (0.35) $ (0.30) Weighted average number of common shares outstanding, basic and diluted 26,765,565 28,761,326 29,348,375 34,118,255 __________________ (1) Net loss available to common stockholders and basic and diluted net loss per common share are computed consistent with annual per share calculations described in Notes 2 and 15 (Net Loss Per Share) of its consolidated financial statements included elsewhere in this Annual Report on Form 10-K.

Summary of Significant Accoun30

Summary of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2015
Summary Of Significant Accounting Policies [Abstract]
Consolidation	Consolidation The Company’s consolidated financial statements include its financial statements, and those of its wholly-owned subsidiaries and a consolidated variable interest entity. Intercompany balances and transactions are eliminated in consolidation. To determine if the Company holds a controlling financial interest in an entity, the Company first evaluates if it is required to apply the variable interest entity (“VIE”) model to the entity. Where the Company holds current or potential rights that give it the power to direct the activities of a VIE that most significantly impact the VIE’s economic performance combined with a variable interest that gives it the right to receive potentially significant benefits or the obligation to absorb potentially significant losses, the Company is the primary beneficiary of that VIE. When changes occur to the design of an entity, the Company reconsiders whether it is subject to the VIE model. The Company continuously evaluates whether it is the primary beneficiary of a consolidated VIE.
Use Of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates, judgments 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 period. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from those estimates.
Cash And Cash Equivalents	Cash and Cash Equivalents The Company classifies all highly liquid investments with stated maturities of three months or less from the date of purchase as cash equivalents. Cash equivalents consisted of certificates of deposit (“CDs”) at December 31, 2015, and CDs and overnight reverse repurchase agreements a t December 31, 2014 .
Restricted Cash	Restricted Cash Pursuant to the terms of the Loan and Security Agreement, the Company has posted collateral to Square 1 Bank N.A., a division of Pacific Western Bank, to collateralize corporate credit card services. The Company classifies the collateral as restricted cash.
Short-term Investments	Short-term Investments The Company classifies reverse repurchase agreements other than overnight reverse repurchase agreements as short-term investments and as available-for-sale. Short-term investments for both 2015 and 2014 include reverse repurchase agreements and CDs with original maturities greater than three months .
Marketable Securities	Marketable Securities The Company classifies all highly liquid investments with stated maturities of greater than three months from the date of purchase as marketable securities. The Company determines the appropriate classification of investments in marketable securities at the time of purchase and re-evaluates such designation at each consolidated balance sheet date. The Company classifies and accounts for marketable securities as available-for-sale. The Company may or may not hold securities with stated maturities greater than 12 months until maturity. After consideration of the risk versus reward objectives, as well as the Company’s liquidity requirements, the Company may sell these securities prior to their stated maturities. These securities are viewed as being available to support current operations. As a result, the Company classifies securities with maturities beyond 12 months as long-term assets as long-term marketable securities in the consolidated balance sheet. The C ompany reports available-for-sale investments at fair value as of each consolidated balance sheet date and records any unrealized gains and losses as a component of stockholders’ equity (deficit). At December 31, 201 4 , investments in equity securities were classified as long-term marketable securities and were carried at fair value, as determined by quoted market prices, and gains were recorded as a component of other comprehensive loss . No such investments were held as of December 31, 2015. The cost of securities sold is determined on a specific identification basis, and realized gains and losses are included in other income (expense) in the consolidated statements of operations. If any adjustment to fair value reflects a decline in the value of the investment, the Company considers available evidence to evaluate the extent to which the decline is “other than temporary” and recognizes the impairment by releasing other comprehensive income to the consolidated statement of operations. There were no such adjustments necessary during the year s ended December 31, 201 5 and 2014 .
Accounts Receivable, Net	Accounts Receivable , net Accounts receivable are uncollateralized customer obligations due under normal trade terms generally requiring payment within 30 days of the invoice date. The Company provides an allowance for doubtful accounts equal to the estimated losses that will be incurred in collection of accounts receivable. This estimate is based on the current review of existing receivables and historical experience in the industry. The allowance and associated accounts receivable are reduced when the receivables are determined to be uncollectible.
Inventories	Inventories The Company states i nventories at the lower of cost or market and consist of raw materials, work-in-process and finished goods. Cost is determined by the average cost method for raw materials and standard cost for work-in-process and finished goods, which approximates actual cost. Market is considered the lower of prevailing replacement cost or net realizable value. Inventories acquired in business combinations are recorded at fair value as of acquisition date.
Property And Equipment, Net	Property and Equipment , net The Company records property and equipment at historical cost or, in the case of a business combination, at fair value on the date of the business combination, less accumulated depreciation and amortization. Depreciation amortization expense is recognized using the straight-line method over the following estimated useful lives: Laboratory and office equipment 3 – 10 years Computer software and equipment 3 – 5 years Furniture 3 – 7 years Vehicles 3 – 5 years Leasehold improvements 3 – 10 years Leasehold improvements are amortized over the shorter of the life of the related asset or the term of the lease. Expenditures for repairs and maintenance of assets are charged to expense as incurred. Costs of major additions and betterments are capitalized and depreciated on a straight-line basis over their useful lives. When property and equipment are disposed of, the cost and respective accumulated depreciation and amortization are removed from the books. Any gain or loss on disposal is recorded in the consolidated statements of operations.
Goodwill	Goodwill Goodwill relates to amounts that arose in connection with the Company’s business combinations (Note 17) and represents the difference between the purchase price and the estimated fair value of the identifiable tangible and intangible net assets when accounted for using the acquisition method of accounting. Goodwill is not amortized, but is subject to periodic review for impairment. The Company tests goodwill at the reporting unit level for impairment on an annual basis and between annual tests, if events and circumstances indicate impairment may exist. Events that would indicate impairment and trigger an interim impairment assessment include, but are not limited to, current economic and market conditions, including a decline in market capitalization, a significant adverse change in legal factors, business climate or operational performance of the business and an adverse action or assessment by a regulator. The Company completed its annual goodwill impairment testing during the third quarter of 2015. The Company elected to bypass the qualitative assessment. The Company determined as of the testing date that it consisted of one operating segment which is comprised of one reporting unit. In performing step one of the assessment, the Company determined that its fair value, determined to be its market capitalization, was greater than its carrying value, determined to be stockholders’ equity. Based on this result, step two of the assessment was not required to be performed, and the Company determined there was no impairment of goodwill during the third quarter of 2015. During the fourth quarter of 2015, the Company completed an interim impairment assessment due to a decline in its market capitalization. In performing step one of the assessment, the Company determined that its fair value exceeded its carrying value, by 93% . Based on this result, step two of the assessment was not required to be performed, and the Company determined there was no impairment of goodwill during the fourth quarter of 2015. Subsequent to December 31, 2015, the Company experienced further declines and fluctuations in its market capitalization. The extent and duration of any decline in the Company’s market capitalization will be assessed in future periods against the Company’s carrying value to assess if there is an indication of impairment of the Company’s goodwill which was $39,781 as of December 31, 2015.
Intangible Assets, Net	Intangible Assets, net The Company’s intangible assets consist of intellectual property rights acquired for currently marketed products and intellectual property rights acquired for in-process research and development (“IPR&D”). All of the Company’s intangible assets were recorded in connection with the Company’s business combinations (Note 17). The Company’s intangible assets are recorded at fair value at the time of their acquisition. The Company amortizes intangible assets over their estimated useful lives once the acquired technology is developed into a commercially viable product. The estimated useful lives of the individual categories of intangible assets are based on the nature of the applicable intangible asset and the expected future cash flows to be derived from the intangible asset. Amortization of intangible assets with finite lives is recognized over the time the intangible assets are estimated to contribute to future cash flows. The Company amortizes finite-lived intangible assets using the straight-line method. Indefinite-lived IPR&D intangible assets are assessed for impairment at least annually. In addition, all intangible assets are reviewed for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends, and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset for recoverability, the Company compares forecasts of undiscounted cash flows for definite-lived intangible assets and discounted cash flows for indefinite-lived IPR&D intangible assets expected to result from the use and eventual disposition of the long-lived asset to its carrying value. An impairment loss would be recognized when estimated undiscounted (definite-lived) or discounted (indefinite-lived) future cash flows expected to result from the use of an asset are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset over its fair value, determined based on discounted cash flows. The Company completed its annual indefinite-lived IPR&D intangible assets impairment testing during the fourth quarter of 2015. The Company elected to bypass the qualitative assessment. For purposes of impairment testing, the fair value of the indefinite-lived IPR&D intangible assets was determined by using the framework of ASC 820, Fair Value Measurement. When determining the fair value of the indefinite-lived IPR&D intangible assets, the Company revisited all assumptions used in measuring the indefinite-lived IPR&D intangible assets at the time of acquisition, and evaluated and considered new and updated data and information available. The Company noted the fair values for all indefinite-lived IPR&D intangible assets were greater than the carrying value. As such, no impairment was recognized as of the annual testing date. I n the quarter ended September 30, 2015 and to date, the Company recorded $43,398 of impairment losses on intangible assets (Note 8).
Derivative Financial Instruments	Derivative Financial Instruments T he Company accounts for its derivative instruments as either assets or liabilities and carries them at fair value. The Comp any’s sole derivative (Note 9 ) was a warrant t o purchase common stock and was adjusted to fair value through current income as it was not designated as a hedging instrument . In 2015, the Company exercised the warrant and subsequently sold the shares of common stock received upon exercise.
Foreign Currency	Foreign Currency With the acquisition of Okapi Sciences (Note 17 ) in 2014, the Company is exposed to effects of foreign currency from translation. Transactions in foreign currencies are translated into the relevant functional currency at the rate of exchange at the date of the transaction. Transaction gains and losses are recognized in other income (expense) in the consolidated statements of operations. The results of operations for subsidiaries, whose functional currency is not the U.S. Dollar, are translated into the U.S. Dollar at the average rates of exchange during the period, with the subsidiaries’ balance sheets translated at the rates accumulated at the balance sheet date. The cumulative effect of these exchange rate adjustments is included in a separate component of other comprehensive income (loss) in the consolidated balance sheets. Gains and losses arising from intercompany foreign currency transactions are included in loss from operations unless the gains and losses arise from long-term investments in subsidiaries . Gains and losses from long-term investments in subsidiaries are included in a separate component of other comprehensive income (loss).
Business Combinations	Business Combinations The Company’s business acquisitions were made at a price above the fair value of the assets acquired and liabilities assumed, resulting in goodwill, based on the Company’s expectations of synergies and other benefits of combining the businesses. These synergies and benefits include elimination of redundant facilities, functions and staffing; use of the Company’s existing commercial infrastructure to expand sales of the products of the acquired businesses; and use of the commercial infrastructure of the acquired businesses to expand product sales in a cost-efficient manner. Significant judgment is required in estimating the fair value of intangible assets and in assigning their respective useful lives. The fair value estimates are based on available historical information and on future expectations and assumptions deemed reasonable by management, but which are inherently uncertain. The Company generally employs the income method to estimate the fair value of intangible assets, which is based on forecasts of the expected future cash flows attributable to the respective assets. Significant estimates and assumptions inherent in the valuations reflect a consideration of other marketplace participants, and include the amount and timing of future cash flows (including expected growth rates and profitability), the underlying product life cycles, economic barriers to entry, a brand’s relative market position and the discount rate applied to the cash flows. Unanticipated market or macroeconomic events and circumstances may occur, which could affect the accuracy or validity of the estimates and assumptions. Net assets acquired are recorded at their fair value and are subject to adjustment upon finalization of the fair value analysis. The Company is not aware of any information that indicates the final fair value analysis will differ materially from the preliminary estimates. Contingent consideration is recorded as a liability and measured at fair value using a discounted cash flow model utilizing significant unobservable inputs, including the probability of achieving each of the potential milestones and an estimated discount rate commensurate with the risks of the expected cash flows attributable to the milestones. Significant increases or decreases in any of the probabilities of success would result in a significantly higher or lower fair value, respectively, and commensurate changes to this liability. At each reporting date, we revalue the contingent consideration obligations to the reporting date fair values and record increases and decreases in the fair values as income or expense in the consolidated statements of operations until actual settlement occurs. Increases or decreases in the fair values of the contingent consideration obligations may result from changes in discount periods and rates, changes in the timing and amount of earn-out criteria and changes in probability assumptions with respect to the likelihood of achieving the various earn-out criteria. On January 6, 2014, the Company acquired Okapi Sciences, a Leuven, Belgium based company with a proprietary antiviral platform and three clinical/development stage product candidates. The aggregate purchase price was approximately $44,439 , which consisted of $14,139 in cash, a promissory note in the principal amount of $15,134 with a maturity date of December 31, 2014 , and a contingent consideration of up to $16,308 with an acquisition fair value of $15,166 . The promissory note bore interest at a rate of 7% per annum, payable quarterly in arrears, and was subject to mandatory prepayment in the event of a specified equity financing by the Company. On February 4, 2014, the promissory note and accrued interest was paid in cash in the amount of $15,158 . On March 17, 2014, the contingent consideration was settled in cash in the amount of $15,235 .
