Ocugen (OCGN) 10-K 10 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Mar. 10, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Trading Symbol	HSGX
Entity Registrant Name	Histogenics Corporation
Entity Central Index Key	1,372,299
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	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		13,274,407
Entity Public Float			$ 56.2

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 30,915	$ 58,527
Prepaid expenses and other current assets	321	796
Total current assets	31,236	59,323
Property and equipment, net	5,213	4,878
Intangible asset, net	200	510
Noncurrent deferred tax assets, net		651
Restricted cash	137	137
Total assets	36,786	65,499
Current liabilities:
Accounts payable	2,253	4,886
Accrued expenses	1,444	1,676
Accrued expenses due to Intrexon (Note 6)	1,546	7
Current portion of deferred rent	126	219
Current portion of deferred lease incentive	407	407
Current portion of equipment loan	583	405
Total current liabilities	6,359	7,600
Deferred rent, long-term	451	379
Deferred lease incentive, long-term	1,017	1,318
Equipment loan, long-term	761	1,345
Noncurrent deferred tax liabilities, net		651
Total liabilities	$ 8,588	$ 11,293
Commitments and contingencies (Note 7)
Stockholders' equity:
Common stock, $0.01 par value; authorized shares-100,000,000 at December 31, 2015 and 2014; 13,273,470 shares issued and outstanding at December 31, 2015 and 12,755,012 shares issued and outstanding at December 31, 2014	$ 132	$ 127
Additional paid-in capital	193,631	187,620
Accumulated deficit	(165,565)	(133,541)
Total stockholders' equity	28,198	54,206
Total liabilities and stockholders' equity	$ 36,786	$ 65,499

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	13,273,470	12,755,012
Common stock, shares outstanding	13,273,470	12,755,012

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Revenue	$ 0	$ 0
Operating expenses:
Research and development	23,243	26,037
General and administrative	8,266	6,565
Impairment of intangible asset	310	60
Total operating expenses	31,819	32,662
Loss from operations	(31,819)	(32,662)
Other income (expense):
Interest expense, net	(133)	(151)
Other (expense) income, net	(72)	13
Change in fair value of warrant liability, other liability and net sales distribution payment liability		10,007
Total other (expense) income, net	(205)	9,869
Net loss	(32,024)	(22,793)
Earnings (loss) attributable to common stockholders-basic and diluted (Note 3)	$ (32,024)	$ (10,510)
Earnings (loss) per common share-basic and diluted (Note 3):	$ (2.42)	$ (6.85)
Weighted-average shares used to compute earnings per common share-basic and diluted (Note 3):	13,231,126	1,534,108

Consolidated Statements of Conv

Consolidated Statements of Convertible Redeemable Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Series A Convertible Redeemable Preferred Stock [Member]	Series A-1 Convertible Redeemable Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Restricted Stock [Member]
Ending Balance at Dec. 18, 2013		$ 42,617	$ 14,454
Issuance of common stock from initial public offering, net of underwriting fees and issuance costs of $8,461, Shares			955,568
Beginning Balance at Dec. 31, 2013		$ 42,617	$ 14,454
Beginning Balance, Shares at Dec. 31, 2013		2,647,350	955,568
Issuance of Series A-1 convertible redeemable preferred stock, net of issuance costs of $10			$ 13,834
Issuance of Series A-1 convertible redeemable preferred stock, net of issuance costs of $10, Shares			955,565
Conversion of preferred and accrued dividends into common stock		$ (42,617)	$ (28,288)
Conversion of preferred and accrued dividends into common stock, Shares		(2,647,350)	(1,911,133)
Beginning Balance at Dec. 31, 2013	$ (75,554)			$ 6	$ 35,188	$ (110,748)
Beginning Balance, Shares at Dec. 31, 2013				582,246			11,795
Issuance of Series A-1 convertible redeemable preferred stock, net of issuance costs of $10	(3,520)				(3,520)
Issuance of warrant as part of the consideration for an equipment line of credit in July 2014	51				51
Vesting of restricted stock, Shares				3,302			(3,302)
Stock-based compensation expense	547				547
Exercise of common stock options	26				26
Exercise of common stock options, Shares				33,988
Conversion of preferred and accrued dividends into common stock	70,905			$ 52	70,853
Conversion of preferred and accrued dividends into common stock, Shares				5,158,407
Conversion of notes payable into common stock	11,100			$ 10	11,090
Conversion of notes payable into common stock, Shares				1,009,115
Settlement of the Other Liability through the conversion of warrants net settled into common stock and the issuance of common stock	1,102				1,102
Settlement of the Other Liability through the conversion of warrants net settled into common stock and the issuance of common stock, Shares				50,370
Extinguishment of Net Sales Distribution Payment Liability redemption provision	15,803				15,803
Issuance of common stock from initial public offering, net of underwriting fees and issuance costs of $8,461	56,539			$ 59	56,480
Issuance of common stock from initial public offering, net of underwriting fees and issuance costs of $8,461, Shares				5,909,091
Net loss	(22,793)					(22,793)
Ending Balance at Dec. 31, 2014	54,206			$ 127	187,620	(133,541)
Ending Balance, Shares at Dec. 31, 2014				12,746,519			8,493
Issuance of common stock from overallotment, net of underwriting fees and issuance costs of $377	4,738			$ 5	4,733
Issuance of common stock from overallotment, net of underwriting fees and issuance costs of $377, Shares				465,000
Issuance of warrant as part of the consideration for an equipment line of credit in July 2014	11				11
Vesting of restricted stock	0			$ 0	0	0	$ 0
Vesting of restricted stock, Shares				3,303			(3,303)
Stock-based compensation expense	1,228				1,228
Exercise of common stock options	$ 39				39
Exercise of common stock options, Shares	53,458			53,458
Net loss	$ (32,024)					(32,024)
Ending Balance at Dec. 31, 2015	$ 28,198			$ 132	$ 193,631	$ (165,565)
Ending Balance, Shares at Dec. 31, 2015				13,268,280			5,190

Consolidated Statements of Con6

Consolidated Statements of Convertible Redeemable Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2014USD ($)$ / shares
Common stock, par value	$ 0.01
Issuance of common stock, net issuance costs | $	$ 8,461
Common Stock [Member]
Common stock, par value	$ 0.01
Restricted Stock [Member]
Common stock, par value	0.01
Series A Convertible Redeemable Preferred Stock [Member]
Temporary equity, par value	$ 0.01
Series A-1 Convertible Redeemable Preferred Stock [Member]
Issuance of convertible redeemable preferred stock, net issuance costs | $	$ 10
Temporary equity, par value	$ 0.01

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (32,024)	$ (22,793)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,614	726
Deferred rent and lease incentive	(322)	541
Impairment of intangible asset	310	60
Stock-based compensation	1,228	547
Warrant expense	11
Non-cash up front fee for note payable to Intrexon, including interest		10,100
Change in fair value of liabilities		(10,007)
Amortization of deferred financing costs		38
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	475	(226)
Other non-current assets		402
Accounts payable	(2,633)	2,026
Accrued expenses	(232)	648
Accrued expenses due to Intrexon	1,539
Net cash used in operating activities	(30,034)	(17,938)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(1,949)	(3,321)
Net cash used in investing activities	(1,949)	(3,321)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from IPO, net of underwriters' fee of $4,550		60,450
Proceeds from overallotment, net of issuance costs	4,738
Proceeds from bridge financing		1,000
Borrowings under equipment term loan		1,750
Payment on equipment term loan	(406)
Issuance of Series A-1 preferred stock, net of issuance costs of $73		10,314
Costs associated with Initial Public Offering		(2,488)
Proceeds from the exercise of common stock options	39	26
Net cash provided by financing activities	4,371	71,052
Net (decrease) increase in cash and cash equivalents	(27,612)	49,793
Cash and cash equivalents-Beginning of period	58,527	8,734
Cash and cash equivalents-End of period	30,915	58,527
Supplemental disclosure of Cash Flow Information:
Cash paid for taxes	79	2
Cash paid for interest	$ 94	18
Supplemental disclosure of noncash investing and financing activities:
Warrant issued in connection with an equipment term loan (Note 10)		51
Issuance of a note payable to Intrexon as consideration for license rights		10,000
Extinguishment of Net Sales Distribution Payment Liability redemption feature		15,803
Adjustment to fair value of Series A-1 Preferred Stock related to the third closing (Note 11)		3,520
IPO [Member]
Supplemental disclosure of noncash investing and financing activities:
Conversion of preferred stock into common stock upon closing of IPO		70,905
Conversion of convertible notes payable and accrued interest into common stock upon closing of IPO		11,100
Conversion of warrants, net settled, into common stock upon closing of IPO		490
Settlement of Other Liability into common stock upon closing of IPO		612
IPO closing costs included in accounts payable and accrued expenses		$ 1,014

Consolidated Statements of Cas8

Consolidated Statements of Cash Flows (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2014USD ($)
Statement of Cash Flows [Abstract]
Payments for underwriter's fee	$ 4,550
Issuance costs	$ 73

