EPIRUS Biopharmaceuticals (EPRSQ) 10-K 29 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Mar. 25, 2016	Jun. 30, 2015
Property and Equipment, Net
Entity Registrant Name	EPIRUS Biopharmaceuticals, Inc.
Entity Central Index Key	1,135,906
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 97,043,791
Entity Common Stock, Shares Outstanding		26,184,349
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 31,515	$ 21,462
Prepaid expenses and other current assets	3,732	1,556
Total current assets	35,247	23,018
Property and equipment, net	2,073	704
In-process research and development		5,500
Intangible assets, net	6,410	3,605
Goodwill	26,361	16,363
Restricted cash	1,924	1,825
Other assets	249	361
Total assets	72,264	51,376
Current liabilities:
Accounts payable	2,051	2,483
Accrued development costs	4,438	876
Accrued expenses	4,003	3,225
Short term debt, net of debt discount	14,833
Accrued purchase price liability	5,493
Deferred revenue	957	50
Current portion of settlement obligation	978
Other current liabilities	343	557
Deferred tax benefit	185	185
Total current liabilities	33,281	7,376
Long term debt, net of debt discount		7,269
Deferred revenue, net of current portion	1,173	946
Deferred tax liability	648	2,166
Deferred tax benefit, net of current portion	369	553
Other non-current liabilities	425	665
Total liabilities	$ 35,896	$ 18,975
Commitments and contingencies (Note 17)
Stockholders' equity:
Preferred stock $0.001 par value; Authorized - 5,000,000 shares; Issued and Outstanding - 0 shares at December 31, 2015 and 2014
Common stock, $0.001 par value; Authorized - 70,000,000 and 300,000,000 shares at December 31, 2015 and December 31, 2014, respectively; Issued - 24,377,573 and 12,934,102 shares at December 31, 2015 and December 31, 2014, respectively; Outstanding - 24,377,573 and 12,920,843 shares at December 31, 2015 and December 31, 2014, respectively	$ 24	$ 13
Additional paid-in capital	175,126	118,959
Accumulated other comprehensive loss	(23)
Accumulated deficit	(138,759)	(86,571)
Total stockholders' equity	36,368	32,401
Total liabilities, convertible preferred stock and stockholders' equity	$ 72,264	$ 51,376

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Jun. 04, 2015	Dec. 31, 2014	Jul. 16, 2014
Condensed Consolidated Balance Sheets
Preferred stock, par value	$ 0.001	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000	5,000,000
Preferred stock, shares issued	0		0
Preferred stock, shares outstanding	0		0
Common stock, par value	$ 0.001	$ 0.001	$ 0.001	$ 0.001
Common stock, shares authorized	70,000,000	70,000,000	300,000,000
Common stock, shares issued	24,377,573		12,934,102
Common stock, shares outstanding	24,377,573		12,920,843

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Condensed Consolidated Statements of Operations and Comprehensive Loss
Revenue	$ 701	$ 4
Cost of revenues	(125)
Operating expenses:
Research and development	30,925	16,286
General and administrative	21,951	22,973
Total operating expenses	52,876	39,259
Loss from operations	(52,300)	(39,255)
Other income (expense):
Interest income (expense), net	(1,332)	(2,672)
Gain on sale of subsidiary	1,016
Change in fair value of warrant liability		(222)
Other income (expense), net	(116)	262
Total other income (expense), net	(432)	(2,632)
Loss before income taxes	(52,732)	(41,887)
Benefit from income taxes	544	43
Net loss	$ (52,188)	$ (41,844)
Net loss per share - basic and diluted	$ (2.29)	$ (6.81)
Weighted average number of common shares used in net loss per share calculation--basic and diluted	22,747,826	6,141,605
Foreign currency translation adjustment	$ (23)
Comprehensive loss	$ (52,211)	$ (41,844)

Statements of Changes in Stockh

Statements of Changes in Stockholders’ Equity - USD ($) $ in Thousands	Series A Convertible Preferred Stock	Series B Convertible Preferred Stock	Common stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Total
Balance at beginning of the period at Dec. 31, 2013	$ 23,348			$ 5,348		$ (44,727)	$ (39,379)
Balance at beginning of the period (in shares) at Dec. 31, 2013	27,248,746		237,026
Increase (Decrease) in Stockholders' Equity
Exercise of preferred stock warrant	$ 6,436	$ 993
Exercise of preferred stock warrant (in shares)	5,101,816	787,402
Issuance of preferred stock upon conversion of convertible debt	$ 13,184
Issuance of preferred stock upon conversion of convertible debt (in shares)	13,184,383
Issuance of preferred/Common stock		$ 30,478
Issuance of preferred stock/Common stock ( in shares)		24,409,444
Issuance of convertible notes				2,071			2,071
Extinguishment of convertible notes		$ 5,013
Debt Conversion, Converted Instrument, Shares Issued		3,947,363
Extinguishment of convertible notes				(1,150)			(1,150)
Exchange of preferred stock for common stock in connection with the Merger	$ (42,968)	$ (36,484)	$ 10	79,442			79,452
Exchange of preferred stock for common stock in connection with the Merger ( in shares)	(45,534,945)	(29,144,209)	9,901,700
Issuance of common stock in connection with the Merger			$ 3	31,321			31,324
Issuance of common stock in connection with the Merger ( in shares)			2,610,871
Exchange of warrants in connection with the Merger				167			167
Exercise of stock options				90			90
Exercise of stock options (in shares)			98,405
Issuance of warrants in connection with Hercules notes				248			248
Issuance of common stock upon vesting of restricted stock units				(297)			(297)
Issuance of common stock upon vesting of restricted stock units ( in shares)			27,540
Stock-based compensation expense and vesting of restricted stock				1,719			1,719
Stock-based compensation expense and vesting of restricted stock ( in shares)			45,301
Net loss						(41,844)	(41,844)
Balance at end of the period at Dec. 31, 2014			$ 13	118,959		(86,571)	32,401
Balance at end of the period (in shares) at Dec. 31, 2014			12,920,843
Increase (Decrease) in Stockholders' Equity
Issuance of preferred/Common stock			$ 11	47,951			47,962
Issuance of preferred stock/Common stock ( in shares)			10,558,208
Stock issued in connection with purchase of Bioceros				4,568			4,568
Stock issued in connection with purchase of Bioceros ( in shares)			788,960
Exercise of stock options				355			355
Exercise of stock options (in shares)			130,920
Retirement of common stock				(177)			(177)
Retirement of common stock (in shares)			(34,617)
Stock-based compensation expense and vesting of restricted stock				3,470			3,470
Stock-based compensation expense and vesting of restricted stock ( in shares)			13,259
Foreign currency translation adjustment					$ (23)		(23)
Net loss						(52,188)	(52,188)
Balance at end of the period at Dec. 31, 2015			$ 24	$ 175,126	$ (23)	$ (138,759)	$ 36,368
Balance at end of the period (in shares) at Dec. 31, 2015			24,377,573

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended		60 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015
Cash flows from operating activities:
Net loss	$ (52,188)	$ (41,844)	$ (138,759)
Adjustments to reconcile net loss to net cash used in operating activities:
Gain on sale of subsidiary	(1,016)
Gain on the change in contingent consideration	(409)
Depreciation and amortization	597	165
Non-cash interest expense	373	2,475
Non-cash accretion expense	170
Deferred taxes	(608)	(185)
Stock-based compensation and vesting of restricted stock	3,470	1,719
Other receivable recovery	(177)
Deferred rent and lease incentive activity	(43)	95
Loss on disposal of equipment	1
Loss on impairment of asset held for sale	1,671
Extinguishment of convertible notes		(22)
Change in fair value of warrants		222
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(1,982)	(276)
Restricted cash	(99)	50
Other non-current assets	111	(304)
Accounts payable	(1,235)	(174)
Accrued expenses and other current liabilities	3,302	1,823
Other non-current liabilities	(196)	(210)
Deferred revenue	698	996
Settlement obligation	978
Net cash used in operating activities	(46,582)	(35,470)
Cash flows from investing activities:
Cash acquired in acquisition	889	13,756
Payment to stockholders of Bioceros	(3,400)
Proceeds from the sale of In process research and development	3,829
Additions to intangible assets		(1,250)
Proceeds from the sale of property & equipment		4
Purchases of property and equipment	(477)	(217)
Net cash provided by investing activities	841	12,293
Cash flows from financing activities
Proceeds from the issuance of common stock, net of costs	47,962
Proceeds from the issuance of preferred stock and warrants		30,478
Proceeds from the issuance of convertible notes		5,000
Proceeds from the issuance of debt, net of fees paid to lender	7,500	7,285
Payment of debt issuance costs		(49)
Proceeds from the exercise of preferred stock warrants		334
Repurchases of common stock		(297)
Proceeds from the exercise of common stock options	355	90
Net cash provided by financing activities	55,817	42,841
Effect of exchange rate changes on cash and cash equivalents	(23)
Net increase (decrease) in cash and cash equivalents	10,053	19,664
Cash and cash equivalents - Beginning of period	21,462	1,798
Cash and cash equivalents - End of period	31,515	21,462	31,515
Supplemental disclosure of cash flow information
Cash paid for interest	913	101
Cash paid for income taxes	40	177
Supplemental schedule of non-cash investing and financing activities:
Amounts in accounts payable for capital expenditure	657	5	$ 657
Conversion of convertible debt and accrued interest into preferred stock and warrants		13,184
Extinguishment of convertible debt and accrued interest into preferred stock		5,013
Exercise of warrants into preferred stock		7,095
Conversion of preferred stock into common stock		79,452
Conversion of preferred stock warrants to equity		167
Issuance of warrants in connection with Hercules debt		248
Leasehold improvements incurred by landlord		477
Fair value of assets and liabilities acquired in the Acquisition (Note 6):
Fair value of assets acquired in the Acquisition	15,697
Fair value of liabilities assumed in the Acquisition	(2,084)
Fair value of net assets acquired in the Acquisition	$ 13,613
Fair value of assets and liabilities acquired in the Merger (Note 5):
Fair value of assets acquired in the Merger		36,223
Fair value of liabilities assumed in the Merger		(4,899)
Fair value of net assets acquired in the Merger		$ 31,324

Organization

Organization	12 Months Ended
	Dec. 31, 2015
Organization
Organization	1. Organization EPIRUS Biopharmaceuticals, Inc. (the “Company”) is a global biopharmaceutical company focused on building a pure-play, sustainable and profitable biosimilar business by improving patient access through cost-effective medicines. The Comp an y’s ability to deliver on this vision is anchored in its strong technical platform and pragmatic approach to development and commercialization. The Company is headquartered in Boston, Massachusetts, with laboratories and technical capabilities, including the Company’s proprietary CHO BC® cell line platform, in Utrecht, the Netherlands, and business operations, clinical and regulatory teams based in Zug, Switzerland. Since its inception, the Company has maintained in-house technical capabilities supported by external vendor laboratories. In September 2015, the Company acquired its primary vendor laboratory, Bioceros Holding B.V., a Netherlands company (“Bioceros”), to expand its biosimilar pipeline and to vertically integrate its product development capabilities. As a result of the acquisition, Bioceros has become the Company’s wholly-owned subsidiary, renamed Epirus Biopharmaceuticals (Netherlands) B.V. See Note 5, “Acquisition,” for additional discussion of the acquisition of Bioceros. Bioceros was focused on the development of monoclonal antibodies (mAbs) . The Company acquired Bioceros’ proprietary CHO BC cell line platform, all related intellectual property rights, a fully equipped laboratory and bioreactor capabilities designed for the development of mAbs and protein therapeutics, with a focus on biosimilars, including capabilities for the production of three new biosimilar product candidates to add to the Company’s pipeline of biosimilar product candidates, as further described below. The Company believes that the addition of Bioceros staff and capabilities, combined with existing in-house expertise, provides the Company with a strong technical foundation to accelerate product development and optimize product quality. Specifically, the Company believes that its ability to rapidly and efficiently conduct and repeat experiments to optimize product quality and cell line titers and process yields will allow it to reduce regulatory risk and manage long term cost of goods. On July 15, 2014, EPIRUS Biopharmaceuticals, Inc., a Delaware corporation and private company ("Private Epirus"), completed its merger with EB Sub, Inc., a wholly-owned subsidiary of Zalicus Inc., a Delaware corporation ("Zalicus") (the "Merger"). As part of the Merger, Zalicus was renamed EPIRUS Biopharmaceuticals, Inc. ("Public Epirus") and Private Epirus was renamed EB Sub, Inc. ("EB Sub"). The boards of directors of Private Epirus and Zalicus approved the Merger on April 15, 2014, and the stockholders of Private Epirus and Zalicus approved the Merger and related matters on July 15, 2014. Following completion of the Merger, EB Sub, Inc. (formerly Private Epirus), is the surviving corporation of the Merger and a wholly-owned subsidiary of Public Epirus. The historical financial statements of Private Epirus have become the historical financial statements of Public Epirus, or the combined company. The terms “Company” and “Epirus” as used in these notes to consolidated financial statements refer to Private Epirus and its subsidiaries prior to the completion of the Merger and to Public Epirus and its subsidiaries subsequent to the completion of the Merger. To date, the Company has devoted substantially all of its efforts to product research and development market research, and raising capital. The Company is subject to a number of risks similar to those of other development stage life science companies, including dependence on key individuals, competition from other companies, the need for development of commercially viable products, and the need to obtain adequate additional financing to fund the development of its product candidates. The Company is also subject to a number of risks similar to other companies in the industry, including rapid technological change, regulatory approval of products, uncertainty of market acceptance of products, competition from substitute products and larger companies, the need to obtain additional financing, compliance with government regulations, protection of proprietary technology, dependence on third parties, product liability, and dependence on key individuals. If the Company does not successfully commercialize any of its product candidates within India or in additional countries, it will be unable to generate recurring product revenue or achieve profitability. As presented in the financial statements, at December 31, 2015, the Company had cash and cash equivalents of $ 31,515 and an accumulated deficit of $138,759 . During the year ended December 31, 2015, the Company incurred a net loss of $52,188 . The Company believes that its existing cash and cash equivalents will be sufficient to fund its current operating plan and capital expenditure requirements into the second quarter of 2016. Going Concern The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern. The Company has net losses for the period from inception (January 2011) through December 31, 2015 of $138,759 , as well as negative cash flows from operating activities. Presently, the Company does not have sufficient cash resources to meet its cash requirements for the twelve months following December 31, 2015. These factors raise substantial doubt about the Company's ability to continue as a going concern. Management is in the process of evaluating various financing alternatives for operations, as the Company will need to finance future research and development activities and general and administrative expenses through fund raising in the public or private equity markets. The consolidated financial statements do not include any adjustments that may be necessary should the Company be unable to continue as a going concern. The Company’s continuation as a going concern is dependent on its ability to obtain additional financing as may be required and ultimately to attain profitability. If the Company raises additional funds through the issuance of equity, the percentage ownership of current shareholders would be reduced, and such securities might have rights, preferences or privileges senior to the common stock. Additional financing may not be available upon acceptable terms, or at all. If adequate funds are not available or are not available on acceptable terms, the Company may not be able to take advantage of prospective business endeavors or opportunities, which could significantly and materially restrict its future plans for developing its business and achieving commercial revenues. If the Company is unable to obtain the necessary capital, the Company may have to cease operations.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation and Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s consolidated financial statements and accompanying notes. The most significant estimates in the Company’s consolidated financial statements relate to the valuation of equity awards, purchase price allocations including fair value estimates of intangible assets, estimated useful lives of fixed assets and intangible assets and accruals relating to development contracts, clinical trials and settlement obligations. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis. The Company’s actual results may differ from these estimates under different assumptions or conditions. Certain prior year amounts have been conformed to the current year presentation. These reclassifications had no impact on net loss or total equity. Principles of Consolidation The consolidated financial statements include the accounts of Epirus and its wholly owned subsidiaries: EB Sub, Inc., a Delaware Corporation, Epirus Biopharmaceuticals Ltd., a United Kingdom corporation, Epirus Biopharmaceuticals (Switzerland) GmbH, a Swiss corporation, Epirus Brasil Tecnologia Ltda, a Brazilian corporation, Epirus Biopharmaceuticals (Netherlands) B.V., a Netherlands corporation, and Zalicus Pharmaceuticals Ltd., a Canadian corporation. All significant intercompany balances and transactions have been eliminated in consolidation. Merger and Exchange Ratio The Merger has been accounted for as a “reverse merger” under the acquisition method of accounting for business combinations with Private Epirus treated as the accounting acquirer of Zalicus. The historical financial statements of Private Epirus have become the historical financial statements of Public Epirus, or the combined company, and are included in this filing labeled Epirus Biopharmaceuticals, Inc. As a result of the Merger, historical common stock, stock options and additional paid-in capital, including share and per share amounts, have been retroactively adjusted to reflect the equity structure of Public Epirus, including the effect of the Merger exchange ratio and the Public Epirus common stock par value of $0.001 per share. See Note 4, “Merger,” for additional discussion of the Merger and the exchange ratio. Reverse Stock Split On July 16, 2014, Public Epirus effected a 1 -for-10 reverse stock split of its outstanding common stock, par value $0.001 per share (“Public Epirus Common Stock”) (the “Reverse Stock Split”). The accompanying consolidated financial statements and these notes to consolidated financial statements, including the Merger exchange ratio (Note 4) applied to historical Private Epirus common stock and stock options, give retroactive effect to the Reverse Stock Split for all periods presented. The shares of Public Epirus Common Stock retained a par value of $0.001 per share. Segment and Geographic Information Operating segments are defined as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker (“CODM”) or decision-making group in making decisions regarding resource allocation and assessing performance. The Company and the Company’s CODM view the Company’s operations and manage its business in one operating segment: the development and commercialization of biosimilar monoclonal antibodies for emerging markets . The Company's entire business is managed by a single management team, which reports to the Chief Executive Officer. As of December 31, 2015 and 2014, all of the Company's long-lived assets were held within the United States, Switzerland and The Netherlands. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of 90 days or less from the date of purchase to be cash equivalents. As of December 31, 2015 and 2014, all cash and cash equivalents are held in depository accounts at six commercial banks. Cash equivalents are reported at fair value. Concentrations of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash, cash equivalents and restricted cash. The Company maintains its cash and cash equivalent balances in the form of checking and savings accounts with financial institutions that management believes are creditworthy. The Company’s investment policy includes guidelines on the quality of the institutions and financial instruments and defines allowable investments that the Company believes minimizes the exposure to concentration of credit risk. The Company has no financial instruments with off-balance-sheet risk of loss. Fair Value of Financial Instruments The Company is required to disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. The Company determines the fair market values of its financial instruments based on the fair value hierarchy, which is a hierarchy of inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing the financial instrument based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the financial instrument and are developed based on the information available in the circumstances. The fair value hierarchy applies only to the valuation inputs used in determining the reported or disclosed fair value of the financial instruments and is not a measure of the investment credit quality. The three levels of the fair value hierarchy, and its applicability to the Company’s financial assets and liabilities, are described below: Level 1 Inputs : Unadjusted quoted prices in active markets that are accessible at the measurement date of identical, unrestricted assets and liabilities. Level 2 Inputs : Quoted prices for similar assets and liabilities, or inputs that are observable, either directly or indirectly, for substantially the full term through corroboration with observable market data. Level 2 includes investments valued at quoted prices adjusted for legal or contractual restrictions specific to the security. Level 3 Inputs : Pricing inputs are unobservable for the assets and liabilities, that is, inputs that reflect the reporting entity’s own assumptions about the assumptions market participants would use in pricing the assets. Level 3 includes private investments that are supported by little or no market activity. The fair value hierarchy level is determined by asset class based on the lowest level of significant input. In periods of market inactivity, the observability of prices and inputs may be reduced for certain instruments. This condition could cause an instrument to be reclassified between levels. During the years ended December 31, 2015 and 2014, there were no transfers between levels. The Company measures cash equivalents at fair value on a recurring basis. The fair value of cash equivalents is determined based on “Level 1” inputs, which consist of quoted prices in active markets for identical assets. The fair value of the Company's note is determined using current applicable rates for similar instruments with similar settlement features as of the balance sheet date. The carrying value of the Company's short term debt approximates its fair value as the Company's interest rate is near current market rates for instruments with similar settlement features. The fair value of the Company's note and contingent consideration was determined using Level 3 inputs. Property and Equipment Property and equipment consists of office furniture, office and computer equipment and leasehold improvements. Expenditures for repairs and maintenance are recorded to expense as incurred, whereas major betterments are capitalized as additions to property and equipment. Property and equipment are recorded at cost and are depreciated when placed into service using the straight-line method of depreciation, based on their estimated useful lives as follows: Asset Description Estimated Useful Lives Furniture and fixtures years Office and computer equipment 3 years Leasehold improvements Shorter of the useful life or remaining lease term Upon retirement or sale, the cost of assets disposed and the related accumulated depreciation is removed from the accounts and any resulting gain or loss is recorded in the consolidated statements of operations. The Company evaluates the potential of its long-lived assets for impairment if events or changes in circumstances indicate that the carrying amount of the assets may not be fully recoverable or that the useful life of the assets is no longer appropriate. The impairment test is based on a comparison of the undiscounted cash flows expected to be generated from the use of the asset group and its eventual disposition to the carrying value of the asset group. If impairment is indicated, the assets are written down by the amount by which the carrying value of the assets exceeds the related fair value of the assets. Any write-downs are treated as permanent reductions in the carrying value of the assets. No such impairment losses have been recorded through December 31, 2015. Restricted Cash Restricted cash represents cash held in depository accounts at financial institutions to collateralize conditional stand-by letter of credits related to the Company’s Boston, Massachusetts and Zug, Switzerland facility lease agreements and the Company’s subleased Cambridge, Massachusetts facility. Restricted cash is reported as non-current unless the restrictions are expected to be released in the next 12 months. Acquisitions Business combinations are accounted for using the acquisition method of accounting. Under the acquisition method of accounting, the tangible and intangible assets acquired and the liabilities assumed are recorded as of the acquisition date at their respective fair values. The Company evaluates a business as an integrated set of activities and assets that is capable of being managed for the purpose of providing a return in the form of dividends, lower costs or other economic benefits and consists of inputs and processes that provide or have the ability to provide outputs. In an acquisition of a business the excess of the fair value of the consideration transferred over the fair value of the net assets acquired is recorded as goodwill. In an acquisition of net assets that does not constitute a business, no goodwill is recognized. The Company’s consolidated financial statements include the results of operations of an acquired business after the completion of the acquisition. In-process Research & Development In-process research & development (“IPR&D”) represents the fair value assigned to research and development assets that were not fully developed at the date of acquisition. IPR&D acquired in a business combination or recognized from the application of push-down accounting is capitalized on the Company’s consolidated balance sheet at its acquisition-date fair value. Until the project is completed, the assets are accounted for as indefinite-lived intangible assets and subject to impairment testing. Upon completion of a project, the carrying value of the related IPR&D is reclassified to intangible assets and is amortized over the estimated useful life of the asset. When performing the impairment assessment, the Company first assesses qualitative factors to determine whether it is necessary to recalculate the fair value of its acquired IPR&D. If the Company determines, as a result of the qualitative assessment, that it is more likely than not that the fair value of acquired IPR&D is less than its carrying amount, it calculates the asset’s fair value. If the carrying value of the Company’s acquired IPR&D exceeds its fair value, then the intangible asset is written down to its fair value. For the year ended December 31, 2015, the Company determined that there was an impairment related to IPR&D acquired in the Merger. As a result, the Company recorded a loss on impairment of IPR&D in the amount of $1,671 for the year ended December 31, 2015. This impairment charge was recorded within research and development expense. For the year ended December 31, 2014, the Company determined that there was no impairment of IPR&D. Intangible Assets The Company amortizes its intangible assets using the straight-line method over its estimated economic life, which ranges from six to 16.5 years. The Company evaluates the potential impairment of its intangible assets if events or changes in circumstances indicate that the carrying amount of the assets may not be fully recoverable or that the useful life of the assets is no longer appropriate. The impairment test is first based on a comparison of the undiscounted cash flows expected to be generated from the use of the asset group and its eventual disposition to the carrying value of the asset group. If impairment is indicated, the assets are written down by the amount by which the carrying value of the assets exceeds the related fair value of the assets. Any write-downs are treated as permanent reductions in the carrying value of the assets. For the years ended December 31, 2015 and 2014, the Company determined that there was no impairment of its intangible assets. Goodwill Goodwill represents the difference between the consideration transferred and the fair value of the net assets acquired under the acquisition method of accounting for push-down accounting. Goodwill is not amortized but is evaluated for impairment within the Company’s single reporting unit on an annual basis, during the fourth quarter, or more frequently if an event occurs or circumstances change that would more likely than not reduce the fair value of the Company’s reporting unit below its carrying amount. When performing the impairment assessment, the accounting standard for testing goodwill for impairment permits a company to first assess the qualitative factors to determine whether the existence of events and circumstances indicates that it is more likely than not that the goodwill is impaired. If the Company believes, as a result of the qualitative assessment, that it is more likely than not that the fair value of goodwill is impaired, the Company must perform the first step of the goodwill impairment test. The Company has determined that goodwill was not impaired as of December 31, 2015 and 2014. To date, the Company has not recognized any impairment charges related to goodwill. Revenue Recognition Multiple-Element Arrangements Under the authoritative guidance for revenue recognition related to multiple-element revenue arrangements, each deliverable within a multiple-element revenue arrangement is accounted for as a separate unit of accounting if both of the following criteria are met: (1) the delivered item or items have value to the customer on a standalone basis and (2) for an arrangement that includes a general right of return relative to the delivered item(s), delivery or performance of the undelivered item(s) is considered probable and substantially in the Company’s control. The Company considers a deliverable to have standalone value if the Company sells this item separately or if the item is sold by another vendor or could be resold by the customer. Deliverables not meeting the criteria for being a separate unit of accounting are accounted for on a combined basis. In the event the Company enters into a contract in which the deliverables are required to be separated, the Company will allocate arrangement consideration to each deliverable in an arrangement based on its relative selling price. The Company determines selling price using vendor-specific objective evidence (“VSOE”), if it exists; otherwise, the Company uses third-party evidence (“TPE”). If neither VSOE nor TPE of selling price exists for a deliverable, the Company uses estimated selling price (“ESP”) to allocate the arrangement consideration. The Company applies appropriate revenue recognition guidance to each unit of accounting. Milestones Contingent consideration from research and development activities that is earned upon the achievement of a substantive milestone is recognized in its entirety in the period in which the milestone is achieved. At the inception of each arrangement that includes milestone payments, the Company evaluates whether each milestone is substantive. This evaluation includes an assessment of whether: (a) the consideration is commensurate with either (1) the entity’s performance to achieve the milestone, or (2) the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the entity’s performance to achieve the milestone, (b) the consideration relates solely to past performance and (c) the consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. The Company evaluates factors such as the scientific, clinical, regulatory, commercial and other risks that must be overcome to achieve the respective milestone, the level of effort and investment required and whether the milestone consideration is reasonable relative to all deliverables and payment terms in the arrangement in making this assessment. Royalty Revenue Under certain license agreements to which the Company is a party, the Company receives royalty payments based upon its licensees’ net sales of products. Generally, under these agreements, the Company receives royalty payments from licensees approximately one quarter in arrears after the licensee has sold the income generating product or products. The Company recognizes royalty revenues when it can reliably estimate such amounts and collectability is reasonably assured. As such, the Company generally recognizes royalty revenues in the quarter reported to it by its licensees. Therefore, royalty revenues are recognized one quarter in arrears from the quarter in which sales by its licensees occurred. Under this accounting policy, the royalty revenues the Company recognizes are not based upon estimates and are typically reported in the same period in which the Company receives payment from its licensees. Deferred Revenue Amounts received prior to satisfying the above revenue recognition criteria are recorded as deferred revenue in the accompanying consolidated balance sheets. Amounts not expected to be recognized within 12 months from the balance sheet date are classified as long-term deferred revenue. Deferred Rent Deferred rent, included within other non-current liabilities, net of the current portion recorded in accrued expenses in the consolidated balance sheet, consists of the difference between cash payments and the recognition of rent expense on a straight-line basis for the facilities the Company occupies. The Company’s lease for its Boston, Massachusetts, facility provides for a rent-free period as well as fixed increases in minimum annual rental payments. The total amount of rental payments due over the lease term is being charged to rent expense ratably over the life of the lease. Other Liabilities In conjunction with the Merger, as discussed in Note 4, the Company assumed a sublease liability for Zalicus’ Cambridge, Massachusetts facility, which is included within other non-current liabilities, net of the current portion recorded in other current liabilities on the consolidated balance sheet. The liability represents the fair value of the difference between the total sublease payments to be received by the Company and the total payment obligation for the Company per the lease agreement. The Company has an operating lease for office space in Boston, Massachusetts. In connection with this lease, the Company and its third party lessor agreed that the lessor would pay for certain leasehold improvements on behalf of the Company. These leasehold improvements are accounted for as a lease incentive obligation, which is recorded in other non-current liabilities, net of the current portion recorded in other current liabilities. This liability is being amortized over the life of the lease and as a reduction to rent expense. Organizational Costs All organizational costs are expensed as incurred. Research and Development Costs Research and development costs are charged to expense as incurred in performing research and development activities. The costs include employee compensation, facilities and overhead, clinical study and related clinical manufacturing costs, regulatory and other related costs. Nonrefundable advanced payments for goods or services to be received in the future for use in research and development activities are deferred and capitalized. The capitalized amounts are expensed as the related goods are delivered or the services are performed. Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as patient enrollment, clinical site activations, or information provided to the Company by its vendors with respect to their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the consolidated financial statements as prepaid or accrued research and development expense, as the case may be. Stock-Based Compensation The Company accounts for grants of stock options and restricted stock based on their grant date fair value and recognizes compensation expense over the award’s vesting period. The Company estimates the fair value of stock options as of the date of grant using the Black-Scholes option-pricing model and restricted stock based on the fair value of the underlying common stock, which is determined as the closing trading price of the Company’s common stock subsequent to the Merger, in which the Company’s common stock became publicly traded, and was determined by management prior to the Merger (Note 15). Stock-based compensation expense represents the cost of the grant date fair value of employee stock option grants recognized over the requisite service period of the awards (usually the vesting period) on a straight-line basis, net of estimated forfeitures. The expense is adjusted for actual forfeitures at the end of each reporting period. Stock-based compensation expense recognized in the consolidated financial statements is based on awards that are ultimately expected to vest. Stock-based awards issued to nonemployees are accounted for based on the fair value of such services received or of the equity instruments issued, whichever is more reliably measured. Awards are revalued at each reporting date and upon vesting and are expensed on a straight-line basis over the vesting period. Income Taxes The Company accounts for income taxes under the liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in operations in the period that includes the enactment date. The Company recognizes net deferred tax assets through the recording of a valuation allowance to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future, in excess of its net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions on the basis of a two-step process whereby: (1) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50% likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability. Net Loss Per Share Basic net loss per share is calculated by dividing net loss by the weighted average shares outstanding during the period, without consideration for common stock equivalents. During periods of income, the Company allocates participating securities a proportional share of income determined by dividing total weighted average participating securities by the sum of the total weighted average common shares and participating securities (the “two-class method”). The Company’s convertible preferred stock, which was exchanged for Public Epirus Common Stock in the Merger, participated in any dividends declared by the Company and were therefore considered to be participating securities. Participating securities have the effect of diluting both basic and diluted earnings per share during periods of income. During periods of loss, the Company allocates no loss to participating securities because they have no contractual obligation to share in the losses of the Company. Diluted net loss per share attributable to common stockholders is calculated by adjusting weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury-stock and if-converted methods. For purposes of the diluted net loss per share calculation, common stock equivalents have been excluded from the calculation of diluted net loss per share, as their effect would be anti-dilutive for all periods presented. Therefore, basic and diluted net loss per share were the same for all periods presented. Comprehensive Loss Comprehensive loss is the change in equity of a company during a period from transactions and other events and circumstances, excluding transactions resulting from investments by owners and distributions to owners. Recent Accounting Pronouncements Going Concern In August 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to continue as a Going Concern. This update is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern within one year of the date of issuance of the entity’s financial statements and to provide related footnote disclosures. This guidance is effective for fiscal years beginning after December 15, 2016, with early application permitted. The Company is currently evaluating what effect, if any, the adoption of this guidance will have on the disclosures included in its consolidated financial statements. Debt Issuance Costs In April 2015, the FASB issued ASU No. 2015-03 , Interest—Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs , which requires that debt issuance costs be presented in the balance sheet as a deduction from the carrying amount of the related liability, rather than as a deferred charge. The updated guidance is effective retroactively for financial statements covering fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. The Company early adopted ASU No. 2015-03 effective December 31, 2015. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements and footnote disclosures. Technical Corrections and Improvements In June 2015, the FASB issued ASU No. 2015-10, Technical Corrections and Improvements . This update covers a wide range of Topics in the ASC. The amendments in this update represent changes to clarify the ASC, correct unintended application of guidance, or make minor improvements to the ASC that are not expected to have a significant effect on current accounting practice or create a significant administrative cost to most entities. Additionally, some of the amendments will make the ASC easier to understand and easier to apply by eliminating inconsistencies, providing needed clarifications, and improving the presentation of guidance in the ASC. The amendments in this update that require transition guidance are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. All other amendments will be effective upon the issuance of this update. The Company does not anticipate that the adoption of this standard will have a material impact on its consolidated financial statements and footnote disclosures. Revenue Recognition In July 2015, the FASB deferred the effective date for ASU No. 2014-09, Revenue from Contracts with Customers, by one year. This update will supersede the revenue recognition requirements in Revenue Recognition (Topic 605) and requires entities to recognize revenue in a way that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. This update is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period, which for the Company is January 1, 2018. Early application is permitted for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. The update can be applied retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of the change recognized at the date of the initial application in retained earnings. The Company is currently evaluating the potential impact the adoption of this update will have on its consolidated financial statements and has not yet selected a transition method. Business Combinations In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement - Period Adjustments . This update eliminates the requirement to restate prior period financial statements for measurement period adjustments following a business combination. The update requires that the cumulative impact of a measurement period adjustment (including the impact on prior periods) be recognized in the reporting period in which the adjustment is identified. The prior period impact of the adjustment should be either presented separately on the face of the income statement or disclosed in the notes. The update is effective for fiscal years beginning after December 15, 2015. The adoption of this update is not expected to have a material impact on the Company’s financial position or results of operations. Income Taxes During November 2015, the FASB issued ASU 2015-17, “Balance Sheet Classification of Deferred Taxes”, which simplifies the presentation of deferred income taxes. This ASU requires that deferred tax assets and liabilities be classified as non-current in a statement of financial position. The standard is effective for public companies for fiscal years beginning after De