Deferred Public Offering Costs	Deferred Public Offering Costs T he Company capitalizes certain legal, accounting and other third-party fees that are directly associated with in-process equity financings as other assets until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ equity (deficit) as a reduction of additional paid-in capital generated as a result of the offering. Should it no longer be considered probable that the equity financing will be consummated, the deferred offering costs would be expensed immediately as a charge to operating expenses in the consolidated statements of operations. On October 16, 2015, the Company entered into a Sales Agreement with Barclays Capital Inc. (“Barclays”) pursuant to which the Company may sell from time to time, at its option, up to an aggregate of $52,000 of shares of its common stock (the “Shares”) through Barclays, as sales agent. As of the date of this filing, the Company has not sold any shares under the Sales Agreement. The Company recorded $189 and $0 of deferred public offering costs as of December 31, 2015 and 2014, respectively.
Income Taxes	Income Taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the consolidated financial statements or in the Company’s tax returns. Deferred taxes are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect in the years in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the consolidated financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.
Debt Issuance Costs, Net	Debt Issuance Costs , net Debt issuance costs, net represent legal and other direct costs related to the Company’s Loan and Security Agreement (Note 10). These costs are recorded as an offset to the carrying value of loans payable on the consolidated balance sheet at the time they are incurred and are amortized to interest expense through the scheduled final principal payment date. During the year ended December 31, 2015, the Company capitalized $360 of debt issuance costs and recognized $129 of amortization expense related to debt issuance costs. During the year ended December 31, 2014, the Company recorded $11 of debt issuance costs and recognized $41 of amortization expense related to debt issuance costs.
Revenue Recognition	Revenue Recognition The Company recognizes revenue when all of the following conditions are met: · there is persuasive evidence of an agreement or arrangement; · delivery of products has occurred or services have been rendered; · the seller’s price to the buyer is fixed or determinable; and · collect i bility is reasonably assured. The Company’s principal revenue streams and their respective accounting treatments are discussed below: (i) Product sales - Revenue for the sale of products is recognized when delivery has occurred and substantially all the risks and rewards of ownership have been transferred to the customer. Revenue for the sale of products are recorded net of sales returns, allowances and discounts . (ii) Licensing and collaboration revenues - Revenues derived from product out-licensing arrangements typically consist of an initial up-front payment on inception of the license and subsequent milestone payments contingent on the achievement of certain clinical and sales milestones. Product out licensing arrangements may require the Company to provide multiple deliverables to the licensee which would require the total selling price to be allocated between each of the separable elements in the arrangement based on their relative selling price s . An element is considered separable if it has value to the customer on a stand-alone basis. The selling price used for each separable element will be based on vendor specific objective evidence (“VSOE”) if available, third party evidence if VSOE is not available, or estimated selling price if neither VSOE nor third party evidence is available. Revenue is then recognized as each of the separable elements to which the revenue has been allocated is delivered. Milestone payments which are non-refundable, non-creditable and contingent on achieving certain development, regulatory, or commercial milestones are recognized as revenues either on achievement of such milestones or over the period the Company has continuing substantive performance obligations.
Research And Development Costs	Research and Development Costs Research and development costs are expensed as incurred. Included in research and development costs are wages, stock-based compensation and employee benefits, and other operational costs related to the Company’s research and development activities, including facility-related expenses, external costs of outside contractors engaged to conduct both preclinical and clinical studies and allocation of corporate costs. Payments received from external parties to fund the Company’s research and development activities are used to reduce the Company’s research and development expenses. If IPR&D is acquired in an asset purchase then the acquired IPR&D is expensed on its acquisition date. Future costs to develop these assets are recorded to research and development expense as they are incurred.
Patent Costs	Patent Costs All patent-related costs incurred in connection with filing and prosecuting patent applications are recorded as selling, general and administrative expenses as incurred, as recoverability of such expenditures is uncertain.
Shipping	Shipping Shipping costs are included in cost of product sales.
Sales tax	Sales Tax The Company collects and remits taxes assessed by various governmental authorities. These taxes may include sales, use and value added taxes. These taxes are recorded on a net basis and are excluded from sales.
Accounting For Stock Based Compensation	Accounting for Stock - Based Compensation The Company’s stock-based compensation program grants awards that may consist of stock options and restricted stock awards. The fair values of stock option grants are determined as of the date of grant using the Black-Scholes option pricing method. This method incorporates the fair value of the Company’s common stock at the date of each grant and various assumptions such as the risk-free interest rate, expected volatility based on the volatility of the Company’s common stock price , expected dividend yield, and expected term of the options. The fair values of restricted stock awards are determined based on the fair value of the Company’s common stock. Prior to the Company’s initial public offering of its common stock in June 2013, the fair value of the common stock was determined by management and the Board of Directors, on the date of grant. Beginning in the first quarter of 2014, the Company began to base expected volatility on the historical volatility of its common stock, as adequate historical data regarding the volatility of its common stock price had become available. The fair values of the stock-based awards, including the effect of estimated forfeitures, are then expensed over the requisite service period, which is generally the award’s vesting period. The Company classifies stock-based compensation expense in the consolidated statements of operations in the same manner in which the respective award recipient’s payroll costs are classified. For stock-based awards granted to consultants and nonemployees, compensation expense is recognized over the period during which services are rendered by such consultants and nonemployees until completed. At the end of each financial reporting period prior to completion of the service, the value of these awards is re-measured using the then-current fair value of the Company’s common stock and updated assumption inputs in the Black-Scholes option pricing model. For stock-based awards granted to employees under the 2010 Equity Incentive Plan (the “2010 Plan”), the Company allows employees to exercise certain awards prior to vesting. However, the employee may not sell or transfer these awards prior to vesting. For most of these awards, the Company has the right, but not the obligation, to repurchase any unvested (but issued) shares of common stock upon termination of employment or service at the lesser of (1) the original purchase price per share or (2) the fair value of the common share on the date of termination. If a stock option is early exercised in this circumstance, the consideration received for an exercise of an option is considered a deposit of the exercise price, and the related dollar amount is recorded as a liability. The unvested shares and liability are reclassified to equity as the award vests. The Company has 90 days from the effective termination of employment or service to repurchase unvested shares that are issued upon the exercise of a stock option prior to its vesting. If, after 90 days, the Company has elected not to repurchase the unvested shares, the shares would become vested in full. The Company would then apply modification accounting and any resulting compensation expense would be immediately recognized related to the award. Upon vesting, these shares would be considered issued and outstanding shares of common stock for accounting purposes. In addition, the Company has granted restricted stock awards subject to repurchase to one employee, under which the Company has the right, but not the obligation, upon termination of the holder’s employment or service, to repurchase unvested shares at the greater of (1) the original purchase price per share or (2) the fair value of the common share on the date of termination (Note 14 ).
Comprehensive Loss	Comprehensive Loss In addition to the Company’s net loss, comprehensive loss during the years ended December 31, 2015 and 2014 include s foreign currency translation adjustments related to the translation of foreign subsidiaries’ balance s heets and unrealized holding gains and losses on available-for-sale securities . For the year ended December 31, 2013, there was no difference between net loss and comprehensive loss.
Net Loss Per Share	Net Loss Per Share The Company follows the two-class method when computing net loss per share, as the Company has issued shares that meet the definition of participating securities. The two-class method determines net loss per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. Restricted stock awards granted by the Company entitle the holder of such awards to dividends declared or paid by the Board of Directors, regardless of whether such awards are unvested, as if such shares were outstanding common shares at the time of the dividend. H owever, the unvested restricted stock awards are not entitled to share in the residual net assets (deficit) of the Company. Accordingly, in periods in which the Company reports a net loss or a net loss attributable to common stockholders resulting from preferred stock dividends, accretion or modifications, net losses are not allocated to participating securitie s. The Company reported a net loss in each of the years ended December 31, 2015, 2014 and 2013. Basic net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock outstanding for the period. Diluted net loss is computed by adjusting net loss to reallocate undistributed earnings based on the potential impact of dilutive securities, including outstanding stock options. Diluted net loss per share is computed by dividing the diluted net loss by the weighted average number of shares of common stock, including potential dilutive shares of common stock assuming the dilutive effect of potentially dilutive securities. For periods in which the Company has reported net losses, diluted net loss per share is the same as basic net loss per share, since their impact would be anti-dilutive to the calculation of net loss per share. Diluted net loss per share is the same as basic net loss per share for each of the years ended December 31, 2015, 2014 and 2013.
Concentration Of Credit Risk And Of Significant Suppliers And Customers	Concentration of Credit Risk and of Significant Suppliers and Customers Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash, cash equivalents, short-term investments and accounts receivable . At December 31, 201 5 , the Company’s short-term investments included reverse repurchase ag reements that are tri-party, have maturities of three months or less at the time of investment and the underlying collateral is U.S. government securities including U.S. treasuries, agency debt and agency mortgage securities . At December 31, 2015 and 201 4 , all of the Company’s fixed income marketable securities were invested in CDs insured by the Federal Deposit Insurance Corporation (“FDIC”). The Company also generally maintains balances in various operating accounts in excess of federally insured limits at two accredited financial institutions. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The Company is dependent on a small number of third-party manufacturers to supply active pharmaceutical ingredients (“API”), and formulated drugs for research and development activities in its programs and commercial supply, which would be adversely affected by a significant interruption in supply.
Fair Value Measurements	Fair Value Measurements Certain assets and liabilities are carried at fair value under GAAP. 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.
Segment And Geographic Information	Segment and Geographic Information Segment Assets The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company is a pet therapeutics company developing compounds to address unmet and under-served medical needs in companion animals. All assets were held in the United States and Belgium as of December 31, 201 5 and December 31, 2014. Total assets were $147,066 and $207,903 at December 31, 2015, and 2014, respectively. Revenue by Geographic Region YEAR ENDED DECEMBER 31, 2015 2014 2013 (dollars in thousands) Revenues United States $ 678 $ 267 $ 123 Belgium — 500 NA Total revenues $ 678 $ 767 $ 123 Long Lived Assets by Geographic Region DECEMBER 31, 2015 2014 (dollars in thousands) Long-lived assets United States $ 2,460 $ 459 Belgium 95 161 Total long-lived assets $ 2,555 $ 620
New Accounting Standards	New Accounting Standards Revenue from Contracts with Customers In May 2014, the Financial Accounting Standards Board (“FASB”) issued guidance on recognizing revenue in contracts with customers. The guidance affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (e.g., insurance contracts or lease contracts). This guidance will supersede the revenue recognition requirements in topic, Revenue Recognition , and most industry-specific guidance. This guidance also supersedes some cost guidance included in subtopic, Revenue Recognition – Construction-Type and Production-Type Contracts . In addition, the existing requirements for the recognition of a gain or loss on the transfer of nonfinancial assets that are not in a contract with a customer (e.g., assets within the scope of topic, Property, Plant, and Equipment , and tangible assets within the scope of topic, Intangibles – Goodwill and Other) are amended to be consistent with the guidance on recognition and measurement (including the constraint on revenue) in this guidance. The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. These changes become effective for the Company on January 1, 2017 and early adoption is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is currently assessing the impact, if any, this new guidance will have on its consolidate d financial statements . In July 2015, the FASB approved a one-year delay in the effective date of the new revenue standard. These changes become effective for the Company on January 1, 2018, and early adoption is permitted but not before the original effective date of January 1, 2017. The Company is currently assessing the impact, if any, this new guidance will have on its consolidate d financial statements . Interest—Imputation of Interest: Simplifying the Presentation of Debt Issuance Costs In April 2015, the FASB issued guidance which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the associated debt liability. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption is permitted and is to be applied on a retrospective basis. The Company elected to early adopt this guidance retrospectively starting in the fourth quarter of 2015. The Company determined that the retrospective application did not have had a material impact on its consolidate d financial statements. Inventory – Simplifying the Measurement of Inventory In July 2015, the FASB issued guidance which requires entities to measure most inventory “at lower of cost and net realizable value” thereby simplifying the current guidance under which an entity must measure inventory at the lower of cost or market. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2016, and interim periods within those fiscal years. Early adoption is permitted and is to be applied on a prospective basis. The Company does not expect that this new guidance will have a material impact on its consolidated financial statements. Income Taxes – Balance Sheet Classification of Deferred Taxes In November 2015, the FASB issued guidance which requires entities to present deferred tax assets and deferred tax liabilities as noncurrent in a classified balance sheet. This guidance simplifies the current guidance in ASC Topic 740, Income Taxes, which requires entities to separately present deferred tax assets and liabilities as current and noncurrent in a classified balance sheet. This guidance is effective for fiscal years beginning after December 15, 2016, and interim periods within those annual periods, with early adoption permitted. During the fourth quarter of 2015, the Company early adopted the guidance as of December 31, 2015 on a prospective basis; prior periods were not retrospectively adjusted. Due to a full valuation allowance recorded against its deferred tax assets as of December 31, 2015, the Company’s consolidated balance sheet contains no deferred tax balances. Leases In February 2016, the FASB issued guidance which requires, for operating leases, a lessee to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments, in its balance sheet. The standard also requires a lessee to recognize a single lease cost, calculated so that the cost of the lease is allocated over the lease term, on a generally straight-line basis. This guidance is effective for financial statements issued for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted and is to be applied on a modified retrospective transition. The Company is currently assessing the effect that adoption of this guidance will have on its consolidated financial statements.