Nature of Business

Nature of Business	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	1. NATURE OF BUSINESS Organization Histogenics Corporation (the “Company”) was incorporated under the laws of the Commonwealth of Massachusetts on June 28, 2000 and has its principal operations in Waltham, Massachusetts. In 2006, the Company’s board of directors approved a corporate reorganization pursuant to which the Company incorporated as a Delaware corporation. The Company is a regenerative medicine company engaged in developing and commercializing products in the musculoskeletal segment of the marketplace. The Company combines cell therapy and tissue engineering technologies to develop products for tissue repair and regeneration focusing on patients suffering from particular cartilage-derived pain and immobility. The Company is developing technology and products to reverse or prevent cartilage damage, including NeoCart for the repair of cartilage lesions. NeoCart is currently in a Phase 3 clinical trial in the United States under a special protocol assessment with the U.S. Food and Drug Administration (“FDA”) for the treatment of knee cartilage damage. On May 13, 2011, the Company completed the acquisition of ProChon Biotech Ltd. (“ProChon”), a privately-held biotechnology company focused on modulating the fibroblast growth factor system to enable it to create more effective solutions for tissue regeneration. ProChon’s products combine cell regeneration technologies with proprietary growth factors and biocompatible scaffolds to restore injured or chronically damaged tissues to normal. The acquisition of ProChon provides the Company with access to a significant portfolio of intellectual property, including proprietary cell growth factors, in addition to furthering opportunities for the use of biomaterials to create more effective solutions for regenerating human tissue. In the aggregate, the fair value of the consideration paid to acquire ProChon was $2,224. The acquisition led to the initial recognition of goodwill, which was subsequently written off in 2011, and intangible assets including IPR&D and a licensing agreement which have been impaired as discussed in Note 2. On December 18, 2014, the Company formed a wholly owned subsidiary, Histogenics Securities Corporation, under the laws of the Commonwealth of Massachusetts. Since its inception, the Company has devoted substantially all of its efforts to product development, recruiting management and technical staff, raising capital, starting up production and building infrastructure and has not generated revenues from its planned principal operations. Expenses have primarily been for research and development and administrative costs. The Company is subject to a number of risks. The developmental nature of its activities is such that significant inherent risks exist in the Company’s operations. Principal among these risks are the successful development of therapeutics, successfully enrolling patients in our clinical trials in a timely manner, ability to obtain adequate financing, obtaining regulatory approval for any of our product candidates in any jurisdiction, compliance with government regulations, protection of proprietary therapeutics, fluctuations in operating results, dependence on key personnel and collaborative partners, adoption of the Company’s products by the physician community, rapid technological changes inherent in the markets targeted, and substitute products and competition from larger companies. Initial public offering On December 3, 2014, the Company completed its initial public offering (“IPO”) whereby the Company sold 5,909,091 shares of common stock at a price of $11.00 per share. The shares began trading on the Nasdaq Global Market on December 3, 2014. Gross proceeds from the offering were $65,000. After giving effect to underwriting discounts and commissions and offering expenses payable by the Company, net proceeds were $56,539. In addition, each of the following occurred in connection with the completion of the IPO on December 3, 2014: • the conversion of all outstanding shares of the Company’s convertible redeemable preferred stock and accrued dividends into 5,158,407 shares of common stock; • the conversion of $11,100 in convertible notes payable and accrued interest into 1,009,115 shares of common stock; • the net exercise of certain warrants into 44,531 shares of common stock and the surrender of 5,839 warrant shares to satisfy the Other Liability, resulting in the settlement of the related warrant liability and Other Liability upon the closing of the IPO of $490 and $612, respectively to additional paid-in capital; • the termination of the redemption provision of the net sales royalty payment; and • the Company is now authorized to issue 100,000,000 shares of common stock and 10,000,000 shares of preferred stock. Basis of Accounting The consolidated financial statements are prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). The consolidated financial statements include the accounts of Histogenics Corporation and its wholly-owned subsidiaries, ProChon and Histogenics Securities Corporation. All significant intercompany accounts and transactions are eliminated in consolidation.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Reclassifications The Company has reclassified certain prior period amounts to conform to the current period presentation. The amounts reclassified impact research and development expenses and general and administrative expenses for the year ended December 31, 2014. Use of Estimates The preparation of the Company’s consolidated financial statements 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, estimated useful lives of fixed assets and intangible assets. The Company bases 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. Foreign Currency Translation The Company’s consolidated financial statements are prepared in U.S. dollars. The Company’s foreign subsidiary uses the U.S. dollar as its functional and reporting currency, as management determined that the U.S. dollar is the primary currency of the economic environment in which the subsidiary operates. When transactions are required to be paid in the local currency of the foreign subsidiary, any resulting foreign currency transaction gain or loss is recorded as a component of “Other income (expense), net” in the consolidated statements of operations. Reverse Stock Split The Company’s board of directors voted to approve a 1-for-10.804 reverse stock split on October 27, 2014, which was effected on November 14, 2014. Accordingly, all historical share and per share amounts in the consolidated financial statements have been retroactively adjusted for all periods presented to give effect to a 1-for-10.804 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 operates in two geographic regions: the United States (Massachusetts) and Israel (Tel Aviv) and views its operations as two operating segments: Histogenics Corporation (United States) and ProChon (Israel) as the CODM reviews separate discrete financial information in making decisions regarding resource allocations and assessing performance. Operating segments that have similar economic characteristics can be aggregated. As the nature of the products, customers, and methods to distribute products are the same and the nature of the regulatory environment, the production processes and historical and estimated future margins are similar, the two operating segments have been aggregated into one reporting segment as they have similar economic characteristics. Information about the Company’s operations in different geographic regions is presented in the tables below: As of December 31, 2015 2014 Long-lived assets: United States $ 5,204 $ 4,866 Israel 9 12 Total long-lived assets $ 5,213 $ 4,878 Fair Value Measurements The carrying amounts reported in the Company’s consolidated financial statements for cash and cash equivalents, accounts payable and accrued liabilities approximate their respective fair values because of the short-term nature of these accounts. Fair value is defined as the price that would be received if selling an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Fair value should be based on the assumptions that market participants would use when pricing an asset or liability and is based on a fair value hierarchy that prioritizes the information used to develop those assumptions. The fair value hierarchy gives the highest priority to quoted prices in active markets (observable inputs) and the lowest priority to the Company’s assumptions (unobservable inputs). Fair value measurements should be disclosed separately by level within the fair value hierarchy. For assets and liabilities recorded at fair value, it is the Company’s policy to maximize the use of observable inputs and minimize the use of unobservable inputs when developing fair value measurements, in accordance with established fair value hierarchy. Fair value measurements for assets and liabilities where there exists limited or no observable market data are based primarily upon estimates, and often are calculated based on the economic and competitive environment, the characteristics of the asset or liability and other factors. Therefore, the results cannot be determined with precision and may not be realized in an actual sale or immediate settlement of the asset or liability. Additionally, there may be inherent weaknesses in any valuation technique, and changes in the underlying assumptions used, including discount rates and estimates of future cash flows, could significantly affect the results of current or future values. Additionally, from time to time, the Company may be required to record at fair value other assets on a nonrecurring basis, such as assets held for sale and certain other assets. These nonrecurring fair value adjustments typically involve application of lower-of-cost-or-market accounting or write-downs of individual assets. The fair value hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets (Level 1), and the lowest priority to unobservable inputs (Level 3). The Company’s financial assets are classified within the fair value hierarchy based on the lowest level of inputs that is significant to the fair value measurement. The three levels of the fair value hierarchy, and its applicability to the Company’s financial assets, are described below. Level 1 Level 2 Level 3 Level 3 valuations are for instruments that are not traded in active markets or are subject to transfer restrictions and may be adjusted to reflect illiquidity and/or non-transferability, with such adjustment generally based on available market evidence. In the absence of such evidence, management’s best estimate is used. There were no Level 3 financial assets at December 31, 2015 and 2014. An adjustment to the pricing method used within either Level 1 or Level 2 inputs could generate a fair value measurement that effectively falls in a lower level in the hierarchy. The Company had no assets or liabilities classified as Level 1, Level 2, or Level 3 as of December 31, 2015 and 2014 other than the money market fund described in the “Cash and Cash Equivalents” section below and there were no material re-measurements of fair value with respect to financial assets and liabilities, during the periods presented, other than those assets and liabilities that are measured at fair value on a recurring basis. Transfers are calculated on values as of the transfer date. There were no transfers between Levels 1, 2 and 3 during the years ended December 31, 2015 and 2014. The Company had liabilities classified as Level 3 prior to December 31, 2014 that were measured by management at fair value on a quarterly basis as described in Note 9. Concentration of Credit Risk Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. The Company has no financial instruments with off-balance sheet risk of loss. Cash and Cash Equivalents Cash and cash equivalents include cash in readily available checking and savings accounts and money market funds. The Company considers all highly liquid investments with an original maturity of three months or less from the date of purchase to be cash equivalents. The Company’s cash equivalents, which consist of money market funds, are measured at fair value on a recurring basis. As of December 31, 2015 and 2014, the carrying amount of cash and cash equivalents was $30,915 and $58,527, respectively, which approximates fair value and was determined based upon Level 1 inputs. Money market funds are valued using quoted market prices with no valuation adjustments applied. Accordingly, these securities are categorized as Level 1 and had a balance of $25,764 and $49,750 as of December 31, 2015 and 2014, respectively, shown in the table below. Description Total Quoted prices in active markets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) December 31, 2015 Money market $ 25,764 $ 25,764 $ — $ — $ 25,764 $ 25,764 $ — $ — Description Total Quoted prices in active markets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) December 31, 2014 Money market $ 49,750 $ 49,750 $ — $ — $ 49,750 $ 49,750 $ — $ — Property and Equipment Property and equipment are recorded at historical cost. Costs for capital assets not yet placed into service are capitalized as construction in progress, and will be depreciated in accordance with the below guidelines once placed into service. Maintenance and repair costs are expensed as incurred. Costs which materially improve or extend the lives of existing assets are capitalized. The Company provides for depreciation and amortization using the straight-line method over the estimated useful lives of the assets, which are as follows: Asset Category Estimated Useful Lives Office equipment 3 to 5 years Laboratory equipment 3 to 5 years Leasehold improvements Shorter of the remaining lease term or useful life Upon retirement or sale, the cost of assets disposed and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is recorded in the consolidated statements of operations. Impairment of Long-Lived Assets Long-lived assets consist primarily of property and equipment and identifiable intangible assets. When impairment indicators exist, the Company’s management evaluates long-lived assets for potential impairment. An impairment loss is recorded if and when events and circumstances indicate that assets might be impaired and the undiscounted cash flows estimated to be generated by those assets are less than the carrying amount of those assets. While the Company’s current and historical operating losses and negative cash flows are indicators of impairment, management believes that future cash flows to be received support the carrying value of its long-lived assets. Impairments, if any, are recognized in earnings. An impairment loss would be recognized in an amount equal to the excess of the carrying amount over the undiscounted expected future cash flows. Intangible Asset As of December 31, 2015 and 2014, the Company’s intangible asset consists of acquired in-process research and development (“IPR&D”) obtained through the acquisition of ProChon. IPR&D represents the fair value assigned to research and development assets that have not been completed at the date of acquisition. The value assigned to acquired IPR&D is determined by estimating the costs to develop the acquired technology into commercially viable products, estimating the resulting revenue from the projects, and discounting the net cash flows to present value. The revenue and costs projections used to value acquired IPR&D were adjusted based on the probability of success of developing a new product. Additionally, the projections considered the relevant market sizes and growth factors, expected trends in technology and the nature and expected timing of new product introductions by the Company and its competitors. The rates utilized to discount the net cash flows to their present value were commensurate with the stage of development of the projects and uncertainties in the economic estimates used in the projections described above. IPR&D is considered an indefinite-lived intangible asset and is assessed for impairment annually or more frequently if impairment indicators exist. 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 believes, 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 fair value using the same methodology as described above. If the carrying value of the Company’s acquired IPR&D exceeds its fair value, then an impairment charge is taken and the intangible asset is written-down to its fair value. For the years ended December 31, 2015 and 2014, the Company determined that there was impairment of its IPR&D of $310 and $60 respectively. The Company performed its annual impairment test of its IPR&D as of December 31, 2015 and 2014 using an income approach, including a discount rate of 13%, applied to probability-adjusted after-tax cash flows. The Company believes that the assumptions are representative of those a market participant would use in estimating the fair value of the IPR&D. The Company notes that the pursuit of the underlying IPR&D has been delayed because the Company’s core focus has been on the development of NeoCart so, there is a risk of further impairment in the near future. Intangible asset, net of accumulated impairment charges, are summarized as follows: As of December 31, 2015 As of December 31, 2014 Cost Accumulated Impairment Net Book Value Cost Accumulated Impairment Net Book Value IPR&D $ 630 $ (430 ) $ 200 $ 630 $ (120 ) $ 510 $ 630 $ (430 ) $ 200 $ 630 $ (120 ) $ 510 Initial Public Offering Costs The Company deferred direct incremental costs attributable with the IPO of its common stock prior to the closing of the IPO. These costs represent legal, accounting and other direct costs related to the Company’s efforts to raise capital through a public sale of its common stock. Upon completion of the IPO, $3,911 of IPO costs were reclassified to additional paid-in capital as a reduction of the IPO proceeds. As of December 31, 2014, the Company had paid $2,897 with the remaining $1,014 included in accounts payable in the consolidated balance sheet. This amount was subsequently paid in 2015. Restricted Cash Restricted cash represents cash held in a depository account at a financial institution to collateralize a conditional stand-by letter of credit related to the Company’s Lexington, Massachusetts facility lease agreement. Restricted cash is reported as non-current unless the restrictions are expected to be released in the next twelve months. Deferred Rent Deferred rent 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 leases for its Waltham, Massachusetts facility and its Lexington, Massachusetts facility provide for fixed increases in minimum annual rental payments. The total amount of rental payments due over each lease term is being charged to rent expense ratably over the life of each lease, respectively. Convertible Redeemable Preferred Stock The Company had classified convertible redeemable preferred stock that was redeemable outside of the Company’s control outside of permanent equity. The Company recorded such redeemable preferred stock at fair value upon issuance, net of any issuance costs or discounts, and the carrying value was increased by periodic accretion to its redemption value up to the date the preferred stock was determined to be redeemable. In the absence of retained earnings these accretion charges are recorded against additional paid in capital, if any, and then to accumulated deficit. All preferred stock was converted to common stock at the IPO date of December 3, 2014. Financial Instruments Indexed to and Potentially Settled in the Company’s Common Stock The Company evaluates all financial instruments issued in connection with its equity offerings when determining the proper accounting treatment for such instruments in the Company’s financial statements. The Company considers a number of generally accepted accounting principles under U.S. GAAP to determine such treatment and evaluates the features of the instrument to determine the appropriate accounting treatment. The Company utilizes the Probability Weighted Expected Return Method (“PWERM”), Option Pricing Model (“OM”) or other appropriate methods to determine the fair value of its derivative financial instruments. For financial instruments indexed to and potentially settled in the Company’s common stock that are determined to be classified as liabilities on the consolidated balance sheet, changes in fair value are recorded as a gain or loss in the Company’s consolidated statement of operations with the corresponding amount recorded as an adjustment to the liability on its consolidated balance sheet. Revenue Recognition The Company’s revenue had principally consisted of BioCart product revenue in Israel, collaboration revenue from a license agreement with AT Grade and government grant funding received from the Internal Revenue Service (“IRS”) as a qualifying therapeutic discovery project (“QTDP”) credit pursuant to the Patient Protection and Affordable Care Act. The Company’s license and collaboration agreement contains multiple elements, all of which are accounted for as collaboration revenue. The Company recognizes revenue when all four of the following criteria are met: (1) persuasive evidence that an agreement exists; (2) delivery of the products and/or services has occurred; (3) the selling price is fixed or determinable; and (4) collectability is reasonably assured. The Company did not recognize any collaboration, product, or grant revenue for the years ended December 31, 2015 and 2014. Research and Development Costs Research and development costs are charged to expense as incurred. These costs include, but are not limited to: license fees related to the acquisition of in-licensed products; employee-related expenses, including salaries, benefits and travel; expenses incurred under agreements with contract research organizations and investigative sites that conduct clinical trials and preclinical studies; the cost of acquiring, developing and manufacturing clinical trial materials; facilities, depreciation and other expenses, which include direct and allocated expenses for rent and maintenance of facilities, insurance and other supplies; and costs associated with preclinical activities and regulatory operations. Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as 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. Collaboration Arrangements Costs reimbursed to a collaborator for work that it performs are recorded as research and development expenses. These reimbursements can include research and development expenses, payments for work performed, or a milestone for which a payment is due, the reimbursements or development milestone achievement are recorded as research and development expense. In September 2014, the Company entered into a collaboration agreement with Intrexon Corporation (“Intrexon”) for the development and commercialization of allogeneic cell therapeutics for the treatment or repair of damaged articular hyaline cartilage in humans, utilizing Intrexon’s proprietary technology (the “Collaboration Agreement”). Under the terms of the Collaboration Agreement, the Company is responsible for the costs of development and commercialization, with some exceptions. Refer to Note 8, Related Party Convertible Promissory Notes Related Parties License Agreements Costs associated with licenses of technology are expensed as incurred and are included in research and development expenses. Patent Costs Costs related to filing and pursuing patent applications are recorded as general and administrative expense as incurred since the recoverability of such expenditures is uncertain. 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 their 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 as determined by management or the value of the services provided, whichever is more readily determinable. 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 year end. Stock-based compensation expense recognized in the consolidated financial statements is based on awards that are ultimately expected to vest. For stock option grants with performance-based milestones, the expense is recorded over the remaining service period after the point when the achievement of the milestone is probable or the performance condition has been achieved. For stock option grants with both performance-based milestones and market conditions, expense is recorded over the derived service period after the point when the achievement of the performance-based milestone is probable or the performance condition has been achieved. The Company did not issue any performance-based awards with market conditions from its inception through December 31, 2014. The Company issued performance-based awards in 2015. The Company accounts for stock options and restricted stock awards to non-employees using the fair value approach. Stock options and restricted stock awards to non-employees are subject to periodic revaluation over their vesting terms. 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 income in the period that includes the enactment date. The Company recognizes net deferred tax assets 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 percent 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. Earnings (Loss) per Common Share Earnings (loss) per common share is calculated using the two-class method, which is an earnings allocation formula that determines earnings (loss) per share for the holders of the Company’s common shares and participating securities. All series of preferred stock contain participation rights in any dividend paid by the Company and are deemed to be participating securities. Earnings available to common stockholders and participating convertible redeemable preferred shares are allocated to each share on an as-converted basis as if all of the earnings for the period had been distributed. The participating securities do not include a contractual obligation to share in losses of the Company and are not included in the calculation of net loss per share in the periods that have a net loss. Diluted earnings per share is computed using the more dilutive of (a) the two-class method, or (b) the if-converted method. The Company allocates earnings first to preferred stockholders based on dividend rights and then to common and preferred stockholders based on ownership interests. The weighted-average number of common shares included in the computation of diluted earnings (loss) gives effect to all potentially dilutive common equivalent shares, including outstanding stock options, warrants, convertible redeemable preferred stock and the potential issuance of stock upon the conversion of the Company’s convertible notes. Common stock equivalent shares are excluded from the computation of diluted earnings (loss) per share if their effect is antidilutive. Recently Adopted Accounting Pronouncements In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes. The new standard requires that deferred tax assets and liabilities be classified as noncurrent in a classified statement of financial position. The Company prospectively adopted this guidance in the fourth quarter of 2015, which resulted in the removal of gross deferred tax assets and liabilities from the Company’s consolidated balance sheet. The net impact was zero and the prior period was not retrospectively adjusted. In June 2014, the FASB issued guidance that eliminates the concept of a development stage entity in its entirety from GAAP. The guidance is intended to reduce the overall cost and complexity associated with financial reporting for development stage entities without reducing the availability of relevant information. The Board also believes the changes will simplify the consolidation accounting guidance by removing the differential accounting requirements for development stage entities. As a result of these changes, there no longer will be any accounting or reporting differences in GAAP between development stage entities and other operating entities. The amendments are effective for annual reporting periods beginning after December 15, 2014. Early application is permitted for any annual reporting period or interim period for which the entity’s financial statements have not yet been issued (public business entities) or made available for issuance (other entities). The Company’s adoption of this guidance as of December 31, 2014 eliminated the disclosure of inception to date information from the Company’s consolidated financial statements. Recently Issued Accounting Pronouncements In November 2014, the FASB issued guidance to eliminate the existing diversity in practice in accounting for hybrid financial instruments issued in the form of a share. A hybrid financial instrument consists of a “host contract” into which one or more derivative terms have been embedded. This guidance requires an entity to consider the terms and features of the entire financial instrument, including the embedded derivative features, in order to determine whether the nature of the host contract is more akin to debt or to equity. This guidance is effective for fiscal years and interim periods beginning after December 15, 2015, with early adoption permitted. A reporting entity should apply this guidance using a modified retrospective approach by recording a cumulative-effect adjustment to equity as of the beginning of the annual period of adoption. Retrospective application is permitted to all relevant prior periods. The Company does not expect that the application of this guidance will have an impact on the presentation of its results of operations, financial position or disclosures. In August 2014, the FASB issued guidance that requires management to assess an entity’s ability to continue as a going concern every reporting period, and provide certain disclosures if management has substantial doubt about the entity’s ability to operate as a going concern, or an express statement if not, by incorporating and expanding upon certain principles that are currently in U.S. auditing standards. This guidance is effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. Early application is permitted. The adoption of this guidance is not expected to have an impact on the Company’s financial position or results of operations. In June 2014, the FASB issued guidance requiring when there is a performance target that affects vesting of equity awards granted and could be achieved after the requisite service period to be treated as a performance condition. A reporting entity should apply existing guidance on stock-based compensation, as it relates to such awards. This guidance is effective for annual periods and interim periods within those annual periods beginning after December 15, 2015 with early adoption permitted using either of two methods: (i) prospective to all awards granted or modified after the effective date; or (ii) retrospective to all awards with performance targets that are outstanding as of the beginning of the earliest annual period presented in the financial statements and to all new or modified awards thereafter, with the cumulative effect of applying this guidance as an adjustment to the opening retained earnings balance as of the beginning of the earliest annual period presented in the financial statements. The Company issued performance-based awards during the year ended December 31, 2015. The Company’s adoption of this guidance is not expected to have a material impact on the consolidated financial statements. In May 2014, the FASB issued guidance that affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (e.g., insurance contracts or lease contracts). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The amendments are effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early application is not permitted. The Company has not had any revenue from contracts with customers from its inception through December 31, 2015. The Company’s adoption of this guidance is not expected to have a material impact on the consolidated financial statements.