Business Agreements

Business Agreements	12 Months Ended
	Dec. 31, 2015
Business Agreements
Business Agreements	3. Business Agreements Sun Pharmaceutical Industries (formerly known as Ranbaxy Laboratories) In January 2014, the Company and Sun Pharmaceutical Industries Limited (formerly known as Ranbaxy Laboratories Limited) (“Sun”) executed a royalty-bearing and non-transferrable license agreement (“Sun License Agreement”) for BOW015 to Sun for a broad range of territories including India, selected Southeast Asian markets and North Africa. Under the terms of the Sun License Agreement, the Company and Sun will pursue the commercialization of BOW015 in India and Sun received the right to sell BOW015 in the territories specified in the agreement. Sun does not have the right to manufacture BOW015. Sun made an upfront payment of $500 upon the execution of the Sun License Agreement and is obligated to pay the Company up to $1,000 if certain development and regulatory approval milestones are achieved and up to $10,000 if certain sales milestones are achieved. Additionally, the Company is entitled to receive royalties in the mid-teens on net sales in the territories, which royalties are subject to reduction or renegotiation in certain limited circumstances. Under certain circumstances of uncured breach by the Company and termination of the Sun License Agreement by Sun, monetary damages of $500 , would be due to Sun . Unless terminated earlier in accordance with the terms of the agreement, the Sun License Agreement expires 20 years following the first commercial sale in the territories. Under the Sun License Agreement, Sun is responsible for all activities related to the commercialization of BOW015 in the territories. The Company is responsible for performing the development activities required for obtaining regulatory approval in India, joint steering committee participation and clinical and commercial supply of product. The Company also agreed to perform the development activities required to obtain regulatory approval in other parts of the territories. These activities and the related fees will be agreed upon by Sun and the Company in future written agreements. The Company has determined that the deliverables under the Sun License Agreement are the license, development activities related to regulatory approval in India, joint steering committee services and the obligation to supply clinical and commercial product. The Company’s obligation to perform future development activities to obtain regulatory approval in other parts of the territories is not a deliverable at the inception of the agreement as the Company will be compensated separately for these activities, and it is uncertain at this time if the Company will ever be requested to perform these activities by Sun. The Company determined that the license and the other activities and services do not have standalone value apart from the requirement for the Company to deliver commercial material. Sun has not been granted a license to manufacture BOW015, which prevents them from using the license and related services for their intended purpose without the involvement of the Company. Therefore, the deliverables are not separable and represent one single unit of accounting. When multiple deliverables are accounted for as a single unit of accounting, the Company bases its revenue recognition pattern on the last to be provided deliverable. As a result, no revenue was recognized until delivery of the commercial supply began. All amounts received from Sun were recorded as deferred revenue prior to the delivery of the commercial supply began. The arrangement includes the delivery of commercial material and therefore does not qualify for the milestone method of revenue recognition as the agreement is not a research and development arrangement. As a result, upon achievement of a milestone, the amounts will be included in the total arrangement consideration. In January 2014 , the Company invoiced Sun $125 related to the filing for approval in India. In March 2014, the Drug Controller General in India approved BOW015 for commercial sale to the Indian market, upon which a payment from Sun of $250 became due and payable and was invoiced in April 2014. In September 2014, the Company executed a supply agreement with Sun, upon which an additional milestone payment of $125 became due. On September 9, 2014, the Company entered into an amendment (the “Sun License Amendment”) to the Sun License Agreement. The Sun License Amendment amended the Sun License Agreement to revise (i) the royalty tiers for net sales based on final product sale forecasts and supply costs in the territory, and (ii) Sun’s obligations with respect to minimum annual sales targets in any given country such that the obligations are subject to a final grant of approval for BOW015 by the applicable regulatory authority for all indications as have been granted for the innovator product in such country. Other than as set forth in the Sun License Amendment, the Sun License Agreement remains in full force and effect following the parties’ execution of the Sun License Amendment. In September 2014, the Company and Sun entered into a supply agreement for BOW015 under which the Company, through its third party manufacturing supplier, will provide Sun with finished products for clinical use, regulatory use and commercialization in accordance with the Sun License Agreement. Under the terms of the supply agreement, the Company’s designated manufacturer will receive consideration from Sun for commercial finished product. Unless terminated earlier in accordance with terms, the Company’s supply agreement with Sun expires 10 years from the effective date, subject to five two -year automatic renewal periods. In November 2014, the Company launched Infimab TM (BOW015) and Sun completed the first commercial sale of Infimab in India, signifying commercial supply of product has commenced. Upon this event, an additional milestone of $250 became due and payable and the Company began to recognize revenue, over the remaining term of the Sun License Agreement, associated with the upfront and milestone payments which were initially recorded as deferred revenue, excluding $500 which will remain deferred until the previously discussed breach and termination right lapses. As subsequent milestones are achieved, these payments will be recognized as revenue over the remaining term of the Sun License Agreement, including the five two -year automatic renewal periods. Royalty revenues from sales of Infimab will be recognized one quarter in arrears in conjunction with the Company’s accounting policy (Note 2). For the fiscal years ended December 31, 2015 and 2014, the Company recorded royalty revenue of $119 and $4 , respectively, related to commercial sales under this agreement. The Company has invoiced Sun for a total of $1,250 in milestone payments, including the upfront payment, and received payments totaling $1,250 through December 31, 2015. Mabxience, S.A. On May 13, 2015, the Company entered into an Exclusive License Agreement (the “MabX Agreement”) with mAbxience S.A., a company organized and existing under the laws of Uruguay and a wholly owned subsidiary of CHEMO Group (“Mabxience”), for the development, manufacturing and commercialization of BOW015. Under the MabX Agreement, the Company licensed to Mabxience an exclusive, royalty-bearing, non-transferable, sublicenseable license to develop, manufacture, commercialize and distribute BOW015 in the Mabxience territory. The Mabxience territory consists of Argentina, Chile, Ecuador, Paraguay, Uruguay and Venezuela. Pursuant to the MabX Agreement, Mabxience will be solely responsible, at its expense, for all aspects of commercialization of licensed product in the Mabxience territory. As consideration for the license granted to Mabxience, the Company is eligible to receive certain non-refundable, non-creditable milestone payments up to $1,500 upon the achievement of certain commercial sales in the Mabxience territory. Specifically, the Company will earn $250 upon the first commercial sale for each first commercial sale in each of the territory countries. In addition, the Company is eligible to receive certain royalty payments in the high teen percentages and distribution payments from Mabxience. These potential milestone and royalty payments have not been earned as of December 31, 2015. Unless terminated earlier in accordance with the terms of the agreement or extended by mutual agreement of the parties, the MabX Agreement expires 15 years following the first commercial sale of BOW015 in the Mabxience territory. Polpharma On July 13, 2015, the Company entered into a Collaboration Agreement (the “Polpharma Collaboration Agreement”) with Swiss Pharma International AG, an affiliate of Pharmaceutical Works Polpharma S.A. (together with Swiss Pharma International AG, “Polpharma”), for the development and commercialization in certain designated territories of the Company’s product candidates, BOW015, BOW050 and BOW070. The designated territories include the European Union (with the exception of Austria, Belgium, Denmark, Finland, Luxembourg, the Netherlands and Sweden, which are reserved for the Company), together with certain countries in the Middle East, Turkey, Russia, and other countries comprising the Commonwealth of Independent States, or CIS. The Company will also retain exclusive rights for the three products in North America and other markets outside of the designated territories, including Switzerland and Norway. Within the designated territories, the Polpharma Collaboration Agreement contains exclusivity provisions such that each of the Company and Polpharma agrees not to exploit any other biosimilar product based on reference product other than the three products licensed under the Polpharma Collaboration Agreement, subject to limited exceptions. Under the Polpharma Collaboration Agreement, the Company and Polpharma have cross-licensed all intellectual property rights and technology relating to their applicable biosimilar development programs to enable the parties to develop and commercialize the three above-mentioned biosimilar products in the designated territories and the Company to develop and commercialize these biosimilar products outside of the designated territories. The three product programs will consist of process development, clinical trials, regulatory, manufacturing and commercialization activities in the designated territories. For such programs, the Company will lead the global product development and clinical programs and will also be responsible for process development, scale-up and manufacturing in the designated territories, both parties will collaborate on regulatory filings in the designated territories, and Polpharma will be responsible for the commercialization of the products in the designated territories. Polpharma has the right to be a second source manufacturer for any of the products, including a right to perform fill and finish production for all three products, subject to certain conditions. A joint management committee will oversee the collaboration on behalf of both parties. Polpharma will bear 51% and the Company will bear 49% of total costs associated with the development programs for the three products in the designated territories. For clinical trial costs incurred in connection with global development, the cost sharing ratio is changed from 100% to 38% of total costs. As a result, Polpharma will bear 19% and the Company will bear 81% of total clinical trial costs incurred. Following commercial launch, profits and losses for the three products in the designated territories will be split 51% for Polpharma and 49% for the Company. For the fiscal year ended December 31, 2015, the Company recorded revenue of $235 related to this agreement. The Company invoiced and received a payment in the amount of $760 from Polpharma in November 2015. As of December 31, 2015, the Company had a deferred revenue balance of $525 related to the payment received for services that will be performed in the first quarter of 2016. Livzon Mabpharm In September 2014, the Company entered into an Exclusive License and Collaboration Agreement (the “Livzon Agreement”) with Livzon Mabpharm Inc. (“Livzon”) for the global development and commercialization of certain antibodies or related biological compounds, including the Company’s BOW015, a biosimilar version of infliximab. Under the Livzon Agreement, the Company and Livzon each agreed to grant the other party, in the other party’s territory, exclusive, royalty-bearing licenses under certain patent rights and know-how to develop, manufacture and commercialize BOW015 and up to four additional compounds chosen by mutual agreement of the parties (collectively, the “Collaboration Compounds”). Livzon’s territory consists of China, Hong Kong, Macau and Taiwan (the “Livzon Territory”), and the Company’s territory consists of the rest of the world. The parties share pre-clinical development expenses for each Collaboration Compound based on certain factors specific to each compound. Each party bears the responsibility and expenses for clinical development and commercialization of each Collaboration Compound in its territory. Livzon will be the preferred supplier of each Collaboration Compound for pre-clinical, clinical, and commercialization purposes, subject to Livzon’s satisfaction of certain performance criteria and subject to the negotiation of a separate supply agreement. As consideration for the license granted to Livzon to develop and commercialize BOW015, the Company is eligible to receive from Livzon a nonrefundable milestone payment of $2,500 upon the achievement of a specified regulatory milestone in the Livzon Territory. The Company is also eligible to receive from Livzon tiered royalties based on a percentage of net sales of BOW015 products in the Livzon Territory ranging from the low- to high-single digits. Any future Collaboration Compounds have cross-milestone and royalty obligations in amounts to be mutually agreed upon at a later date. If not terminated earlier or extended by mutual agreement of the parties, the Livzon Agreement expires in its entirety 20 years from the effective date. The Company determined that the substantive terms of the Livzon Agreement are those relating to the license granted to Livzon to develop and commercialize BOW015 and the related Technology Transfer, as defined in the Agreement, which is the know-how to develop and manufacture BOW015 as described above. Under the Livzon Agreement, Livzon is responsible for all activities related to the commercialization of BOW015 in the Livzon Territory. The Company is responsible for the Technology Transfer and a small amount of advisory services to Livzon. The Company has determined that the deliverables under the Livzon Agreement are the license, Technology Transfer and a small amount of advisory services. Additional obligations that may arise under the Livzon Agreement are not deliverables at the inception of the Livzon Agreement as the Company will be compensated separately for these activities, and it is uncertain at this time if the Company will ever be requested to perform these activities by Livzon. The Company determined that the license, Technology Transfer and advisory services do not have standalone value. The Technology Transfer is required to enable Livzon to manufacture BOW015. Without such capability, Livzon would not be able to use the license and services for their intended purpose without the involvement of the Company. Therefore, the deliverables are not separable and represent one single unit of accounting. When multiple deliverables are accounted for as a single unit of accounting, the Company bases its revenue recognition pattern on the last to be provided deliverable. The Company determined that the specified regulatory milestone is not substantive due to the lack of development activities required from the Company subsequent to the execution of the Livzon Agreement. As a result of the factors above, no revenue will be recognized until the milestone is achieved and the $2,500 will be recognized as revenue after the milestone is achieved, over the remaining period of the Technology Transfer. As of December 31, 2014, no amounts have been paid and no amounts have become due and payable under the Livzon Agreement. On September 24, 2015, the Company entered into a New Collaboration Compound Supplement to the Collaboration Agreement (the “Livzon Supplement Agreement”) with Livzon. The Livzon Supplement Agreement amends the Livzon Agreement to add the Company’s product candidate, BOW070, a biosimilar version of Actemra ® (tocilizumab), as one of the additional compounds to be developed and commercialized pursuant to the terms of the Livzon Agreement. Under the Livzon Supplement Agreement, the Company and Livzon each granted the other party, in the other party’s territory, exclusive, royalty-bearing licenses under certain patent rights and know-how to develop, manufacture and commercialize BOW070. Livzon’s territory consists of China, Hong Kong, Macau and Taiwan, and the Company’s territory consists of the rest of the world. Livzon will be responsible for certain pre-clinical development activities, including analytical and process development, characterization work and formulation development, with the costs for such pre-clinical development activities to be borne by both parties, and each party will be responsible at its sole expense for clinical development, regulatory filings and approvals, and commercialization of BOW070 in each such party’s territory. Livzon will be a preferred supplier of BOW070 for clinical and commercialization purposes, subject to Livzon’s satisfaction of certain performance criteria. As part of such preferred supplier designation, the parties have agreed to certain minimum supply price and purchase commitments following commercial launch of BOW070. The Company will pay a total of $4,500 to Livzon to complete the pre-clinical development activities, consisting of: (i) an initial cash payment of $1,500 within 10 days of entry into the Livzon Supplement Agreement, which amount was paid on October 10, 2015, and (ii) three additional cash payments of $1,000 each upon the achievement of certain pre-clinical development milestones. The Company is expensing costs under the Supplement Agreement, as incurred, over the period that the work is performed (currently estimated at 18 months). For the fiscal year ended December 31, 2015, the Company recorded expense of $500 under the Livzon Supplement Agreement. Each of the parties is eligible to receive from the other party royalty payments, based on gross margin of BOW070 in the other party’s territory, ranging from the low- to mid-single digit percentages. As of December 31, 2015, Livzon owned approximately 6.4 % of the Company’s issued and outstanding common stock.