Summary Of Significant Accoun31

Summary Of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Summary Of Significant Accounting Policies [Abstract]
Estimated Useful Lives Of Property, Plant And Equipment	Laboratory and office equipment 3 – 10 years Computer software and equipment 3 – 5 years Furniture 3 – 7 years Vehicles 3 – 5 years Leasehold improvements 3 – 10 years
Schedule Of Revenue By Geographic Region	YEAR ENDED DECEMBER 31, 2015 2014 2013 (dollars in thousands) Revenues United States $ 678 $ 267 $ 123 Belgium — 500 NA Total revenues $ 678 $ 767 $ 123
Schedule Of Long-Lived Assets By Geographic Region	DECEMBER 31, 2015 2014 (dollars in thousands) Long-lived assets United States $ 2,460 $ 459 Belgium 95 161 Total long-lived assets $ 2,555 $ 620

Fair Value Of Financial Asset32

Fair Value Of Financial Assets And Liabilities (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Of Financial Assets And Liabilities [Abstract]
Summary Of Information About Company's Financial Assets And Liabilities Subject To Fair Value Measurement On Recurring Basis	FAIR VALUE MEASUREMENTS AS OF CARRYING DECEMBER 31, 2015 USING: VALUE LEVEL 1 LEVEL 2 LEVEL 3 TOTAL Assets: Cash equivalents: Certificates of deposit $ 6,972 $ — $ 6,972 $ — $ 6,972 Money market fund 35 35 — — 35 Short-term investments: Short-term marketable securities – certificates of deposit 747 — 747 — 747 Reverse repurchase agreements 58,700 — 58,700 — 58,700 $ 66,454 $ 35 $ 66,419 $ — $ 66,454 FAIR VALUE MEASUREMENTS AS OF CARRYING DECEMBER 31, 2014 USING: VALUE LEVEL 1 LEVEL 2 LEVEL 3 TOTAL Assets: Cash equivalents: Certificates of deposit $ 6,972 $ — $ 6,972 $ — $ 6,972 Money market fund 45 — 45 — 45 Short-term investments: Short-term marketable securities – certificate of deposit 249 — 249 — 249 Reverse repurchase agreements 88,000 — 88,000 — 88,000 Long-term marketable securities: Common stock 2,452 2,452 — — 2,452 Derivative financial instruments 1,108 — 1,108 — 1,108 $ 98,826 $ 2,452 $ 96,374 $ — $ 98,826 Liabilities: Contingent consideration $ 4,248 $ — $ — $ 4,248 $ 4,248 $ 4,248 $ — $ — $ 4,248 $ 4,248
Change In Fair Value Of Company's Contingent Consideration Payable Measured At Fair Value On Recurring Basis	2015 2014 As of January 1, $ 4,248 $ 4,115 Initial recognition of contingent consideration payable — 15,166 Cash settlement of contingent consideration earned (3,000) (15,235) Derecognition of remaining contingent consideration recorded in the consolidated statement of operations (within selling, general and administrative) (1,248) 202 As of December 31, $ — $ 4,248
Carrying Amounts And Estimated Fair Value Of Company's Financial Assets And Liabilities Not Measured At Fair Value On Recurring Basis	DECEMBER 31, 2015 CARRYING VALUE FAIR VALUE Financial liabilities: Loan payable (Level 2) $ 39,710 $ 40,569 DECEMBER 31, 2014 CARRYING VALUE FAIR VALUE Financial liabilities: Loan payable (Level 2) $ 14,963 $ 14,933
Fair Value Information About Impaired Intangible Assets	FAIR VALUE CARRYING DECEMBER 31, 2015 VALUE LEVEL 1 LEVEL 2 LEVEL 3 IMPAIRMENT Intellectual property rights for currently marketed products $ 6,057 $ — $ — $ 6,057 $ 28,862 Intellectual property rights acquired for in-process research and development 9,010 — — 9,010 14,536 $ 15,067 $ — $ — $ 15,067 $ 43,398

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2015
Investments [Abstract]
Fair Value Of Available-For-Sale Marketable Securities	DECEMBER 31, 2015 GROSS GROSS AMORTIZED UNREALIZED UNREALIZED FAIR COST GAINS LOSSES VALUE Short-term marketable securities: Certificates of deposit $ 747 $ — $ — $ 747 Total $ 747 $ — $ — $ 747 DECEMBER 31, 2014 GROSS GROSS AMORTIZED UNREALIZED UNREALIZED FAIR COST GAINS LOSSES VALUE Short-term marketable securities: Certificate of deposit $ 249 $ — $ — $ 249 Long-term marketable securities: Common stock 1,200 1,252 — 2,452 Total $ 1,449 $ 1,252 $ — $ 2,701

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2015
Inventories [Abstract]
Components Of Inventories	DECEMBER 31, DECEMBER 31, 2015 2014 Raw materials $ 120 115 Work-in-process 441 $ 206 Finished goods 745 106 $ 1,306 $ 427

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2015
Property And Equipment, Net [Abstract]
Schedule Of Property And Equipment, Net	DECEMBER 31, DECEMBER 31, 2015 2014 Laboratory and office equipment $ 527 $ 478 Computer equipment and software 2,039 68 Furniture 132 71 Vehicles 11 34 Leasehold improvements 91 102 Construction in process 185 49 Total property and equipment 2,985 802 Less: Accumulated depreciation and amortization (430) (182) Property and equipment, net $ 2,555 $ 620

Goodwill (Tables)

Goodwill (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Summary Of Goodwill	GROSS IMPAIRMENT NET CARRYING AMOUNT LOSSES CARRYING VALUE Goodwill $ 39,781 $ — $ 39,781
Summary Of Change In The Net Book Value Of Goodwill	2015 2014 As of January 1, $ 41,398 $ 25,646 Acquisition — 17,909 Effect of foreign currency exchange (1,617) (2,157) As of December 31, $ 39,781 $ 41,398

Intangible Assets, Net (Tables)

Intangible Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Summary Of Change In The Net Book Value Of Other Intangible Assets	2015 2014 As of January 1, $ 62,323 $ 38,354 Acquisitions — 29,400 Amortization expense (1,544) (1,891) Effect of foreign currency exchange (2,314) (3,540) Impairment (43,398) — As of December 31, $ 15,067 $ 62,323
Estimated Aggregate Amortization Expense Of Intangible Assets	YEAR ENDING DECEMBER 31, 2016 $ 381 2017 381 2018 381 2019 381 2020 $ 381
Summary Of Unamortized Intangible Assets	NET CARRYING VALUE AS OF DECEMBER 31, Unamortized intangible assets: 2015 2014 Intellectual property rights acquired for in-process research and development $ 9,010 $ 25,860
Summary Of Amortized Intangible Assets	GROSS NET CARRYING ACCUMULATED CARRYING AVERAGE Amortized intangible assets: VALUE AMORTIZATION VALUE USEFUL LIFE Intellectual property rights for currently marketed products: BLONTRESS $ 28,572 $ 23,103 $ 5,469 20 Years TACTRESS TM(1) $ 10,080 $ 9,492 $ 588 8.25 Years (1) TACTRESS received a conditional license in early 2014 which initiated amortization for this intangible.

Derivative Financial Instrume38

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2015
Derivative Financial Instruments [Abstract]
Derivative Instrument At Gross Fair Value As Reflected	FAIR VALUE OF DERIVATIVES NOT DESIGNATED AS HEDGING INSTRUMENT DECEMBER 31, 2015 DECEMBER 31, 2014 Derivative assets: Warrant (Notes 3 and 12) $ — $ 1,108
Gain Recognized In Other Income (Expense)	GAIN RECOGNIZED IN OTHER INCOME (EXPENSE) YEAR ENDED DECEMBER 31, 2015 2014 2013 Derivative assets: Warrant $ 1,274 $ 465 $ NA

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2015
Debt [Abstract]
Schedule Of Loan Payable Balance	Principal amounts Term Loan, due October 16, 2019 $ 35,000 Revolving Line, due October 16, 2017 5,000 Add: accretion of final payment and termination fees 77 Less: unamortized debt issuance costs (367) Loan payable $ 39,710
Estimated Future Principal Payments Under Additional Term Loan	YEARS ENDING DECEMBER 31, 2016 $ — 2017 15,500 2018 14,000 2019 10,500 2020 — Thereafter — Total $ 40,000

Accrued Expenses, Other Curre40

Accrued Expenses, Other Current Liabilities And Other Long-Term Liabilities (Tables)	12 Months Ended
	Dec. 31, 2015
Accrued Expenses, Other Current Liabilities And Other Long-Term Liabilities [Abstract]
Summary Of Accrued Expenses	DECEMBER 31, DECEMBER 31, 2015 2014 Accrued expenses: Accrued payroll and related expenses $ 1,922 $ 2,017 Accrued professional fees 388 429 Accrued royalty expense 1 72 Accrued interest expense 238 41 Accrued research and development costs 1,111 663 Accrued milestone 500 — Accrued other 87 7 Total accrued expenses $ 4,247 $ 3,229 Other current liabilities: Early exercise of stock-based awards $ 29 46 Other 8 $ — $ 37 $ 46 Other long-term liabilities: Deferred income $ 122 $ 30 $ 122 $ 30

Stock-Based Awards (Tables)

Stock-Based Awards (Tables)	12 Months Ended
	Dec. 31, 2015
2010 Equity Incentive Plan [Member]
Compensation Related Costs, Share-based Payments [Line Items]
Summary Of Stock Option Activity	WEIGHTED SHARES WEIGHTED AVERAGE ISSUABLE AVERAGE REMAINING AGGREGATE UNDER EXERCISE CONTRACTUAL INTRINSIC OPTIONS PRICE TERM VALUE (IN YEARS) Outstanding as of December 31, 2014 170,466 $ 1.71 8.05 $ 2,746 Granted — — Exercised (57,652) 0.43 Forfeited (26,324) 0.45 Expired — — Outstanding as of December 31, 2015 86,490 $ 2.95 7.09 $ 228 Options vested and expected to vest as of December 31, 2015 85,385 $ 2.92 7.09 $ 227 Options exercisable as of December 31, 2015 86,213 $ 2.94 7.09 $ 228
Summary Of Restricted Stock Activity	WEIGHTED AVERAGE GRANT SHARES DATE FAIR VALUE Unvested restricted common stock as of December 31, 2014 91,334 $ 0.94 Restricted common stock issued — — Restricted common stock vested (54,256) 0.37 Restricted common stock forfeited — — Unvested restricted common stock as of December 31, 2015 37,078 $ 0.36
2013 Equity Incentive Plan [Member]
Compensation Related Costs, Share-based Payments [Line Items]
Summary Of Stock Option Activity	WEIGHTED SHARES WEIGHTED AVERAGE ISSUABLE AVERAGE REMAINING AGGREGATE UNDER EXERCISE CONTRACTUAL INTRINSIC OPTIONS PRICE TERM VALUE (IN YEARS) Outstanding as of December 31, 2014 1,481,866 $ 17.13 8.96 $ 3,835 Granted 523,350 16.14 Exercised (32,761) 8.76 Forfeited (182,945) 18.96 Expired (61,311) 23.55 Outstanding as of December 31, 2015 1,728,199 $ 16.57 8.31 $ — Options vested and expected to vest as of December 31, 2015 1,642,972 $ 16.59 8.31 $ — Options exercisable as of December 31, 2015 610,406 $ 16.54 7.88 $ —
Summary Of Restricted Stock Activity	WEIGHTED AVERAGE GRANT SHARES DATE FAIR VALUE Unvested restricted common stock as of December 31, 2014 277,844 $ 16.92 Restricted common stock issued 230,400 17.14 Restricted common stock vested (151,131) 15.85 Restricted common stock forfeited (23,850) 14.00 Unvested restricted common stock as of December 31, 2015 333,263 $ 17.77
Data Used To Determine Value Of Stock Option Grants	YEAR ENDED DECEMBER 31, 2015 2014 2013 Risk-free interest rate 1.38 % 1.88 % 1.59 % Expected term (in years) 6.1 6.1 6.1 Expected volatility 70 % 84 % 66 % Expected dividend yield — % — % — %
Summary Of Stock-Based Compensation Expense Related To Stock Options And Restricted Stock	YEAR ENDED DECEMBER 31, 2015 2014 2013 Research and development $ 1,646 $ 1,611 $ 419 Cost of product sales 118 48 — Selling, general and administrative 6,828 5,471 606 $ 8,592 $ 7,130 $ 1,025

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2015
Net Loss Per Share [Abstract]
Schedule Of Basic And Diluted Net Loss Per Share Attributable To Common Stockholders	YEAR ENDED DECEMBER 31, 2015 2014 2013 Numerator: Net loss attributable to common stockholders $ (84,054) $ (38,816) $ (6,938) Denominator: Weighted average shares outstanding – basic and diluted 34,355,525 29,767,429 11,059,382 Net loss per share attributable to common stockholders – basic and diluted (1) $ (2.45) $ (1.30) $ (0.63) __________________ (1) All per share amounts and shares outstanding for all periods reflect the 1-for- 1.662 reverse stock split, which was effective May 22, 2013.