Earnings (Loss) Per Common Shar

Earnings (Loss) Per Common Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Earnings (Loss) Per Common Share	3. EARNINGS (LOSS) PER COMMON SHARE Basic and diluted earnings (loss) per common share are calculated as follows: Year Ended December 31, 2015 2014 Numerator: Net loss $ (32,024 ) $ (22,793 ) Extinguishment of Net Sales Distribution Payment Liability redemption provision — 15,803 Adjustment to fair value of Series A-1 Preferred Stock (Note 11) — (3,520 ) Earnings (loss) attributable to common stockholders—basic and diluted $ (32,024 ) $ (10,510 ) Denominator: Weighted-average number of common shares used in earnings (loss) per share—basic and diluted 13,231,126 1,534,108 Earnings (loss) per share—basic and diluted $ (2.42 ) $ (6.85 ) The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares outstanding, as they would be anti-dilutive (in common stock equivalent shares): As of December 31, 2015 2014 Restricted stock and options to purchase common stock 1,227,957 546,176 Warrants exercisable into common stock 166,403 162,704 The necessary conditions were met upon the closing of the Company’s IPO on December 8, 2014 resulting in the net exercise of warrants into 44,531 shares of the Company’s common stock and settlement of the Other Liability through the transfer of shares from the Company’s investors. The closing of the Company’s IPO also resulted in the conversion of the Company’s redeemable preferred stock and dividends into 5,158,407 shares of the Company’s common stock. The table above does not include the preferred stock and warrants of 4,558,483 and 47,898 that were converted and exercised during the year ended December 31, 2014. In March 2015, in connection with a consulting agreement entered into for an interim chief financial officer, the Company issued a common stock warrant as compensation to the consulting firm. The warrant provides the holder with the right to purchase an aggregate of 7,398 shares of the Company’s common stock at a per share exercise price of $9.75, the closing price of the Company’s common stock on the date of issuance. The warrant vests and becomes exercisable in monthly installments over 24 months beginning March 31, 2015. The warrant expires on the tenth anniversary of issuance. The warrant is equity classified and accounted for using the fair value approach. The fair value of the warrant is estimated using the Black-Scholes option pricing model and is subject to re-measurement at each reporting period until the measurement date is reached. On December 21, 2015 the Company terminated the consulting agreement resulting in the forfeiture of 50% (3,699) of the shares. The remaining 3,699 shares are vested and exercisable on December 31, 2015. The Company issued equity-classified warrants on July 20, 2012 and July 9, 2014 which are immediately exercisable into 161,977 and 6,566 shares of common stock. The warrants issued on July 20, 2012 are included in the table above for the year ended December 31, 2014, as they would be anti-dilutive for that period. Of the warrants issued on July 20, 2012, 5,839 of the warrant shares were surrendered on December 3, 2014 when the Company completed its IPO The remaining 156,138 warrants issued on July 20, 2012 remained outstanding as of December 31, 2015 along with the warrants issued on July 9, 2014 which both are included in the table above for the years ended December 31, 2015 and 2014 as they would be anti-dilutive for the period. See Note 10, Non-Recurring Fair Value Measurements

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	12 Months Ended
	Dec. 31, 2015
Text Block [Abstract]
Prepaid Expenses and Other Current Assets	4. PREPAID EXPENSES AND OTHER CURRENT ASSETS Prepaid expenses and other current assets consisted of the following: As of December 31, 2015 2014 Deposits $ 67 $ 505 Undelivered laboratory and office equipment 17 78 Insurance 42 67 Other current assets 195 146 Prepaid expenses and other current assets $ 321 $ 796