Merger

Merger	12 Months Ended
	Dec. 31, 2015
Merger
Merger	4. Merger As described in Note 1, “Organization,” on July 15, 2014, the Company completed the Merger with Zalicus. Pursuant to the Merger Agreement, each share of capital stock of Private Epirus was exchanged for 0.13259 shares of Public Epirus Common Stock (the “Exchange Ratio”). All Private Epirus stock options granted under the Private Epirus stock option plans (whether or not then exercisable) that were outstanding prior to the effective time of the Merger, and all warrants to purchase Private Epirus capital stock that were outstanding prior to the effective time of the Merger were exchanged at the same ratio as described below. Upon the consummation of the Merger, equity holders of Private Epirus were issued an aggregate of 10,288,180 shares of Public Epirus Common Stock, plus 1,152,042 and 21,996 shares of Public Epirus Common Stock which could be issued in the future upon exercise of stock options and warrants, respectively. After the Effective Time, all outstanding and unexercised Private Epirus stock options assumed by Zalicus may be exercised solely for shares of Public Epirus Common Stock and all outstanding and unexercised warrants to purchase Private Epirus capital stock may be exercised solely for shares of Public Epirus Common Stock. The number of shares of Public Epirus Common Stock subject to each Private Epirus stock option or warrant assumed by Zalicus was determined by multiplying (a) the number of shares of Private Epirus common stock that were subject to such Private Epirus stock option or warrant, as in effect immediately prior to the Effective Time, by (b) the exchange ratio, as defined in the merger agreement, and rounding the resulting number down to the nearest whole number of shares of Public Epirus Common Stock. The per share exercise price for the Public Epirus Common Stock issuable upon exercise of each Private Epirus stock option or warrant assumed by Zalicus was determined by dividing (a) the per share exercise price of Private Epirus common stock subject to such Private Epirus stock option or warrant, as in effect immediately prior to the Effective Time, by (b) the Exchange Ratio and rounding the resulting exercise price up to the nearest whole cent. All Zalicus equity awards granted prior to the Merger remained legally outstanding. The Merger has been accounted for as a reverse acquisition under the acquisition method of accounting with Private Epirus treated as the accounting acquirer and Zalicus treated as the acquired company for financial reporting purposes. Private Epirus was determined to be the accounting acquirer based upon the terms of the Merger and other factors, such as relative voting rights and the composition of the combined company’s board of directors and senior management. Accordingly, the Zalicus tangible and identifiable intangible assets acquired and liabilities assumed were recorded at fair value as of the date of acquisition, with the excess consideration transferred recorded as goodwill. See Note 15, “Stock-Based Compensation,” for additional details regarding the accounting treatment for the equity awards of Private Epirus and Zalicus. The acquisition-date fair value of the consideration transferred is as follows: Number of shares of Public Epirus Common Stock owned by Zalicus stockholders (1) Multiplied by the price per share of Public Epirus Common Stock (2) $ Fair value of shares of Public Epirus Common Stock owned by Zalicus stockholders $ Acquisition-date fair value of assumed Zalicus equity awards attributable to precombination services (3) $ Total consideration transferred $ (1) The stock transferred in the table above is comprised of 2,610,871 common shares outstanding at the time of the Merger plus 25,000 restricted stock units (RSUs) that vested immediately upon the closing of the Merger. The fair value of shares of Public Epirus Common Stock owned by Zalicus shareholders of $31,104 includes approximately $1 related to fractional shares resulting from the Reverse Stock Split. (2) The shares outstanding are multiplied by the closing trading price of Public Epirus Common Stock as of the Merger date. (3) Consideration transferred includes approximately $220 of Zalicus equity awards assumed and deemed attributable to precombination services to Zalicus. The fair value of the equity awards at July 15, 2014 was determined using a Black-Scholes option-pricing model with the following ranges of assumptions: exercise price of $14.70 per share to $591.00 per share; underlying stock value of $11.80 per share; expected volatility of 66.02%; expected term of 0.1 years to 6.0 years; and risk-free interest rate of 1.91% . The following table summarizes the estimated fair values of the assets acquired and liabilities assumed at the date of acquisition: July 15, 2014 Cash and cash equivalents $ In-process research and development Goodwill Restricted cash Other assets Total assets acquired Accounts payable Accrued expenses Other current liabilities Other liabilities Deferred tax liabilities Total liabilities assumed Total net assets acquired $ The purchase price allocation was prepared on a preliminary basis and was subject to change as additional information becomes available concerning the tax basis of the assets acquired and the liabilities assumed. All adjustments to the purchase price allocation were made within one year from July 15, 2014, the acquisition date. For acquired working capital accounts such as accounts receivable, prepaid expenses and other current assets, accounts payable and certain accrued expenses, the Company determined that no fair value adjustments were required due to the short timeframe until settlement for these assets and liabilities. The fair value of the IPR&D was determined using the multi-period excess earnings method, a variation of the income approach, including a discount rate of 13.1% applied to the projected cash flows. The Company believes the assumptions used are consistent and representative of those a market participant would use in estimating the fair value of the IPR&D. The Company will not begin amortizing the IPR&D asset until the research and development is complete and the asset is reclassified to a definite-lived amortizing asset. Goodwill is calculated as the difference between the 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 was recorded as an indefinite-lived asset and is not currently being amortized but is tested for impairment on an annual basis or when indications of impairment exist. Other liabilities of $391 and $376 of other current liabilities relates to a sublease liability assumed for Zalicus’ Cambridge, Massachusetts facility. The liability represents the fair value of the difference between the total sublease payments and the total payments for the facility per the lease agreement. The original lease and the sublease agreement terminate in January 2017. The deferred tax liability represents the temporary difference associated with the $5,500 value of the IPR&D asset, which is not deductible for tax purposes. During the year ended December 31, 2015, the Company completed its analysis of the tax basis of the IPR&D asset and reduced the preliminary deferred tax liability of $2,166 to $1,430 resulting in an adjustment to goodwill of $736 . The operating results of Zalicus for the period from July 16, 2014 to December 31, 2014, including an operating loss of $25 , have been included in the Company’s consolidated financial statements as of and for the year ended December 31, 2014. During the year ended December 31, 2015, the operating results for Zalicus were immaterial. The Company incurred a total of $5,779 in transaction costs in connection with the Merger, excluding Zalicus transaction costs, which were included in general and administrative expense within the consolidated statements of income for the year ended December 31, 2014. The following supplemental unaudited pro forma information presents the Company’s financial results as if the acquisition of Zalicus had occurred on January 1, 2013: Year Ended December 31, 2014 2013 Total revenues, net $ $ Net loss $ $ The above unaudited pro forma information was determined based on the historical GAAP results of the Company and Zalicus. The unaudited pro forma consolidated results are not necessarily indicative of what the Company’s consolidated results of operations actually would have been if the acquisition was completed on January 1, 2013. The unaudited pro forma consolidated net loss includes pro forma adjustments primarily relating to the following non-recurring items directly attributable to the business combination: (1) Elimination of $8,673 of transaction costs for both the Company and Zalicus from the year ended December 31, 2014, and inclusion of these transaction costs in the year ended December 31, 2013; (2) Elimination of $355 of stock-based compensation expense related to the acceleration of vesting of previously unvested Zalicus awards in connection with the Merger from the year ended December 31, 2014, and inclusion of this charge in the year ended December 31, 2013; (3) Elimination of $1,980 of expense related to severance agreements from the year ended December 31, 2014, and inclusion of this charge in the year ended December 31, 2013; and (4) Elimination of $222 and $789 of other expense related to the change in the fair values of liability-classified warrants from the years ended December 31, 2014 and 2013, respectively, as the Company’s outstanding warrants were reclassified to equity in connection with their exchange in the Merger.

Acquisition

Acquisition	12 Months Ended
	Dec. 31, 2015
Acquisition
Acquisition	5. Acquisition On September 9, 2015, the Company entered into a stock purchase agreement (the “Stock Purchase Agreement”) whereby it acquired 100% of the voting interests of Bioceros Holding B.V. (“Bioceros”), enabling the Company to expand its biosimilar pipeline and vertically integrate product development capabilities. Bioceros was a privately-held, Netherlands-based biopharmaceutical R&D company focused on the development of mAbs and generation of GMP-ready cell lines. From the Bioceros platform, the Company will expand its pipeline with the addition of three preclinical product candidates: BOW080, a proposed biosimilar to eculizumab (reference biologic Soliris ® ); BOW090, a proposed biosimilar to ustekinumab (reference biologic STELARA ® ); and BOW100, a proposed biosimilar to golimumab (reference biologic SIMPONI ® ). Soliris, marketed by Alexion Pharmaceuticals, is currently indicated to treat ultra-rare blood disorders, including paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS). SIMPONI and STELARA are marketed by Janssen Pharmaceuticals and indicated in inflammatory and immune mediated disorders. The Company will pay a total of $14,100 in consideration consisting of: (i) an initial cash payment of $3,400 at closing, (ii) a second cash payment of $1,700 , to be paid on the first anniversary of the closing date , (iii) an initial issuance of 788,960 shares of the Company’s common stock, $0.001 par value per share (the “Common Stock”), with a value of $4,000 using a 10 day pre-closing date average price for issuance of $5.07 (value of $4,568 on acquisition date) and (iv) a second issuance of shares of Common Stock with a value of $5,000 , calculated based on the Company’s stock price as set forth in the Stock Purchase Agreement, to be issued on the date that is six months after the closing date (“Second Installment Shares”) , subject to the Company’s setoff rights with regard to the second cash payment and Second Installment Shares. Of the Second Installment Shares, shares with an undiscounted value of $1,015 are to be issued to Bioceros key employees and are subject to those employees’ continued employment. In addition, the shareholders of Bioceros would receive a pro rata share of a net cash payout equal to the aggregate amount of: (a) Bioceros’ net working capital as the acquisition date; plus (b) revenue agreements signed from select Bioceros customers subsequent to the acquisition date and through December 31, 2015; in excess of (c) $1,200 , calculated as set forth in the Stock Purchase Agreement. As of September 9, 2015, the Company estimated this amount to be $409 . Second Installment Shares As described above, shares with an undiscounted value of $1,015 from the Second Installment Shares are to be issued to Bioceros key employees and are subject to those employees’ continued employment. Pursuant to the Stock Purchase Agreement, 75% of the shares to be issued to Bioceros key employees on March 9, 2016 in connection with the Second Installment Shares will be held in an escrow account and released in three equal installments 12 , 18 and 24 months after the closing date, unless the employee is terminated for cause or voluntarily resigns prior to each release date. The other 25% will be issued as of March 9, 2016, unless the employee is terminated for cause or voluntarily resigns prior to this date. As a result, the consideration related to such $1,015 of shares was determined to be attributable to post-combination service to Epirus and will be recognized as stock-based compensation expense by the combined company as the shares vest. The Company recognized $126 of stock-based compensation expense related to the Second Installment Shares for the key employees in the consolidated statement of operations and comprehensive loss for the year ended December 31, 2015. The acquisition-date fair value of the consideration transferred is as follows: Initial equity consideration paid at closing Initial shares issued to Bioceros shareholders Price per Epirus share at issuance $ $ Initial cash consideration paid at closing Total consideration paid at closing Settlement of preexisting Epirus accounts payable to Bioceros (1) Second Installment Shares, excluding key employee stock compensation expense (2) Net cash payout (3) Final payment of cash consideration (4) Preliminary estimated purchase price $ (1) Represents the settlement of preexisting accounts payable to Bioceros as a result of activity prior to the transaction . (2) Represents the fair value of the undiscounted $3,985 of Second Installment Shares to be paid and issued on March 9, 2016, which excludes the undiscounted $1,015 of shares to be issued to Bioceros key employees contingent upon the delivery of postcombination service to the Company, as described above. This amount has been recorded as a liability on the Company’s consolidated balance sheet, because it represents an obligation to issue a variable number of shares based on a fixed dollar amount of $3,985 , and recorded at fair value utilizing a discount rate of 10.7% . (3) Represents the fair value of the net cash payout to be made pursuant to the Stock Purchase Agreement. This amount has been recorded as a contingent consideration liability on the Company’s consolidated balance sheet as of September 9, 2015 and recorded at fair value utilizing a discount rate of 10.7% . The amount of the net cash payout is dependent on revenue agreements signed from select Bioceros customers subsequent to the acquisition date and through December 31, 2015 . (4) Represents the fair value of the final cash payment of $1,700 , which, pursuant to the Stock Purchase Agreement, the Company will pay on September 9, 2016. This amount has been recorded as a liability on the Company’s consolidated balance sheet as of September 9, 2016 and recorded at fair value utilizing a discount rate of 10.7% . The following table summarizes the preliminary estimated fair values of the assets acquired and liabilities assumed at the date of acquisition: (in thousands) Cash and cash equivalents $ Deferred tax assets Accounts receivable Prepaid expenses and other current assets Property and equipment, net Intangible assets, net Goodwill Accounts payable Accrued expenses and other current liabilities Deferred revenue Deferred tax liabilities Net assets acquired $ During the measurement period, the Company made adjustments to the provisional amounts reported as the estimated fair values of assets acquired and liabilities assumed as part of the Acquisition. Compared to the provisional values reported as of September 30, 2015, the fair values presented in the table above reflect increases to cash and cash equivalents of $56 , intangible assets of $1,199 , accounts payable of $25 and decreases to prepaid expenses, other current assets and accounts receivable of $112 , goodwill of $1,478 , accrued expenses of $232 , deferred tax assets of $168 and deferred tax liability of $300 . As of December 31, 2015, the Company evaluated the net cash payout liability of $ 4 09 and reduced the fair value to $0 . This reduction was recorded as a credit to general and administrative expenses in the Company’s consolidated statement of operations for the fiscal year ended December 31, 2015. As of December 31, 2015, the liability associated with the Second Installment shares and the final cash payment were $3,909 and $1,584 , respectively, and are presented on the consolidated balance sheet as accrued purchase price liability. In March 2016, there was an amendment to the Stock Purchase Agreement (Note 22). The purchase price allocation has been prepared on a preliminary basis and is subject to change as additional information becomes available concerning the fair value and tax basis of the assets acquired and the liabilities assumed. The purchase price allocation will remain preliminary until Epirus completes a final valuation of the assets acquired and liabilities assumed, including deferred tax assets and liabilities, deferred revenue and the identification and valuation of all intangible assets, as of the transaction closing date. The excess of consideration transferred over the estimated fair value of net identifiable assets acquired will be allocated to goodwill, which represents the expected synergies between the companies and acquired workforce. Goodwill is not expected to be deductible for tax purposes. The final determination of the allocation of consideration transferred is expected to be completed as soon as practicable, but will in no event exceed one year from September 9, 2015, the closing date. The final amounts allocated to assets acquired and liabilities assumed could differ significantly from the amounts presented above. For acquired working capital accounts such as accounts receivable, prepaid expenses and other current assets, including deferred tax assets, accounts payable and certain accrued expenses, Epirus determined that no preliminary fair value adjustments were required due to the short timeframe until settlement for these assets and liabilities. The Company acquired gross contractual accounts receivable of $49 , which it determined represents fair value and expects to collect in full. Intangible asset, or acquired know how technology, currently represent the preliminary estimated fair value for the CHO BC® cell line platform and cell line technology platform which will be the platform for future research. Based on the estimated time to commercialization and other factors, the intangible asset is being amortized over a six year expected useful life, which is the estimated period of time the Company expects to receive benefit from the platform during its development processes. The estimated fair value of the intangible was determined based on a cost approach. The present value of the investment costs was then determined utilizing an estimated risk-adjusted discount rate. The estimated fair value may be adjusted based upon the final valuation and any such adjustments could be significant. The final valuation is expected to be completed within one year from the acquisition closing date. If the platform becomes impaired or is abandoned, the carrying value of the related intangible asset will be written down to its fair value and an impairment charge will be recorded in the period in which the impairment occurs. Goodwill represents the excess of the preliminary estimated purchase price over the preliminary estimated fair value of the assets acquired and liabilities assumed and recognizes results from the expected synergies from combining operations of the Bioceros technical team’s expertise and the Company’s existing pipeline and management expertise. The Company believes that the addition of Bioceros staff and capabilities, combined with existing in-house expertise, provides the Company with a strong technical foundation to accelerate product development and optimize product quality. Goodwill will not be amortized, but will be evaluated for impairment on an annual basis or more frequently if an event occurs or circumstances change that would more-likely-than-not reduce the fair value below its carrying amount. In the event that Epirus determines that the value of goodwill has become impaired, an impairment charge will be recorded in the period in which the determination is made. Deferred revenue balances were preliminarily adjusted to amounts that represent the estimated costs to fulfill the underlying obligations plus a normal profit margin, consistent with what the Company determined to be a market participant’s estimate of such costs and profit margin. The deferred tax liability relates to the temporary difference associated with the preliminary estimated value of the intangible asset and has been estimated using a 25% effective tax rate. The operating results of Bioceros for the period from September 10, 2015 to December 31, 2015, include net revenue of $ 186 and net loss of $96 which have been included in the Company’s consolidated financial statements as of and for the year ended December 31, 2015. The Company incurred a total of approximately $ 754 in transaction costs in connection with the transaction, excluding Bioceros transaction costs, which were included in selling, general and administrative expense within the consolidated statement of operations and comprehensive loss for the year ended December 31, 2015. The following supplemental unaudited pro forma information represents the Company’s financial results as if the acquisition had occurred on January 1, 2014. Years Ended December 31, 2015 2014 Total revenues, net $ $ Net loss $ $ The above unaudited pro forma information was determined based on the historical GAAP results of the Company and Bioceros. The unaudited pro forma consolidated results are not necessarily indicative of what the Company’s consolidated results of operations and comprehensive loss actually would have been if the acquisition was completed on January 1, 2014. The unaudited pro forma consolidated net loss includes pro forma adjustments primarily relating to the following non-recurring items directly attributable to the business combination. (1) Elimination of $964 transaction costs for both the Company and Bioceros from the year ended December 31, 2015, and inclusion of these transactions costs in the year ended December 31, 2014; (2) The adjustment for stock compensation expense that would have been charged assuming the key employees of Bioceros, increased the expense by $374 and $500 for the years ended December 31, 2015 and 2014, respectively; (3) To eliminate intercompany net revenue from Bioceros to Epirus recorded in Bioceros’ historical financial statements and the corresponding amount recorded as research and development expense in the Epirus historical financial statements; (4) To eliminate the income recorded related to the change in the net cash payout contingent consideration liability from the year ended December 31, 2015, and include this gain in the year ended December 31, 2014.

Disposition

Disposition	12 Months Ended
	Dec. 31, 2015
Discontinued Operations and Disposal Groups [Abstract]
Disposition	6. Disposition On October 1, 2015, the Company entered into and closed a Share Purchase Agreement (the “Purchase Agreement”) with Taro Pharmaceuticals Inc. (“Taro”) for the sale by the Company to Taro of all of the shares of Zalicus Pharmaceuticals Ltd., the Company’s Canadian subsidiary that holds the Company’s product candidate Z944 and certain related assets (collectively, the “Z944 Assets”) which the Company acquired as a result of its merger with Zalicus Inc. in July 2014 (the “Zalicus Ltd. Sale”). As a result of the Zalicus Ltd. Sale, the Company received from Taro payment comprised of Canadian Dollar (“CAD”) $5,000 in cash and a non-interest bearing, limited recourse promissory note in the amount of CAD $5,000 with a maturity date of July 1, 2017 (the “Promissory Note”). The Promissory Note is repayable either in cash or through Taro’s transfer back of the Z944 Assets, including any further developments made by Taro to such assets, to the Company. No repayment of the Promissory Note is required until such maturity date. If Taro elects to repay the Promissory Note in cash and continue development of the Z944 Assets, the Company will also be entitled to additional payments of up to USD $7,500 upon achievement of certain development milestones for the Z944 Assets, up to USD $30,000 upon achievement of certain sales milestones for the Z944 Assets, and mid-single digit percentage royalty payments upon global commercial sales of products developed with the Z944 Assets, with such percentage to be reduced in the event of commercial sales of competing generic products under certain circumstances. The Purchase Agreement further requires Taro to use customary commercially reasonable efforts to develop the Z944 Assets, subject to the Company’s reversion right to such assets for any material breach following standard notice and cure periods. During the year ended December 31, 2015, the Company recognized a gain on the Zalicus Ltd. Sale of $1,016 representing the difference between the carrying value of the net assets of Zalicus Pharmaceuticals Ltd. and the initial cash payment received. The Company will account for the Promissory Note, milestone payments and royalty payments from the Purchase Agreement as a contingent gain to be recorded when realizable.

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2015
Prepaid Expenses and Other Current Assets
Prepaid Expenses and Other Current Assets	7. Prepaid and Other Current Assets Prepaid expenses and other current assets consisted of the following: As of December 31, 2015 2014 Prepaid development expenses $ $ Prepaid other expenses Accounts receivable Other current assets Total prepaids and other current assets $ $

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2015
Property and Equipment, Net
Property and Equipment, Net	8. Property and Equipment, Net Property and equipment consisted of the following: As of December 31, 2015 2014 Laboratory equipment $ $ — Leasehold improvements Computer equipment Furniture and fixtures Total property and equipment Less: accumulated depreciation Property and equipment, net $ $ Depreciation expense related to property and equipment amounted to $211 and $83 for the years ended December 31, 2015 and 2014, respectively.