Commitments And Contingencies (

Commitments And Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies [Abstract]
Future Minimum Lease Payments For Operating Leases	YEAR ENDING DECEMBER 31, 2016 598 2017 605 2018 590 2019 466 2020 and thereafter 526 Total $ 2,785
Summary Of Contractual Contingent Purchase Price Consideration Obligation	Maximum Remaining Remaining Earn-out Earn-out Estimated Potential Period Fair Value Payments Acquisition as of as of as of made Date Fair December 31, December 31, December 31, during Acquisition Acquisition Date Value 2015 2015 2015 2015 Vet Therapeutics October 15, 2013 $ 3,810 $ — — $ — $ 3,000 $ — — $ — $ 3,000

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2015
Business Acquisition [Line Items]
Summary Of Proforma Financial Information	YEAR ENDED DECEMBER 31, 2014 2013 (Unaudited) (Unaudited) Revenue $ 767 $ 2,570 Loss from operations (41,314) (22,977) Loss before income taxes $ (39,979) $ (24,448) Net loss per share before income taxes – basic and diluted $ (1.34) $ (1.95)
Okapi Sciences NV [Member]
Business Acquisition [Line Items]
Acquisition Date Fair Value Of Consideration Transferred	Cash consideration $ 14,139 Fair value of promissory note 15,134 Fair value of contingent consideration 15,166 Fair value of total consideration 44,439 Less cash acquired (1,063) Total consideration transferred, net of cash acquired $ 43,376
Allocation Of Purchase Price To Assets Acquired And Liabilities Assumed	Cash $ 1,063 Accounts receivable 149 Other receivables 60 Prepaid expenses and other current assets 82 Property and equipment 217 Other long-term assets 18 Identifiable intangible assets 29,400 Accounts payable and accrued expenses (586) Deferred revenue (83) Deferred tax liabilities, net (3,786) Long-term debt (4) Total identifiable net assets 26,530 Goodwill 17,909 Total net assets acquired 44,439 Less: Promissory note 15,134 Contingent consideration 15,166 Cash paid $ 14,139
Components Of Intangible Assets Acquired	FAIR VALUE USEFUL LIFE AT-006 $ 3,400 13 years AT-007 13,500 15 years AT-008 5,300 13 years AT-011 7,200 14 years Total intangible assets $ 29,400
Vet Therapeutics Inc., [Member]
Business Acquisition [Line Items]
Acquisition Date Fair Value Of Consideration Transferred	Cash consideration $ 30,005 Fair value of promissory note 3,000 Fair value of merger shares 14,700 Fair value of contingent consideration 3,810 Fair value of total consideration 51,515 Less cash acquired (12) Total consideration transferred, net of cash acquired $ 51,503
Allocation Of Purchase Price To Assets Acquired And Liabilities Assumed	Cash $ 12 Inventories 173 Other current assets 5 Property and equipment 73 Other long-term assets 3 Identifiable intangible assets 38,652 Accounts payable and accrued expenses (273) Deferred revenue (55) Deferred tax liabilities, net (12,722) Total identifiable net assets $ 25,868 Goodwill 25,646 Total net assets acquired $ 51,514 Less: Merger shares 14,700 Promissory note 3,000 Contingent consideration 3,810 Cash paid $ 30,005
Components Of Intangible Assets Acquired	FAIR VALUE USEFUL LIFE AT-004 (Antibody for B-cell lymphoma) $ 28,572 20 years AT-005 (Antibody for T-cell lymphoma) 10,080 20 years Total intangible assets subject to amortization $ 38,652

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Taxes [Abstract]
Components Of Income From Continuing Operations Before Income Taxes Benefit	YEAR ENDED DECEMBER 31, 2015 2014 2013 U.S. $ (65,481) $ (34,256) $ (19,660) Non-U.S. (20,271) (6,003) — Income from continuing operations $ (85,752) $ (40,259) $ (19,660)
Components Of Income Tax Benefit From Operations	YEAR ENDED DECEMBER 31, 2015 2014 2013 Current: Federal $ — $ — $ State — — Deferred: Federal — — 10,782 State — — 1,940 Foreign 1,698 1,443 — Total $ 1,698 $ 1,443 $ 12,722
Reconciliation Of U.S. Federal Statutory Income Tax Rate To Effective Income Tax Rate	YEAR ENDED DECEMBER 31, 2015 2014 2013 Federal statutory income tax rate 34.0 % 34.0 % 34.0 % State income taxes, net of federal tax benefit 2.5 1.1 7.2 Non-deductible expenses (1.1) (3.0) (2.5) Research credits 0.4 0.8 0.9 Losses benefitted/(not benefitted) (33.8) (29.3) 25.3 Total 2.0 % 3.6 % 64.9 %
Net Deferred Tax Assets	YEAR ENDED DECEMBER 31, 2015 2014 2013 Net operating loss carry forwards $ 26,670 $ 12,196 $ 3,180 Capitalized start-up costs 6,645 7,151 3,751 Tax credit carry forwards 1,308 1,062 784 Other temporary differences 3,451 1,469 1,421 Capitalized research and development, net 11,911 10,378 5,788 Total deferred tax assets 49,985 32,256 14,924 Valuation allowance (46,885) (14,747) (3,118) Net deferred tax assets 3,100 17,509 11,806 Intangibles, net (3,041) (19,356) (11,790) Depreciation (59) (18) (16) Total deferred tax liabilities (3,100) (19,374) (11,806) Net deferred tax liability $ — $ (1,865) $ —
Changes In Valuation Allowance For Deferred Tax Assets	YEAR ENDED DECEMBER 31, 2015 2014 2013 Valuation allowance as of beginning of year $ 14,747 $ 3,118 $ 8,065 Decreases recorded as income tax benefit — — (4,947) Increases due to acquisitions — 271 — Increases due to operations 32,138 11,358 — Valuation allowance as of end of year $ 46,885 $ 14,747 $ 3,118

Selected Quarterly Financial 46

Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2015
Selected Quarterly Financial Data [Abstract]
Selected Quarterly Financial Data	2015 First Second Third Fourth Quarter Quarter Quarter Quarter Net revenue $ 156 $ 230 $ 229 $ 63 Gross profit 46 121 91 55 Net loss (8,774) (7,983) (54,442) (12,855) Basic and diluted– loss per common share: Net loss per common share (1) $ (0.26) $ (0.23) $ (1.58) $ (0.37) Weighted average number of common shares outstanding, basic and diluted 34,193,994 34,278,105 34,405,646 34,540,001 2014 First Second Third Fourth Quarter Quarter Quarter Quarter Net revenue $ 176 $ 300 $ 43 $ 248 Gross profit 176 300 43 (85) Net loss (9,152) (9,278) (10,130) (10,256) Basic and diluted– loss per common share: Net loss per common share (1) $ (0.34) $ (0.32) $ (0.35) $ (0.30) Weighted average number of common shares outstanding, basic and diluted 26,765,565 28,761,326 29,348,375 34,118,255 __________________ (1) Net loss available to common stockholders and basic and diluted net loss per common share are computed consistent with annual per share calculations described in Notes 2 and 15 (Net Loss Per Share) of its consolidated financial statements included elsewhere in this Annual Report on Form 10-K.

The Company And Basis Of Pres47

The Company And Basis Of Presentation (Details) $ in Thousands	Oct. 16, 2015USD ($)item	Dec. 31, 2015USD ($)segmentitem
The Company And Basis Of Presentation [Line Items]
Date of incorporation		Dec. 1, 2010
Number of operating segments | segment		1
Culmulative net loss		$ 152,018
Term Loan And Revolving Credit Facility [Member]
The Company And Basis Of Presentation [Line Items]
Principal amount of debt		40,000
Loan Agreement [Member]
The Company And Basis Of Presentation [Line Items]
Unrestricted net cash proceeds from the issuance of equity securities and/or payments related to partnering transactions required to receive under loan agreement	$ 45,000	$ 45,000
Number of approved products required for interest only payment extension term | item	3	3

Summary Of Significant Accoun48

Summary Of Significant Accounting Policies (Details) $ in Thousands	Apr. 07, 2014USD ($)	Mar. 17, 2014USD ($)	Feb. 04, 2014USD ($)	Jan. 06, 2014USD ($)item	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)segmentitem	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of operating segments | segment							1
Goodwill impairment loss					$ 0	$ 0	$ 0
Ratio of fair value to carrying value					93.00%
Goodwill					$ 39,781		39,781	$ 41,398	$ 25,646
Impairment of acquired intangible assets					0	$ 43,398	43,398
Contingent consideration, value, high	$ 16,308
Settlement of contingent liability							3,000	15,235
Deferred public offering costs					189		189	0
Debt issuance costs							360	11
Expense related to debt issuance costs							$ 129	41
Number of financial institutions | item							2
Total assets					$ 147,066		$ 147,066	$ 207,903
Okapi Sciences NV [Member]
Summary Of Significant Accounting Policies [Line Items]
Goodwill				$ 17,909
Number of clinical/development stage product candidates | item				3
Purchase price of acquisition				$ 44,439
Aggregate merger consideration, cash paid				14,139
Aggregate merger consideration, principal amount of promissory note issued				15,134
Contingent consideration, value, high				16,308
Contingent consideration	$ 15,166			15,166
Settlement of contingent liability		$ 15,235
Promissory Note [Member] | Okapi Sciences NV [Member]
Summary Of Significant Accounting Policies [Line Items]
Aggregate merger consideration, principal amount of promissory note issued				$ 15,134
Interest rate				7.00%
Promissory note maturity date							Dec. 31, 2014
Payment of promissory note			$ 15,158

Summary Of Significant Accoun49

Summary Of Significant Accounting Policies (Estimated Useful Lives Of Property, Plant And Equipment) (Details)	12 Months Ended
	Dec. 31, 2015
Laboratory and Office Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Laboratory and Office Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Computer Software And Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Computer Software And Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Furniture [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Furniture [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	7 years
Vehicles [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Vehicles [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years

Summary Of Significant Accoun50

Summary Of Significant Accounting Policies (Schedule Of Revenue By Geographic Region) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Total revenues	$ 63	$ 229	$ 230	$ 156	$ 248	$ 43	$ 300	$ 176	$ 678	$ 767	$ 123
United States [Member]
Segment Reporting Information [Line Items]
Total revenues									$ 678	267	$ 123
Belgium [Member]
Segment Reporting Information [Line Items]
Total revenues										$ 500

Summary Of Significant Accoun51

Summary Of Significant Accounting Policies (Schedule Of Long-Lived Assets By Geographic Region) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total long lived assets	$ 2,555	$ 620
United States [Member]
Segment Reporting Information [Line Items]
Total long lived assets	2,460	459
Belgium [Member]
Segment Reporting Information [Line Items]
Total long lived assets	$ 95	$ 161

Fair Value Of Financial Asset52

Fair Value Of Financial Assets And Liabilities (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jan. 02, 2015	Oct. 15, 2013
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value, assets, Level 1 to Level 2 transfers				$ 2,452
Fair value, assets and liabilities, transfers between levels			$ 0		$ 0
Contingent consideration				4,248
Cash paid for contingent consideration			$ 3,000	15,166
Change in fair value of contingent consideration			$ (1,248)	(133)	$ 305
Contingent consideration, fair value				$ 4,248
Vet Therapeutics Inc., [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration							$ 3,810
Vet Therapeutics Inc., [Member] | AT-004 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration						$ 3,000
Cash paid for contingent consideration	$ 3,000
Change in fair value of contingent consideration		$ (1,248)	$ 1,248
Contingent consideration, fair value			$ 0