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property and Equipment	5. PROPERTY AND EQUIPMENT Property and equipment consisted of the following: As of December 31, 2015 2014 Office equipment $ 539 $ 467 Laboratory equipment 4,337 2,978 Leasehold improvements 7,683 7,503 Construction in progress 547 270 Software 96 35 Total property and equipment 13,202 11,253 less: accumulated depreciation (7,989 ) (6,375 ) Property and equipment, net $ 5,213 $ 4,878 Depreciation expense related to property and equipment amounted to $1,614 and $726 for the years ended December 31, 2015 and 2014, respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2015
Payables and Accruals [Abstract]
Accrued Expenses	6. ACCRUED EXPENSES Accrued expenses consisted of the following: As of December 31, 2015 2014 Accrued compensation $ 758 $ 814 Accrued clinical expenses 138 384 Accrued fees for technology transfer agreement — 350 Accrued other 548 128 Accrued expenses due to Intrexon 1,546 7 Total accrued expenses $ 2,990 $ 1,683 On April 15, 2014, the Company entered into a technology transfer agreement with a collagen manufacturer for a non-exclusive, non-transferable, non-sublicensable perpetual, irrevocable, worldwide, royalty-free right and license to use its proprietary process to make Type 1 bovine collagen. Pursuant to the agreement, the Company paid fees of $400 and will pay additional fees totaling $350. In addition, the Company has agreed to reimburse the collagen manufacturer for mutually agreed upon expenses in connection with such technology. This agreement will remain in effect until either party provides written notice to terminate the agreement.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. COMMITMENTS AND CONTINGENCIES Operating Leases The Company leases office and research facilities in Waltham, Massachusetts under a non-cancellable operating lease, which expires in 2017. Terms of the agreement provide for an initial rent-free period and future rent escalation, and provide that in addition to minimum lease rental payments, the Company is responsible for a pro-rata share of common area operating expenses. In January 2014, the Company entered into an agreement to sublease an additional facility in Waltham, Massachusetts. The term of the sublease extended from February 1, 2014 through July 30, 2015. In June 2014, the Company entered into a lease agreement to rent a facility in Lexington, Massachusetts. The commencement date of the lease was July 9, 2014 with a term that extends through June 1, 2023. Terms of the lease agreement provide for an initial rent-free period and future rent escalation, and provide that in addition to minimum lease rental payments, the Company is responsible for a pro-rata share of operating expenses. The Company’s wholly-owned subsidiary, ProChon, leases a facility in Woburn, Massachusetts which expires in 2016. Aggregate minimum annual lease commitments of the Company under its non-cancellable operating leases as of December 31, 2015 are as follows: For the Year Ended December 31, 2016 $ 2,272 2017 2,266 2018 754 2019 586 2020 596 Thereafter 1,534 Total minimum lease payments $ 8,008 Rent expense under operating lease agreements amounted to approximately $1,116 and $900 for the years ended December 31, 2015 and 2014, respectively. As an inducement to enter into its Waltham facility lease, the lessor agreed to provide the Company with a construction allowance of up to $3,184 towards the total cost of tenant improvements. The Company has recorded these costs in the consolidated balance sheet as leasehold improvements, with the corresponding liability as deferred lease incentive. This liability is amortized on a straight-line basis over the term of the lease as a reduction of rent expense. As an inducement to enter into its Lexington facility lease, the lessor agreed to provide the Company with a construction allowance of up to $996 towards the total cost of tenant improvements. A portion of the tenant improvements was under construction as of December 31, 2014, and the Company has recorded these costs as construction in progress within property and equipment, net, with the corresponding liability in accounts payable. The construction in progress was fully completed at December 31, 2015. The completed portion is recorded within leasehold improvements and included as a deferred lease incentive liability in the consolidated balance sheet. Rent expense is recognized on a straight-line basis over the term of the lease and is reduced by the construction allowance. 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. Licensing agreements and the Company’s commitments under the agreements are as follows: Hydrogel License In May 2005, the Company entered into an exclusive license agreement with Angiotech Pharmaceuticals (US), Inc. for the use of certain patents, patent applications, and knowledge related to the manufacture and use of a hydrogel material in conjunction with NeoCart and certain other products (“Hydrogel License Agreement”). As of December 31, 2015, the Company has paid an aggregate $3,200 in commercialization milestones under the terms of the Hydrogel License Agreement, which has been expensed to research and development. Under the terms of the Hydrogel License Agreement, the Company’s future commitments include: • A one-time $3,000 payment upon approval of an eligible product by the FDA; and • Single digit royalties on the net sales of NeoCart and certain other future products. Tissue Regeneration License In April 2001, the Company entered into an exclusive license agreement with The Board of Trustees of the Leland Stanford Junior University (“Stanford University”) for the use of certain technology to develop, manufacture and sell licensed products in the field of growth and regeneration of cartilage (“Tissue Regeneration License Agreement”). The term of the Tissue Regeneration License Agreement extends to the expiration date of Stanford University’s last to expire domestic or foreign patents. As of December 31, 2015, the Company has paid an aggregate $709 in patent reimbursement costs, royalty fees, and commercialization milestone payments under the terms of the Tissue Regeneration License Agreement, which have been recorded to research and development expense. Under the terms of the Tissue Regeneration License Agreement, the Company’s future commitments include: • A one-time $300 payment upon approval of an eligible product by the FDA; • An annual minimum non-refundable royalty fee of $10 for the life of the license that may be used to offset up to 50% of each earned royalty described below; and • Low single digit royalties on net sales. Honeycomb License In March 2013, the Company entered into a license agreement with Koken Co., Ltd. (“Koken”) and paid a fee for a non-exclusive, non-transferable and non-sublicensable right to use its know-how related to the process for manufacturing atelocollagen honeycomb sponge materials, which is used in scaffolds (the “Honeycomb License Agreement”). Under the terms of the Honeycomb License Agreement, future commitments will be based on the amount of materials supplied to the Company and may vary from period to period over the term of the agreement. Plasmid License In January 2008, the Company entered into an exclusive license agreement with Yeda Research and Development Co., Ltd. (“Yeda”) for rights relating to high level expression of heterologous proteins and plasmid p80 BS (the “Plasmid License Agreement”), which rights are jointly owned by Yeda and the Company. Under the terms of the Plasmid License Agreement, the Company was granted an exclusive worldwide license to manufacture, use and sell heterologous proteins and plasmid p80 BS. The Company is required to pay Yeda a yearly, non-refundable license fee of $2, which is creditable against royalties payable by the Company to Yeda during the one-year period in which such fee was paid. Yeda is also entitled to low single digit royalties on net sales of the licensed products and on net sales for combination products (meaning the combination of the licensed product with at least one other active ingredient, material or medical device that would have a clinical effect if administered independently) and a low double digit percentage of all of the Company’s sublicensing receipts. Tissue Processor Sub-License In December 2005, the Company entered into an exclusive agreement to sub-license certain technology from Purpose, Co. (“Purpose”), which is owned by a stockholder of the Company (“Sub-License Agreement”). Purpose entered into the original license agreement (“Original Agreement”) with Brigham and Women’s Hospital, Inc. (“Brigham and Women’s”) in August 2001. The Original Agreement shall remain in effect for the licensed patents owned by Brigham and Women’s unless extended or terminated as provided for in the agreement. The technology is to be used to develop, manufacture, use and sell licensed products that cultivate cell or tissue development. The Sub-License Agreement extends to the expiration date of the last to expire domestic or foreign patents covered by the agreement. As of December 31, 2015, the Company has paid an aggregate $941 over the term of the Sub-License Agreement in royalty and sub-license payments under the terms of the Sub-License Agreement, which was recorded to research and development expense in the condensed consolidated statements of operations. The Sub-License Agreement was amended and restated in June 2012. Under the amended and restated agreement, the Company made Purpose the sole supplier of equipment the Company uses in its manufacturing processes, and granted Purpose distribution rights of the Company’s products for certain territories. In exchange, Purpose allowed for the use of its technology (owned or licensed) and manufactured and serviced exogenous tissue processors by the Company. Under the terms of the agreement, as amended, Purpose granted the Company (a) exclusive rights to all of Purpose’s technology (owned or licensed) related to the exogenous tissue processors, (b) continued supply of exogenous tissue processors during the Company’s clinical trials, and (c) rights to manufacture the exogenous tissue processors at any location the Company chooses. In exchange for such consideration, the Company granted Purpose an exclusive license in Japan for the use of all of the Company’s technology and made a payment of $250 to reimburse Purpose for development costs on a next generation tissue processer. In addition to the above, the Company’s future commitments under the terms of the Original Agreement and Sub-License Agreement include: • A minimum non-refundable annual royalty fee of $20, for the life of the license; • $200 in potential milestone payments; and • Low single digit royalties on net sales of a licensed product The OCS Agreement In connection with its research and development, the Company received grants in 2004 from the Office of Chief Scientist of the Ministry of Industry and Trade in Israel (“OCS”) in the aggregate of $1,100 for funding the fibroblast growth factor (“FGF”) program. In consideration for this grant, the Company is committed to pay royalties at a rate of 3-5% of the sales of sponsored products developed using the grant money, up to the amount of the participation payments received plus interest if the sponsored product is produced in Israel. If the manufacturing of the sponsored product takes place outside of Israel, the royalties can increase up to, but no more than, 300% of grants received, depending on the percentage of the manufacturing of sponsored product that takes place outside of Israel. Engineering Agreement The Company entered into an agreement with a development corporation to purchase a multi-unit bioreactor system, which is expected to allow the Company to add additional manufacturing capacity for its current NeoCart production process. Pursuant to the agreement, the Company has made payments of $377 with a remaining $190 due upon the Company’s acceptance of the system, which is expected in 2016. Collagen Supply Agreement In September 2015, the Company entered into an agreement with Collagen Solutions (UK) Limited (the “Supplier”) to purchase soluble collagen that meets specifications provided by the Company. The initial term of the agreement is three years and will automatically renew from year to year thereafter unless otherwise terminated with at least 180 days’ notice by either party. Pursuant to the agreement, starting 12 months after entering into the agreement, the Company will be required to order a minimum amount of material and/or services totaling $150 from the Supplier in each calendar year until the expiration of the initial term of the agreement. The Company is also committed to pay a non-refundable payment totaling $123 by the end of 2015. As of December 31, 2015, the Company has paid an aggregate $93 under the terms of the agreement. Payment of the remaining amount of $30 is expected to be paid in 2016 per agreement with the supplier, which has been recorded to research and development expense as of December 31, 2015.

Related Party Convertible Promi

Related Party Convertible Promissory Notes	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Related Party Convertible Promissory Notes	8. RELATED PARTY CONVERTIBLE PROMISSORY NOTES On September 30, 2014, as part of the exclusive channel collaboration agreement with Intrexon (the “ECC”), the Company issued a promissory note to Intrexon in the amount of $10,000. The promissory note bore interest at 6.0% per annum. All principal and accrued interest was due and payable on the earliest to occur of the IPO, the maturity date of September 30, 2015, or the closing of a deemed liquidation event. The Company could elect to make payment either in cash or shares of the Company’s common stock in the event of an IPO or the closing of a deemed liquidation event. The note was classified in short term liabilities in the consolidated balance sheet until it was converted with the accrued interest, upon completion of the Company’s IPO on December 3, 2014, into 918,206 shares of the Company’s common stock. In November 2014, the Company authorized the issuance of convertible promissory notes to certain of its existing stockholders in a principal amount of up to $2,500 as part of a bridge financing. The notes were convertible into shares of common stock of the Company, or cash, as specified, upon the earliest to occur of: (i) September 30, 2015; (ii) the IPO; and (iii) the closing of a corporate transaction, as defined therein. The convertible promissory notes accrued interest at a rate of 6% per annum. On November 6, 2014, $1,000 of notes were issued to, and cash was received from, an existing stockholder. The note was classified in short term liabilities in the consolidated balance sheet until it was converted, upon completion of the Company’s IPO into 90,909 shares of the Company’s common stock.