Goodwill, IPR&D and Intangible

Goodwill, IPR&D and Intangible Assets, Net	12 Months Ended
	Dec. 31, 2015
Goodwill, IPR&D and Intangible Assets, Net
Goodwill, IPR&D and Intangible Assets, Net	9. Goodwill, IPR&D and Intangible Assets, Net Goodwill The following table represents changes in goodwill for the fiscal year ended December 31, 2015: Balance at December 31, 2014 $ Adjustment for Zalicus deferred tax liability Goodwill related to Bioceros acquisition Balance at December 31, 2015 $ As of December 31, 2015, there were no accumulated impairment losses associated with goodwill. Goodwill has been assigned to the Company’s single reporting unit, which is the single operating segment by which the CODM manages the Company (Note 2). IPR&D In connection with the Merger in 2014, the Company recognized IPR&D related to the Company’s product candidate Z944. The carrying value of the IPR&D related to Z944 as of December 31, 2014 was $5,500 . See Note 4 “Merger” for additional details. This asset was sold on October 1, 2015 as part of a Share Purchase Agreement with Taro Pharmaceuticals, Inc. As a result, in September 2015, the Company performed an impairment analysis of this asset and recognized an impairment charge of $1,671 which was recorded within research and development expense in the Company’s consolidated statement of operations and reduced the carrying value of the IPR&D asset to $3,829 . The Company determined the fair value of the IPR&D utilizing the income approach. Intangibles In November 2014, the Company received the necessary approvals to manufacture and market BOW015 in India. Upon such approval for commercialization in India, the $2,437 of IPR&D associated with BOW015 was reclassified from an indefinite-lived asset to a finite lived asset. During the year ended December 31, 2014 the Company began amortizing the intangible asset over its expected useful life of approximately 16.5 years. The Company determined the useful life of the asset based upon the period over which the Company expects to earn future economic benefit for BOW015. The Company recognizes amortization expense utilizing the straight-line method. In September 2014 and October 2014, the Company entered into an agreement with Moksha8 to terminate the Company’s revenue sharing payment obligations with respect to products that are biosimilars to infliximab, in exchange for payments of $1,400 . In connection with the payments under the Amendment and Second Amendment, in September 2014, the Company recorded an intangible asset of $1,250 , which will be amortized over the expected useful life of the intangible asset associated with BOW015, described above. In connection with the Bioceros acquisition in September 2015, the Company recognized an intangible asset related to Bioceros’ platform technology. During the year ended December 31, 2015, the Company began amortizing the intangible asset over its expected useful life of approximately six years. The carrying value of the intangible asset related to the platform technology as of December 31, 2015 was $3,191 . See Note 5, “Acquisition,” for additional details. Intangible assets, net of accumulated amortization is as follows: As of December 31, 2015 2014 Intangible assets (excluding IPR&D) $ $ Less: accumulated amortization—intangible assets Intangible assets, net (excluding IPR&D) $ $ Amortization expense, which is included within research and development expense in the consolidated statements of operations and comprehensive loss, was $386 and $82 for the years ended December 31, 2015 and 2014, respectively. The estimated aggregate amortization of intangible assets as of December 31, 2015, for each of the five succeeding years and thereafter is as follows: December 31, 2015 2016 $ 2017 2018 2019 2020 2021 and thereafter Total $

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2015
Accrued Expenses
Accrued Expenses	10. Accrued Expenses Accrued expenses consisted of the following: As of December 31, 2015 2014 Accrued compensation $ $ Accrued professional fees Accrued interest expense Other Total accrued expenses $ $

Debt

Debt	12 Months Ended
	Dec. 31, 2015
Debt
Debt	11. Debt 2013 Notes On March 10, 2014, the $12,500 principal amount of convertible notes outstanding at December 31, 2013, plus accrued but unpaid interest of $684 , were converted into 13,184,383 shares of Series A convertible preferred stock. March 2014 Notes On March 10, 2014, the Company issued and sold $5,000 of convertible notes to finance the operations of the Company. The notes bore interest at a rate of 8% per annum, had a maturity date of April 30, 2014 and provided the holders of the notes with 20% warrant coverage. On April 15, 2014, the $5,000 principal amount of convertible notes issued in March 2014, plus accrued and unpaid interest of $13 , were converted into 3,947,363 shares of Series B Preferred and the warrants became exercisable into 787,402 shares of Series B Preferred at an exercise price per share of $0.01 . Hercules Notes On September 30, 2014, the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Hercules Technology Growth Capital, Inc. (“Hercules”). Under the Loan Agreement, Hercules will provide the Company with access to two term loans with an aggregate principal amount of up to $15,000 (collectively, the "Loan"). The first term loan ("Tranche 1"), with a principal amount of $7,500 , was funded on October 1, 2014. The second term loan ("Tranche 2"), with a principal amount of up to $7,500 , was funded on May 29, 2015. The Loan is repayable in monthly installments until April 1, 2018, including an initial interest-only period of 18 months after funding of Tranche 1. Any amounts remaining outstanding at April 1, 2018 will become due immediately. The interest rate is a floating interest rate equal to the greater of (i) 7.95% , or (ii) the sum of (A) 7.95% , plus (B) the Prime Rate minus 3.25% per annum. An end of term charge equal to 3.00% of the aggregate original principal balance of the Loan is payable at maturity, including in the event of any prepayment, and is being accrued as interest expense over the term of the loan using the effective interest method. Borrowings under the 2014 Loan Agreement are collateralized by substantially all assets of the Company. If the Company repays all or a portion of the term loans prior to maturity, it will pay Hercules a prepayment fee as follows: (i) 2.00% if the prepayment occurs in the first 18 months following the funding date and (ii) no fee if the prepayment occurs after the first 18 months following the funding date. Pursuant to the Loan Agreement, subject to certain terms, Hercules was granted the right to participate, in an amount of up to $1,000 , in subsequent sales and issuances of the Company’s equity securities to one or more investors for cash for financing purposes in an offering that is broadly marketed to multiple investors and at the same terms as the other investors. In connection with the Loan Agreement, on September 30, 2014, the Company issued to Hercules a warrant to purchase 64,194 shares of Public Epirus Common Stock at an exercise price of $7.01 per share. In addition, the Company has the ability to settle up to $2.0 million of the Note with its common stock at a fixed price that is 15% above the warrant exercise price or 248,093 shares at $8.06 . See Note 12, “Warrants,” for further description of the warrant. As of December 31, 2015, the Company had outstanding borrowings under the Loan Agreement of $15,000 . Due to the going concern opinion issued as of December 31, 2015 and the fact that the Note may be declared immediately due by Hercules, upon the occur re nce of a material adverse change in the Company’s business, the Company has recorded all amounts due under the Note as a short-term debt obligation. As of December 31, 2015, the short-term debt obligation was $14,833 , net of a debt discount of $167 . Amortization of the debt discount, which was recorded as interest expense in the statement of operations, was approximately $89 and $14 for the years ended December 31, 2015 and December 31, 2014, respectively. Future principal payments, which exclude the 3% end of term charge that will be payable upon repayment of the notes in full, in connection with the Loan Agreement, as of December 31, 2015 are as follows: Principal Payments 2016 $ 2017 2018 Total $

Warrants

Warrants	12 Months Ended
	Dec. 31, 2015
Warrants
Warrants	12. Warrants Prior to the Merger, Zalicus issued warrants to purchase common stock to certain third parties. Zalicus issued warrants to purchase 148 shares of common stock to General Electric Capital Corporation with an exercise price of $405.00 per share that expired on June 28, 2015 and warrants to purchase 1,079 , 1,887 and 3,737 shares of common stock to Oxford at exercise prices of $83.40 , $135.00 and $68.40 per share, respectively. The Oxford warrants expire on December 22, 2017. In March 2014, the Company issued warrants, in connection with a convertible notes issuance, to purchase 1,000,000 shares of Series A Preferred with an exercise price of $0.01 per share (Note 11). Upon the Series B Preferred financing described in Notes 11 and 14, these warrants became exercisable into 787,402 shares of Series B Preferred at an exercise price of $0.01 per share. The aggregate fair value of such warrants at their issuance date was $1,171 . Each warrant was immediately exercisable and expires approximately seven years from the original date of issuance. Each warrant was exercisable on either a physical settlement or net share settlement basis. In April 2014, warrants to purchase 5,101,816 shares Series A Preferred were exercised into 5,101,816 shares of Series A Preferred. In April 2014, the warrants to purchase Series B Preferred were exercised into 787,402 shares of Series B Preferred. In connection with the Merger on July 15, 2014, all of the Company’s outstanding warrants exercisable for shares of preferred stock were exchanged for warrants exercisable for shares of Public Epirus Common Stock, which resulted in the reclassification of the liability-classified warrants to additional paid-in capital. As described in Note 11, the Company entered into a Loan Agreement with Hercules under which the Company was given access to up to $15,000 of term loans. As consideration for the Loan Agreement, on September 30, 2014, the Company issued Hercules warrant to purchase 64,194 shares of its common stock at an exercise price of $7.01 per share, which expires five years from issuance. The Warrant’s fair value of $248 at September 30, 2014 was determined using a Black ‑Scholes option ‑pricing model with the following assumptions: expected volatility of 61.68%; contractual term of five years; and risk ‑free interest rate of 1.78% . As of December 31, 2015 and 2014, all of the Company’s outstanding warrants were classified in equity. The following warrants to purchase common stock were outstanding: As of December 31, 2015 Number of Shares Underlying Warrants Exercise Price Per Share Common Stock $ Common Stock $ Common Stock $ Common Stock $ Common Stock $ Common Stock $ As of December 31, 2014 Number of Shares Underlying Warrants Exercise Price Per Share Common Stock $ Common Stock $ Common Stock $ Common Stock $ Common Stock $ Common Stock $ Common Stock $

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
Fair Value Measurements
Fair Value Measurements	13. Fair Value Measurements As of December 31, 2015 Level 1 Level 2 Level 3 Total Assets Cash and cash equivalents $ $ — $ — $ $ $ — $ — $ As of December 31, 2014 Level 1 Level 2 Level 3 Total Assets Cash and cash equivalents $ $ — $ — $ $ $ — $ — $ The reconciliation of the contingent consideration measured at fair value on a recurring basis using unobservable inputs (Level 3) is as follows: Balance at December 31, 2014 $ — Addition of contingent consideration related to Bioceros acquisition Remeasurement of Bioceros contingent consideration Balance at December 31, 2015 $ — The contingent consideration obligation represents the fair value of the net cash payout to former Bioceros shareholders, which is equal to the aggregate amount of: (a) Bioceros’ net working capital as the acquisition date; plus (b) revenue generated from Bioceros customers subsequent to the acquisition date and through December 31, 2015; in excess of (c) $1,200 , calculated as set forth in the Stock Purchase Agreement. The amount of the contingent consideration obligation is dependent on the amount of revenue generated by the Company from Bioceros customers through December 31, 2015. The estimates of fair value may not be indicative of the amounts that could be realized in a third-party exchange. Accordingly, the use of different market assumptions and/or different valuation techniques could result in materially different fair value estimates. The significant unobservable inputs to the valuation were management’s expectation for the amounts of the revenues generated from customers and a discount rate of 10.7% . The fair value of the contingent consideration obligation recognized on the acquisition date was estimated by applying a risk adjusted discount rate of 10.7% to the potential revenue generated resulting from probability weighted revenue projections. The Company revised its estimate related to the net cash payout based on actual revenue generated from Bioceros customers and net working capital as of the acquisition date and determined it would be less than $1,200 . Accordingly, the Company adjusted the fair value of the contingent consideration obligation to reflect a zero balance as of December 31, 2015. The Company does not anticipate to make a payment in connection with the net cash payout. As of December 31, 2015 and 2014, the Company did not have any liabilities measured at fair value on a recurring basis.

Capital Stock

Capital Stock	12 Months Ended
	Dec. 31, 2015
Capital Stock
Capital Stock	14. Capital Stock As of December 31, 2015, the Company had authorized 70,000,000 shares of common stock, $0.001 par value per share, of which 24,377,573 shares were issued and outstanding. Additionally, as of December 31, 2015, the Company had authorized 5,000,000 shares of preferred stock, $0.001 par value per share, of which zero were issued and outstanding . As of June 4, 2015, the Company amended its certificate of incorporation to decrease the authorized capital stock of the Company from 305,000,000 to 75,000,000 shares, which included 70,000,000 shares of common stock, $0.001 par value per share and 5,000,000 shares of preferred stock, $0.001 par value per share. Reserved for Future Issuance The Company has reserved for future issuances the following number of shares of common stock: Year Ended December 31, 2015 2014 Stock-based compensation awards Warrants to purchase common stock Settlement of short-term debt (Note 11) Total In addition, Second Inst allment Shares issuable to former Bioceros shareholders with a value of $5,000 to be issued in March 2016 are reserved for future is suance as of December 31, 2015 (Note 5). Convertible Preferred Stock In April 2014, Epirus closed an initial Series B Preferred financing with an issuance of 24,409,444 shares for aggregate proceeds of approximately $31,000 . Upon the closing of such financing, the $5,000 principal amount of convertible notes issued in March 2014, plus accrued and unpaid interest of $13 , were converted into 3,947,363 shares of Series B Preferred (Note 11). Upon the closing of the Merger, all outstanding shares of preferred stock were exchanged for shares of Public Epirus Common Stock as part of the Merger at the Exchange Ratio. See Note 4, “Merger,” for additional details. As of December 31, 2015, the Company did not have any convertible preferred stock issued or outstanding.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2015
Stock-Based Compensation
Stock-Based Compensation	15. Stock-Based Compensation On April 2, 2015, the board of directors of the Company adopted the 2015 Equity Incentive Plan (“2015 Plan”) and on June 4, 2015, the stockholders of the Company approved the 2015 Plan. Pursuant to the 2015 Plan, 1,700,000 shares of common stock were initially authorized for issuance. The 2015 Plan provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, restricted and unrestricted stock and stock units, performance awards, cash-based awards and awards that are convertible into or otherwise based on the Company’s common stock. As of December 31, 2015, the Company had 394,402 shares available for issuance under the 2015 Plan. The 2015 Plan includes an “evergreen provision” that allows for an annual increase in the number of shares of common stock available for issuance under the 2015 Plan, which annual increase will be added on the first day of each fiscal year from 2016 through 2025, inclusive, and will be equal to the least of (i) 1,000,000 shares of common stock, (ii) 4% of the outstanding shares on that date or (iii) such lesser amount determined by the Compensation Committee. Private Epirus adopted the 2011 Equity Incentive Plan, as amended (“2011 Plan”), pursuant to which 740,470 shares of common stock were initially authorized for issuance to employees, officers, directors, consultants and advisors of the Private Epirus. The 2011 Plan provides for the grant of incentive stock options, non-statutory stock options, rights to purchase restricted stock, stock appreciation rights, phantom stock awards and stock units. In connection with the issuance of restricted common stock, Private Epirus maintains a repurchase right and shares of restricted common stock are released from such repurchase right over a period of time of continued service by the recipient. Recipients of incentive stock options shall be eligible to purchase shares of the Private Epirus common stock at an exercise price equal to no less than the estimated fair value of such stock on the date of grant. In April 2014, the Private Epirus board of directors amended the terms of the 2011 Plan to increase the authorized number of shares of common stock available for issuance under the 2011 Plan from 740,470 to 1,504,752 . As described in Note 4, through the Merger, all outstanding and unexercised Private Epirus stock options under the 2011 Plan were assumed by Public Epirus under the 2004 Plan. In December 2004, the board of directors and stockholders of Zalicus adopted the 2004 Incentive Plan ("2004 Plan"), which was effective on November 9, 2005. The 2004 Plan provides for the grant of incentive stock options, non-statutory stock options, restricted stock and unrestricted stock awards, stock appreciation rights, cash awards, performance awards and restricted stock units. Awards under the 2004 Plan may be granted to employees, directors, consultants and advisors. In August 2014, the Company submitted a Form S-8 Registration Statement (“S-8") to the SEC. As reflected in the S-8, the Company amended the 2004 Plan to increase the number of shares available for issuance under the 2004 Plan by 3,000,000 shares of common stock. As of December 31, 2015, the Company had no shares available for issuance. Terms of stock award agreements are determined by the board of directors, subject to the provisions provided in the 2015 Plan, the 2011 Plan and the 2004 Plan. Stock options generally vest over a four -year period: 25% on the first anniversary of the original vesting date, with the balance vesting monthly over the remaining three years, unless they contain specific performance and/or market-based vesting provisions. Options are exercisable over a maximum term of 10 years from the grant date. For the years ended December 31, 2015 and 2014, the Company recognized stock-based compensation expense of approximately $3,470 and $1,719 , respectively, in connection with its stock-based payment awards. The Company recorded a reduction in stock-based compensation expense for the year ended December 31, 2015 of $100 resulting from the modification of an award for a former officer of the Company, Stock-based compensation expense for the year ended December 31, 2014 includes $355 of postcombination stock-based compensation expense resulting from the acceleration of vesting of previously unvested Zalicus stock options and RSUs, which occurred upon the termination of certain Zalicus employees following the Merger, and $303 related to restricted stock issued to a non-employee. As described in Note 4, through the Merger, outstanding Zalicus equity awards remained legally outstanding without change to any agreement terms. Such Zalicus equity awards were assumed to have been exchanged for equity awards of the Company, the accounting acquirer. As a result, the portion of the acquisition-date fair value of the Zalicus equity awards attributable to precombination service to Zalicus, $220 , was treated as a component of consideration transferred. See Note 4, “Merger.” The exchange of the Private Epirus stock options for stock options to purchase Public Epirus Common Stock was treated as a modification of the awards. The modification of the stock options did not result in any incremental compensation expense as the modification did not increase the fair value of the stock options. Stock Options A summary of stock option activity during the year ended December 31, 2015 is as follows: Weighted- Average Weighted- Remaining Average Contractual Aggregate Number Exercise Term Intrinsic of Options Price (in years) Value Outstanding at December 31, 2014 $ Granted Exercised Cancelled Outstanding at December 31, 2015 $ $ Vested and expected to vest at: December 31, 2015 $ $ Exercisable at: December 31, 2015 $ $ Weighted average grant-date fair value of options granted during the period $ Cash received upon exercise of options $ The aggregate intrinsic value in the table above represents the value (the difference between the Company’s common stock fair value on December 31, 2015 and the exercise price of the options, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on December 31, 2015. The total intrinsic value of options exercised in the years ended December 31, 2015 and 2014 was $ 547 and $71 , respectively. As of December 31, 2015, there was $11 ,284 of total unrecognized stock-based compensation expense related to stock options granted under the plans. The expense is expected to be recognized over a weighted-average period of 3.10 years. In order to determine the fair value of each employee stock award on the grant date, the Company used the Black-Scholes option-pricing model. During the years ended December 31, 2015 and 2014, respectively, the range of assumptions used in the Black-Scholes pricing model for new grants and grants issued or accelerated in connection with the Merger were as follows: Year Ended December 31, 2015 2014 Risk-free interest rate 1.48% - 1.96% 1.80% - 2.09% Expected volatility 61.40% - 89.05% 63.96% - 66.07% Expected term (in years) Expected dividend yield Risk-Free Interest Rate. The risk-free interest rate assumption is based on observed interest rates appropriate for the expected term of the stock option grants. Expected Volatility. D ue to the Company’s limited operating history and lack of Company-specific historical or implied volatility, the expected volatility assumption is based on historical volatilities of a peer group of similar companies whose share prices are publicly available. The peer group was developed based on companies in the biotechnology and medical device industries. Expected Term. The expected term represents the period of time that options are expected to be outstanding. The Company utilizes the expected terms from an analysis of peer group companies to support the expected term used in the Black-Scholes model, as it does not believe it has sufficient historical data to support this assumption. Expected Dividend Yield. T he expected dividend yield assumption is based on the fact that the Company has never paid cash dividends and has no intention to pay future cash dividends. Restricted Stock Award In April 2014, the Company granted 53,036 shares of restricted common stock to a non-employee for consulting services. The restricted stock award is subject to certain performance-based vesting conditions under which 25% of the award vested on April 15, 2014, 50% vested on September 25, 2014 and the remaining 25% of the award would vest following the successful achievement of certain performance milestones and the passage of time. As of December 31, 2015, the Company had no outstanding shares of nonvested restricted common stock. As of December 31, 2014, the Company had outstanding 13,259 shares of nonvested restricted common stock at a weighted average grant date fair value of $5.08 . During the years ended December 31, 2015 and 2014, the Company recorded $58 and $98 , respectively, in stock compensation expense related to the nonvested restricted common stock award. A summary of the restricted stock activity during the year ended December 31, 2015 is as follows: Weighted- Restricted Average Grant Stock Date Fair Value Nonvested at December 31, 2014 $ Granted — Vested Cancelled — — Nonvested at December 31, 2015 — $ — RSUs A summary of the activity of nonvested restricted stock units (“RSUs”) for the year ended December 31, 2015 is as follows: Weighted- Average Number Weighted- Remaining of Average Contractual Aggregate Restricted Grant Date Term Intrinsic Stock Units Fair Value (in years) Value Nonvested at December 31, 2014 — $ — — $ — Granted — Vested — — — Cancelled — Nonvested at December 31, 2015 $ $ Vested and expected to vest at: December 31, 2015 $ $ Exercisable at: December 31, 2015 — $ — — $ — As of December 31, 2015, there was $972 of total unrecognized stock-based compensation expense related to nonvested RSUs. The expense is expected to be recognized over a weighted-average period of 2.93 years. During February 2015, the Company issued 117,131 RSUs to certain employees, which vest with respect to one quarter (1/4) of the RSUs on the first anniversary of the grant date and an additional one quarter (1/4) on each anniversary thereafter until the fourth anniversary of the grant date. In addition, the Company issued 9,490 RSUs to certain employees as merit grants in lieu of annual raises. These RSUs vest in full on the first year anniversary of the grant date. Employee Stock Purchase Plan The Company has an Employee Stock Purchase Plan (“ESPP”) that permits eligible employees to enroll in a six -month offering period. Participants may purchase shares of the Company’s Common Stock, through payroll deductions, at a price equal to 85% of the fair market value of the Common Stock on the first day of the applicable six-month offering period, or the last day of the applicable six-month offering period, whichever is lower. Purchase dates under the ESPP occur on or about June 1 and December 1 of each year. During the year ended December 31, 2015, the Company recorded stock-based compensation expense of $4 . As of December 31, 2015, 352,722 shares of the Company’s Common Stock remain available for issuance under the ESPP. As of December 31, 2015, there was $21 of total unrecognized stock-based compensation expense related to the ESPP. The expense is expected to be recognized over a period of five months. The fair value of the option component of the shares purchased under the ESPP was estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions: Year Ended December 31, 2015 Risk-free interest rate Expected volatility Expected term (in years) Expected dividend yield