Fair Value Of Financial Asset53

Fair Value Of Financial Assets And Liabilities (Summary Of Information About Company's Financial Assets And Liabilities Subject To Fair Value Measurement On Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets:
Short-term marketable securities - certificates of deposit	$ 747	$ 249
Reverse repurchase agreements	58,700	88,000
Long-term marketable securities - common stock		2,452
Derivative financial instruments		1,108
Assets, fair value	$ 66,454	98,826
Liabilities:
Contingent consideration		4,248
Liabilities, fair value		4,248
Carrying Value [Member]
Assets:
Short-term marketable securities - certificates of deposit	$ 747	249
Reverse repurchase agreements	58,700	88,000
Long-term marketable securities - common stock		2,452
Derivative financial instruments		1,108
Assets, fair value	66,454	98,826
Liabilities:
Contingent consideration		4,248
Liabilities, fair value		4,248
Certificates Of Deposit [Member]
Assets:
Cash equivalents	6,972	6,972
Certificates Of Deposit [Member] | Carrying Value [Member]
Assets:
Cash equivalents	6,972	6,972
Money Market Funds [Member]
Assets:
Cash equivalents	35	45
Money Market Funds [Member] | Carrying Value [Member]
Assets:
Cash equivalents	35	45
Level 1 [Member]
Assets:
Long-term marketable securities - common stock		2,452
Assets, fair value	35	2,452
Level 1 [Member] | Money Market Funds [Member]
Assets:
Cash equivalents	35
Level 2 [Member]
Assets:
Short-term marketable securities - certificates of deposit	747	249
Reverse repurchase agreements	58,700	88,000
Derivative financial instruments		1,108
Assets, fair value	66,419	96,374
Level 2 [Member] | Certificates Of Deposit [Member]
Assets:
Cash equivalents	$ 6,972	6,972
Level 2 [Member] | Money Market Funds [Member]
Assets:
Cash equivalents		45
Level 3 [Member]
Liabilities:
Contingent consideration		4,248
Liabilities, fair value		$ 4,248

Fair Value Of Financial Asset54

Fair Value Of Financial Assets And Liabilities (Change In Fair Value Of Company's Contingent Consideration Payable Measured At Fair Value On Recurring Basis) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value Of Financial Assets And Liabilities [Abstract]
As of January 1	$ 4,248	$ 4,115
Initial recognition of contingent consideration payable		15,166
Cash settlement of contingent consideration earned	(3,000)	(15,235)
Derecognition of remaining contingent consideration recorded in the consolidated statement of operations (within selling, general and administrative)	$ (1,248)	202
As of the end of the period		$ 4,248

Fair Value Of Financial Asset55

Fair Value Of Financial Assets And Liabilities (Carrying Amounts And Estimated Fair Value Of Company's Financial Assets And Liabilities Not Measured At Fair Value On Recurring Basis) (Details) - Level 2 [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan payable, Carrying Amount	$ 39,710	$ 14,963
Loan payable, Fair Value	$ 40,569	$ 14,933

Fair Value Of Financial Asset56

Fair Value Of Financial Assets And Liabilities (Fair Value Information About Impaired Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impairment charge	$ 0	$ 43,398	$ 43,398
Intellectual Property Rights For Currently Marketed Products [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impairment charge			28,862
Intellectual Property Rights Aquired For In-Process Research And Development [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impairment charge			14,536
Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Intangible assets, fair value	15,067		15,067
Level 3 [Member] | Intellectual Property Rights For Currently Marketed Products [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Intangible assets, fair value	6,057		6,057
Level 3 [Member] | Intellectual Property Rights Aquired For In-Process Research And Development [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Intangible assets, fair value	9,010		9,010
Carrying Value [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Intangible assets, fair value	15,067		15,067
Carrying Value [Member] | Intellectual Property Rights For Currently Marketed Products [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Intangible assets, fair value	6,057		6,057
Carrying Value [Member] | Intellectual Property Rights Aquired For In-Process Research And Development [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Intangible assets, fair value	$ 9,010		$ 9,010

Investments (Narrative) (Detail

Investments (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Investments [Abstract]
Unrealized gains		$ 1,252
Reverse repurchase agreements, collateral securities, percentage of principal and interest required	102.00%

Investments (Fair Value Of Avai

Investments (Fair Value Of Available-For-Sale Marketable Securities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 747	$ 1,449
Gross Unrealized Gains		$ 1,252
Gross Unrealized Losses
Fair Value	$ 747	$ 2,701
Certificates Of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 747	$ 249
Gross Unrealized Gains
Gross Unrealized Losses
Fair Value	$ 747	$ 249
Common Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,200
Gross Unrealized Gains		$ 1,252
Gross Unrealized Losses
Fair Value		$ 2,452

Inventories (Components Of Inve

Inventories (Components Of Inventories) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventories [Abstract]
Raw materials	$ 120	$ 115
Work-in-process	441	206
Finished goods	745	106
Total inventories	$ 1,306	$ 427

Property And Equipment, Net (Na

Property And Equipment, Net (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property And Equipment, Net [Abstract]
Depreciation expense	$ 296	$ 152	$ 16
Gain (loss) on assets sold	$ 0	$ 0	$ 0

Property And Equipment, Net (Sc

Property And Equipment, Net (Schedule Of Property And Equipment, Net) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Total property and equipment	$ 2,985	$ 802
Less: Accumulated depreciation and amortization	(430)	(182)
Property and equipment, net	2,555	620
Laboratory And Office Equipment [Member]
Total property and equipment	527	478
Computer Equipment And Software [Member]
Total property and equipment	2,039	68
Furniture [Member]
Total property and equipment	132	71
Vehicles [Member]
Total property and equipment	11	34
Leasehold Improvements [Member]
Total property and equipment	91	102
Construction In Progress [Member]
Total property and equipment	$ 185	$ 49

Goodwill (Narrative) (Details)

Goodwill (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Jan. 06, 2014	Dec. 31, 2013	Oct. 15, 2013
Goodwill [Line Items]
Goodwill impairment loss	$ 0	$ 0	$ 0
Ratio of fair value to carrying value	93.00%
Goodwill	$ 39,781		$ 39,781	$ 41,398		$ 25,646
Goodwill Acquired During Period				$ 17,909
Vet Therapeutics Inc., [Member]
Goodwill [Line Items]
Goodwill							$ 25,646
Okapi Sciences NV [Member]
Goodwill [Line Items]
Goodwill					$ 17,909

Goodwill (Summary Of Goodwill)

Goodwill (Summary Of Goodwill) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill And Intangible Assets Disclosure [Abstract]
Gross Carrying Amount	$ 39,781
Impairment Losses
Net Carrying Value	$ 39,781	$ 41,398	$ 25,646

Goodwill (Summary Of Change In

Goodwill (Summary Of Change In The Net Book Value Of Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
As of January 1	$ 41,398	$ 25,646
Acquisition		17,909
Effect of foreign currency exchange	(1,617)	(2,157)
As of December 31,	$ 39,781	$ 41,398

Intangible Assets, Net (Narrati

Intangible Assets, Net (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Intangible Assets [Line Items]
Impairment charge	$ 0	$ 43,398	$ 43,398
Net carrying value	15,067		15,067	$ 62,323	$ 38,354
Amortization of intangible assets			1,544	$ 1,891	$ 298
AT-007 [Member]
Intangible Assets [Line Items]
Impairment charge		8,717
Net carrying value		2,202
AT-011 [Member]
Intangible Assets [Line Items]
Impairment charge		5,819
AT-004 [Member]
Intangible Assets [Line Items]
Impairment charge		20,228	20,228
Net carrying value	5,469	5,546	$ 5,469
Average useful life			20 years
AT-005 [Member]
Intangible Assets [Line Items]
Impairment charge		8,634	$ 8,634
Net carrying value	$ 588	$ 606	$ 588
Average useful life			8 years 3 months

Intangible Assets, Net (Summary

Intangible Assets, Net (Summary Of Change In The Net Book Value Of Other Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill And Intangible Assets Disclosure [Abstract]
As of January 1,			$ 62,323	$ 38,354
Acquisitions				29,400
Amortization expense			(1,544)	(1,891)	$ (298)
Effect of foreign currency exchange			(2,314)	(3,540)
Impairment	$ 0	$ (43,398)	(43,398)
As of December 31,	$ 15,067		$ 15,067	$ 62,323	$ 38,354

Intangible Assets, Net (Estimat

Intangible Assets, Net (Estimated Aggregate Amortization Expense Of Intangible Assets) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
2,016	$ 381
2,017	381
2,018	381
2,019	381
2,020	$ 381

Intangible Assets, Net (Summa68

Intangible Assets, Net (Summary Of Unamortized Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Intellectual Property Rights Acquired For In-process Research And Development [Member]
Acquired Indefinite-lived Intangible Assets [Line Items]
Net carrying value	$ 9,010	$ 25,860

Intangible Assets, Net (Summa69

Intangible Assets, Net (Summary Of Amortized Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Net carrying value	$ 15,067		$ 62,323	$ 38,354
AT-004 [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying value	28,572
Accumulated amortization	23,103
Net carrying value	$ 5,469	$ 5,546
Average useful life	20 years
AT-005 [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying value	$ 10,080
Accumulated amortization	9,492
Net carrying value	$ 588	$ 606
Average useful life	8 years 3 months

Derivative Financial Instrume70

Derivative Financial Instruments (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Derivative Instruments Gain Loss [Line Items]
Gain on sale of common stock	$ 341
Warrant [Member]
Derivative Instruments Gain Loss [Line Items]
Gain/(loss) recognized in other income/(expense)	$ 1,274	$ 465

Derivative Financial Instrume71

Derivative Financial Instruments (Derivative Instrument At Gross Fair Value As Reflected) (Details) $ in Thousands	Dec. 31, 2014USD ($)
Warrant [Member]
Derivative assets:
Fair value of derivatives not designated as hedge instrument	$ 1,108

Derivative Financial Instrume72

Derivative Financial Instruments (Gain Recognized In Other Income (Expense)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Warrant [Member]
Derivative assets:
Gain/(loss) recognized in other income/(expense)	$ 1,274	$ 465

Debt (Narrative) (Details)

Debt (Narrative) (Details) $ in Thousands	Oct. 16, 2015USD ($)item	Dec. 31, 2015USD ($)item	Dec. 31, 2014USD ($)
Debt Instrument [Line Items]
Debt issuance costs including interest expense		$ 556
Debt issuance costs		360	$ 11
Interest expense		196
Expense related to debt issuance costs		129	41
Credit Facility [Member]
Debt Instrument [Line Items]
Interest expense		$ 1,579	$ 875
Promissory Note [Member] | Vet Therapeutics Inc., [Member]
Debt Instrument [Line Items]
Date of maturity		Dec. 31, 2014
Prior Loan Agreement [Member]
Debt Instrument [Line Items]
Interest rate		5.50%
Repayment of debt	$ 15,000
Term Loan [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	35,000
Aggregate principal amount borrowed	$ 35,000
Interest only payment term		18 months
Principal and accrued interest payment term		30 months
Interest only payment extension term		1 year
Principal amount of debt		$ 35,000
Number of approved products required for interest only payment extension term | item	4
Date of maturity		Oct. 16, 2019
Final payment commitment fee percentage	3.30%
Revolving Line [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 5,000
Amount borrowed	$ 5,000
Principal amount of debt		$ 5,000
Date of maturity		Oct. 16, 2017
Termination commitment fee percentage	3.30%
Unused capacity commitment fee percentage	0.25%
Credit Extensions [Member]
Debt Instrument [Line Items]
Interest rate	6.91%
Excess interest rate over prime rate	3.66%
Loan Agreement [Member]
Debt Instrument [Line Items]
Number of approved products required for interest only payment extension term | item	3	3
Facility fee	$ 150
Agency fee	$ 100
Debt default interest rate	4.00%
Unrestricted net cash proceeds from the issuance of equity securities and/or payments related to partnering transactions required to receive under loan agreement	$ 45,000	$ 45,000
Minimum liquidity	$ 20,000

Debt (Schedule Of Loan Payable

Debt (Schedule Of Loan Payable Balance) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Add: accretion of final payment and termination fees	$ 77
Less: unamortized debt issuance costs	(367)
Loan payable	39,710	$ 14,963
Term Loan [Member]
Principal amounts	$ 35,000
Date of maturity	Oct. 16, 2019
Revolving Line [Member]
Principal amounts	$ 5,000
Date of maturity	Oct. 16, 2017

Debt (Estimated Future Principa

Debt (Estimated Future Principal Payments Under Additional Term Loan) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Debt [Abstract]
2,016
2,017	$ 15,500
2,018	14,000
2,019	$ 10,500
2,020
Thereafter
Total	$ 40,000

Accrued Expenses, Other Curre76

Accrued Expenses, Other Current Liabilities And Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued expenses:
Accrued payroll and related expenses	$ 1,922	$ 2,017
Accrued professional fees	388	429
Accrued royalty expense	1	72
Accrued interest expense	238	41
Accrued research and development costs	1,111	663
Accrued milestone	500
Accrued other	87	7
Total accrued expenses	4,247	3,229
Early exercise of stock-based awards	29	46
Other	8
Other current liabilities, Total	37	46
Deferred income	122	30
Other long term liabilities, Total	$ 122	$ 30