Warrants, Other Liability and N

Warrants, Other Liability and Net Sales Distribution Payment Liability	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Warrants, Other Liability and Net Sales Distribution Payment Liability	9. WARRANTS, OTHER LIABILITY AND NET SALES DISTRIBUTION PAYMENT LIABILITY Warrant Liability and Other Liability In connection with the issuance of the Series A Preferred on July 20, 2012, the Company issued Common Stock Warrants (the “Common Stock Warrants”) to each participating investor. The Common Stock Warrants were exercisable into an aggregate of 47,828 shares of the Company’s common stock upon a defined liquidity event of either a sale of the Company or an IPO. On December 3, 2014, the Company completed its IPO and the Common Stock Warrants were net settled into 44,531 shares of common stock to satisfy the Other Liability obligation. Net Sales Distribution Payment In connection with the sale of Series A-1 Preferred, purchasers of Series A Preferred forfeited their right to receive a 2% net sales distribution payment described in Note 11. The 2% net sales distribution payment was replaced with a new royalty agreement under which the purchasers of Series A-1 Preferred in the Second Closing (“Royalty Recipients”) are entitled to receive a net sales distribution payment equal to 3% of net sales during the calendar year. At the election of the Royalty Recipients, all or a portion of the net sales distribution payments were required to be redeemed by the Company. The Royalty Recipients could elect to have each net sales percentage point redeemed for $10,000 payable in cash or the Company’s common stock. On October 14, 2014, the Company entered into an amended and restated royalty agreement with the Royalty Recipients which provided for a redemption provision of the net sales royalty payment to be terminated upon the closing of the Company’s IPO (the “A&R Royalty Agreement”). As the A&R Royalty Agreement was entered into directly as a result of the investors’ interest in the Company as stockholders, the change in value of the net sales payment liability of $15,803 was recorded to additional paid-in-capital and was also treated as an addition of earnings attributable to common stockholders in the calculation of net income (loss) per share. On December 3, 2014, the Company completed its IPO and the redemption provision was terminated. The net sales distribution payment of 3% remains in place. Fair Value Methodology The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs at December 31, 2014: Year Ended 2014 Beginning balance $ 26,912 Change in fair value of Net Sales Distribution Payment Liability (10,007 ) Extinguishment of liabilities (16,905 ) Ending balance $ — Significant increases (decreases) in the significant unobservable inputs used in the fair value measurement of the level 3 liabilities would result in a significantly higher (lower) fair value measurement.

Non-Recurring Fair Value Measur

Non-Recurring Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Non-Recurring Fair Value Measurements	10. NON-RECURRING FAIR VALUE MEASUREMENTS Affiliates of an Advisor Warrant In connection with the issuance of the Series A Preferred on July 20, 2012, the Company issued a warrant to purchase its common stock to affiliates of an advisor. The warrant provides the holders with the right to purchase an aggregate of 161,977 shares of the Company’s common stock at a per share exercise price of $0.01. The warrants are exercisable, in whole or in part, immediately upon issuance and may be exercised on a cashless basis. The warrants expire on the tenth anniversary of issuance. The fair value of the warrants as of July 20, 2012 was estimated using the OM with the following inputs: (a) risk-free interest rate of 0.22%; (b) implied volatility of the Company’s common stock of 99%; and (c) the expected term to a liquidity event of 1.7 years. The fair value of the warrants as of July 20, 2012 was $117, which was recorded as a reduction to Series A Preferred and a credit to additional paid-in capital. On December 3, 2014, the Company completed its IPO and warrants for 5,839 shares of common stock were surrendered to partially settle the Other Liability and common stock was issued by the Company to Purpose, Co. for the warrant shares surrendered. As of December 31, 2015 and 2014, warrants to purchase an aggregate of 156,138 shares of the Company’s common stock at an exercise price of $0.01 are outstanding. Equipment Loan On July 9, 2014, the Company entered into a loan and security agreement with Silicon Valley Bank for a loan to purchase equipment. The amount of the loan is $1,750 and bears interest at prime plus 2.75% or (6.00% at December 31, 2014) and is payable in equal monthly installments over 36 months beginning six months after the funding dates, which ranged from August 2014 to November 2014. The Company granted Silicon Valley Bank a warrant to purchase 6,566 shares of common stock at a per share exercise price of $7.99. The warrant is exercisable, in whole or in part, immediately upon issuance and may be exercised on a cashless basis and expires on the tenth anniversary of issuance. The fair value of the warrant as of July 9, 2014 was estimated at $51 with the following inputs: (a) risk-free interest rate of 2.58%; (b) implied volatility of the Company’s common stock of 87%; (c) the expected term of 10 years. The fair value of the warrant was recorded as a debt issuance cost with a corresponding credit to additional paid-in capital. At December 31, 2015, the warrant to purchase 6,566 shares remains outstanding.

Capital and Convertible Redeema

Capital and Convertible Redeemable Preferred Stock	12 Months Ended
	Dec. 31, 2015
Text Block [Abstract]
Capital and Convertible Redeemable Preferred Stock	11. CAPITAL AND CONVERTIBLE REDEEMABLE PREFERRED STOCK On July 20, 2012, the Company entered into a stock purchase agreement with outside investors to issue an aggregate of up to 4,535,357 shares of Series A Preferred at $10.80 per share. The initial round closed on July 20, 2012 and in conjunction with this round the Company issued and sold an aggregate of 2,647,350 shares of Series A Preferred and Common Stock Warrants to purchase up to 47,828 shares of common stock to the investors, and a warrant to purchase 161,977 shares of common stock to an advisor. Subject to the Company’s achievement of certain milestones or the approval of at least a majority of the holders of the outstanding Series A Preferred shares to waive such milestone conditions, investors also committed to invest an additional $20,648 from the sale of Series A Preferred Stock in a second closing no later than March 2015. In December 2013, the holders of the outstanding Series A Preferred shares agreed to waive the milestone conditions that were previously required to close the second round of the financing. On December 18, 2013, the Company entered into an Amended and Restated Series A and A-1 Preferred Stock Purchase Agreement, whereby the Company sold 955,568 shares of Series A-1 Preferred Stock, par value $0.01, at a price of $10.80 per share and the 3% net sales distribution payment royalty agreement discussed below, resulting in aggregate proceeds of $10,324, half of the $20,648 noted above. Subject to the Company’s achievement of certain milestones or the approval of at least a majority of the holders of the outstanding Series A Preferred and Series A-1 Preferred shares to waive such milestone conditions, investors committed to invest the remaining $10,324 from the sale of Series A-1 Preferred Stock, which was to close no later than December 31, 2014. In connection with the closing of the second round on December 18, 2013, holders of Series A Preferred forfeited their right to receive a 2% net sales distribution payment. The 2% net sales distribution payment was replaced with a new, freestanding royalty agreement under which the purchasers of the Series A-1 Preferred in the Second Closing are entitled to receive a net sales distribution payment equal to 3% of net sales during the calendar year, discussed in Note 9. The 2% net sales distribution payment was an embedded right in the Series A Preferred. The forfeiture of this right resulted in an extinguishment of all 2,647,350 outstanding shares of Series A Preferred. Immediately following the extinguishment, 2,647,350 shares of the Series A Preferred were reissued (without the right to the 2% net sales distribution payment) and recorded at their fair value of $42,617 or $16.10 per share. The 955,568 shares of Series A-1 Preferred were recorded at their fair value of $14,454 or $15.13 per share. The redemption feature relating to the new 3% net sales distribution payment was initially accounted for as a freestanding financial instrument, was recorded at its fair value of $13,100 as a long-term liability in 2014. As part of the extinguishment, the Company recorded a reduction of additional paid-in capital of $28,000, representing the difference between the extinguished carrying value of Series A Preferred of $31,910 and the fair value of the net consideration transferred to stockholders of $59,910. The $28,000 is also treated as a reduction of earnings attributable to common stockholders in the calculation of net income (loss) per share. On October 14, 2014, the Company entered into an amended and restated royalty agreement with the Royalty Recipients which provided for redemption provision of the net sales royalty payment to be terminated upon the closing of the Company’s IPO (the “A&R Royalty Agreement”). As the A&R Royalty Agreement was entered into directly as a result of the investors’ interest in the Company as stockholders, the change in value of the net sales payment liability of $15,803 was recorded to additional paid-in-capital and was also treated as an addition of earnings attributable to common stockholders in the calculation of net income (loss) per share. On December 3, 2014, the Company completed its IPO and the redemption provision of the net sales royalty payment was terminated. In May 2014, the milestone conditions required to close the third round of the financing had been met. On May 27, 2014, the Company sold 955,565 shares of Series A-1 Preferred Stock, par value $0.01, at a price of $10.80 per share, resulting in aggregate proceeds of $10,324, the second half of the $20,648 noted above. The Company incurred $10 of issuance costs with this financing. As part of the financing, the Company recorded a reduction of additional-paid-in capital of $3,520, representing the amount to bring the preferred stock from the net transaction amount of $10,314 to the fair value of $13,834 or $14.48 per share. The $3,520 is also treated as a reduction of earnings attributable to common stockholders in the calculation of net income (loss) per share. In November 2014, in preparation for the IPO, the Company effected a reverse stock split in which each of the Company’s stockholders received one share of common stock in exchange for 10.804 shares of common stock. In December 2014, in connection with the completion of the IPO, the Company completed the conversion of all outstanding shares of the Company’s convertible redeemable preferred stock into 5,158,407 shares of common stock. Common Stock The holders of shares of common stock are entitled to one vote per share. The holders of shares of common stock are not entitled to receive dividends, unless declared by the Company’s board of directors out of legally available funds, if ever. Reserved for future issuance The Company has reserved for future issuance the following number of shares of common stock: As of December 31, Vesting of restricted stock 5,191 Options to purchase common stock 1,222,767 Common stock warrants (equity) 166,403 Total 1,394,361 Convertible Redeemable Preferred Stock The Company had issued several series of convertible redeemable preferred stock. From and after the date of issuance of any shares of convertible preferred stock, dividends accrued at a rate of eight percent (8.0%) per annum payable in cash or shares at the option of the holder, when and as declared by the Company’s board of directors. As of December 31, 2014, no dividends had been declared or paid. The Company had recorded cumulative accrued dividends for the convertible preferred stock of $3,307 as of December 31, 2013. Upon the closing of the IPO on December 3, 2014, all of the outstanding shares of the Company’s convertible redeemable preferred stock and accrued dividends were converted into 5,158,407 shares of its common stock. As of December 31, 2014, the Company does not have any convertible redeemable preferred stock issued or outstanding. The following describes each series of convertible redeemable preferred stock previously issued. Series A Convertible Redeemable Preferred Stock On July 20, 2012, the Company entered into a stock purchase agreement to raise up to $49,000 through the sale of shares of a Series A Preferred, $0.01 par value per share, at a purchase price per share of $10.80 per share. In conjunction with the closing of this financing, the Company issued and sold an aggregate of 2,647,350 shares of Series A Preferred Stock at a price per share of $10.80 for an aggregate purchase price of $26.5 million, net of issuance costs (Series A Financing). Series A-1 Convertible Redeemable Preferred Stock On December 18, 2013, the Company entered into an Amended and Restated Series A and A-1 Preferred Stock Purchase Agreement (the “Stock Purchase Agreement”), whereby the Company sold 955,568 shares of Series A-1 General Rights, Preferences and Privileges The holders of shares of the Series A Preferred and Series A-1 Preferred (collectively, the “Preferred Stock”) were entitled to the number of votes equal to the number of whole shares of common stock into which the shares of the applicable series of Preferred Stock held by such holder were convertible on any matter presented to the stockholders of the Company for their action or consideration at any meeting of stockholders of the Company or by written consent of stockholders in lieu of meetings. Dividends accrued at a rate per annum of 8.0%, payable in cash or in shares at the option of the holder, when and as declared by the board of directors. In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company, the holders of the Preferred Stock then outstanding were entitled to be paid out of the assets of the Company available for distribution to stockholders an amount per share equal to $10.80, plus any accrued but unpaid dividends. Net Sales Distribution Payment Within 45 days of the end of each calendar year, the Company shall pay the Royalty Recipients a payment equal to, in the aggregate, 3% of net sales during such calendar year, which is the Net Sales Distribution Payment. The Net Sales Distribution Payment shall be distributed pro rata based on the percentages set forth in the freestanding royalty agreement entered into in connection with the closing of the December 18, 2013 financing previously discussed. Net sales shall mean the gross amount received by the Company, its affiliates and their sub-licensees for sales of the Company’s products less (a) intercompany sales, (b) amounts repaid or credited by reason of actual rejection or return of applicable products, (c) reasonable and customary trade, quantity or cash rebates or discounts to the extent allowed, (d) amounts for outbound transportation, insurance, handling or shipping, and (e) taxes, customs duties and other governmental charges levied on or measured by sales of products, as adjusted for rebates and refunds. If any product is sold for non-cash consideration, net sales shall be calculated based on the average non-discounted cash amount charged to independent third parties for the product during the same period in the same country or based upon the fair value of the product. As part of the “Stock Purchase Agreement, at the election of the Royalty Recipients, all or a portion of the net sales payments could be redeemed by the Company. The Royalty Recipients could elect to have each net sales percentage point redeemed for $10,000 payable in cash or the Company’s common stock. If the Royalty Recipients choose to elect common stock, the fair value per share will be determined as follows: (a) if the Company was publicly-traded, the average of the 10-day trailing closing price, or (b) if not publicly-traded, the fair market value as determined by board of directors. The Royalty Recipients could exercise their redemption right any time after January 1, 2017 and prior to January 1, 2019, provided, however, that each election must be at least six months apart. As noted in Note 9, Warrants, Other Liability, and Net Sales Distribution Payment Liability