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Taxes
Income Taxes	16. Income Taxes During 2013, the Company realized a deferred tax benefit as a result of the transfer of intellectual property to the Company’s subsidiary, Epirus Biopharmaceuticals (Switzerland) GmbH, a Swiss Corporation. However, because the transfer is an intercompany transaction and is eliminated in consolidation, the Company cannot recognize a tax benefit. As a result, the deferred tax benefit of $943 related to the sale of intellectual property was deferred and was presented on the balance sheet as a deferred tax benefit at December 31, 2013. It is being recognized in earnings as the intellectual property asset is amortized in Switzerland over a period of five years, which is the expected tax amortization period for the intellectual property. For the year ended December 31, 2015, the Company has recorded an income tax benefit of approximately $544 , which is primarily due to a tax benefit of approximately $185 from the amortization of the Company’s deferred tax benefit related to the 2013 transfer of intellectual property described above and approximately $434 of in-process research & development impairment in Canada and offset by approximately $37 of withholding tax in Switzerland and $32 in income tax in the Netherlands. The component of U.S. and foreign loss from continuing operations before income taxes are as follows: Year Ended December 31, 2015 2014 United States $ $ Foreign Loss before income taxes: $ $ Deferred taxes are recognized for temporary differences between the basis of assets and liabilities for financial statement and income tax purposes. The Company’s deferred tax assets and liabilities are comprised of the following: As of December 31, 2015 2014 Deferred tax assets Current assets: Accrued rent $ - $ Accrued expenses - Gross current deferred tax assets - Non-current assets: Net operating loss - U.S. $ $ Research and development credits License/start-up expenditures Accrued rent Accrued expenses and other — Stock based compensation Capitalized research and development/patent intangibles Capitalized research and developmet RBIL Limitation — Foreign investment tax credit — Net operating loss - foreign Gross non-current deferred tax assets $ $ Gross Deferred tax assets $ $ Deferred tax liabilities Non-current: Depreciation Swiss IP amortization Bioceros acquired intangibles Identifiable intangible assets - IPR&D - Total non-current deferred tax liabilities $ $ Gross deferred taxes $ $ Valuation allowance Net deferred tax liability $ $ The Company has recorded a net deferred tax liability of $648 related to the acquired intangible assets, other accrual liabilities and deferred revenue in the Netherlands. The Company evaluated the positive and negative evidence bearing upon the realizability of the deferred tax assets. Based on the Company’s history of operating losses, the Company has concluded that it is more likely than not that the benefit of its deferred tax assets will not be realized in all jurisdictions except the Netherlands. The Netherlands is in a net deferred tax liability position as of December 31, 2015. The valuation allowance increase during the year ended December 31, 2015 is primarily due to the increase in the current year net operating losses offset by the disposition of Canadian deferred balances as a result of the Company’s sale of its Canadian entity. A reconciliation of income tax expense computed at the statutory federal income tax rate to income taxes as reflected in the financial statements is as follows: Year Ended December 31, 2015 2014 Income tax benefit using U.S. federal statutory rate $ $ State income taxes, net of federal benefit Other permanent differences Foreign rate differential Tax credits Other items Tax benefit related to the IPR&D transfer IPR&D impairment charge benefit — Foreign withholding taxes Net change in valuation allowance Income tax benefit $ $ As of December 31, 2015 and 2014, the Company had U.S. federal net operating loss carryforwards of approximately $38.8 million and $31.0 million, respectively and state net operating loss carryforwards of approximately $27.6 million and $21.3 million, respectively, which may be available to offset future income tax liabilities and expire at various dates through 2035. In addition, as of December 31, 2015 and 2014, the Company had foreign net operating loss carryforwards of approximately $82 million and $145 million, respectively, which may be available to offset future income tax liabilities. The decrease in foreign net operating losses is primarily due to the loss of net operating losses as a result of the Company’s sale of its Canadian entity offset by the current year loss in Switzerland. Net operating loss carryforwards are unlimited in the United Kingdom and Brazil, Switzerland allows for a seven year carryforward. The Company had generated NOL carryforwards from stock-based compensation deduction in excess of expense recognized for financial reporting purposes (“excess tax benefit”). Excess tax benefits are realized when they reduce the taxes payable, as determined by using a “with and without” method, and are credited to additional paid-in capital, rather than a reduction of the income tax provision. As of December 31, 2015 and 2014, the Company had approximately $21 and $77 excess tax benefits, respectively, which will be credited to additional paid-in capital when realized. As of December 31, 2015 and 2014, the Company had federal research and development tax credit carryforwards of approximately $1.2 million and $0.5 million, respectively, available to reduce future tax liabilities which expire at various dates through 2035. As of December 31, 2015 and 2014, the Company had state research and development tax credit carryforwards of approximately $0.2 million and $0.2 million, respectively, available to reduce future tax liabilities, which expire at various dates through 2030. Under the provision of the Internal Revenue Code, the net operating loss and tax credit carryforwards are subject to review and possible adjustment by the Internal Revenue Service and state tax authorities. Net operating loss and tax credit carryforwards may become subject to an annual limitation in the event of certain cumulative changes in the ownership interest of significant shareholders over a three ‑year period in excess of 50%, as defined under Sections 382 and 383 of the Internal Revenue Code, respectively, as well as similar state provisions. This could limit the amount of tax attributes that can be utilized annually to offset future taxable income or tax liabilities. The amount of the annual limitation is determined based on the value of the company immediately prior to the ownership change. Subsequent ownership changes may further affect the limitation in future years. The federal and state net operating loss carryforward and tax credit carryforward are net of the limitation due to Sections 382 and 383. A full valuation allowance has been provided against the net operating loss and tax credit carryforwards as of December 31, 2015. For years through December 31, 2015, the Company generated research credits but has not conducted a study to document the qualified activities. This study may result in an adjustment to the Company’s research and development credit carryforwards; however, until a study is completed and any adjustment is known, no amounts are being presented as an uncertain tax position. A full valuation allowance has been provided against the Company’s research and development credits and, if an adjustment is required, this adjustment would be offset by an adjustment to the deferred tax asset established for the research and development credit carryforwards and the valuation allowance. The Company will recognize interest and penalties related to uncertain tax positions in income tax expense. As of December 31, 2015 and 2014, the Company had no accrued interest or penalties related to uncertain tax positions and no amounts have been recognized in the Company’s statements of operations and comprehensive loss. The Company files income tax returns in the U.S., various state jurisdictions and foreign jurisdictions for its foreign subsidiaries. The federal and state income tax returns are generally subject to tax examinations for the tax years ended 2012 through 2015. The foreign income tax returns are generally subject to examinations for the tax years ended 2011 through 2015. To the extent the Company has tax attribute carryforwards, the tax years in which the attribute was generated may still be adjusted upon examination by the Internal Revenue Service, state or foreign tax authorities to the extent utilized in a future period. There are no currently ongoing or pending examinations in any jurisdiction. During November 2015, the FASB issued ASU 2015-17, “Balance Sheet Classification of Deferred Taxes”, which simplifies the presentation of deferred income taxes. This ASU requires that deferred tax assets and liabilities be classified as non-current in a statement of financial position. The standard is effective for public companies for fiscal years beginning after December 15, 2016, including interim periods within that reporting period. Early adoption is permitted for any interim and annual financial statements that have not yet been issued. The Company early adopted ASU 2015-17 effective December 31, 2015 on a prospective basis. Adoption of this ASU resulted in a reclassification of the net current deferred tax asset of $109 and the net current deferred tax liability of $80 to the net non-current deferred tax liability in the Company’s consolidated balance sheet as of December 31, 2015. No prior periods were retrospectively adjusted.

Commitments

Commitments	12 Months Ended
	Dec. 31, 2015
Commitments
Commitments	17. Commitments On May 15, 2015, the Company amended its March 2013 operating lease for office space in Boston, Massachusetts (the “Second Amendment”). The Second Amendment provides the Company additional square footage of approximately 3,000 square feet. The Company has committed to lease this space for a period of six years. The Second Amendment contains rent escalation that is being accounted for as rent expense under the straight-line method. The Company will record rent expense of approximately $14 per month on a straight-line basis over the effective lease term. On September 9, 2015, the Company acquired Bioceros, located in Utrecht, The Netherlands. As part of the acquisition, the Company acquired a lease for approximately 5,800 square feet consisting of lab and office space. The lease is for 7 years, commencing on January 1, 2011 and ending December 31, 2018. The Company will record approximately $25 per month on a straight-line basis over the effective lease term. On October 15, 2015, the Company signed a lease for approximately 4,400 square feet of office space in Zug, Switzerland. The Company has committed to lease this space through March 31, 2017 and will record approximately $17 per month on a straight-line basis over the effective lease term. As of December 31, 2015, future minimum lease payments under all of the Company’s operating leases are as follows: December 31, 2015 2016 $ 2017 2018 2019 2020 2021 and thereafter Total $ Less: Future sublease payments to be received Net future lease payments $ Rent expense under operating lease agreements amounted to approximately $727 and $366 for the years ended December 31, 2015 and 2014, respectively. Rent expense is reported net of sublease income. License Agreements From time to time, the Company enters into various licensing agreements whereby the Company may use certain technologies in conjunction with its product research and development. Catalent Pharma Solutions, LLC In January 2009, Moksha8 entered into a cell line sale agreement (“the Cell Line Agreement”) with Catalent Pharma Solutions (“Catalent”) for the acquisition of a gene expression cell line for BOW015 (“the GPEx Cell Line,”) developed by Catalent for Moksha8 pursuant to a separate development and manufacturing agreement dated July 14, 2008. The Cell Line Agreement was assigned to the Company on May 14, 2009, and was amended July 31, 2009 to revise certain payment-related terms. Under the terms of the Cell Line Agreement, the Company exercised an option to acquire all rights in the GPEx Cell Line for development and commercialization of products using the GPEx Cell Line, namely BOW015, subject to certain obligations to make contingent payments to Catalent. The Company paid Catalent approximately $100 on execution of the Cell Line Agreement, and paid a further approximately $100 upon exercise of its option to complete the purchase of the GPEx Cell Line. The Company is required to make additional payments to Catalent of up to approximately $700 in the aggregate upon the achievement of certain development and regulatory milestones. In March 2013, the Company paid approximately $200 to Catalent upon the occurrence of certain clinical trial events for BOW015. Pursuant to the agreement, the Company will be obligated to pay approximately $500 upon the achievement of certain development and regulatory milestones. In addition, the Company will be required to pay a contingent sale fee in the form of royalties on worldwide net sales of BOW015 and any other product manufactured using the GPEx Cell Line at a percentage in the very low single digits for a period of 20 years following the first commercial sale of such product, and thereafter at a rate of less than one percent. Either the Company or Catalent may terminate the Cell Line Agreement on 60 days' notice for the other party's material breach of the agreement, or for the other party's insolvency, and in the event of Catalent's termination for the Company’s material breach of the Cell Line Agreement, the Company’s ownership rights in the GPEx Cell Line would revert to Catalent. If the Company terminates the Cell Line Agreement for Catalent's breach, it will retain ownership of the GPEX Cell Line, but its payment obligations to Catalent will terminate.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2015
Net Loss Per Share
Net Loss Per Share	18. Net Loss Per Share The Company computes basic and diluted loss per share using a methodology that gives effect to the impact of outstanding participating securities (the “two-class method”). As the years ended December 31, 2015 and 2014 resulted in net losses, there is no income allocation required under the two-class method or dilution attributed to weighted-average shares outstanding in the calculation of diluted loss per share. The following potentially dilutive securities outstanding, prior to the use of the treasury stock method, have been excluded from the computation of diluted weighted-average shares outstanding for the years ended December 31, 2015 and 2014, as they would be anti-dilutive. In addition, Second Installment Shares issuable to former Bioceros shareholders with a value of $5,000 to be issued in March 2016 have been excluded from the computation of basic and diluted weighted-average shares outstanding for the year ended December 3 1 , 2015 (Note 5). As of December 31, 2015 2014 Options to purchase common stock Settlement of loan agreement Nonvested restricted stock units — Warrants to purchase common stock Employee stock purchase plan — Nonvested restricted stock awards —

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2015
Employee Benefits.
Employee Benefits	19. Employee Benefits Effective January 1, 2013, the Company adopted a defined contribution 401(k) plan for employees who are at least 21 years of age. Employees are eligible to participate in the plan beginning on the first day of the calendar quarter following their date of hire. Under the terms of the plan, employees may make voluntary contributions as a percentage of compensation. As of December 31, 2015, the Company has not made any matching contributions since the adoption of the 401(k) plan.

Related Parties

Related Parties	12 Months Ended
	Dec. 31, 2015
Related Parties.
Related Parties	20. Related Parties As discussed in Note 3, in September 2014, the Company entered into an Exclusive License and Collaboration Agreement (the “Livzon Collaboration Agreement”) with Livzon Mabpharm Inc. (“Livzon”) for the global development and commercialization of certain antibodies or related biological compounds, including the Company’s BOW015, a biosimilar version of infliximab. In September 2015, the Company entered into a New Collaboration Compound Supplement with Livzon to add BOW070, a biosimilar version of tocilizumab, as a compound to be governed by the Livzon Collaboration Agreement. As of December 31, 2015, Livzon owned approximately 6.4% of the Company’s issued and outstanding common stock. As discussed in Note 3, in September 2014 and October 2014, the Company entered into a series of amendments (collectively, the “amendments”) to that certain Revenue and Negotiation Rights Agreement between the Company and Moksha8 Pharmaceuticals, Inc. (“Moksha8”), dated as of December 31, 2010 (the “Moksha8 Revenue Agreement”). Moksha8 is owned in part by Montreux Equity Partners and TPG Capital, which are also shareholders of the Company. As of December 31, 2015, Montreux Equity Partners owned approximately 1% of the Company’s issued and outstanding common stock and TPG Capital owned approximately 9% of the Company’s issued and outstanding common stock.

Legal Proceedings

Legal Proceedings	12 Months Ended
	Dec. 31, 2015
Legal Proceedings
Legal Proceedings	21. Legal Proceedings From time to time, the Company is involved in legal proceedings and claims of various types and accounts for these legal proceedings in accordance with ASC Topic 450, “Contingencies.” The Company records a liability in its consolidated financial statements for these matters when a loss is considered probable and the amount of loss can be reasonably estimated. The Company reviews these estimates each accounting period as additional information is known and adjusts the loss provision when appropriate. If the loss is not probable or cannot be reasonably estimated, a liability is not recorded in its consolidated financial statements. Reliance Life Sciences Dispute In December 2014, Reliance Life Sciences Pvt Ltd, or RLS, the Company’s BOW015 contract manufacturer for India, exercised its three -year termination for-convenience right with respect to the parties’ Manufacturing and Supply Agreement, dated as of May 14, 2014 and as amended from time to time (the “RLS Agreement”), which would have caused the RLS Agreement to terminate in December 2017. In addition, in March 2015, RLS initiated an arbitration proceeding under the RLS Agreement alleging that the RLS Agreement grants RLS exclusive global supply rights for BOW015, that the terms of the Company’s collaboration agreements with Fujifilm Diosynth Biotechnologies U.S.A., Inc. and Livzon MabPharm Inc. violate the RLS Agreement, and sought to terminate the RLS Agreement. The proceeding initiated by RLS sought a declaratory judgment, but did not seek any monetary damages. On April 22, 2015, the Company entered into a Settlement Agreement with RLS (the “Settlement Agreement”). Pursuant to the Settlement Agreement, the parties finalized the remaining BOW015 batch production schedule with RLS agreeing to manufacture 1 5 final batches of BOW015 on or before June 30, 2016 with the Company’s option to have RLS manufacture an additional 5 batches on or before December 31, 2016. In January 2016, the Company amended the Settlement Agreement (Note 22). RLS has also agreed to use reasonable commercial efforts to transfer the existing Indian marketing authorization for BOW015 granted by the Drug Controller General of India (“DCGI”) to the Company or its designee, with all costs of the transfer to be borne by the Company and subject to the DCGI’s approval of such transfer. The Company has agreed to pay to RLS a fee of approximately $2,250 , payable in four installments over the course of the final batch manufacture, with the final installment to be paid no later than ten days after June 30, 2016. Pursuant to the Settlement Agreement, on May 4, 2015, RLS withdrew the arbitration proceeding it initiated, and the parties have agreed to release each other from all causes of actions or claims, present and future, arising under the RLS Agreement. Following the satisfaction by both parties of all of the terms of the Settlement Agreement, the RLS Agreement and related agreements between the parties shall be terminated and neither party shall have any further rights or obligations thereunder . The Company made the first payment of $750 on April 27, 2015 and made an additional payment of $500 on September 10, 2015. For the year ended December 31, 2015, the Company recorded a charge of $2,228 to general and administrative expenses, which represents the net present value of the installment payments due under the Settlement Agreement. In addition, the Company recorded a one-time charge of $1,800 to research and development expense in the year ended December 31, 2015, which represents the Company’s portion of the purchase obligation of the 15 binding forecasted batches to be manufactured by RLS. As of December 31, 2015, the Company has paid $561 towards this obligation.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2015
Subsequent Events
Subsequent Events	22. Subsequent Events In January 2016, the Company entered into an amendment to the Settlement Agreement with RLS to extend the time for RLS to manufacture the 15 final batches from June 30, 2016 to June 30, 2017. On February 29, 2016, the Company entered into an At-the-Market Sales Agreement (the “Sales Agreement”) with BTIG, LLC (“BTIG”), pursuant to which the Company may sell at its option from time to time up to an aggregate of $30 million in shares of the Company’s common stock, through BTIG, as sales agent (the “Offering”). Sales of the common stock made pursuant to the Sales Agreement, if any, will be made under the Company’s previously filed and currently effective Registration Statement on Form S-3 (File No. 333-205420) and a related prospectus supplement. The Company will pay BTIG a commission equal to 3% of the gross proceeds from the sale of shares of common stock under the Sales Agreement, if any. Pursuant to the terms of the Sales Agreement, the Company also provided BTIG with customary indemnification rights. The Company has also agreed to reimburse BTIG for its reasonable out-of-pocket expenses, including the fees and disbursements of counsel to BTIG, incurred in connection with the Offering. The Company intends to use the net proceeds from the Offering for general corporate purposes, which may include research and development expenditures, clinical trial expenditures, commercialization activities and working capital. As of March 25, 2016, proceeds under this Sales Agreement have not been material. On March 8, 2016, the Company entered into the First Amendment to the Stock Purchase Agreement between the Company and seller representatives of Bioceros (the “First Amendment”). The First Amendment removes any future employment requirements of Bioceros key employees to receive the Second Installment Shares, removes the lock-up period for the Second Installment Shares and updates the maximum equity consideration to be issued pursuant to the Stock Purchase Agreement from 10% to 19.99% of the aggregate number of the Company’s total shares outstanding on the date preceding the date of the Stock Purchase Agreement. On March 9, 2016, the Company issued 1,772,107 shares of common stock with a 10 day trailing price of $2.82 , in accordance with the Stock Purchase Agreement and the First Amendment.