Agreements (RaQualia Pharma Inc

Agreements (RaQualia Pharma Inc Narrative) (Details) $ in Thousands	Jul. 12, 2012USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2016USD ($)	Mar. 31, 2016USD ($)	Oct. 31, 2014USD ($)	Dec. 27, 2010USD ($)agreement
RaQualia Agreements [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Number of license agreements | agreement							2
Accrued milestones			$ 0
Milestones paid			0
Royalty payments			$ 0
RaQualia Agreements [Member] | Subsequent Event [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable					$ 3,000
AT-001 [Member] | RaQualia API Agreement [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Receivable on agreement execution	$ 800
Eligible research and development funding	$ 800
Accounts receivable for successful development and delivery		$ 800				$ 800
Deferred revenue recognized		1,600
Deferred revenue		$ 800
Maximum [Member] | RaQualia Agreements [Member] | Scenario, Forecast [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable				$ 11,500
Maximum [Member] | AT-001 [Member] | RaQualia Agreements [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable							$ 10,000
Maximum [Member] | AT-002 [Member] | RaQualia Agreements [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable							$ 8,500

Agreements (Pacira Pharmaceutic

Agreements (Pacira Pharmaceuticals, Inc. Narrative) (Details) - AT-003 [Member] - Pacira Agreement [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 05, 2012
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones paid	$ 500
Royalty payments	0
Accrued milestones	$ 0
Maximum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable			$ 42,000
Regulatory Milestones [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable			2,000
Commercial Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable			$ 40,000
Scenario, Forecast [Member] | Multiple Milestones [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable		$ 2,000

Agreements (Other Narrative) (D

Agreements (Other Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jan. 02, 2015
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty expense	$ 84	$ 72	$ 1
Blontress And Tactress Agreements [Member] | AT-004 [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable				$ 405
Royalty expense	$ 84	$ 72	$ 70
Blontress And Tactress Agreements [Member] | AT-004 [Member] | Minimum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Accrued royalties				$ 70

Agreements (Elanco Animal Healt

Agreements (Elanco Animal Health Narrative) (Details) - USD ($) $ in Thousands	Feb. 25, 2016	Feb. 24, 2015	Jan. 02, 2015	Mar. 31, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Oct. 15, 2013
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Licensing revenue							$ 500	$ 15
Current liability						$ 5,684	9,468
Cash paid for contingent consideration						$ 3,000	15,166
Contingent consideration							$ 4,248
Vet Therapeutics Inc., [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Contingent consideration									$ 3,810
Elanco Agreement [Member] | Vet Therapeutics Inc., [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payment for termination of license agreement		$ 2,500
Milestones payable		$ 500
Current liability				$ 500	$ 500
Contingent consideration						$ 3,000
Agreement term						2 years
AT-004 [Member] | Vet Therapeutics Inc., [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Cash paid for contingent consideration				$ 3,000
Contingent consideration			$ 3,000
AT-004 [Member] | NAH Agreement [Member] | Vet Therapeutics Inc., [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Consideration recognized related to milestones			$ 3,000
Licensing revenue					$ 3,000
Subsequent Event [Member] | Elanco Agreement [Member] | Vet Therapeutics Inc., [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable	$ 500
Subsequent Event [Member] | Elanco Agreement [Member] | Vet Therapeutics Inc., [Member] | Maximum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty revenue	$ 500
Subsequent Event [Member] | AT-004 [Member] | Elanco Agreement [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Interest						10.00%

Agreements (Kansas Bioscience A

Agreements (Kansas Bioscience Authority Narrative) (Details) - Kansas Bioscience Authority ("KBA") Programs [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Recognized income	$ 0	$ 62	$ 478
Amount received during life of agreement		$ 641
Agreement term	10 years

Agreements (Advaxis Inc. Narrat

Agreements (Advaxis Inc. Narrative) (Details) $ / shares in Units, $ in Thousands	Mar. 19, 2014USD ($)item$ / sharesshares	May. 31, 2015USD ($)shares	Apr. 30, 2015USD ($)shares	Jan. 31, 2015USD ($)shares	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Research and Development Arrangement, Contract to Perform for Others [Line Items]
In-process research and development						$ 2,157
Gain on sale of common stock					$ 341
Advaxis Agreement [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Number of products | item	3
Number of types of cancer | item	3
Cash payment related to license agreement	$ 2,500
Common stock acquired | shares	306,122
Common stock called by warrant acquired | shares	153,061
In-process research and development	$ 657
Sale of common stock, shares | shares			181,151	124,971
Proceeds from sale of common stock		$ 2,724	$ 3,233	$ 1,500
Gain on sale of common stock		$ 341	$ 2,523	$ 1,010
Shares received from exercise of warrant | shares		116,411
Net share settlement exercise price		$ 750
Advaxis Agreement [Member] | Common Stock [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Cash payment related to license agreement	1,200
Advaxis Agreement [Member] | Warrant [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Cash payment related to license agreement	$ 643
Warrants exercisable date					Mar. 19, 2024
Exercise price per share of additional warrants | $ / shares	$ 4.90
Advaxis Agreement [Member] | Common Stock and Warrant [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Cash payment related to license agreement	$ 1,843
Advaxis Agreement [Member] | Product Sales [Member] | Royalties [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Concentration risk percentage	10.00%
Advaxis Agreement [Member] | Clinical Development And Regulatory Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Number of products | item	4
Milestones payable	$ 6,000
Advaxis Agreement [Member] | Commercial Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable	28,500
Licensed Technology [Member] | Advaxis Agreement [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Cash payment related to license agreement	$ 657

Agreements (Vet-Stem, Inc. Narr

Agreements (Vet-Stem, Inc. Narrative) (Details) - USD ($) $ in Thousands	Jun. 12, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2016
Research and Development Arrangement, Contract to Perform for Others [Line Items]
In-process research and development			$ 2,157
Development expenses		$ 24,964	$ 19,985	$ 10,925
AT-016 [Member] | Vet-Stem Agreement [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
License fee	$ 500
In-process research and development	500
Development expenses	3,600
Milestones paid		300
Royalty payments		0
Accrued milestones		$ 0
AT-016 [Member] | Vet-Stem Agreement [Member] | Maximum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable	$ 4,200
Scenario, Forecast [Member] | Multiple Milestones [Member] | AT-016 [Member] | Vet-Stem Agreement [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable					$ 700

Agreements (Atopix Therapeutics

Agreements (Atopix Therapeutics Ltd. Narrative) (Details) - USD ($) $ in Thousands	Oct. 10, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Research and Development Arrangement, Contract to Perform for Others [Line Items]
In-process research and development			$ 2,157
AT-018 [Member] | Atopix Agreement [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
License fee	$ 1,000
In-process research and development	1,000
Milestones paid		$ 500	0
Royalty payments		0	0
Accrued milestones		0	0
Accrued royalties		$ 0	$ 0
AT-018 [Member] | Atopix Agreement [Member] | Maximum [Member] | Clinical Development And Regulatory Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Milestones payable	$ 4,000

Agreements (Exclusive Option Pr

Agreements (Exclusive Option Programs Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Development expenses	$ 24,964	$ 19,985	$ 10,925
Exclusive Option Programs [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Development expenses	$ 270	$ 307	$ 915

Common Stock (Details)

Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 16, 2015	Sep. 22, 2014	Feb. 03, 2014	Oct. 15, 2013	Oct. 13, 2013	Jun. 26, 2013	May. 22, 2013	Jul. 31, 2013	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Common stock outstanding, shares										34,563,816	34,147,861
Number of fractional shares issued for reverse stock split							0
Issuance of preferred/common stock, net of issuance cost, shares		5,175,000	5,150,000					6,612,500
Share issue price		$ 9.25	$ 19					$ 6
Underwriting discount and commission		$ 2,872	$ 5,871					$ 2,777
Offering expenses		412	$ 1,472					$ 2,617
Convertible preferred stock converted into common stock						13,351,902
Issuance of common stock relating to Vet Therapeutics, Inc. acquisition									$ 14,700
Proceeds from issuance of private placement									$ 19,750
Net proceeds from public offering		$ 44,827
Aggregate common stock available to sell	$ 52,000
Percentage of commission on gross proceeds from sale of shares	2.75%
Private Placement [Member]
Class of Stock [Line Items]
Issuance of preferred/common stock, net of issuance cost, shares					1,234,375
Share issue price					$ 16
Proceeds from issuance of private placement					$ 19,750
Series A Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Percentage of elected shareholder to convert common stock						75.00%
Vet Therapeutics Inc., [Member]
Class of Stock [Line Items]
Issued of stock to Vet Therapeutics				624,997
Issuance of common stock relating to Vet Therapeutics, Inc. acquisition				$ 14,700
Unvested Restricted Stock [Member]
Class of Stock [Line Items]
Common stock outstanding, shares										441,800	561,651

Stock-Based Awards (Narrative)

Stock-Based Awards (Narrative) (Details)	Jan. 01, 2016shares	Aug. 31, 2013itemshares	Dec. 31, 2016	Dec. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2013USD ($)$ / sharesshares	Dec. 31, 2012shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from stock options exercised | $				$ 312,000	$ 225,000	$ 153,000
One Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested, other than options						33,447
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested, other than options				71,459
Unrecognized stock-based compensation expense, other than options | $				$ 30,000	$ 76,000
2010 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested, other than options				37,078	91,334
Weighted average grant date fair value, grants | $ / shares
Award, expiration period				10 years
Grants in period
Expirations in period
Vesting period				90 days
Incremental expense for stock option awards | $					$ 327,000
Incremental expense for restricted stock award | $					649,000
Stock option exercises				57,652
2010 Equity Incentive Plan [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of options exercised | $				$ 786,000	871,000	$ 4,840,000
Proceeds from stock options exercised | $				25,000	19,000	$ 153,000
Weighted average grant date fair value of options granted | $ / shares						$ 2.48
Fair value stock awards, vested | $				140,000	765,000	$ 98,000
Proceed from early options exercised | $				$ 0	$ 0	$ 97,000
2010 Equity Incentive Plan [Member] | Stock Option [Member] | Former President [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards modified | item		2
Expirations in period		9,228
Stock option exercises		269,817
2010 Equity Incentive Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested, other than options				37,078	91,334	237,740
Weighted average grant date fair value, grants | $ / shares				$ 0	$ 0	$ 2.59
Grants in period							3
Fair value stock awards, vested | $				$ 731,000	$ 2,615,000	$ 2,257,000
Issuance of restricted stock awards to employees, in shares						76,496
Proceeds from the issuance of restricted stock | $						$ 0
2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense for options outstanding | $				$ 10,372,000
Unvested, other than options				333,263	277,844
Unrecognized stock-based compensation expense, other than options | $				$ 4,570,000
Unrecognized stock-based compensation expense, recognition period				2 years 4 months 13 days
Unrecognized stock-based compensation expense, other than options, recognition period				1 year 8 months 5 days
Weighted average grant date fair value, grants | $ / shares				$ 17.14
Award, expiration period				10 years
Grants in period				523,350
Shares available for future grant				847,103
Expirations in period				61,311
Shares authorized for issuance						3,222,298
Percentage increase of shares						4.00%
Stock option exercises				32,761
2013 Equity Incentive Plan [Member] | Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of options exercised | $				$ 267,000	$ 214,000	$ 0
Proceeds from stock options exercised | $				$ 287,000	$ 206,000	$ 0
Weighted average grant date fair value of options granted | $ / shares				$ 10.09	$ 12.84	$ 9.16
Award, expiration period				10 years
Grants in period				523,350
Fair value stock awards, vested | $				$ 5,660,000	$ 1,888,000	$ 0
2013 Equity Incentive Plan [Member] | Stock Option [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				25.00%
2013 Equity Incentive Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value stock awards, vested, other than options | $				$ 1,893,000	$ 94,000	$ 25,000
Weighted average grant date fair value, grants | $ / shares				$ 17.14	$ 16.73	$ 18.91
Proceeds from the issuance of restricted stock | $				$ 0	$ 0	$ 0
2013 Equity Incentive Plan [Member] | Restricted Stock [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				33.30%
2013 Equity Incentive Plan [Member] | Restricted Stock [Member] | Scenario, Forecast [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			8.33%
Minimum [Member] | 2010 Equity Incentive Plan [Member] | Stock Option [Member] | Former President [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration date of options		Aug. 9, 2013
Minimum [Member] | 2010 Equity Incentive Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period						2 years
Maximum [Member] | 2010 Equity Incentive Plan [Member] | Stock Option [Member] | Former President [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration date of options		Jan. 31, 2014
Maximum [Member] | 2010 Equity Incentive Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period						4 years
Maximum [Member] | 2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum increase in shares authorized						1,203,369
Subsequent Event [Member] | 2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual increase in shares	1,203,369