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	12. STOCK-BASED COMPENSATION Restricted Stock Awards and Stock Options The Company adopted the 2012 Equity Incentive Plan, as amended (“2012 Plan”) in July 2012 pursuant to which 609,389 shares of common stock were authorized for issuance to employees, officers, directors, consultants and advisors of the Company as of December 31, 2014. Upon the closing of the IPO on December 3, 2014, no further grants will be made under the 2012 Plan as the 2013 Equity Incentive Plan (“2013 Plan”) replaced the 2012 Plan on this date. The 2012 Plan provided 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, the Company 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 Company’s common stock at an exercise price equal to no less than the estimated fair value of such stock on the date of grant. Stock options generally vest 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. The maximum term of stock options granted under the 2012 Plan is ten years. In determining the exercise prices for options granted, the board of directors considered the fair value of the common stock as of the measurement date. The fair value of the common stock was determined by the board of directors based on a variety of different factors, including valuations prepared by third party valuation specialists, Company’s financial position, the status of development efforts within the Company, the composition and ability of the current scientific and management teams, the current climate in the marketplace, the illiquid nature of the Company’s common stock, arm’s length sale of the Company’s preferred stock, the effect of the rights and preferences of the preferred stockholders, and the prospects of a liquidity event, among others. 2013 Equity Incentive Plan The Company’s board of directors adopted the 2013 Plan in November 2013 which the stockholders approved in October 2014. Under the 2013 Plan, 518,327 shares of common stock are authorized for issuance to employees, directors, consultants and advisors of the Company as of December 31, 2014, for which no awards have been granted. The 2013 Plan provides for the grant of incentive stock options, non-statutory stock options, rights to purchase restricted stock, stock appreciation rights and stock units. In connection with the issuance of restricted common stock, the Company 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 stock options shall be eligible to purchase shares of the Company’s common stock at an exercise price equal to no less than the estimated fair value of such stock on the date of grant. Stock options generally vest 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. The maximum term of stock options granted under the 2013 Plan is ten years. The number of shares reserved for issuance under the 2013 Plan will be increased automatically on the first business day of each of our fiscal years during the term of the 2013 Plan, commencing in 2015, by a number equal to the lowest of: (a) 181,414 shares of common stock; (b) 3.5% of the total number of shares of common stock then outstanding on December 31 of the prior year; or (c) the number of shares determined by the Company’s Board of Directors (the “EIP Evergreen Provision”). To the extent any awards under the 2013 Plan are forfeited, terminate, expire, lapse without the issuance of shares, or if the Company repurchases shares subject to awards under the 2013 Plan, those shares will again become available for issuance under the 2013 Plan. Accordingly, the number of shares of common stock available for issuance under the EIP was increased by 181,414 shares effective January 1, 2016. 2013 Employee Stock Purchase Plan The Company’s board of directors adopted the 2013 Employee Stock Purchase Plan (“2013 ESPP”) in November 2013 which the stockholders approved in October 2014. The 2013 ESPP became effective upon the closing of the IPO on December 3, 2014. The Company’s 2013 ESPP qualifies under Section 423 of the Internal Revenue Code. Under the 2013 ESPP, 103,665 shares of the Company’s common stock are authorized for issuance to eligible employees. The number of shares reserved for issuance under the 2013 ESPP will automatically be increased on the first business day of each of the Company’s fiscal years, commencing in 2015, by a number equal to the lowest of 51,832 shares of common stock; 1% of the shares of common stock outstanding on the last business day of the prior fiscal year; or the number of shares determined by the Company’s Board of Directors (the “EIP Evergreen Provision”). On January 16, 2015, the Company increased the authorized shares by 51,832, for a total of 155,497 share of the Company’s common stock authorized for issuance to eligible employees under the 2013 ESPP. The number of shares reserved under the 2013 ESPP will automatically be adjusted in the event of a stock split, stock dividend or a reverse stock split (including an adjustment to the per-purchase period share limit). The Company’s 2013 ESPP permits each eligible employee to purchase common stock through payroll deductions. No activity under the Plan in 2015 and 2014. Stock option activity under the 2012 and 2013 plans is summarized as follows: Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Outstanding at December 31, 2014 537,683 $ 6.19 8.9 $ 2,488 Granted 914,722 7.74 Exercised (53,458 ) 0.76 Cancelled (176,180 ) 8.13 Outstanding at December 31, 2015 1,222,767 $ 7.31 9.0 $ (4,679 ) Vested and expected to vest at December 31, 2014 451,153 $ 5.83 8.9 $ 2,247 Vested and expected to vest at December 31, 2015 1,133,925 $ 7.29 9.0 $ (4,293 ) Exercisable at December 31, 2014 139,798 $ 1.84 8.1 $ 1,239 Exercisable at December 31, 2015 318,733 $ 4.60 7.6 $ (351 ) As of December 31, 2015 and December 31, 2014, the unrecognized compensation cost related to outstanding options was $3,959 and $2,373, respectively, and is expected to be recognized as expense over approximately 2.68 years and 2.67 years, respectively. The intrinsic value of options exercised during the years ended December 31, 2015 and 2014 was $301 and $196, respectively. As of December 31, 2015, the weighted average grant date fair value of vested options was $3.80 and the weighted average grant date fair value of shares outstanding was $4.49. Additional information about the Company’s stock option activity is as follows: Years Ended December 31, 2015 2014 Weighted-average grant date fair value per share of employee option grants within the year $ 4.08 $ 6.70 Cash received upon exercise of options 39 26 Restricted stock awards under the 2012 and 2013 plans are summarized as follows: Number of Shares Weighted Average Grant Date Fair Value Unvested at December 31, 2014 8,493 $ 1.04 Vesting of restricted stock (3,303 ) 1.00 Unvested at December 31, 2015 5,190 $ 1.07 As of December 31, 2015 and December 31, 2014, the unrecognized compensation cost related to restricted stock awards was $4 and $7, respectively, and is expected to be recognized as expense over approximately 1.18 years and 2.15 years, respectively. Stock-Based Compensation Expense The Company granted stock options to employees for the years ended December 31, 2015 and 2014. 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 award. Stock options and restricted stock issued to non-board member, non-employees are accounted for using the fair value approach and are subject to periodic revaluation over their vesting terms. For all periods from inception to date, stock-based compensation for all options granted and restricted stock awards are classified as research and development expense and general and administrative expense. Stock compensation expense amounted to $1,228 and $547 for the years ended December 31, 2015 and 2014, respectively. Included in the table below is restricted stock-based compensation expense of $4 and $3, respectively, recorded in general and administrative expense during the years ended December 31, 2015 and 2014. Stock-based compensation is as follows: Years Ended December 31, 2015 2014 Research and development $ 451 $ 181 General and administrative 777 366 Total stock-based compensation expense $ 1,228 $ 547 The weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee stock option grants were as follows: Years Ended December 31, 2015 2014 Risk-free interest rate 1.68 % 1.83 % Expected volatility 62.6 % 104.5 % Expected term (in years) 6.04 6.08 Expected dividend yield 0.0 % 0.0 % The weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of the non-employee stock option grants were as follows: Years Ended December 31, 2015 2014 Risk-free interest rate 1.79 % 0.89 % Expected volatility 63.2 % 99.4 % Expected term (in years) 6.16 2.47 Expected dividend yield 0.0 % 0.0 % Risk-free Interest Rate Expected Volatility Expected Term Expected Dividend Yield

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	13. INCOME TAXES For the years ended December 31, 2015 and 2014, the Company did not record a current or deferred income tax expense or benefit due to current and historical losses incurred by the Company. The components of loss before income taxes were as follows: As of December 31, 2015 2014 U.S. $ (31,332 ) $ (22,240 ) Foreign (692 ) (553 ) Total $ (32,024 ) $ (22,793 ) A reconciliation of income tax expense (benefit) computed at the statutory federal income tax rate to income taxes as reflected in the financial statements is as follows: As of December 31, 2015 2014 Federal income tax (benefit) at statutory rate 34.0 % 34.0 % Increase income tax benefit resulting from: Permanent differences (1.2 )% (4.8 )% Change in valuation allowance (31.7 )% (29.2 )% Other (1.1 )% 0.0 % Income tax expense (benefit) 0.0 % 0.0 % Deferred taxes are recognized for temporary differences between the basis of assets and liabilities for financial statement and income tax purposes. The significant components of the Company’s deferred tax assets and liabilities are comprised of the following: As of December 31, 2015 2014 Deferred tax assets: Net operating loss carryforwards $ 28,200 $ 18,933 Depreciation and amortization 6,688 7,235 Accrued expenses 1,183 698 Capitalized start-up costs 8,531 7,276 Capitalized R&D — 27 Other 259 67 Deferred tax assets before valuation allowance 44,861 34,236 Valuation allowance (43,751 ) (31,966 ) 1,110 2,270 Deferred tax liabilities IPR&D (36 ) (121 ) Change in accounting method (1,074 ) (2,149 ) (1,110 ) (2,270 ) Net deferred tax assets $ — $ — The Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets. As of December 31, 2015 and 2014, based on the Company’s history of operating losses, the Company has concluded that it is not more likely than not that the benefit of its deferred tax assets will be realized. Accordingly, the Company has provided a full valuation allowance for deferred tax assets as of December 31, 2015 and 2014. The valuation allowance increased $11,785 during the year ended December 31, 2015, due primarily to net operating losses generated and capitalized expenses. The valuation allowance increased by $7,710 during the year ended December 31, 2014, due primarily to net operating losses generated and capitalized expenses. 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. We early adopted ASU 2015-17 effective December 31, 2015 on a prospective basis. Adoption of this ASU resulted in the removal of gross deferred tax assets and liabilities from the Company’s Consolidated Balance Sheet at December 31, 2015. The impact was zero. No prior periods were retrospectively adjusted. The Company had recorded a current net deferred tax liability of $651 and a noncurrent net deferred tax asset of $651 as of December 31, 2014. The classification of deferred tax assets and liabilities is primarily related to the timing of the reversal of the deferred tax liability related to a change of accounting method in 2013. As of December 31, 2015 and 2014, the Company had U.S. federal NOL carryforwards of $55,662, and $31,230, respectively, which may be available to offset future income tax liabilities and expire at various dates through 2035. As of December 31, 2015 and 2014, the Company also had U.S. state NOL carryforwards of $55,502 and $31,176, respectively, which may be available to offset future income tax liabilities and expire at various dates through 2035. At December 31, 2015 and 2014, the Company also had $25,627 and $25,128, respectively, of foreign NOL carryforwards which may be available to offset future income tax liabilities, which carryforwards do not expire. Utilization of the NOL and research and development credit carryforwards may be subject to a substantial annual limitation due to ownership change limitations that have occurred or that could occur in the future, as required by Section 382 and Section 383 of the Code, as well as similar state and foreign provisions. These ownership changes may limit the amount of NOL and research and development credit carryforwards that can be utilized annually to offset future taxable income and tax, respectively. In general, an “ownership change” as defined by Section 382 of the Code results from a transaction or series of transactions over a three-year period resulting in an ownership change of more than 50 percentage points of the outstanding stock of a company by certain stockholders. The Company has completed a study to assess whether an ownership change has occurred or whether there have been multiple ownership changes since its formation. The results of this study indicated that the Company experienced ownership changes as defined by Section 382 of the Code. The Company has not recorded NOLs that, as a result of these restrictions, will expire unused. Accordingly, the Company has recorded NOL carryforwards net of these limitations, which are approximately $47,170 in 2014 and 2015. The changes in the Company’s unrecognized tax benefits are summarized as follows: As of December 31, 2015 2014 Unrecognized tax benefit, beginning of year $ 811 $ 935 Increase (decrease) related to current year positions (124 ) (124 ) Unrecognized tax benefit, end of year $ 687 $ 811 As of December 31, 2015 and 2014, the total amount of unrecognized tax benefits was $687 and $811, respectively. The uncertain tax positions giving rise to the unrecognized tax benefits relate primarily to methods of accounting, used in the Company’s tax returns, which accelerated certain deductions for federal income tax purposes. The reversal of the unrecognized tax benefits would not have any impact on effective tax rates in future periods and are not expected to create cash tax liabilities upon settlement due to the Company’s ability to utilize both pre-change and post-change NOLs. The Company believes that it is reasonably possible that $124 of its unrecognized tax benefits may be recognized by the end of 2016. 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 consolidated statements of operations. The Company files income tax returns in the United States, and various state and foreign jurisdictions. The federal, state and foreign income tax returns are generally subject to tax examinations for the tax years ended December 31, 2011 through December 31, 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.