Summary of Significant Accoun29

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Summary of Significant Accounting Policies
Basis of Presentation and Use of Estimates	Basis of Presentation and Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s consolidated financial statements and accompanying notes. The most significant estimates in the Company’s consolidated financial statements relate to the valuation of equity awards, purchase price allocations including fair value estimates of intangible assets, estimated useful lives of fixed assets and intangible assets and accruals relating to development contracts, clinical trials and settlement obligations. The Company bases its estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis. The Company’s actual results may differ from these estimates under different assumptions or conditions. Certain prior year amounts have been conformed to the current year presentation. These reclassifications had no impact on net loss or total equity.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of Epirus and its wholly owned subsidiaries: EB Sub, Inc., a Delaware Corporation, Epirus Biopharmaceuticals Ltd., a United Kingdom corporation, Epirus Biopharmaceuticals (Switzerland) GmbH, a Swiss corporation, Epirus Brasil Tecnologia Ltda, a Brazilian corporation, Epirus Biopharmaceuticals (Netherlands) B.V., a Netherlands corporation, and Zalicus Pharmaceuticals Ltd., a Canadian corporation. All significant intercompany balances and transactions have been eliminated in consolidation.
Merger and Exchange Ratio	Merger and Exchange Ratio The Merger has been accounted for as a “reverse merger” under the acquisition method of accounting for business combinations with Private Epirus treated as the accounting acquirer of Zalicus. The historical financial statements of Private Epirus have become the historical financial statements of Public Epirus, or the combined company, and are included in this filing labeled Epirus Biopharmaceuticals, Inc. As a result of the Merger, historical common stock, stock options and additional paid-in capital, including share and per share amounts, have been retroactively adjusted to reflect the equity structure of Public Epirus, including the effect of the Merger exchange ratio and the Public Epirus common stock par value of $0.001 per share. See Note 4, “Merger,” for additional discussion of the Merger and the exchange ratio.
Reverse Stock Split	Reverse Stock Split On July 16, 2014, Public Epirus effected a 1 -for-10 reverse stock split of its outstanding common stock, par value $0.001 per share (“Public Epirus Common Stock”) (the “Reverse Stock Split”). The accompanying consolidated financial statements and these notes to consolidated financial statements, including the Merger exchange ratio (Note 4) applied to historical Private Epirus common stock and stock options, give retroactive effect to the Reverse Stock Split for all periods presented. The shares of Public Epirus Common Stock retained a par value of $0.001 per share.
Segment and Geographic Information	Segment and Geographic Information Operating segments are defined as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker (“CODM”) or decision-making group in making decisions regarding resource allocation and assessing performance. The Company and the Company’s CODM view the Company’s operations and manage its business in one operating segment: the development and commercialization of biosimilar monoclonal antibodies for emerging markets . The Company's entire business is managed by a single management team, which reports to the Chief Executive Officer. As of December 31, 2015 and 2014, all of the Company's long-lived assets were held within the United States, Switzerland and The Netherlands.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of 90 days or less from the date of purchase to be cash equivalents. As of December 31, 2015 and 2014, all cash and cash equivalents are held in depository accounts at six commercial banks. Cash equivalents are reported at fair value.
Concentrations of Credit Risk and Off-Balance Sheet Risk	Concentrations of Credit Risk and Off-Balance Sheet Risk Financial instruments that potentially subject the Company to concentrations of credit risk are primarily cash, cash equivalents and restricted cash. The Company maintains its cash and cash equivalent balances in the form of checking and savings accounts with financial institutions that management believes are creditworthy. The Company’s investment policy includes guidelines on the quality of the institutions and financial instruments and defines allowable investments that the Company believes minimizes the exposure to concentration of credit risk. The Company has no financial instruments with off-balance-sheet risk of loss.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company is required to disclose information on all assets and liabilities reported at fair value that enables an assessment of the inputs used in determining the reported fair values. The Company determines the fair market values of its financial instruments based on the fair value hierarchy, which is a hierarchy of inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing the financial instrument based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the inputs that market participants would use in pricing the financial instrument and are developed based on the information available in the circumstances. The fair value hierarchy applies only to the valuation inputs used in determining the reported or disclosed fair value of the financial instruments and is not a measure of the investment credit quality. The three levels of the fair value hierarchy, and its applicability to the Company’s financial assets and liabilities, are described below: Level 1 Inputs : Unadjusted quoted prices in active markets that are accessible at the measurement date of identical, unrestricted assets and liabilities. Level 2 Inputs : Quoted prices for similar assets and liabilities, or inputs that are observable, either directly or indirectly, for substantially the full term through corroboration with observable market data. Level 2 includes investments valued at quoted prices adjusted for legal or contractual restrictions specific to the security. Level 3 Inputs : Pricing inputs are unobservable for the assets and liabilities, that is, inputs that reflect the reporting entity’s own assumptions about the assumptions market participants would use in pricing the assets. Level 3 includes private investments that are supported by little or no market activity. The fair value hierarchy level is determined by asset class based on the lowest level of significant input. In periods of market inactivity, the observability of prices and inputs may be reduced for certain instruments. This condition could cause an instrument to be reclassified between levels. During the years ended December 31, 2015 and 2014, there were no transfers between levels. The Company measures cash equivalents at fair value on a recurring basis. The fair value of cash equivalents is determined based on “Level 1” inputs, which consist of quoted prices in active markets for identical assets. The fair value of the Company's note is determined using current applicable rates for similar instruments with similar settlement features as of the balance sheet date. The carrying value of the Company's short term debt approximates its fair value as the Company's interest rate is near current market rates for instruments with similar settlement features. The fair value of the Company's note and contingent consideration was determined using Level 3 inputs.
Property and Equipment	Property and Equipment Property and equipment consists of office furniture, office and computer equipment and leasehold improvements. Expenditures for repairs and maintenance are recorded to expense as incurred, whereas major betterments are capitalized as additions to property and equipment. Property and equipment are recorded at cost and are depreciated when placed into service using the straight-line method of depreciation, based on their estimated useful lives as follows: Asset Description Estimated Useful Lives Furniture and fixtures years Office and computer equipment 3 years Leasehold improvements Shorter of the useful life or remaining lease term Upon retirement or sale, the cost of assets disposed and the related accumulated depreciation is removed from the accounts and any resulting gain or loss is recorded in the consolidated statements of operations. The Company evaluates the potential of its long-lived assets for impairment if events or changes in circumstances indicate that the carrying amount of the assets may not be fully recoverable or that the useful life of the assets is no longer appropriate. The impairment test is based on a comparison of the undiscounted cash flows expected to be generated from the use of the asset group and its eventual disposition to the carrying value of the asset group. If impairment is indicated, the assets are written down by the amount by which the carrying value of the assets exceeds the related fair value of the assets. Any write-downs are treated as permanent reductions in the carrying value of the assets. No such impairment losses have been recorded through December 31, 2015.
Restricted Cash	Restricted Cash Restricted cash represents cash held in depository accounts at financial institutions to collateralize conditional stand-by letter of credits related to the Company’s Boston, Massachusetts and Zug, Switzerland facility lease agreements and the Company’s subleased Cambridge, Massachusetts facility. Restricted cash is reported as non-current unless the restrictions are expected to be released in the next 12 months.
Acquisitions	Acquisitions Business combinations are accounted for using the acquisition method of accounting. Under the acquisition method of accounting, the tangible and intangible assets acquired and the liabilities assumed are recorded as of the acquisition date at their respective fair values. The Company evaluates a business as an integrated set of activities and assets that is capable of being managed for the purpose of providing a return in the form of dividends, lower costs or other economic benefits and consists of inputs and processes that provide or have the ability to provide outputs. In an acquisition of a business the excess of the fair value of the consideration transferred over the fair value of the net assets acquired is recorded as goodwill. In an acquisition of net assets that does not constitute a business, no goodwill is recognized. The Company’s consolidated financial statements include the results of operations of an acquired business after the completion of the acquisition.
In-process Research & Development	In-process Research & Development In-process research & development (“IPR&D”) represents the fair value assigned to research and development assets that were not fully developed at the date of acquisition. IPR&D acquired in a business combination or recognized from the application of push-down accounting is capitalized on the Company’s consolidated balance sheet at its acquisition-date fair value. Until the project is completed, the assets are accounted for as indefinite-lived intangible assets and subject to impairment testing. Upon completion of a project, the carrying value of the related IPR&D is reclassified to intangible assets and is amortized over the estimated useful life of the asset. When performing the impairment assessment, the Company first assesses qualitative factors to determine whether it is necessary to recalculate the fair value of its acquired IPR&D. If the Company determines, as a result of the qualitative assessment, that it is more likely than not that the fair value of acquired IPR&D is less than its carrying amount, it calculates the asset’s fair value. If the carrying value of the Company’s acquired IPR&D exceeds its fair value, then the intangible asset is written down to its fair value. For the year ended December 31, 2015, the Company determined that there was an impairment related to IPR&D acquired in the Merger. As a result, the Company recorded a loss on impairment of IPR&D in the amount of $1,671 for the year ended December 31, 2015. This impairment charge was recorded within research and development expense. For the year ended December 31, 2014, the Company determined that there was no impairment of IPR&D.
Intangible Assets	Intangible Assets The Company amortizes its intangible assets using the straight-line method over its estimated economic life, which ranges from six to 16.5 years. The Company evaluates the potential impairment of its intangible assets if events or changes in circumstances indicate that the carrying amount of the assets may not be fully recoverable or that the useful life of the assets is no longer appropriate. The impairment test is first based on a comparison of the undiscounted cash flows expected to be generated from the use of the asset group and its eventual disposition to the carrying value of the asset group. If impairment is indicated, the assets are written down by the amount by which the carrying value of the assets exceeds the related fair value of the assets. Any write-downs are treated as permanent reductions in the carrying value of the assets. For the years ended December 31, 2015 and 2014, the Company determined that there was no impairment of its intangible assets.
Goodwill	Goodwill Goodwill represents the difference between the consideration transferred and the fair value of the net assets acquired under the acquisition method of accounting for push-down accounting. Goodwill is not amortized but is evaluated for impairment within the Company’s single reporting unit on an annual basis, during the fourth quarter, or more frequently if an event occurs or circumstances change that would more likely than not reduce the fair value of the Company’s reporting unit below its carrying amount. When performing the impairment assessment, the accounting standard for testing goodwill for impairment permits a company to first assess the qualitative factors to determine whether the existence of events and circumstances indicates that it is more likely than not that the goodwill is impaired. If the Company believes, as a result of the qualitative assessment, that it is more likely than not that the fair value of goodwill is impaired, the Company must perform the first step of the goodwill impairment test. The Company has determined that goodwill was not impaired as of December 31, 2015 and 2014. To date, the Company has not recognized any impairment charges related to goodwill.
Revenue Recognition	Revenue Recognition Multiple-Element Arrangements Under the authoritative guidance for revenue recognition related to multiple-element revenue arrangements, each deliverable within a multiple-element revenue arrangement is accounted for as a separate unit of accounting if both of the following criteria are met: (1) the delivered item or items have value to the customer on a standalone basis and (2) for an arrangement that includes a general right of return relative to the delivered item(s), delivery or performance of the undelivered item(s) is considered probable and substantially in the Company’s control. The Company considers a deliverable to have standalone value if the Company sells this item separately or if the item is sold by another vendor or could be resold by the customer. Deliverables not meeting the criteria for being a separate unit of accounting are accounted for on a combined basis. In the event the Company enters into a contract in which the deliverables are required to be separated, the Company will allocate arrangement consideration to each deliverable in an arrangement based on its relative selling price. The Company determines selling price using vendor-specific objective evidence (“VSOE”), if it exists; otherwise, the Company uses third-party evidence (“TPE”). If neither VSOE nor TPE of selling price exists for a deliverable, the Company uses estimated selling price (“ESP”) to allocate the arrangement consideration. The Company applies appropriate revenue recognition guidance to each unit of accounting. Milestones Contingent consideration from research and development activities that is earned upon the achievement of a substantive milestone is recognized in its entirety in the period in which the milestone is achieved. At the inception of each arrangement that includes milestone payments, the Company evaluates whether each milestone is substantive. This evaluation includes an assessment of whether: (a) the consideration is commensurate with either (1) the entity’s performance to achieve the milestone, or (2) the enhancement of the value of the delivered item(s) as a result of a specific outcome resulting from the entity’s performance to achieve the milestone, (b) the consideration relates solely to past performance and (c) the consideration is reasonable relative to all of the deliverables and payment terms within the arrangement. The Company evaluates factors such as the scientific, clinical, regulatory, commercial and other risks that must be overcome to achieve the respective milestone, the level of effort and investment required and whether the milestone consideration is reasonable relative to all deliverables and payment terms in the arrangement in making this assessment. Royalty Revenue Under certain license agreements to which the Company is a party, the Company receives royalty payments based upon its licensees’ net sales of products. Generally, under these agreements, the Company receives royalty payments from licensees approximately one quarter in arrears after the licensee has sold the income generating product or products. The Company recognizes royalty revenues when it can reliably estimate such amounts and collectability is reasonably assured. As such, the Company generally recognizes royalty revenues in the quarter reported to it by its licensees. Therefore, royalty revenues are recognized one quarter in arrears from the quarter in which sales by its licensees occurred. Under this accounting policy, the royalty revenues the Company recognizes are not based upon estimates and are typically reported in the same period in which the Company receives payment from its licensees.
Deferred Revenue	Deferred Revenue Amounts received prior to satisfying the above revenue recognition criteria are recorded as deferred revenue in the accompanying consolidated balance sheets. Amounts not expected to be recognized within 12 months from the balance sheet date are classified as long-term deferred revenue.
Deferred Rent	Deferred Rent Deferred rent, included within other non-current liabilities, net of the current portion recorded in accrued expenses in the consolidated balance sheet, consists of the difference between cash payments and the recognition of rent expense on a straight-line basis for the facilities the Company occupies. The Company’s lease for its Boston, Massachusetts, facility provides for a rent-free period as well as fixed increases in minimum annual rental payments. The total amount of rental payments due over the lease term is being charged to rent expense ratably over the life of the lease.
Other Liabilities	Other Liabilities In conjunction with the Merger, as discussed in Note 4, the Company assumed a sublease liability for Zalicus’ Cambridge, Massachusetts facility, which is included within other non-current liabilities, net of the current portion recorded in other current liabilities on the consolidated balance sheet. The liability represents the fair value of the difference between the total sublease payments to be received by the Company and the total payment obligation for the Company per the lease agreement. The Company has an operating lease for office space in Boston, Massachusetts. In connection with this lease, the Company and its third party lessor agreed that the lessor would pay for certain leasehold improvements on behalf of the Company. These leasehold improvements are accounted for as a lease incentive obligation, which is recorded in other non-current liabilities, net of the current portion recorded in other current liabilities. This liability is being amortized over the life of the lease and as a reduction to rent expense.
Organizational Costs	Organizational Costs All organizational costs are expensed as incurred.
Research and Development Costs	Research and Development Costs Research and development costs are charged to expense as incurred in performing research and development activities. The costs include employee compensation, facilities and overhead, clinical study and related clinical manufacturing costs, regulatory and other related costs. Nonrefundable advanced payments for goods or services to be received in the future for use in research and development activities are deferred and capitalized. The capitalized amounts are expensed as the related goods are delivered or the services are performed. Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as patient enrollment, clinical site activations, or information provided to the Company by its vendors with respect to their actual costs incurred. Payments for these activities are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected in the consolidated financial statements as prepaid or accrued research and development expense, as the case may be.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for grants of stock options and restricted stock based on their grant date fair value and recognizes compensation expense over the award’s vesting period. The Company estimates the fair value of stock options as of the date of grant using the Black-Scholes option-pricing model and restricted stock based on the fair value of the underlying common stock, which is determined as the closing trading price of the Company’s common stock subsequent to the Merger, in which the Company’s common stock became publicly traded, and was determined by management prior to the Merger (Note 15). Stock-based compensation expense represents the cost of the grant date fair value of employee stock option grants recognized over the requisite service period of the awards (usually the vesting period) on a straight-line basis, net of estimated forfeitures. The expense is adjusted for actual forfeitures at the end of each reporting period. Stock-based compensation expense recognized in the consolidated financial statements is based on awards that are ultimately expected to vest. Stock-based awards issued to nonemployees are accounted for based on the fair value of such services received or of the equity instruments issued, whichever is more reliably measured. Awards are revalued at each reporting date and upon vesting and are expensed on a straight-line basis over the vesting period.
Income Taxes	Income Taxes The Company accounts for income taxes under the liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in operations in the period that includes the enactment date. The Company recognizes net deferred tax assets through the recording of a valuation allowance to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future, in excess of its net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions on the basis of a two-step process whereby: (1) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50% likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability.
Net Loss Per Share	Net Loss Per Share Basic net loss per share is calculated by dividing net loss by the weighted average shares outstanding during the period, without consideration for common stock equivalents. During periods of income, the Company allocates participating securities a proportional share of income determined by dividing total weighted average participating securities by the sum of the total weighted average common shares and participating securities (the “two-class method”). The Company’s convertible preferred stock, which was exchanged for Public Epirus Common Stock in the Merger, participated in any dividends declared by the Company and were therefore considered to be participating securities. Participating securities have the effect of diluting both basic and diluted earnings per share during periods of income. During periods of loss, the Company allocates no loss to participating securities because they have no contractual obligation to share in the losses of the Company. Diluted net loss per share attributable to common stockholders is calculated by adjusting weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury-stock and if-converted methods. For purposes of the diluted net loss per share calculation, common stock equivalents have been excluded from the calculation of diluted net loss per share, as their effect would be anti-dilutive for all periods presented. Therefore, basic and diluted net loss per share were the same for all periods presented.
Comprehensive Loss	Comprehensive Loss Comprehensive loss is the change in equity of a company during a period from transactions and other events and circumstances, excluding transactions resulting from investments by owners and distributions to owners.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Going Concern In August 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to continue as a Going Concern. This update is intended to define management’s responsibility to evaluate whether there is substantial doubt about an organization’s ability to continue as a going concern within one year of the date of issuance of the entity’s financial statements and to provide related footnote disclosures. This guidance is effective for fiscal years beginning after December 15, 2016, with early application permitted. The Company is currently evaluating what effect, if any, the adoption of this guidance will have on the disclosures included in its consolidated financial statements. Debt Issuance Costs In April 2015, the FASB issued ASU No. 2015-03 , Interest—Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs , which requires that debt issuance costs be presented in the balance sheet as a deduction from the carrying amount of the related liability, rather than as a deferred charge. The updated guidance is effective retroactively for financial statements covering fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. The Company early adopted ASU No. 2015-03 effective December 31, 2015. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements and footnote disclosures. Technical Corrections and Improvements In June 2015, the FASB issued ASU No. 2015-10, Technical Corrections and Improvements . This update covers a wide range of Topics in the ASC. The amendments in this update represent changes to clarify the ASC, correct unintended application of guidance, or make minor improvements to the ASC that are not expected to have a significant effect on current accounting practice or create a significant administrative cost to most entities. Additionally, some of the amendments will make the ASC easier to understand and easier to apply by eliminating inconsistencies, providing needed clarifications, and improving the presentation of guidance in the ASC. The amendments in this update that require transition guidance are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. All other amendments will be effective upon the issuance of this update. The Company does not anticipate that the adoption of this standard will have a material impact on its consolidated financial statements and footnote disclosures. Revenue Recognition In July 2015, the FASB deferred the effective date for ASU No. 2014-09, Revenue from Contracts with Customers, by one year. This update will supersede the revenue recognition requirements in Revenue Recognition (Topic 605) and requires entities to recognize revenue in a way that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. This update is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period, which for the Company is January 1, 2018. Early application is permitted for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. The update can be applied retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of the change recognized at the date of the initial application in retained earnings. The Company is currently evaluating the potential impact the adoption of this update will have on its consolidated financial statements and has not yet selected a transition method. Business Combinations In September 2015, the FASB issued ASU No. 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement - Period Adjustments . This update eliminates the requirement to restate prior period financial statements for measurement period adjustments following a business combination. The update requires that the cumulative impact of a measurement period adjustment (including the impact on prior periods) be recognized in the reporting period in which the adjustment is identified. The prior period impact of the adjustment should be either presented separately on the face of the income statement or disclosed in the notes. The update is effective for fiscal years beginning after December 15, 2015. The adoption of this update is not expected to have a material impact on the Company’s financial position or results of operations. Income Taxes During November 2015, the FASB issued ASU 2015-17, “Balance Sheet Classification of Deferred Taxes”, which simplifies the presentation of deferred income taxes. This ASU requires that deferred tax assets and liabilities be classified as non-current in a statement of financial position. The standard is effective for public companies for fiscal years beginning after December 15, 2016, including interim periods within that reporting period. Early adoption is permitted for any interim and annual financial statements that have not yet been issued. The Company early adopted ASU 2015-17 effective December 31, 2015 on a prospective basis. Adoption of this ASU resulted in a reclassification of the net current deferred tax asset of $109 and the net current deferred tax liability of $80 to the net non-current deferred tax liability in the Company’s consolidated balance sheet as of December 31, 2015. No prior periods were retrospectively adjusted. Leases In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) . This update improves financial reporting around leasing transactions and more closely aligns accounting for leases with the recently issued International Financial Reporting Standard. The update requires a lessee to recognize assets and liabilities on the balance sheet for operating leases and changes many key definitions, including the definition of a lease. The update includes a short-term lease exception for leases with a term of 12 months or less, in which a lessee can make an accounting policy election not to recognize lease assets and lease liabilities. Lessees will continue to differentiate between finance leases (previously referred to as capital leases) and operating leases, using classification criteria that are substantially similar to the previous guidance. This update is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years, with earlier application permitted. The Company is currently evaluating the effect of this update on its consolidated financial statements.

Summary of Significant Accoun30

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Summary of Significant Accounting Policies
Schedule of Property and equipment estimated useful lives	Property and equipment are recorded at cost and are depreciated when placed into service using the straight-line method of depreciation, based on their estimated useful lives as follows: Asset Description Estimated Useful Lives Furniture and fixtures years Office and computer equipment 3 years Leasehold improvements Shorter of the useful life or remaining lease term

Merger (Tables)

Merger (Tables) - Zalicus	12 Months Ended
	Dec. 31, 2015
Schedule of acquisition-date fair value of consideration transferred	The acquisition-date fair value of the consideration transferred is as follows: Number of shares of Public Epirus Common Stock owned by Zalicus stockholders (1) Multiplied by the price per share of Public Epirus Common Stock (2) $ Fair value of shares of Public Epirus Common Stock owned by Zalicus stockholders $ Acquisition-date fair value of assumed Zalicus equity awards attributable to precombination services (3) $ Total consideration transferred $ (1) The stock transferred in the table above is comprised of 2,610,871 common shares outstanding at the time of the Merger plus 25,000 restricted stock units (RSUs) that vested immediately upon the closing of the Merger. The fair value of shares of Public Epirus Common Stock owned by Zalicus shareholders of $31,104 includes approximately $1 related to fractional shares resulting from the Reverse Stock Split. (2) The shares outstanding are multiplied by the closing trading price of Public Epirus Common Stock as of the Merger date. (3) Consideration transferred includes approximately $220 of Zalicus equity awards assumed and deemed attributable to precombination services to Zalicus. The fair value of the equity awards at July 15, 2014 was determined using a Black-Scholes option-pricing model with the following ranges of assumptions: exercise price of $14.70 per share to $591.00 per share; underlying stock value of $11.80 per share; expected volatility of 66.02%; expected term of 0.1 years to 6.0 years; and risk-free interest rate of 1.91% .
Summary of estimated fair values of the assets acquired and liabilities assumed at the date of acquisition	The following table summarizes the estimated fair values of the assets acquired and liabilities assumed at the date of acquisition: July 15, 2014 Cash and cash equivalents $ In-process research and development Goodwill Restricted cash Other assets Total assets acquired Accounts payable Accrued expenses Other current liabilities Other liabilities Deferred tax liabilities Total liabilities assumed Total net assets acquired $
Supplemental unaudited pro forma information as if acquisition had occurred on January 1, 2013	The following supplemental unaudited pro forma information presents the Company’s financial results as if the acquisition of Zalicus had occurred on January 1, 2013: Year Ended December 31, 2014 2013 Total revenues, net $ $ Net loss $ $

Acquisition (Tables)

Acquisition (Tables) - Bioceros	12 Months Ended
	Dec. 31, 2015
Schedule of acquisition-date fair value of consideration transferred	The acquisition-date fair value of the consideration transferred is as follows: Initial equity consideration paid at closing Initial shares issued to Bioceros shareholders Price per Epirus share at issuance $ $ Initial cash consideration paid at closing Total consideration paid at closing Settlement of preexisting Epirus accounts payable to Bioceros (1) Second Installment Shares, excluding key employee stock compensation expense (2) Net cash payout (3) Final payment of cash consideration (4) Preliminary estimated purchase price $ (1) Represents the settlement of preexisting accounts payable to Bioceros as a result of activity prior to the transaction . (2) Represents the fair value of the undiscounted $3,985 of Second Installment Shares to be paid and issued on March 9, 2016, which excludes the undiscounted $1,015 of shares to be issued to Bioceros key employees contingent upon the delivery of postcombination service to the Company, as described above. This amount has been recorded as a liability on the Company’s consolidated balance sheet, because it represents an obligation to issue a variable number of shares based on a fixed dollar amount of $3,985 , and recorded at fair value utilizing a discount rate of 10.7% . (3) Represents the fair value of the net cash payout to be made pursuant to the Stock Purchase Agreement. This amount has been recorded as a contingent consideration liability on the Company’s consolidated balance sheet as of September 9, 2015 and recorded at fair value utilizing a discount rate of 10.7% . The amount of the net cash payout is dependent on revenue agreements signed from select Bioceros customers subsequent to the acquisition date and through December 31, 2015 . (4) Represents the fair value of the final cash payment of $1,700 , which, pursuant to the Stock Purchase Agreement, the Company will pay on September 9, 2016. This amount has been recorded as a liability on the Company’s consolidated balance sheet as of September 9, 2016 and recorded at fair value utilizing a discount rate of 10.7% .
Summary of estimated fair values of the assets acquired and liabilities assumed at the date of acquisition	The following table summarizes the preliminary estimated fair values of the assets acquired and liabilities assumed at the date of acquisition: (in thousands) Cash and cash equivalents $ Deferred tax assets Accounts receivable Prepaid expenses and other current assets Property and equipment, net Intangible assets, net Goodwill Accounts payable Accrued expenses and other current liabilities Deferred revenue Deferred tax liabilities Net assets acquired $
Supplemental unaudited pro forma information as if acquisition had occurred on January 1, 2013	The following supplemental unaudited pro forma information represents the Company’s financial results as if the acquisition had occurred on January 1, 2014. Years Ended December 31, 2015 2014 Total revenues, net $ $ Net loss $ $

Prepaid Expenses and Other Cu33

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Prepaid Expenses and Other Current Assets
Schedule of prepaid expenses and other current assets	Prepaid expenses and other current assets consisted of the following: As of December 31, 2015 2014 Prepaid development expenses $ $ Prepaid other expenses Accounts receivable Other current assets Total prepaids and other current assets $ $

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2015
Property and Equipment, Net
Components of Property and Equipment	Property and equipment consisted of the following: As of December 31, 2015 2014 Laboratory equipment $ $ — Leasehold improvements Computer equipment Furniture and fixtures Total property and equipment Less: accumulated depreciation Property and equipment, net $ $

Goodwill, IPR&D and Intangibl35

Goodwill, IPR&D and Intangible Assets, Net (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill, IPR&D and Intangible Assets, Net
Schedule of changes in Goodwill	The following table represents changes in goodwill for the fiscal year ended December 31, 2015: Balance at December 31, 2014 $ Adjustment for Zalicus deferred tax liability Goodwill related to Bioceros acquisition Balance at December 31, 2015 $
Schedule of intangible assets, net of accumulated amortization	Intangible assets, net of accumulated amortization is as follows: As of December 31, 2015 2014 Intangible assets (excluding IPR&D) $ $ Less: accumulated amortization—intangible assets Intangible assets, net (excluding IPR&D) $ $
Schedule of estimated aggregate amortization of intangible assets	The estimated aggregate amortization of intangible assets as of December 31, 2015, for each of the five succeeding years and thereafter is as follows: December 31, 2015 2016 $ 2017 2018 2019 2020 2021 and thereafter Total $

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2015
Accrued Expenses
Components of Accrued expenses	Accrued expenses consisted of the following: As of December 31, 2015 2014 Accrued compensation $ $ Accrued professional fees Accrued interest expense Other Total accrued expenses $ $

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2015
Debt
Schedule of future principal payments	Future principal payments, which exclude the 3% end of term charge that will be payable upon repayment of the notes in full, in connection with the Loan Agreement, as of December 31, 2015 are as follows: Principal Payments 2016 $ 2017 2018 Total $

Warrants (Tables)

Warrants (Tables)	12 Months Ended
	Dec. 31, 2015
Common stock
Schedule of warrants to purchase stock outstanding	The following warrants to purchase common stock were outstanding: As of December 31, 2015 Number of Shares Underlying Warrants Exercise Price Per Share Common Stock $ Common Stock $ Common Stock $ Common Stock $ Common Stock $ Common Stock $ As of December 31, 2014 Number of Shares Underlying Warrants Exercise Price Per Share Common Stock $ Common Stock $ Common Stock $ Common Stock $ Common Stock $ Common Stock $ Common Stock $

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Measurements
Schedule of financial assets and liabilities measured at fair value on a recurring basis	As of December 31, 2015 Level 1 Level 2 Level 3 Total Assets Cash and cash equivalents $ $ — $ — $ $ $ — $ — $ As of December 31, 2014 Level 1 Level 2 Level 3 Total Assets Cash and cash equivalents $ $ — $ — $ $ $ — $ — $
Schedule of changes in the fair value of liabilities determined using Level 3 inputs	The reconciliation of the contingent consideration measured at fair value on a recurring basis using unobservable inputs (Level 3) is as follows: Balance at December 31, 2014 $ — Addition of contingent consideration related to Bioceros acquisition Remeasurement of Bioceros contingent consideration Balance at December 31, 2015 $ —

Capital Stock (Tables)

Capital Stock (Tables)	12 Months Ended
	Dec. 31, 2015
Capital Stock
Schedule of common stock shares reserved for future issuances	The Company has reserved for future issuances the following number of shares of common stock: Year Ended December 31, 2015 2014 Stock-based compensation awards Warrants to purchase common stock Settlement of short-term debt (Note 11) Total