Stock-Based Awards (Summary Of

Stock-Based Awards (Summary Of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
2010 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Issuable Under Options, Outstanding as of December 31, 2014	170,466
Shares Issuable Under Options, Granted
Shares Issuable Under Options, Exercised	(57,652)
Shares Issuable Under Options, Forfeited	(26,324)
Shares Issuable Under Options, Expired
Shares Issuable Under Options, Outstanding as of September 30, 2015	86,490	170,466
Shares Issuable Under Options, Options vested and expected to vest as of December 31, 2014	85,385
Shares Issuable Under Options, Options exercisable as of December 31, 2014	86,213
Weighted Average Exercise Price, Outstanding as of December 31, 2014	$ 1.71
Weighted Average Exercise Price, Granted
Weighted Average Exercise Price, Exercised	$ 0.43
Weighted Average Exercise Price, Forfeited	$ 0.45
Weighted Average Exercise Price, Expired
Weighted Average Exercise Price, Outstanding as of September 30, 2015	$ 2.95	$ 1.71
Weighted Average Exercise Price, Options vested and expected to vest as of December 31, 2014	2.92
Weighted Average Exercise Price, Options exercisable as of September 30, 2015	$ 2.94
Weighted Average Remaining Contractual Term, Outstanding	7 years 1 month 2 days	8 years 18 days
Weighted Average Remaining Contractual Term, Options vested and expected	7 years 1 month 2 days
Weighted Average Remaining Contractual Term, Options exercisable	7 years 1 month 2 days
Aggregate Intrinsic Value, Outstanding	$ 228	$ 2,746
Aggregate Intrinsic Value, Options vested and expected	227
Aggregate Intrinsic Value, Options exercisable	$ 228
2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Issuable Under Options, Outstanding as of December 31, 2014	1,481,866
Shares Issuable Under Options, Granted	523,350
Shares Issuable Under Options, Exercised	(32,761)
Shares Issuable Under Options, Forfeited	(182,945)
Shares Issuable Under Options, Expired	(61,311)
Shares Issuable Under Options, Outstanding as of September 30, 2015	1,728,199	1,481,866
Shares Issuable Under Options, Options vested and expected to vest as of December 31, 2014	1,642,972
Shares Issuable Under Options, Options exercisable as of December 31, 2014	610,406
Weighted Average Exercise Price, Outstanding as of December 31, 2014	$ 17.13
Weighted Average Exercise Price, Granted	16.14
Weighted Average Exercise Price, Exercised	8.76
Weighted Average Exercise Price, Forfeited	18.96
Weighted Average Exercise Price, Expired	23.55
Weighted Average Exercise Price, Outstanding as of September 30, 2015	16.57	$ 17.13
Weighted Average Exercise Price, Options vested and expected to vest as of December 31, 2014	16.59
Weighted Average Exercise Price, Options exercisable as of September 30, 2015	$ 16.54
Weighted Average Remaining Contractual Term, Outstanding	8 years 3 months 22 days	8 years 11 months 16 days
Weighted Average Remaining Contractual Term, Options vested and expected	8 years 3 months 22 days
Weighted Average Remaining Contractual Term, Options exercisable	7 years 10 months 17 days
Aggregate Intrinsic Value, Outstanding		$ 3,835

Stock-Based Awards (Summary O89

Stock-Based Awards (Summary Of Restricted Stock Activity) (Details)	12 Months Ended
	Dec. 31, 2015$ / sharesshares
2010 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted common stock as of December 31, 2014, Shares | shares	91,334
Restricted common stock issued, Shares | shares
Restricted common stock vested, Shares | shares	(54,256)
Restricted common stock forfeited, Shares | shares
Unvested restricted common stock as of September 30, 2015, Shares | shares	37,078
Unvested restricted common stock as of December 31, 2014, Weighted Average Grant Date Fair Value | $ / shares	$ 0.94
Restricted common stock issued, Weighted Average Grant Date Fair Value | $ / shares
Restricted common stock vested, Weighted Average Grant Date Fair Value | $ / shares	$ 0.37
Restricted common stock forfeited, Weighted Average Grant Date Fair Value | $ / shares
Unvested restricted common stock as of September 30, 2015, Weighted Average Grant Date Fair Value | $ / shares	$ 0.36
2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted common stock as of December 31, 2014, Shares | shares	277,844
Restricted common stock issued, Shares | shares	230,400
Restricted common stock vested, Shares | shares	(151,131)
Restricted common stock forfeited, Shares | shares	23,850
Unvested restricted common stock as of September 30, 2015, Shares | shares	333,263
Unvested restricted common stock as of December 31, 2014, Weighted Average Grant Date Fair Value | $ / shares	$ 16.92
Restricted common stock issued, Weighted Average Grant Date Fair Value | $ / shares	17.14
Restricted common stock vested, Weighted Average Grant Date Fair Value | $ / shares	15.85
Restricted common stock forfeited, Weighted Average Grant Date Fair Value | $ / shares	14
Unvested restricted common stock as of September 30, 2015, Weighted Average Grant Date Fair Value | $ / shares	$ 17.77

Stock-Based Awards (Data Used T

Stock-Based Awards (Data Used To Determine Value Of Stock Option Grants) (Details) - 2013 Equity Incentive Plan [Member]	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	1.38%	1.88%	1.59%
Expected term (in years)	6 years 1 month 6 days	6 years 1 month 6 days	6 years 1 month 6 days
Expected volatility	70.00%	84.00%	66.00%
Expected dividend yield

Stock-Based Awards (Summary O91

Stock-Based Awards (Summary Of Stock-Based Compensation Expense Related To Stock Options And Restricted Stock) (Details) - 2013 Equity Incentive Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 8,592	$ 7,130	$ 1,025
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	1,646	1,611	419
Cost of Product Sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	118	48
Selling, General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 6,828	$ 5,471	$ 606

Net Loss Per Share (Narrative)

Net Loss Per Share (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock Options [Member]
Dilutive Securities Included And Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock excluded from diluted net loss per share	1,814,689	1,789,305	1,294,146

Net Loss Per Share (Schedule Of

Net Loss Per Share (Schedule Of Basic And Diluted Net Loss Per Share Attributable To Common Stockholders) (Details) $ / shares in Units, $ in Thousands	May. 22, 2013	Dec. 31, 2015USD ($)$ / sharesshares	Sep. 30, 2015USD ($)$ / sharesshares	Jun. 30, 2015USD ($)$ / sharesshares	Mar. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Sep. 30, 2014USD ($)$ / sharesshares	Jun. 30, 2014USD ($)$ / sharesshares	Mar. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2013USD ($)$ / sharesshares
Numerator:
Net loss attributable to common stockholders | $		$ (12,855)	$ (54,442)	$ (7,983)	$ (8,774)	$ (10,256)	$ (10,130)	$ (9,278)	$ (9,152)	$ (84,054)	$ (38,816)	$ (6,938)
Denominator:
Weighted average shares outstanding, basic and diluted | shares		34,540,001	34,405,646	34,278,105	34,193,994	34,118,255	29,348,375	28,761,326	26,765,565	34,355,525	29,767,429	11,059,382
Net loss per share, basic and diluted | $ / shares		$ (0.37)	$ (1.58)	$ (0.23)	$ (0.26)	$ (0.30)	$ (0.35)	$ (0.32)	$ (0.34)	$ (2.45)	$ (1.30)	$ (0.63)
Reverse stock split ratio on shares	1.662											1.662

Commitments And Contingencies94

Commitments And Contingencies (Narrative) (Details) - USD ($) $ in Thousands	Oct. 15, 2013	Mar. 31, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jan. 02, 2015
Business Acquisition Contingent Consideration [Line Items]
Rent expense				$ 678	$ 565	$ 177
Contingent consideration					4,248
Cash paid for contingent consideration				$ 3,000	15,166
Change in fair value of contingent consideration				$ (1,248)	$ (133)	$ 305
Vet Therapeutics Inc., [Member]
Business Acquisition Contingent Consideration [Line Items]
Contingent consideration	$ 3,810
Fair value of contingent consideration	$ 3,810
AT-004 [Member] | Vet Therapeutics Inc., [Member]
Business Acquisition Contingent Consideration [Line Items]
Contingent consideration							$ 3,000
Cash paid for contingent consideration		$ 3,000
Change in fair value of contingent consideration			$ (1,248)	$ 1,248
Fair value of contingent consideration			$ 0

Commitments And Contingencies95

Commitments And Contingencies (Future Minimum Lease Payments For Operating Leases) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Commitments And Contingencies [Abstract]
2,016	$ 598
2,017	605
2,018	590
2,019	466
2020 and thereafter	526
Total	$ 2,785

Commitments And Contingencies96

Commitments And Contingencies (Summary Of Contractual Contingent Purchase Price Consideration Obligation) (Details) - USD ($) $ in Thousands	Mar. 05, 2015	Mar. 17, 2014	Dec. 31, 2015	Dec. 31, 2014	Jan. 06, 2014	Oct. 15, 2013
Business Acquisition, Contingent Consideration [Line Items]
Maximum Remaining Earn-out Potential
Remaining Earn-out Period			0 years
Estimated fair value				$ 4,248
Payments made during 2015			$ 3,000	$ 15,235
Vet Therapeutics Inc., [Member]
Business Acquisition, Contingent Consideration [Line Items]
Acquisition date			Oct. 15, 2013
Maximum Remaining Earn-out Potential
Remaining Earn-out Period			0 years
Estimated fair value						$ 3,810
Payments made during 2015	$ 3,000		$ 3,000
Okapi Sciences NV [Member]
Business Acquisition, Contingent Consideration [Line Items]
Acquisition date			Jan. 6, 2014
Estimated fair value					$ 15,166
Payments made during 2015		$ 15,235

Business Combinations (Narrativ

Business Combinations (Narrative) (Details) $ / shares in Units, $ in Thousands	Mar. 05, 2015USD ($)	Apr. 07, 2014USD ($)	Apr. 04, 2014shares	Mar. 17, 2014USD ($)	Feb. 04, 2014USD ($)	Jan. 06, 2014USD ($)item	Oct. 15, 2013USD ($)$ / sharesshares	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Sep. 30, 2014USD ($)	Jun. 30, 2014USD ($)	Mar. 31, 2014USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Business Acquisition [Line Items]
Number of clinical/development state product candidates | item						3
Contingent consideration, value, high		$ 16,308
Estimated fair value												$ 4,248					$ 4,248
Settlement of contingent liability																$ 3,000	15,235
Total revenues								$ 63	$ 229	$ 230	$ 156	248	$ 43	$ 300	$ 176	678	767	$ 123
Total consideration paid, net of cash acquired																	12,075	30,994
Impairment charge								0	43,398							43,398
Fair market value of publicly traded common stock | $ / shares							$ 27.67
Discount for lack of marketability							15.00%
Goodwill								$ 39,781				$ 41,398				39,781	41,398	25,646
Pre-tax increase in income																$ (85,752)	(40,259)	(19,660)
Okapi Sciences NV [Member]
Business Acquisition [Line Items]
Acquisition date																Jan. 6, 2014
Purchase price of acquisition						$ 44,439
Aggregate merger consideration, cash paid						14,139
Aggregate merger consideration, principal amount of promissory note issued						15,134
Contingent consideration, value, high						16,308
Estimated fair value						15,166
Settlement of contingent liability				$ 15,235
Total revenues																	452
Total consideration paid, net of cash acquired						43,376											43,376
Goodwill						17,909
Okapi Sciences NV [Member] | Acquisition-related Costs [Member]
Business Acquisition [Line Items]
Pre-tax increase in income																	440
Okapi Sciences NV [Member] | Promissory Note [Member]
Business Acquisition [Line Items]
Aggregate merger consideration, principal amount of promissory note issued						$ 15,134
Promissory note maturity date																Dec. 31, 2014
Payment of promissory note					$ 15,158
Debt Instrument interest rate percentage						7.00%
Okapi Sciences NV [Member] | General and Administrative [Member]
Business Acquisition [Line Items]
Contingent consideration difference in fair value and settlement amount				$ 69
Okapi Sciences NV [Member] | Maximum [Member]
Business Acquisition [Line Items]
Aggregate merger consideration, shares issued/issuable | shares			1,060,740
Okapi Sciences NV [Member] | Minimum [Member]
Business Acquisition [Line Items]
Aggregate merger consideration, shares issued/issuable | shares			707,160
Vet Therapeutics Inc., [Member]
Business Acquisition [Line Items]
Acquisition date																Oct. 15, 2013
Purchase price of acquisition							$ 51,515
Aggregate merger consideration, cash paid							30,005
Aggregate merger consideration, principal amount of promissory note issued							3,000
Contingent consideration, value, high							5,000
Estimated fair value							3,810
Settlement of contingent liability	$ 3,000															$ 3,000
Total revenues																	$ 273	123
Total consideration paid, net of cash acquired							$ 51,503
Aggregate merger consideration, shares issued/issuable | shares							624,997
Aggregate merger consideration, value of shares issued							$ 14,700
Goodwill							25,646
Vet Therapeutics Inc., [Member] | Acquisition-related Costs [Member]
Business Acquisition [Line Items]
Pre-tax increase in income																		1,639
Vet Therapeutics Inc., [Member] | Promissory Note [Member]
Business Acquisition [Line Items]
Aggregate merger consideration, principal amount of promissory note issued							$ 3,000
Promissory note maturity date																Dec. 31, 2014
Payment of promissory note					$ 3,020
Debt Instrument interest rate percentage							7.00%
Vet Therapeutics Inc., [Member] | General and Administrative [Member]
Business Acquisition [Line Items]
Business acquisition expenses																		$ 1,369
AT-007 [Member]
Business Acquisition [Line Items]
Impairment charge									8,717
AT-011 [Member]
Business Acquisition [Line Items]
Impairment charge									$ 5,819