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Employee Benefits	14. EMPLOYEE BENEFITS The Company has 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 percent of compensation. No matching contributions have been made by the Company since the adoption of the 401(k) plan.

Related Parties

Related Parties	12 Months Ended
	Dec. 31, 2015
Related Party Transactions [Abstract]
Related Parties	15. RELATED PARTIES Intrexon Corporation In September 2014, the Company entered into a collaboration agreement with Intrexon for the development and commercialization of allogeneic cell therapeutics for the treatment or repair of damaged articular hyaline cartilage in humans, utilizing Intrexon’s proprietary technology. The term of the Collaboration Agreement commences upon the effective date, September 30, 2014, and continues until either written notice of termination is given by the Company within ninety days, or if either party creates a material breach that cannot be remedied within sixty days. Under the terms of the Collaboration Agreement, the Company is solely responsible for the costs of development and commercialization with the following exceptions: (i) the establishment of certain manufacturing capabilities and facilities; (ii) the cost of basic research related to Intrexon’s proprietary technology outside of costs related to the collaboration products; (iii) payments related to supplemental in-licensed third party IP; (iv) costs of filing, prosecution and maintenance of Intrexon patents; and (v) any other costs mutually agreed upon as being the responsibility of Intrexon. As consideration, the Company paid Intrexon an up-front fee of $10,000 in the form of a convertible promissory note as an access fee for commercial license rights to the Intrexon IP granted in the Collaboration Agreement, and will pay commercialization milestones and sales milestones as achieved. Refer to Note 8, Related Party Convertible Promissory Notes The amounts payable upon milestone events are as follows: • $500 within 30 days of the first instance of the achievement of the Investigational New Drug (“IND”) Filing Milestone Event; • $2,500 within 30 days of the first instance of the achievement of the IND Acceptance Milestone Event; • $3,000 within 30 days of the first instance of the achievement of the Phase III Milestone Event; • $5,000 within 30 days of the first instance of the achievement of the Approval Milestone Event; and • $1,000 within 30 days of each instance of the achievement of the Approval Amendment Milestone Event. The cumulative sales milestones from the sale of products developed under the ECC are as follows: • $5,000 within 30 days of the first instance that cumulative net sales reach $300,000; • $7,500 within 30 days of the first instance that cumulative net sales reach $650,000; and • $10,000 within 30 days of the first instance that cumulative net sales reach $1,000,000. As part of the Collaboration Agreement, Intrexon made an equity purchase commitment to participate in a qualified financing, as defined therein, and will purchase $15,000 worth of the Company’s common stock as part of, or in connection with the qualified financing. On December 3, 2014, the Company completed its IPO and the $10,000 promissory note to Intrexon and accrued interest were converted into 918,206 shares of the Company’s common stock. In addition, Intrexon participated in the IPO purchasing $19,496 worth of the Company’s common stock, or 1,772,364 shares. In 2014, the Company also initiated research and development activities with Intrexon and incurred expenses of $3,100 and $14 in 2015 and 2014 respectively. At December 31, 2015, the Company owes Intrexon $1,546, which is in accrued expenses. See Note 6, Accrued Expenses Related Party Convertible Promissory Notes. Purpose, Co. In June 2012, the Company entered into an agreement with Purpose, Co. to amend its previous agreements. In the previous agreements, Purpose, Co. granted the Company a perpetual license to its patents related to its exogenous tissue processor which is used in the development of the Company’s products. In exchange, the Company granted Purpose, Co. a perpetual license to all of the Company’s biotechnology and biomaterial for use in Japan. The agreement provides for Purpose, Co. to manufacture and sell machinery to the Company for cost until the Company’s products become commercially viable. The Company has also agreed to pay royalties on any third-party revenue generated using Purpose, Co.’s licensed technology. Under the June 2012 amendment, the Company received exclusive rights to all of Purpose, Co.’s technology related to the exogenous tissue processor, continued supply of exogenous tissue processors during the Company’s clinical trials, and rights to manufacture the exogenous tissue processors at any location the Company chooses. In exchange for such consideration, the Company named Purpose, Co. the sole manufacturer of equipment and also clarified the geographic territories of the exclusive license that Purpose Co. was granted for use of the Company’s technology. Also, the Company agreed to reimburse Purpose, Co. for $250 of development costs on a next generation tissue processer. Refer to the discussion under Note 7, Tissue Processor Sub-License The amounts that have been paid to Purpose, Co. under this agreement were $187 and $173 for the years ended December 31, 2015 and 2014, respectively.