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2015
Summary of stock option activity	A summary of stock option activity during the year ended December 31, 2015 is as follows: Weighted- Average Weighted- Remaining Average Contractual Aggregate Number Exercise Term Intrinsic of Options Price (in years) Value Outstanding at December 31, 2014 $ Granted Exercised Cancelled Outstanding at December 31, 2015 $ $ Vested and expected to vest at: December 31, 2015 $ $ Exercisable at: December 31, 2015 $ $ Weighted average grant-date fair value of options granted during the period $ Cash received upon exercise of options $
Summary of restricted stock activity	A summary of the restricted stock activity during the year ended December 31, 2015 is as follows: Weighted- Restricted Average Grant Stock Date Fair Value Nonvested at December 31, 2014 $ Granted — Vested Cancelled — — Nonvested at December 31, 2015 — $ —
Summary of the activity of nonvested RSUs	A summary of the activity of nonvested restricted stock units (“RSUs”) for the year ended December 31, 2015 is as follows: Weighted- Average Number Weighted- Remaining of Average Contractual Aggregate Restricted Grant Date Term Intrinsic Stock Units Fair Value (in years) Value Nonvested at December 31, 2014 — $ — — $ — Granted — Vested — — — Cancelled — Nonvested at December 31, 2015 $ $ Vested and expected to vest at: December 31, 2015 $ $ Exercisable at: December 31, 2015 — $ — — $ —
Stock Options
Summary of range of assumptions used in the Black-Scholes pricing model for grants and grants issued or accelerated in connections with the Merger	During the years ended December 31, 2015 and 2014, respectively, the range of assumptions used in the Black-Scholes pricing model for new grants and grants issued or accelerated in connection with the Merger were as follows: Year Ended December 31, 2015 2014 Risk-free interest rate 1.48% - 1.96% 1.80% - 2.09% Expected volatility 61.40% - 89.05% 63.96% - 66.07% Expected term (in years) Expected dividend yield
Employee Stock Purchase Plan
Summary of range of assumptions used in the Black-Scholes pricing model for grants and grants issued or accelerated in connections with the Merger	The fair value of the option component of the shares purchased under the ESPP was estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions: Year Ended December 31, 2015 Risk-free interest rate Expected volatility Expected term (in years) Expected dividend yield

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Taxes
Schedule of loss from continuing operations before income taxes	Year Ended December 31, 2015 2014 United States $ $ Foreign Loss before income taxes: $ $
Summary of Deferred Taxes	As of December 31, 2015 2014 Deferred tax assets Current assets: Accrued rent $ - $ Accrued expenses - Gross current deferred tax assets - Non-current assets: Net operating loss - U.S. $ $ Research and development credits License/start-up expenditures Accrued rent Accrued expenses and other — Stock based compensation Capitalized research and development/patent intangibles Capitalized research and developmet RBIL Limitation — Foreign investment tax credit — Net operating loss - foreign Gross non-current deferred tax assets $ $ Gross Deferred tax assets $ $ Deferred tax liabilities Non-current: Depreciation Swiss IP amortization Bioceros acquired intangibles Identifiable intangible assets - IPR&D - Total non-current deferred tax liabilities $ $ Gross deferred taxes $ $ Valuation allowance Net deferred tax liability $ $
Summary of the reconciliation of income tax expense computed at the statutory federal income tax rate to income taxes	Year Ended December 31, 2015 2014 Income tax benefit using U.S. federal statutory rate $ $ State income taxes, net of federal benefit Other permanent differences Foreign rate differential Tax credits Other items Tax benefit related to the IPR&D transfer IPR&D impairment charge benefit — Foreign withholding taxes Net change in valuation allowance Income tax benefit $ $

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments
Schedule of future minimum lease payments	December 31, 2015 2016 $ 2017 2018 2019 2020 2021 and thereafter Total $ Less: Future sublease payments to be received Net future lease payments $

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2015
Net Loss Per Share
Summary of potentially dilutive securities outstanding excluded from the computation of diluted weighted-average shares outstanding	The following potentially dilutive securities outstanding, prior to the use of the treasury stock method, have been excluded from the computation of diluted weighted-average shares outstanding for the years ended December 31, 2015 and 2014, as they would be anti-dilutive. In addition, Second Installment Shares issuable to former Bioceros shareholders with a value of $5,000 to be issued in March 2016 have been excluded from the computation of basic and diluted weighted-average shares outstanding for the year ended December 3 1 , 2015 (Note 5). As of December 31, 2015 2014 Options to purchase common stock Settlement of loan agreement Nonvested restricted stock units — Warrants to purchase common stock Employee stock purchase plan — Nonvested restricted stock awards —

Organization (Details)

Organization (Details) $ in Thousands	12 Months Ended		60 Months Ended
	Dec. 31, 2015USD ($)product	Dec. 31, 2014USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2013USD ($)
Organization
Number of biosimilar product candidates | product	3
Cash and cash equivalents	$ 31,515	$ 21,462	$ 31,515	$ 1,798
Accumulated deficit	(138,759)	(86,571)	(138,759)
Net loss	$ (52,188)	$ (41,844)	$ (138,759)

Summary of Significant Accoun46

Summary of Significant Accounting Policies (Details) $ / shares in Units, $ in Thousands	Jul. 16, 2014$ / shares	Dec. 31, 2015USD ($)segmentinstrument$ / sharesitem	Dec. 31, 2014USD ($)$ / shares	Jun. 04, 2015$ / shares
Reverse stock split
Reverse stock split conversion ratio	0.1
Common stock, par value | $ / shares	$ 0.001	$ 0.001	$ 0.001	$ 0.001
Segment and Geographic Information
Number of operating segments | segment		1
Concentrations of Credit Risk and Off-Balance Sheet Risk
Financial instruments held | instrument		0
Cash and Cash Equivalents
Number of banks in which Company holds cash and cash equivalents in depository accounts | item		6
Fair Value of Financial Instruments
Asset transfers between Levels		$ 0	$ 0
Property and Equipment
Impairment losses		0
In-Process R&D
Impairment charge of IPR&D		1,671	0
Intangible Assets
Impairment of intangible assets		0	$ 0
Net Current Deferred Tax Asset
Income Taxes
Reclassification adjustment		109
Net Current Deferred Tax Liability
Income Taxes
Reclassification adjustment		$ (80)
Minimum
Intangible Assets
Intangible asset, useful life		6 years
Maximum
Intangible Assets
Intangible asset, useful life		16 years 6 months
Furniture And Fixtures
Property and Equipment
Estimated useful life		5 years
Office and computer equipment
Property and Equipment
Estimated useful life		3 years

Business Agreements (Details)

Business Agreements (Details) $ in Thousands	Sep. 24, 2015USD ($)item	Jul. 13, 2015product	Nov. 30, 2015USD ($)	Nov. 30, 2014USD ($)	Sep. 30, 2014USD ($)item	Apr. 30, 2014USD ($)	Jan. 31, 2014USD ($)	Dec. 31, 2015USD ($)item	Dec. 31, 2014USD ($)	Dec. 31, 2015USD ($)	May. 13, 2015USD ($)
Business Agreements
Royalty revenue								$ 701	$ 4
Intangible asset									5,500
Livzon Mabpharm Inc
Business Agreements
Ownership percentage								6.40%		6.40%
Royalty Bearing And Non Transferable License Agreement | Sun Pharmaceutical Industries Limited | BOW015
Business Agreements
Upfront payment received							$ 500
Maximum payments to be received for achievement of certain development and regulatory approval milestones								$ 1,000		$ 1,000
Maximum payments to be received for achievement of certain sales milestones								10,000		10,000
Amount payable for breach of license agreement								$ 500		500
Term of agreement								20 years
Number of units of accounting for recognition of revenue of deliverables | item								1
Revenue recognized from rights under agreement								$ 0
Invoiced amount					$ 125	$ 250	$ 125			1,250
Proceeds received as per agreement										1,250
Royalty Bearing And Non Transferable License Agreement | Sun Pharmaceutical Industries Limited | Infimab
Business Agreements
Royalty revenue								119	4
Invoiced amount				$ 250
Deferred revenue over the remaining term of license agreement				$ 500
Supplement Agreement | Sun Pharmaceutical Industries Limited | BOW015
Business Agreements
Term of agreement					10 years
Number of automatic renewals | item					5
Automatic renewal period					2 years
Supplement Agreement | Livzon Mabpharm Inc | BOW070
Business Agreements
Total payments to be made for the completion of the pre-clinical development activities	$ 4,500
Initial payment to be made for pre-clinical development activities upon entry into Supplement Agreement	$ 1,500
Initial payment term for pre-clinical development activities upon entry into Supplement Agreement	10 days
Number of additional payments to be made for the achievement of certain pre-clinical development milestones | item	3
Payments to be made for the achievement of certain pre-clinical development milestones	$ 1,000
Estimated period for expensing costs	18 months
Expense recorded	$ 500
Exclusive License and Collaboration Agreement | Mabxience S.A | BOW015
Business Agreements
Amount that could be earned for each first commercial sale in each territory country								$ 250
Term of agreement								15 years
Exclusive License and Collaboration Agreement | Mabxience S.A | BOW015 | Maximum
Business Agreements
Maximum payments to be received for achievement of certain sales milestones											$ 1,500
Exclusive License and Collaboration Agreement | Livzon Mabpharm Inc | BOW015
Business Agreements
Payments to be received for achievement of specified regulatory milestones					$ 2,500
Term of agreement					20 years
Proceeds received as per agreement									0
Amount due per agreement									$ 0
Maximum additional compounds subject to exclusive, royalty-bearing licenses | item					4
Collaboration Agreement
Business Agreements
Percentage of costs under development program		49.00%
Cost sharing ratio percentage for costs incurred in connection with global development		100.00%
Cost sharing ratio percentage for clinical trial costs incurred in connection with global development		38.00%
Percentage of clinical trial costs incurred in connection with global development		81.00%
Percentage of profits and losses sharing under development programs		49.00%
Collaboration Agreement | Polpharma
Business Agreements
Royalty revenue								$ 235
Invoiced amount			$ 760
Deferred revenue over the remaining term of license agreement								$ 525		$ 525
Number of product programs | product		3
Percentage of costs under development program		51.00%
Percentage of clinical trial costs incurred in connection with global development		19.00%
Percentage of profits and losses sharing under development programs		51.00%
Collaboration Agreement | Polpharma | North America
Business Agreements
Number of products exclusive rights retained | product		3

Merger (Details)

Merger (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 15, 2014	Jul. 15, 2014	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015
Acquisition-date fair value of the consideration transferred
Stock-based compensation expense				$ 3,470	$ 1,719
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Goodwill			$ 16,363	26,361	16,363		$ 26,361
Deferred tax liabilities			0	(757)	0		(757)
Supplemental unaudited pro forma information:
Net loss				(52,188)	(41,844)		$ (138,759)
Zalicus
Merger
Number of shares of acquiree received for each share of acquirer exchanged		0.13259
Aggregate number of acquiree shares received for acquirer shares		10,288,180
Number of acquiree shares received for future issuance upon exercise of stock options		1,152,042
Number of acquiree shares received for future issuance upon exercise of warrants		21,996
Acquisition-date fair value of the consideration transferred
Number of Public Epirus Common Stock owned by Zalicus stockholders (1)		2,635,871
Multiplied by the price per share of Public Epirus Common Stock (2) (in dollars per share)	$ 11.80	$ 11.80
Fair value of shares of Public Epirus Common Stock owned by Zalicus stockholders		$ 31,104
Acquisition-date fair value of assumed Zalicus equity awards attributable to precombination		220
Total consideration transferred		31,324
Amount of fractional shares resulting from Reverse Stock Split included as consideration		$ 1
Share price (in dollars per share)	$ 11.80	$ 11.80
Volatility rate		66.02%
Risk-free interest rate		1.91%
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Cash and cash equivalents	$ 13,756	$ 13,756
In-process research and development	5,500	5,500
Goodwill	14,127	14,127
Restricted cash	1,850	1,850
Other assets	253	253
Total assets acquired	35,486	35,486
Accounts payable	(1,584)	(1,584)
Accrued expenses	(381)	(381)
Other current liabilities	(376)	(376)
Other liabilities	(391)	(391)
Deferred tax liabilities	(1,430)	(1,430)
Total liabilities assumed	(4,162)	(4,162)
Total net assets acquired	$ 31,324	$ 31,324
Goodwill adjustment				736
Operating loss from date of acquisition included in financial statements			$ (25)
Business Combination, Acquisition Related Costs					5,779
Supplemental unaudited pro forma information:
Total revenues, net				2,739	14,731
Net loss				$ (32,410)	(69,630)
Zalicus | Transaction Costs
Supplemental unaudited pro forma information:
Net loss					8,673
Zalicus | stock-based compensation expense
Supplemental unaudited pro forma information:
Net loss					355
Zalicus | severance agreements
Supplemental unaudited pro forma information:
Net loss					1,980
Zalicus | other expense related to the change in the fair values of liability-classified warrants
Supplemental unaudited pro forma information:
Net loss					$ 222	$ 789
Zalicus | In Process Research and Development
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Discount rate (as a percent)		13.10%
Zalicus | Minimum
Acquisition-date fair value of the consideration transferred
Exercise price (in dollars per share)	$ 14.70	$ 14.70
Expected term	1 month 6 days
Zalicus | Maximum
Acquisition-date fair value of the consideration transferred
Exercise price (in dollars per share)	$ 591	$ 591
Expected term	6 years
Zalicus | Common stock
Acquisition-date fair value of the consideration transferred
Number of Public Epirus Common Stock owned by Zalicus stockholders (1)		2,610,871
Zalicus | Restricted stock units vested upon closing of business combination
Acquisition-date fair value of the consideration transferred
Number of Public Epirus Common Stock owned by Zalicus stockholders (1)		25,000
Preliminary | Zalicus
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Deferred tax liabilities	$ (2,166)	$ (2,166)

Acquisition (Details)

Acquisition (Details)	Sep. 09, 2015USD ($)$ / shares	Sep. 09, 2015USD ($)product$ / sharesshares	Dec. 31, 2015USD ($)$ / shares	Dec. 31, 2015USD ($)product$ / shares	Dec. 31, 2014USD ($)$ / shares	Jun. 04, 2015$ / shares	Jul. 16, 2014$ / shares
Acquisition
Number of biosimilar product candidates | product				3
Common stock, par value | $ / shares			$ 0.001	$ 0.001	$ 0.001	$ 0.001	$ 0.001
Stock-based compensation expense				$ 3,470,000	$ 1,719,000
Acquisition-date fair value of the consideration transferred
Initial cash consideration paid at closing				3,400,000
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Goodwill			$ 26,361,000	26,361,000	16,363,000
Cash payout of liability				409,000
Accrued purchase price liability			5,493,000	5,493,000
Revenue				701,000	4,000
Operating loss				$ 52,300,000	39,255,000
Period for final determination of allocation of consideration transferred, from acquisition date				1 year
Minimum
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Intangible asset, useful life				6 years
Bioceros
Acquisition
Percentage of voting rights acquired	100.00%	100.00%
Number of biosimilar product candidates | product		3
Total consideration		$ 14,100,000
Cash payment liability	$ 1,700,000	$ 1,700,000
Number of installments in which shares will be released				$ 3
Acquisition-date fair value of the consideration transferred
Initial shares issued to Bioceros shareholders (in shares) | shares		788,960
Price per Epirus share at issuance | $ / shares	$ 5.79	$ 5.79
Initial equity consideration paid at closing		$ 4,568,000
Initial cash consideration paid at closing	$ 3,400,000	3,400,000
Total consideration paid at closing		7,968,000
Settlement of preexisting Expirus accounts payable to Bioceros		(87,000)
Second Installment Shares, excluding key employee stock compensation expense		3,788,000
Net cash payout		409,000
Final payment of cash consideration		1,535,000
Preliminary estimated purchase price		13,613,000
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Cash and cash equivalents	889,000	889,000
Deferred tax assets	161,000	161,000
Accounts receivable	49,000	49,000
Prepaid expenses and other current assets	226,000	226,000
Property and equipment, net	447,000	447,000
Intangible assets, net	3,191,000	3,191,000
Goodwill	10,734,000	10,734,000
Accounts payable	(146,000)	(146,000)
Accrued expenses and other liabilities	(704,000)	(704,000)
Deferred revenue	(436,000)	(436,000)
Deferred tax liabilities	(798,000)	(798,000)
Total net assets acquired	13,613,000	13,613,000
Gross contractual accounts receivable	49,000	$ 49,000
Intangible asset, useful life		6 years
Effective tax rate		25.00%
Revenue			186,000
Operating loss			96,000
Transaction costs				754,000
Supplemental unaudited pro forma information:
Total revenues, net				1,728,000	2,474,000
Net loss				(50,985,000)	(41,720,000)
Bioceros | Cash and cash equivalents
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Adjustments to fair value of assets				56,000
Bioceros | Intangible assets
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Adjustments to fair value of assets				1,199,000
Bioceros | Accounts payable
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Adjustments to fair value of assets				25,000
Bioceros | Prepaid expenses, other current assets and accounts receivable
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Adjustments to fair value of assets				112,000
Bioceros | Goodwill
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Adjustments to fair value of assets				1,478,000
Bioceros | Accrued liabilities
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Adjustments to fair value of assets				232,000
Bioceros | Deferred tax assets
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Adjustments to fair value of assets				168,000
Bioceros | Deferred tax liability
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Adjustments to fair value of assets				300,000
Bioceros | Final Cash Payment
Acquisition
Cash payment liability	$ 409,000	$ 409,000	0	0
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Accrued purchase price liability			1,584,000	1,584,000
Bioceros | Initial Issuance
Acquisition
Common stock, par value | $ / shares	$ 0.001	$ 0.001
Value of common stock issuable	$ 4,000,000	$ 4,000,000
Period of pre-closing date average price	10 days
Pre-closing date average price | $ / shares	$ 5.07	$ 5.07
Fair value of issuance of shares related to acquisition	$ 4,568,000	$ 4,568,000
Bioceros | Second Installment Shares
Acquisition
Fair value of issuance of shares related to acquisition	5,000,000	5,000,000
Estimated fair values of the assets acquired and liabilities assumed at the date of acquisition:
Accrued purchase price liability			$ 3,909,000	$ 3,909,000
Bioceros | First Installment
Acquisition
Period after closing date after which shares will be released to key employees				12 months
Bioceros | Second Installment
Acquisition
Period after closing date after which shares will be released to key employees				18 months
Bioceros | Third Installment
Acquisition
Period after closing date after which shares will be released to key employees				24 months
Bioceros | Transaction Costs
Supplemental unaudited pro forma information:
Pro forma adjustments				$ (964,000)
Bioceros | Adjustment For Stock Compensation Expense That Would Have Been Charged [Member]
Supplemental unaudited pro forma information:
Pro forma adjustments				374,000	$ 500,000
Bioceros | Minimum
Acquisition
Threshold for payment of cash received from customers	1,200,000	$ 1,200,000
Key Employees of Acquired Company | Bioceros
Acquisition
Percentage of shares that will vest on first vesting date		75.00%
Percentage of shares that will vest on subsequent vesting date		25.00%
Stock-based compensation expense				$ 126,000
Key Employees of Acquired Company | Bioceros | Second Installment Shares
Acquisition
Fair value of issuance of shares related to acquisition	1,015,000	$ 1,015,000
Estimate of Fair Value Measurement | Bioceros
Acquisition
Cash payment liability	1,700,000	1,700,000
Fair value of issuance of shares related to acquisition	$ 3,985,000	$ 3,985,000
Acquisition-date fair value of the consideration transferred
Discount rate (as a percent)		10.70%		10.70%

Disposition (Details)

Disposition (Details) CAD in Thousands, $ in Thousands	Oct. 01, 2015CAD	Dec. 31, 2015USD ($)	Oct. 01, 2015USD ($)
Gain on sale of subsidiary		$ 1,016
Zalicus Pharmaceuticals, Ltd | Discontinued Operations, Disposed of by Sale
Proceeds from purchase agreement | CAD	CAD 5,000
Limited recourse promissory note | CAD	CAD 5,000
Gain on sale of subsidiary		$ 1,016
Z944 | Zalicus Pharmaceuticals, Ltd | Discontinued Operations, Disposed of by Sale
Maximum payments to be received for achievement of certain development and regulatory approval milestones			$ 7,500
Maximum payments to be received for achievement of certain sales milestones			$ 30,000

Prepaid Expenses and Other Cu51

Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Prepaid Expenses and Other Current Assets
Prepaid development expenses	$ 2,281	$ 457
Prepaid other expenses	668	638
Accounts receivable	130	4
Other current assets	653	457
Total prepaid and other current assets	$ 3,732	$ 1,556

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Property and Equipment
Total property and equipment	$ 2,373	$ 793
Less: accumulated depreciation	(300)	(89)
Property and equipment, net	2,073	704
Depreciation expense	211	83
Leasehold Improvements
Property and Equipment
Total property and equipment	1,268
Laboratory equipment
Property and Equipment
Total property and equipment	518	504
Computer equipment
Property and Equipment
Total property and equipment	303	173
Furniture And Fixtures
Property and Equipment
Total property and equipment	$ 284	$ 116

Goodwill, IPR&D and Intangibl53

Goodwill, IPR&D and Intangible Assets, Net (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Change in Goodwill
Goodwill, Beginning Balance	$ 16,363
Adjustment for Zalicus deferred tax liability	(736)
Goodwill related to Bioceros acquisition	10,734
Goodwill, Ending Balance	26,361
Accumulated goodwill impairment losses	$ 0

Goodwill, IPR&D and Intangibl54

Goodwill, IPR&D and Intangible Assets, Net (Details 2) - USD ($) $ in Thousands	Sep. 09, 2015	Sep. 30, 2015	Nov. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Oct. 31, 2014	Sep. 30, 2014
Intangible Assets
Intangible asset					$ 5,500
Impairment of intangible assets				$ 0	0
Intangible assets, net of accumulated amortization
Total Intangible Assets				6,878	3,687
Less: accumulated amortization--intangible assets				(468)	(82)
Intangible assets, net				6,410	3,605
Bioceros
Intangible Assets
Intangible asset, useful life	6 years
In Process Research and Development
Intangible assets, net of accumulated amortization
Amortization expense				$ 386	82
Z944 | In Process Research and Development
Intangible Assets
Intangible asset		$ 3,829			$ 5,500
Impairment of intangible assets		$ 1,671
BOW015 | In Process Research and Development
Intangible Assets
Reclassification from indefinite lived asset to finite lived asset			$ 2,437
Intangible asset, useful life				16 years 6 months
BOW015 | Moksha8 Pharmaceuticals Inc
Intangible Assets
Intangible asset							$ 1,250
Payment to terminate payment obligations under agreement						$ 1,400
Platform Technology | Bioceros
Intangible Assets
Intangible asset				$ 3,191
Intangible asset, useful life	6 years

Goodwill, IPR&D and Intangibl55

Goodwill, IPR&D and Intangible Assets, Net (Details 3) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Estimated future amortization expense related to finite-lived purchased intangible assets
2,016	$ 757
2,017	757
2,018	757
2,019	757
2,020	757
2021 and thereafter	2,625
Total	$ 6,410	$ 3,605

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued Expenses
Accrued compensation	$ 2,057	$ 1,244
Accrued professional fees	1,502	1,822
Accrued interest expense	264	71
Other	180	88
Total accrued expenses	$ 4,003	$ 3,225

Debt (Details)