Business Combinations (Acquisit

Business Combinations (Acquisition Date Fair Value Of Consideration Transferred - Okapi Sciences NV) (Details) - USD ($) $ in Thousands	Apr. 07, 2014	Jan. 06, 2014	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Total consideration transferred, net of cash acquired			$ 12,075	$ 30,994
Okapi Sciences NV [Member]
Business Acquisition [Line Items]
Cash consideration		$ 14,139
Fair value of promissory note		15,134
Fair value of contingent consideration	$ 15,166	15,166
Fair value of total consideration		44,439
Less cash acquired		(1,063)
Total consideration transferred, net of cash acquired		$ 43,376	$ 43,376

Business Combinations (Allocati

Business Combinations (Allocation Of Purchase Price To Assets Acquired And Liabilities Assumed - Okapi Sciences NV) (Details) - USD ($) $ in Thousands	Apr. 07, 2014	Jan. 06, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Oct. 15, 2013
Business Acquisition [Line Items]
Identifiable intangible assets						$ 38,652
Goodwill			$ 39,781	$ 41,398	$ 25,646
Okapi Sciences NV [Member]
Business Acquisition [Line Items]
Cash		$ 1,063
Accounts receivable		149
Other receivables		60
Prepaid expenses and other current assets		82
Property and equipment		217
Other long-term assets		18
Identifiable intangible assets		29,400
Accounts payable and accrued expenses		(586)
Deferred revenue		(83)
Deferred tax liabilities, net		(3,786)
Long-term debt		(4)
Total identifiable net assets		26,530
Goodwill		17,909
Total net assets acquired		44,439
Less:
Promissory note		15,134
Contingent consideration	$ 15,166	15,166
Cash paid		$ 14,139

Business Combinations (Componen

Business Combinations (Components Of Intangible Assets Acquired - Okapi Sciences NV) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Jan. 06, 2014	Oct. 15, 2013
Business Acquisition [Line Items]
Total intangible assets, fair value			$ 38,652
Okapi Sciences NV [Member]
Business Acquisition [Line Items]
Total intangible assets, fair value		$ 29,400
Okapi Sciences NV [Member] | AT-006 [Member]
Business Acquisition [Line Items]
Total intangible assets, fair value		3,400
Total intangible assets, useful life	13 years
Okapi Sciences NV [Member] | AT-007 [Member]
Business Acquisition [Line Items]
Total intangible assets, fair value		13,500
Total intangible assets, useful life	15 years
Okapi Sciences NV [Member] | AT-008 [Member]
Business Acquisition [Line Items]
Total intangible assets, fair value		5,300
Total intangible assets, useful life	13 years
Okapi Sciences NV [Member] | AT-011 [Member]
Business Acquisition [Line Items]
Total intangible assets, fair value		$ 7,200
Total intangible assets, useful life	14 years

Business Combinations (Acqui101

Business Combinations (Acquisition Date Fair Value Of Consideration Transferred - Vet Therapeutics Inc.) (Details) - USD ($) $ in Thousands	Oct. 15, 2013	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Total consideration transferred, net of cash acquired		$ 12,075	$ 30,994
Vet Therapeutics Inc., [Member]
Business Acquisition [Line Items]
Cash consideration	$ 30,005
Fair value of promissory note	3,000
Fair value of merger shares	14,700
Fair value of contingent consideration	3,810
Fair value of total consideration	51,515
Less cash acquired	(12)
Total consideration transferred, net of cash acquired	$ 51,503

Business Combinations (Alloc102

Business Combinations (Allocation Of Purchase Price To Assets Acquired And Liabilities Assumed - Vet Therapeutics Inc) (Details) - USD ($) $ in Thousands	Oct. 15, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Identifiable intangible assets	$ 38,652
Goodwill		$ 39,781	$ 41,398	$ 25,646
Vet Therapeutics Inc., [Member]
Business Acquisition [Line Items]
Cash	12
Inventories	173
Other current assets	5
Property and equipment	73
Other long-term assets	3
Identifiable intangible assets	38,652
Accounts payable and accrued expenses	(273)
Deferred revenue	(55)
Deferred tax liabilities, net	(12,722)			$ (12,722)
Total identifiable net assets	25,868
Goodwill	25,646
Total net assets acquired	51,514
Less:
Merger Shares	14,700
Promissory note	3,000
Contingent consideration	3,810
Cash paid	$ 30,005

Business Combinations (Compo103

Business Combinations (Components Of Intangible Assets Acquired - Vet Therapeutics Inc) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Oct. 15, 2013
Business Acquisition [Line Items]
Total intangible assets, fair value		$ 38,652
AT-004 [Member]
Business Acquisition [Line Items]
Total intangible assets, fair value		28,572
AT-005 [Member]
Business Acquisition [Line Items]
Total intangible assets, fair value		10,080
Vet Therapeutics Inc., [Member]
Business Acquisition [Line Items]
Total intangible assets, fair value		$ 38,652
Vet Therapeutics Inc., [Member] | AT-004 [Member]
Business Acquisition [Line Items]
Total intangible assets, useful life	20 years
Vet Therapeutics Inc., [Member] | AT-005 [Member]
Business Acquisition [Line Items]
Total intangible assets, useful life	20 years

Business Combinations (Summary

Business Combinations (Summary Of Proforma Financial Information - Okapi Sciences NV) (Details) - Okapi Sciences NV And Vet Therapeutics [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2013
Business Acquisition [Line Items]
Revenue	$ 767	$ 2,570
Loss from operations	(41,314)	(22,977)
Loss before income taxes	$ (39,979)	$ (24,448)
Net loss per share before income taxes – basic and diluted	$ (1.34)	$ (1.95)

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jan. 06, 2014	Oct. 15, 2013	Dec. 31, 2012
Income Taxes [Line Items]
Excess tax deducation capitalized	$ 1,209
Income tax benefit	$ 1,698	$ 1,443	$ 12,722
Effective income tax rate	2.00%	3.60%	64.90%
Deferred tax liability, net		$ 1,865
Valuation allowance	$ 46,885	14,747	$ 3,118			$ 8,065
Deferred tax benefit	1,698
Unrecognized Tax Benefits	0	0
Accrued interest or penalities related to uncertain tax position	0	0
Recognized accrued or interest or penalities	$ 0	$ 0
Vet Therapeutics Inc., [Member]
Income Taxes [Line Items]
Deferred tax liabilities recognized			12,722		$ 12,722
Okapi Sciences NV [Member]
Income Taxes [Line Items]
Deferred tax liabilities recognized				$ 3,786
Research and Development [Member]
Income Taxes [Line Items]
Tax credit carryforward, expiration	Dec. 31, 2031
Excess tax deducation capitalized	$ 4,038
Amortization period	15 years
Tax Year 2031 [Member]
Income Taxes [Line Items]
Operating loss carryforward, expiration	Dec. 31, 2031
Tax Year 2020 [Member]
Income Taxes [Line Items]
Operating loss carryforward, expiration	Dec. 31, 2020
Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 44,247
Change in valuation allowance			(10,782)
Federal [Member] | Research and Development [Member]
Income Taxes [Line Items]
Tax credit carryforwards	935
State And Local Jurisdiction [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	42,381
Change in valuation allowance			$ (1,940)
State And Local Jurisdiction [Member] | Research and Development [Member]
Income Taxes [Line Items]
Tax credit carryforwards	567
Foreign Tax Authority [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 31,546

Income Taxes (Components Of Inc

Income Taxes (Components Of Income From Continuing Operations Before Income Taxes Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Abstract]
U.S.	$ (65,481)	$ (34,256)	$ (19,660)
Non-U.S.	(20,271)	(6,003)
Income from continuing operations	$ (85,752)	$ (40,259)	$ (19,660)

Income Taxes (Components Of 107

Income Taxes (Components Of Income Tax Benefit From Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current:
Federal
State
Deferred:
Federal			$ 10,782
State			1,940
Foreign	$ 1,698	$ 1,443
Total	$ 1,698	$ 1,443	$ 12,722

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of U.S. Federal Statutory Income Tax Rate To Effective Income Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Abstract]
Federal statutory income tax rate	34.00%	34.00%	34.00%
State income taxes, net of federal tax benefit	2.50%	1.10%	7.20%
Non-deductible expenses	(1.10%)	(3.00%)	(2.50%)
Research credits	0.40%	0.80%	0.90%
Losses benefitted/(not benefitted)	(33.80%)	(29.30%)	25.30%
Total	2.00%	3.60%	64.90%

Income Taxes (Net Deferred Tax

Income Taxes (Net Deferred Tax Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Abstract]
Net operating loss carry forwards	$ 26,670	$ 12,196	$ 3,180
Capitalized start-up costs	6,645	7,151	3,751
Tax credit carryforwards	1,308	1,062	784
Other temporary differences	3,451	1,469	1,421
Capitalized research and development, net	11,911	10,378	5,788
Total deferred tax assets	49,985	32,256	14,924
Valuation allowance	(46,885)	(14,747)	(3,118)	$ (8,065)
Net deferred tax assets	3,100	17,509	11,806
Intangibles, net	(3,041)	(19,356)	(11,790)
Depreciation	(59)	(18)	(16)
Total deferred tax liabilities	$ (3,100)	(19,374)	$ (11,806)
Net deferred tax liability		$ (1,865)

Income Taxes (Changes In Valuat

Income Taxes (Changes In Valuation Allowance For Deferred Tax Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Abstract]
Valuation allowance as of beginning of year	$ 14,747	$ 3,118	$ 8,065
Decreases recorded as income tax benefit			(4,947)
Increases due to acquisitions		271
Increases due to operations	32,138	11,358
Valuation allowance as of end of year	$ 46,885	$ 14,747	$ 3,118

Variable Interest Entity (Detai

Variable Interest Entity (Details) € in Thousands, $ in Thousands	Sep. 15, 2015EUR (€)	Sep. 15, 2015USD ($)	Jul. 31, 2015USD ($)
Variable Interest Entity [Line Items]
Additional borrowings available	€ 300	$ 335
ViroVet [Member]
Variable Interest Entity [Line Items]
Ownership interest paid			$ 2
Committed investment			$ 4
Ownership interest			28.00%
Convertible Loan Agreement [Member]
Variable Interest Entity [Line Items]
Interest rate	7.00%	7.00%

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
MPM Asset Management, LLC [Member]
Related Party Transaction [Line Items]
Rent paid	$ 50	$ 67	$ 67
Agreement period start date	Feb. 9, 2013
Agreement period end date	Dec. 31, 2013
Rent and services paid		60	52
MPM Heartland House, LLC [Member]
Related Party Transaction [Line Items]
Rent paid	$ 131	113	60
Agreement period start date	May 1, 2013
Agreement period end date	Dec. 31, 2015
Rent and services paid	$ 33	$ 33	$ 5

Selected Quarterly Financial113

Selected Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net revenue	$ 63	$ 229	$ 230	$ 156	$ 248	$ 43	$ 300	$ 176	$ 678	$ 767	$ 123
Gross profit	55	91	121	46	(85)	43	300	176
Net loss	$ (12,855)	$ (54,442)	$ (7,983)	$ (8,774)	$ (10,256)	$ (10,130)	$ (9,278)	$ (9,152)	$ (84,054)	$ (38,816)	$ (6,938)
Basic and diluted– loss per common share:
Net loss per common share	$ (0.37)	$ (1.58)	$ (0.23)	$ (0.26)	$ (0.30)	$ (0.35)	$ (0.32)	$ (0.34)	$ (2.45)	$ (1.30)	$ (0.63)
Weighted average shares outstanding, basic and diluted	34,540,001	34,405,646	34,278,105	34,193,994	34,118,255	29,348,375	28,761,326	26,765,565	34,355,525	29,767,429	11,059,382
Vet Therapeutics Inc., [Member]
Net revenue										$ 273	$ 123

Uncategorized Items - petx-2015

Label	Element	Value
Proceeds From Issuance Initial Public Offering	us-gaap_ProceedsFromIssuanceInitialPublicOffering	$ 34,274,000
Proceeds From Issuance Initial Public Offering	us-gaap_ProceedsFromIssuanceInitialPublicOffering	$ 90,507,000