Debt (Details) $ / shares in Units, $ in Thousands	Sep. 30, 2015	Sep. 30, 2014USD ($)loan$ / sharesshares	Apr. 15, 2014USD ($)$ / sharesshares	Mar. 10, 2014USD ($)shares	Apr. 30, 2014USD ($)shares	Dec. 31, 2015USD ($)shares	Dec. 31, 2014USD ($)shares	May. 29, 2015USD ($)	Oct. 01, 2014USD ($)	Mar. 31, 2014$ / sharesshares
Debt
Shares reserved for future issuances | shares						4,473,256,000	4,744,399,000
Short-term Debt						$ 14,833
Long-term debt obligation							$ 7,269
Series B Convertible Preferred Stock
Debt
Number of shares issued upon conversion of debt | shares					3,947,363		3,947,363
Series A Preferred Stock Or Qualified Financing Securities Warrants Exercise Price Dollars 0.01 | Series B Convertible Preferred Stock
Debt
Number of shares issuable upon exercise of warrants | shares										787,402
Convertible Debt Issued 2013
Debt
Outstanding principal amount converted				$ 12,500
Outstanding interest amount converted				$ 684
Convertible Debt Issued 2013 | Series A Convertible Preferred Stock
Debt
Number of shares issued upon conversion of debt | shares				13,184,383
Convertible Debt Issued 2014
Debt
Proceeds received from debt issuance				$ 5,000
Interest rate (as a percent)				8.00%
Warrant coverage (as a percent)				20.00%
Outstanding principal amount converted			$ 5,000		$ 5,000
Outstanding interest amount converted			$ 13		$ 13
Convertible Debt Issued 2014 | Series B Convertible Preferred Stock
Debt
Number of shares issued upon conversion of debt | shares			3,947,363
Exercise Price (in dollars per share) | $ / shares										$ 0.01
Convertible Debt Issued 2014 | Series A Preferred Stock Or Qualified Financing Securities Warrants Exercise Price Dollars 0.01 | Series B Convertible Preferred Stock
Debt
Number of shares issuable upon exercise of warrants | shares			787,402
Exercise Price (in dollars per share) | $ / shares			$ 0.01
Hercules Notes
Debt
Number of term loans | loan		2
Aggregate principal amount		$ 15,000
Percentage of prepayment fees		2.00%
Amount of prepayment fees, in case loan is repaid after 18 months		$ 0
Right to participate in sales and issuance of equity						1,000
Number of shares issuable upon exercise of warrants | shares		64,194
Exercise Price (in dollars per share) | $ / shares		$ 7.01
Outstanding borrowings		$ 2,000				15,000
Percentage of common stock price above warrant exercise price		15.00%
Shares reserved for future issuances | shares		248,093
Common stock fixed price above warrant exercise price | $ / shares		$ 8.06
Short-term Debt						14,833
Unamortized Debt Discount						167
Amortization of the debt discount included in interest expense						$ 89	$ 14
Hercules Notes | Minimum
Debt
Interest rate (as a percent)						7.95%
Hercules Notes | Prime Rate | Minimum
Debt
Interest rate (as a percent)						7.95%
Applicable margin ( as a percent)						3.25%
Base rate						Prime Rate
Hercules Term Loan One
Debt
Aggregate principal amount									$ 7,500
Number of monthly repayment installments	18 months
Hercules Term Loan Two
Debt
Aggregate principal amount								$ 7,500

Debt (Details 2)

Debt (Details 2) - Hercules Notes - USD ($) $ in Thousands	Sep. 30, 2014	Dec. 31, 2015
Debt
Term charge	3.00%	3.00%
Future principal payments
2,016		$ 3,693
2,017		5,940
2,018		5,367
Total	$ 2,000	$ 15,000

Warrants (Details)

Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 30, 2014	Apr. 30, 2014	Mar. 31, 2014	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2015	Apr. 15, 2014
Assumptions to estimate the fair value of warrants
Fair value of warrants	$ 248			$ 248
Expected volatility				61.68%
Expected term				5 years
Risk-free interest rate				1.78%
Common stock | Exercise Price 0.08
Warrants to purchase common stock
Number of Shares Underlying Warrants					1,379	1,379
Exercise Price (in dollars per share)					$ 0.08	$ 0.08
Common stock | Exercise price 7.01
Warrants to purchase common stock
Number of Shares Underlying Warrants					64,194	64,194
Exercise Price (in dollars per share)					$ 7.01	$ 7.01
Common stock | Exercise Price 7.55
Warrants to purchase common stock
Number of Shares Underlying Warrants					20,616	20,616
Exercise Price (in dollars per share)					$ 7.55	$ 7.55
Common stock | Exercise Price 68.40
Warrants to purchase common stock
Number of Shares Underlying Warrants					3,737	3,737
Exercise Price (in dollars per share)					$ 68.40	$ 68.40
Common stock | Exercise Price 68.40 | Zalicus
Warrants to purchase common stock
Number of Shares Underlying Warrants					3,737
Exercise Price (in dollars per share)					$ 68.40
Common stock | Exercise Price 83.40
Warrants to purchase common stock
Number of Shares Underlying Warrants					1,079	1,079
Exercise Price (in dollars per share)					$ 83.40	$ 83.40
Common stock | Exercise Price 83.40 | Zalicus
Warrants to purchase common stock
Number of Shares Underlying Warrants					1,079
Exercise Price (in dollars per share)					$ 83.40
Common stock | Exercise Price 135.00
Warrants to purchase common stock
Number of Shares Underlying Warrants					1,887	1,887
Exercise Price (in dollars per share)					$ 135	$ 135
Common stock | Exercise Price 135.00 | Zalicus
Warrants to purchase common stock
Number of Shares Underlying Warrants					1,887
Exercise Price (in dollars per share)					$ 135
Common stock | Exercise Price 405.00
Warrants to purchase common stock
Number of Shares Underlying Warrants					148
Exercise Price (in dollars per share)					$ 405
Common stock | Exercise Price 405.00 | Zalicus
Warrants to purchase common stock
Number of Shares Underlying Warrants					148
Exercise Price (in dollars per share)					$ 405
Series A Convertible Preferred Stock
Warrants to purchase common stock
Number of shares issued upon exercise of warrants		5,101,816			5,101,816
Series B Convertible Preferred Stock
Warrants to purchase common stock
Number of shares issued upon exercise of warrants		787,402			787,402
Series A Preferred Stock Warrants
Warrants to purchase common stock
Number of Shares Underlying Warrants		5,101,816
Series A Preferred Stock Or Qualified Financing Securities Warrants Exercise Price Dollars 0.01 | Series B Convertible Preferred Stock
Warrants to purchase common stock
Number of Shares Underlying Warrants			787,402
Convertible Debt Issued 2014 | Series B Convertible Preferred Stock
Warrants to purchase common stock
Exercise Price (in dollars per share)			$ 0.01
Convertible Debt Issued 2014 | Series A Preferred Stock Warrants Exercise Price Dollars 1.00
Warrants to purchase common stock
Number of Shares Underlying Warrants			1,000,000
Exercise Price (in dollars per share)			$ 0.01
Warrants, term			7 years
Assumptions to estimate the fair value of warrants
Fair value of warrants			$ 1,171
Convertible Debt Issued 2014 | Series A Preferred Stock Or Qualified Financing Securities Warrants Exercise Price Dollars 0.01 | Series B Convertible Preferred Stock
Warrants to purchase common stock
Number of Shares Underlying Warrants							787,402
Exercise Price (in dollars per share)							$ 0.01
Hercules Notes
Warrants to purchase common stock
Aggregate principal amount	$ 15,000			$ 15,000
Number of Shares Underlying Warrants	64,194			64,194
Exercise Price (in dollars per share)	$ 7.01			$ 7.01
Warrants, term	5 years

Fair Value Measurements - (Deta

Fair Value Measurements - (Details) - Recurring - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 31,515	$ 21,462
Total assets	31,515	21,462
Level 1
Assets
Cash and cash equivalents	31,515	21,462
Total assets	31,515	$ 21,462
Level 3
Liabilities
Contingent consideration	$ 0

Fair Value Measurements - (De61

Fair Value Measurements - (Details 2) - USD ($) $ in Thousands	Sep. 09, 2015	Dec. 31, 2015
Fair value measurements
Remeasurement of Bioceros contingent consideration		$ 409
Estimate of Fair Value Measurement | Bioceros
Fair value measurements
Discount rate (as a percent)	10.70%	10.70%
Recurring | Level 3
Fair value measurements
Addition of contingent consideration related to Bioceros acquisition		$ 409
Remeasurement of Bioceros contingent consideration		(409)
Balance at the end of the period		0
Minimum | Bioceros
Fair value measurements
Cash received from Bioceros customers		$ 1,200

Capital Stock (Details)

Capital Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 04, 2015	Jun. 03, 2015	Apr. 15, 2014	Apr. 30, 2014	Dec. 31, 2014	Dec. 31, 2015	Jul. 16, 2014
Capital Stock
Common stock, shares authorized	70,000,000				300,000,000	70,000,000
Common stock, par value	$ 0.001				$ 0.001	$ 0.001	$ 0.001
Common stock, shares issued					12,934,102	24,377,573
Common stock, shares outstanding					12,920,843	24,377,573
Preferred stock, shares authorized	5,000,000				5,000,000	5,000,000
Preferred stock, par value	$ 0.001				$ 0.001	$ 0.001
Preferred stock, shares issued					0	0
Preferred stock, shares outstanding					0	0
Authorized capital stock	75,000,000	305,000,000
Shares reserved for future issuances					4,744,399,000	4,473,256,000
Convertible Debt Issued 2014
Capital Stock
Outstanding principal amount converted			$ 5,000	$ 5,000
Outstanding interest amount converted			$ 13	$ 13
Settlement of short-term debt
Capital Stock
Shares reserved for future issuances					248,093,000	248,093,000
Warrants to purchase common stock
Capital Stock
Shares reserved for future issuances					93,040,000	92,892,000
Options to purchase common stock
Capital Stock
Shares reserved for future issuances					4,403,266,000	4,132,271,000
Series B Convertible Preferred Stock
Capital Stock
Issuance of shares				24,409,444	24,409,444
Proceeds from issuance of shares				$ 31,000
Number of shares issued upon conversion of debt				3,947,363	3,947,363
Series B Convertible Preferred Stock | Convertible Debt Issued 2014
Capital Stock
Number of shares issued upon conversion of debt			3,947,363
Second Installment Shares
Capital Stock
Shares reserved for future issuances						5,000,000

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 15, 2014	Jul. 15, 2014	Aug. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Jun. 04, 2015	Apr. 01, 2014	Dec. 31, 2011
Stock-Based Compensation
Stock-based compensation expense				$ 3,470	$ 1,719
Reduced share based compensation expense				$ 100
Remaining vesting period				3 years
Weighted average fair value
Cash received from exercise of stock options				$ 355	$ 90
Zalicus
Stock-Based Compensation
Acquisition-date fair value of assumed Zalicus equity awards attributable to precombination services		$ 220
Weighted-average assumptions
Risk-free interest rate		1.91%
Expected volatility		66.02%
Minimum | Zalicus
Weighted-average assumptions
Expected term	1 month 6 days
Maximum | Zalicus
Weighted-average assumptions
Expected term	6 years
Employees of acquirees | Zalicus
Stock-Based Compensation
Stock-based compensation expense				355
Non employees of acquirees | Zalicus
Stock-Based Compensation
Stock-based compensation expense				$ 303
Stock Options
Stock-Based Compensation
Vesting Period				4 years
Vesting percentage in first anniversary				25.00%
Maximum term of a stock option				10 years
Number of Options
Outstanding at the beginning of the period				1,652,882
Granted				2,269,247
Exercised				(130,920)
Cancelled				(177,782)
Outstanding at the end of the period				3,613,427	1,652,882
Vested and expected to vest at end of period				3,438,732
Exercisable at end of period				699,459
Weighted-Average Exercise Price
Outstanding at the beginning of the period				$ 10.03
Granted				7.50
Exercised				2.71
Cancelled				7.83
Outstanding at the end of the period				8.81	$ 10.03
Vested and expected to vest at end of period				8.90
Exercisable at end of period				$ 14.73
Weighted-Average Remaining Contractual Term
Outstanding at end of period				8 years 9 months 18 days	8 years 10 months 24 days
Vested and expected to vest at end of period				8 years 9 months 18 days
Exercisable at end of period				7 years 8 months 12 days
Aggregate Intrinsic Value
Outstanding at end of period				$ 485	$ 1,628
Vested and expected to vest at end of period				482
Exercisable at end of period				316
Total intrinsic value of options exercised				$ 547	$ 71
Weighted average fair value
Weighted average grant-date fair value of options granted during the period				$ 4.86
Cash received from exercise of stock options				$ 355
Unrecognized stock-based compensation expense
Unrecognized stock-based compensation expense				$ 11,284
Unrecognized stock-based compensation expense, Recognition period				3 years 1 month 6 days
Weighted-average assumptions
Expected term				6 years	6 years
Expected dividend yield				0.00%	0.00%
Stock Options | Minimum
Weighted-average assumptions
Risk-free interest rate				1.48%	1.80%
Expected volatility				61.40%	63.96%
Stock Options | Maximum
Weighted-average assumptions
Risk-free interest rate				1.96%	2.09%
Expected volatility				89.05%	66.07%
2004 Plan
Stock-Based Compensation
Increase in number of shares available for issuance			3,000,000
Shares available for issuance				0
2011 Plan
Stock-Based Compensation
Authorized number of shares							1,504,752	740,470
2015 Plan
Stock-Based Compensation
Authorized number of shares						1,700,000
Shares available for issuance				394,402
Annual increase to shares available for issuance, minimum alternative				1,000,000
Annual increase to shares available for issuance, percentage alternative				4.00%

Stock-Based Compensation (Det64

Stock-Based Compensation (Details 2) - USD ($) $ / shares in Units, $ in Thousands	Sep. 25, 2014	Apr. 15, 2014	Feb. 28, 2015	Apr. 30, 2014	Dec. 31, 2015	Dec. 31, 2014
Aggregate Intrinsic value
Stock-based compensation expense					$ 3,470	$ 1,719
Nonvested restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares
Granted			117,131		126,621
Cancelled					(2,179)
Non-vested at end of period					124,442
Vested and expected to vest at the end of period ( in units)					116,964
Weighted-Average Exercise Price
Granted, Weighted-Average Grant Date Fair Value					$ 10.53
Cancelled					10.53
Nonvested at the end of the period					10.53
Vested and expected to vest at end of period					$ 10.53
Weighted Average Remaining Contractual Term
Non-vested Weighted Average Remaining Contractual Term (in years)					2 years 10 months 24 days
Vested and expected to vest at the end of period ( in years)					2 years 10 months 24 days
Aggregate Intrinsic value
Non-vested, Aggregate Intrinsic Value					$ 385
Vested and expected to vest, Aggregate Intrinsic Value					361
Unrecognized stock-based compensation expense					$ 972
Unrecognized stock-based compensation expense, Recognition period					2 years 11 months 5 days
Percentage of shares that will vest on first vesting date			25.00%
Percentage of shares that will vest on subsequent vesting date			25.00%
Nonvested restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares
Non-vested at beginning of period					13,259
Vested					(13,259)
Non-vested at end of period					0	13,259
Weighted-Average Exercise Price
Nonvested at the beginning of the period					$ 5.08
Granted, Weighted-Average Grant Date Fair Value						$ 5.08
Vested, Weighted-Average Grant Date Fair Value					$ 5.08
Nonvested at the end of the period						$ 5.08
Aggregate Intrinsic value
Stock-based compensation expense					$ 58	$ 98
Nonvested restricted stock awards | Vendor for consulting services
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares
Granted				53,036
Aggregate Intrinsic value
Vesting percentage	50.00%	25.00%			25.00%
RSU Issued As Merit Grants
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares
Granted			9,490
2004 Plan
Aggregate Intrinsic value
Shares available for issuance					0
2015 Plan
Aggregate Intrinsic value
Shares available for issuance					394,402
Employee Stock Purchase Plan
Aggregate Intrinsic value
Risk-free interest rate					0.42%
Expected volatility					76.01%
Expected term					6 months
Expected dividend yield					0.00%
Unrecognized stock-based compensation expense					$ 21
Unrecognized stock-based compensation expense, Recognition period					5 months
Stock-based compensation expense					$ 4
Shares available for issuance					352,722
Offering period					6 months
Percentage of market price					85.00%

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred tax assets deferred gain on intercompany sale of intangible assets			$ 943
Income tax expense (benefit)	$ (544)	$ (43)
Components of U.S. and foreign loss from continuing operations before income taxes
United States	(6,145)	(16,149)
Foreign	(46,587)	(25,738)
Loss before income taxes	(52,732)	$ (41,887)
SWITZERLAND
Amortization period			5 years
Income tax expense (benefit)	37
NETHERLANDS
Income tax expense (benefit)	32
In Process Research and Development
Income tax expense (benefit)	(185)
In Process Research and Development | CANADA
Income tax expense (benefit)	$ (434)

Income Taxes (Details 2)

Income Taxes (Details 2) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets
Accrued rent		$ 208
Accrued expenses		539
Gross current deferred tax assets		747
Non-current assets:
Net operating loss - U.S.	$ 14,261	11,660
Research and development credits	1,362	573
License/start-up expenditures	205	222
Accrued Rent	125	111
Accrued expenses and other	642
Stock-based compensation	941	147
Capitalized research and development/patent intangibles	4,645	5,611
Capitalized research and development RBIL Limitation	714
Foreign investment tax credit		4,370
Net operating loss - foreign	16,458	35,546
Gross non-current deferred tax assets	39,353	58,240
Gross Deferred tax assets	39,353	58,987
Non-current deferred tax liabilities:
Depreciation	(14)	(14)
Swiss IP amortization	(153)	(85)
Bioceros acquired intangibles	(757)	0
Identifiable intangible assets - IPR&D		(2,166)
Total non-current deferred tax liabilities	(924)	(2,265)
Gross deferred taxes	38,429	56,722
Valuation allowance	(39,077)	(58,888)
Net deferred tax (liability)	$ (648)	$ (2,166)

Income Taxes (Details 3)

Income Taxes (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Effective Income Tax Rate Reconciliation, Amount
Income tax benefit using U.S. federal statutory rate	$ (17,929)	$ (14,241)
State income taxes, net of federal benefit	(270)	(296)
Other permanent differences	(304)	2,985
Foreign rate differential	6,615	3,836
Tax credits	(795)	(223)
Other items	(811)	503
Tax benefit related to the IPR&D transfer	(185)	(185)
IPR&D impairment charge benefit	(434)
Foreign withholding taxes	37	101
Net change in valuation allowance	13,532	7,477
Income tax expense (benefit)	$ (544)	$ (43)

Income Taxes (Details 4)

Income Taxes (Details 4) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 38,800	$ 31,000
Excess tax benefits credited to additional paid-in capital	21	77
Uncertain tax positions	0
Interest or penalties related to uncertain tax positions	0
Net Current Deferred Tax Asset
Operating Loss Carryforwards [Line Items]
Reclassification adjustment	109
Net Current Deferred Tax Liability
Operating Loss Carryforwards [Line Items]
Reclassification adjustment	$ (80)
SWITZERLAND
Operating Loss Carryforwards [Line Items]
Term of net operating loss carryforward	7 years
U.S. Federal and State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 27,600	21,300
Research and development tax credit carryforwards	1,200	500
State
Operating Loss Carryforwards [Line Items]
Research and development tax credit carryforwards	200	200
Foreign
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 82,000	$ 145,000

Committments (Details)

Committments (Details) $ in Thousands	May. 15, 2015ft²	Mar. 31, 2013USD ($)	Jan. 31, 2009USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Oct. 15, 2015ft²	Sep. 09, 2015ft²
Commitments
Lease term of office lab				7 years
Lessor Leasing Arrangements, Operating Leases, Term of Contract				7 years
Future minimum lease payments
2,016				$ 2,399
2,017				1,092
2,018				644
2,019				655
2,020				666
2021 and Thereafter				464
Total				5,920
Less: Future sublease payments to be received				(1,124)
Net future lease payments				4,796
Total rent expense				727	$ 366
Boston office facility lease
Commitments
Additional Area of lease | ft²	3,000
Term of lease	6 years
Lease Monthly Rate				14
Utrecht, The Netherlands
Commitments
Additional Area of lease | ft²							5,800
Lease Monthly Rate				25
Zug, Switzerland
Commitments
Additional Area of lease | ft²						4,400
Lease Monthly Rate				$ 17
Moksha8 Pharmaceuticals Inc | License Agreements | Catalent Pharma Solutions, LLC | BOW015
License Agreements
Payments made as per agreement			$ 100
Payments made upon exercise of its option			100
Aggregate payments upon the achievement of certain development and regulatory milestones		$ 500	$ 700
Milestone payments on clinical trial		$ 200
Period of commercial sale of product				20 years
Maximum percentage paid				1
Period of notice for termination of agreement				60 days

Net Loss Per Share (Details)

Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Second Installment Shares issuable
Net Loss Per Share
Securities excluded from the computation of diluted weighted-average shares outstanding	5,000,000
Options to purchase common stock
Net Loss Per Share
Securities excluded from the computation of diluted weighted-average shares outstanding	3,613,427	1,652,882
Settlement of short-term debt
Net Loss Per Share
Securities excluded from the computation of diluted weighted-average shares outstanding	248,093	248,093
Nonvested restricted stock units
Net Loss Per Share
Securities excluded from the computation of diluted weighted-average shares outstanding	124,442
Warrants to purchase common stock
Net Loss Per Share
Securities excluded from the computation of diluted weighted-average shares outstanding	92,892	93,040
Employee Stock Purchase Plan
Net Loss Per Share
Securities excluded from the computation of diluted weighted-average shares outstanding	2,871
Nonvested restricted stock awards | Common stock
Net Loss Per Share
Securities excluded from the computation of diluted weighted-average shares outstanding		13,259

Employee Benefits (Details)

Employee Benefits (Details)	12 Months Ended
	Dec. 31, 2015
Employee Benefits.
Minimum age of the employees to participate in defined contribution plan	21 years

Related Parties (Details)

Related Parties (Details)	Dec. 31, 2015
Livzon Mabpharm Inc
Related Parties
Percentage of ownership owned	6.40%
Montreux Equity Partners
Related Parties
Percentage of ownership owned	1.00%
TPG Capital
Related Parties
Percentage of ownership owned	9.00%

Legal Proceedings (Details)

Legal Proceedings (Details) $ in Thousands	Sep. 10, 2015USD ($)	Apr. 27, 2015USD ($)	Apr. 22, 2015USD ($)installmentitem	Jan. 31, 2016item	Dec. 31, 2014	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Legal Proceedings
General and Administrative Expense						$ 21,951	$ 22,973
One-time charge of research and development expense						30,925	$ 16,286
BOW015 | Reliance Life Sciences Ltd
Legal Proceedings
Termination period					3 years
BOW015 | Reliance Life Sciences Ltd | Settlement Agreement
Legal Proceedings
Number of final batches to be manufactured on or before June 30,2016 | item			15
Number of final batches to be manufactured on or before December 31, 2016 | item			5
Agreed to pay as a fee			$ 2,250
Number of installments for payable of amount agreed | installment			4
Maximum payment term for final installment			10 days
Payment amount	$ 500	$ 750
General and Administrative Expense						2,228
One-time charge of research and development expense						1,800
Payment towards obligation						$ 561
Subsequent event | Settlement Agreement
Legal Proceedings
Number of final batches to be manufactured on or before June 30,2016 | item				15

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent event $ / shares in Units, $ in Millions	Mar. 09, 2016$ / sharesshares	Feb. 29, 2016USD ($)	Jan. 31, 2016item	Mar. 08, 2016
At-the-Market Sales Agreement
Subsequent Events
Aggregate value of shares authorized to be sold | $		$ 30
Commission from the sale of shares		3.00%
Stock Purchase Agreement
Subsequent Events
Issuance of shares | shares	1,772,107
Trailing period (in days)	10 days
Trailing share price (in dollars per share) | $ / shares	$ 2.82
Stock Purchase Agreement | Minimum
Subsequent Events
Percentage of the aggregate number of shares outstanding				10.00%
Stock Purchase Agreement | Maximum
Subsequent Events
Percentage of the aggregate number of shares outstanding				19.99%
Settlement Agreement
Subsequent Events
Number of final batches to be manufactured on or before June 30,2016 | item			15