Summary of Significant Accoun24

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Reclassifications	Reclassifications The Company has reclassified certain prior period amounts to conform to the current period presentation. The amounts reclassified impact research and development expenses and general and administrative expenses for the year ended December 31, 2014.
Use of Estimates	Use of Estimates The preparation of the Company’s consolidated financial statements 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, estimated useful lives of fixed assets and intangible assets. The Company bases 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.
Foreign Currency Translation	Foreign Currency Translation The Company’s consolidated financial statements are prepared in U.S. dollars. The Company’s foreign subsidiary uses the U.S. dollar as its functional and reporting currency, as management determined that the U.S. dollar is the primary currency of the economic environment in which the subsidiary operates. When transactions are required to be paid in the local currency of the foreign subsidiary, any resulting foreign currency transaction gain or loss is recorded as a component of “Other income (expense), net” in the consolidated statements of operations.
Reverse Stock Split	Reverse Stock Split The Company’s board of directors voted to approve a 1-for-10.804 reverse stock split on October 27, 2014, which was effected on November 14, 2014. Accordingly, all historical share and per share amounts in the consolidated financial statements have been retroactively adjusted for all periods presented to give effect to a 1-for-10.804
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 operates in two geographic regions: the United States (Massachusetts) and Israel (Tel Aviv) and views its operations as two operating segments: Histogenics Corporation (United States) and ProChon (Israel) as the CODM reviews separate discrete financial information in making decisions regarding resource allocations and assessing performance. Operating segments that have similar economic characteristics can be aggregated. As the nature of the products, customers, and methods to distribute products are the same and the nature of the regulatory environment, the production processes and historical and estimated future margins are similar, the two operating segments have been aggregated into one reporting segment as they have similar economic characteristics. Information about the Company’s operations in different geographic regions is presented in the tables below: As of December 31, 2015 2014 Long-lived assets: United States $ 5,204 $ 4,866 Israel 9 12 Total long-lived assets $ 5,213 $ 4,878
Fair Value Measurements	Fair Value Measurements The carrying amounts reported in the Company’s consolidated financial statements for cash and cash equivalents, accounts payable and accrued liabilities approximate their respective fair values because of the short-term nature of these accounts. Fair value is defined as the price that would be received if selling an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Fair value should be based on the assumptions that market participants would use when pricing an asset or liability and is based on a fair value hierarchy that prioritizes the information used to develop those assumptions. The fair value hierarchy gives the highest priority to quoted prices in active markets (observable inputs) and the lowest priority to the Company’s assumptions (unobservable inputs). Fair value measurements should be disclosed separately by level within the fair value hierarchy. For assets and liabilities recorded at fair value, it is the Company’s policy to maximize the use of observable inputs and minimize the use of unobservable inputs when developing fair value measurements, in accordance with established fair value hierarchy. Fair value measurements for assets and liabilities where there exists limited or no observable market data are based primarily upon estimates, and often are calculated based on the economic and competitive environment, the characteristics of the asset or liability and other factors. Therefore, the results cannot be determined with precision and may not be realized in an actual sale or immediate settlement of the asset or liability. Additionally, there may be inherent weaknesses in any valuation technique, and changes in the underlying assumptions used, including discount rates and estimates of future cash flows, could significantly affect the results of current or future values. Additionally, from time to time, the Company may be required to record at fair value other assets on a nonrecurring basis, such as assets held for sale and certain other assets. These nonrecurring fair value adjustments typically involve application of lower-of-cost-or-market accounting or write-downs of individual assets. The fair value hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets (Level 1), and the lowest priority to unobservable inputs (Level 3). The Company’s financial assets are classified within the fair value hierarchy based on the lowest level of inputs that is significant to the fair value measurement. The three levels of the fair value hierarchy, and its applicability to the Company’s financial assets, are described below. Level 1 Level 2 Level 3 Level 3 valuations are for instruments that are not traded in active markets or are subject to transfer restrictions and may be adjusted to reflect illiquidity and/or non-transferability, with such adjustment generally based on available market evidence. In the absence of such evidence, management’s best estimate is used. There were no Level 3 financial assets at December 31, 2015 and 2014. An adjustment to the pricing method used within either Level 1 or Level 2 inputs could generate a fair value measurement that effectively falls in a lower level in the hierarchy. The Company had no assets or liabilities classified as Level 1, Level 2, or Level 3 as of December 31, 2015 and 2014 other than the money market fund described in the “Cash and Cash Equivalents” section below and there were no material re-measurements of fair value with respect to financial assets and liabilities, during the periods presented, other than those assets and liabilities that are measured at fair value on a recurring basis. Transfers are calculated on values as of the transfer date. There were no transfers between Levels 1, 2 and 3 during the years ended December 31, 2015 and 2014. The Company had liabilities classified as Level 3 prior to December 31, 2014 that were measured by management at fair value on a quarterly basis as described in Note 9
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. The Company has no financial instruments with off-balance sheet risk of loss.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include cash in readily available checking and savings accounts and money market funds. The Company considers all highly liquid investments with an original maturity of three months or less from the date of purchase to be cash equivalents. The Company’s cash equivalents, which consist of money market funds, are measured at fair value on a recurring basis. As of December 31, 2015 and 2014, the carrying amount of cash and cash equivalents was $30,915 and $58,527, respectively, which approximates fair value and was determined based upon Level 1 inputs. Money market funds are valued using quoted market prices with no valuation adjustments applied. Accordingly, these securities are categorized as Level 1 and had a balance of $25,764 and $49,750 as of December 31, 2015 and 2014, respectively, shown in the table below. Description Total Quoted prices in active markets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) December 31, 2015 Money market $ 25,764 $ 25,764 $ — $ — $ 25,764 $ 25,764 $ — $ — Description Total Quoted prices in active markets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) December 31, 2014 Money market $ 49,750 $ 49,750 $ — $ — $ 49,750 $ 49,750 $ — $ —
Property and Equipment	Property and Equipment Property and equipment are recorded at historical cost. Costs for capital assets not yet placed into service are capitalized as construction in progress, and will be depreciated in accordance with the below guidelines once placed into service. Maintenance and repair costs are expensed as incurred. Costs which materially improve or extend the lives of existing assets are capitalized. The Company provides for depreciation and amortization using the straight-line method over the estimated useful lives of the assets, which are as follows: Asset Category Estimated Useful Lives Office equipment 3 to 5 years Laboratory equipment 3 to 5 years Leasehold improvements Shorter of the remaining lease term or useful life Upon retirement or sale, the cost of assets disposed and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is recorded in the consolidated statements of operations.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets consist primarily of property and equipment and identifiable intangible assets. When impairment indicators exist, the Company’s management evaluates long-lived assets for potential impairment. An impairment loss is recorded if and when events and circumstances indicate that assets might be impaired and the undiscounted cash flows estimated to be generated by those assets are less than the carrying amount of those assets. While the Company’s current and historical operating losses and negative cash flows are indicators of impairment, management believes that future cash flows to be received support the carrying value of its long-lived assets. Impairments, if any, are recognized in earnings. An impairment loss would be recognized in an amount equal to the excess of the carrying amount over the undiscounted expected future cash flows.
Intangible Assets	Intangible Asset As of December 31, 2015 and 2014, the Company’s intangible asset consists of acquired in-process research and development (“IPR&D”) obtained through the acquisition of ProChon. IPR&D represents the fair value assigned to research and development assets that have not been completed at the date of acquisition. The value assigned to acquired IPR&D is determined by estimating the costs to develop the acquired technology into commercially viable products, estimating the resulting revenue from the projects, and discounting the net cash flows to present value. The revenue and costs projections used to value acquired IPR&D were adjusted based on the probability of success of developing a new product. Additionally, the projections considered the relevant market sizes and growth factors, expected trends in technology and the nature and expected timing of new product introductions by the Company and its competitors. The rates utilized to discount the net cash flows to their present value were commensurate with the stage of development of the projects and uncertainties in the economic estimates used in the projections described above. IPR&D is considered an indefinite-lived intangible asset and is assessed for impairment annually or more frequently if impairment indicators exist. 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 believes, 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 fair value using the same methodology as described above. If the carrying value of the Company’s acquired IPR&D exceeds its fair value, then an impairment charge is taken and the intangible asset is written-down to its fair value. For the years ended December 31, 2015 and 2014, the Company determined that there was impairment of its IPR&D of $310 and $60 respectively. The Company performed its annual impairment test of its IPR&D as of December 31, 2015 and 2014 using an income approach, including a discount rate of 13%, applied to probability-adjusted after-tax cash flows. The Company believes that the assumptions are representative of those a market participant would use in estimating the fair value of the IPR&D. The Company notes that the pursuit of the underlying IPR&D has been delayed because the Company’s core focus has been on the development of NeoCart so, there is a risk of further impairment in the near future. Intangible asset, net of accumulated impairment charges, are summarized as follows: As of December 31, 2015 As of December 31, 2014 Cost Accumulated Impairment Net Book Value Cost Accumulated Impairment Net Book Value IPR&D $ 630 $ (430 ) $ 200 $ 630 $ (120 ) $ 510 $ 630 $ (430 ) $ 200 $ 630 $ (120 ) $ 510
Initial Public Offering Costs	Initial Public Offering Costs The Company deferred direct incremental costs attributable with the IPO of its common stock prior to the closing of the IPO. These costs represent legal, accounting and other direct costs related to the Company’s efforts to raise capital through a public sale of its common stock. Upon completion of the IPO, $3,911 of IPO costs were reclassified to additional paid-in capital as a reduction of the IPO proceeds. As of December 31, 2014, the Company had paid $2,897 with the remaining $1,014 included in accounts payable in the consolidated balance sheet. This amount was subsequently paid in 2015.
Restricted Cash	Restricted Cash Restricted cash represents cash held in a depository account at a financial institution to collateralize a conditional stand-by letter of credit related to the Company’s Lexington, Massachusetts facility lease agreement. Restricted cash is reported as non-current unless the restrictions are expected to be released in the next twelve months.
Deferred Rent	Deferred Rent Deferred rent 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 leases for its Waltham, Massachusetts facility and its Lexington, Massachusetts facility provide for fixed increases in minimum annual rental payments. The total amount of rental payments due over each lease term is being charged to rent expense ratably over the life of each lease, respectively.
Convertible Redeemable Preferred Stock	Convertible Redeemable Preferred Stock The Company had classified convertible redeemable preferred stock that was redeemable outside of the Company’s control outside of permanent equity. The Company recorded such redeemable preferred stock at fair value upon issuance, net of any issuance costs or discounts, and the carrying value was increased by periodic accretion to its redemption value up to the date the preferred stock was determined to be redeemable. In the absence of retained earnings these accretion charges are recorded against additional paid in capital, if any, and then to accumulated deficit. All preferred stock was converted to common stock at the IPO date of December 3, 2014.
Financial Instruments Indexed to and Potentially Settled in the Company's Common Stock	Financial Instruments Indexed to and Potentially Settled in the Company’s Common Stock The Company evaluates all financial instruments issued in connection with its equity offerings when determining the proper accounting treatment for such instruments in the Company’s financial statements. The Company considers a number of generally accepted accounting principles under U.S. GAAP to determine such treatment and evaluates the features of the instrument to determine the appropriate accounting treatment. The Company utilizes the Probability Weighted Expected Return Method (“PWERM”), Option Pricing Model (“OM”) or other appropriate methods to determine the fair value of its derivative financial instruments. For financial instruments indexed to and potentially settled in the Company’s common stock that are determined to be classified as liabilities on the consolidated balance sheet, changes in fair value are recorded as a gain or loss in the Company’s consolidated statement of operations with the corresponding amount recorded as an adjustment to the liability on its consolidated balance sheet.
Revenue Recognition	Revenue Recognition The Company’s revenue had principally consisted of BioCart product revenue in Israel, collaboration revenue from a license agreement with AT Grade and government grant funding received from the Internal Revenue Service (“IRS”) as a qualifying therapeutic discovery project (“QTDP”) credit pursuant to the Patient Protection and Affordable Care Act. The Company’s license and collaboration agreement contains multiple elements, all of which are accounted for as collaboration revenue. The Company recognizes revenue when all four of the following criteria are met: (1) persuasive evidence that an agreement exists; (2) delivery of the products and/or services has occurred; (3) the selling price is fixed or determinable; and (4) collectability is reasonably assured. The Company did not recognize any collaboration, product, or grant revenue for the years ended December 31, 2015 and 2014.
Research and Development Costs	Research and Development Costs Research and development costs are charged to expense as incurred. These costs include, but are not limited to: license fees related to the acquisition of in-licensed products; employee-related expenses, including salaries, benefits and travel; expenses incurred under agreements with contract research organizations and investigative sites that conduct clinical trials and preclinical studies; the cost of acquiring, developing and manufacturing clinical trial materials; facilities, depreciation and other expenses, which include direct and allocated expenses for rent and maintenance of facilities, insurance and other supplies; and costs associated with preclinical activities and regulatory operations. Costs for certain development activities, such as clinical trials, are recognized based on an evaluation of the progress to completion of specific tasks using data such as 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. Collaboration Arrangements Costs reimbursed to a collaborator for work that it performs are recorded as research and development expenses. These reimbursements can include research and development expenses, payments for work performed, or a milestone for which a payment is due, the reimbursements or development milestone achievement are recorded as research and development expense. In September 2014, the Company entered into a collaboration agreement with Intrexon Corporation (“Intrexon”) for the development and commercialization of allogeneic cell therapeutics for the treatment or repair of damaged articular hyaline cartilage in humans, utilizing Intrexon’s proprietary technology (the “Collaboration Agreement”). Under the terms of the Collaboration Agreement, the Company is responsible for the costs of development and commercialization, with some exceptions. Refer to Note 8, Related Party Convertible Promissory Notes Related Parties
License Agreements	License Agreements Costs associated with licenses of technology are expensed as incurred and are included in research and development expenses.
Patent Costs	Patent Costs Costs related to filing and pursuing patent applications are recorded as general and administrative expense as incurred since the recoverability of such expenditures is uncertain.
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 their 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 as determined by management or the value of the services provided, whichever is more readily determinable. 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 year end. Stock-based compensation expense recognized in the consolidated financial statements is based on awards that are ultimately expected to vest. For stock option grants with performance-based milestones, the expense is recorded over the remaining service period after the point when the achievement of the milestone is probable or the performance condition has been achieved. For stock option grants with both performance-based milestones and market conditions, expense is recorded over the derived service period after the point when the achievement of the performance-based milestone is probable or the performance condition has been achieved. The Company did not issue any performance-based awards with market conditions from its inception through December 31, 2014. The Company issued performance-based awards in 2015. The Company accounts for stock options and restricted stock awards to non-employees using the fair value approach. Stock options and restricted stock awards to non-employees are subject to periodic revaluation over their vesting terms.
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 income in the period that includes the enactment date. The Company recognizes net deferred tax assets 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 percent 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.
Earnings (Loss) per Common Share	Earnings (Loss) per Common Share Earnings (loss) per common share is calculated using the two-class method, which is an earnings allocation formula that determines earnings (loss) per share for the holders of the Company’s common shares and participating securities. All series of preferred stock contain participation rights in any dividend paid by the Company and are deemed to be participating securities. Earnings available to common stockholders and participating convertible redeemable preferred shares are allocated to each share on an as-converted basis as if all of the earnings for the period had been distributed. The participating securities do not include a contractual obligation to share in losses of the Company and are not included in the calculation of net loss per share in the periods that have a net loss. Diluted earnings per share is computed using the more dilutive of (a) the two-class method, or (b) the if-converted method. The Company allocates earnings first to preferred stockholders based on dividend rights and then to common and preferred stockholders based on ownership interests. The weighted-average number of common shares included in the computation of diluted earnings (loss) gives effect to all potentially dilutive common equivalent shares, including outstanding stock options, warrants, convertible redeemable preferred stock and the potential issuance of stock upon the conversion of the Company’s convertible notes. Common stock equivalent shares are excluded from the computation of diluted earnings (loss) per share if their effect is antidilutive.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes. The new standard requires that deferred tax assets and liabilities be classified as noncurrent in a classified statement of financial position. The Company prospectively adopted this guidance in the fourth quarter of 2015, which resulted in the removal of gross deferred tax assets and liabilities from the Company’s consolidated balance sheet. The net impact was zero and the prior period was not retrospectively adjusted. In June 2014, the FASB issued guidance that eliminates the concept of a development stage entity in its entirety from GAAP. The guidance is intended to reduce the overall cost and complexity associated with financial reporting for development stage entities without reducing the availability of relevant information. The Board also believes the changes will simplify the consolidation accounting guidance by removing the differential accounting requirements for development stage entities. As a result of these changes, there no longer will be any accounting or reporting differences in GAAP between development stage entities and other operating entities. The amendments are effective for annual reporting periods beginning after December 15, 2014. Early application is permitted for any annual reporting period or interim period for which the entity’s financial statements have not yet been issued (public business entities) or made available for issuance (other entities). The Company’s adoption of this guidance as of December 31, 2014 eliminated the disclosure of inception to date information from the Company’s consolidated financial statements. Recently Issued Accounting Pronouncements In November 2014, the FASB issued guidance to eliminate the existing diversity in practice in accounting for hybrid financial instruments issued in the form of a share. A hybrid financial instrument consists of a “host contract” into which one or more derivative terms have been embedded. This guidance requires an entity to consider the terms and features of the entire financial instrument, including the embedded derivative features, in order to determine whether the nature of the host contract is more akin to debt or to equity. This guidance is effective for fiscal years and interim periods beginning after December 15, 2015, with early adoption permitted. A reporting entity should apply this guidance using a modified retrospective approach by recording a cumulative-effect adjustment to equity as of the beginning of the annual period of adoption. Retrospective application is permitted to all relevant prior periods. The Company does not expect that the application of this guidance will have an impact on the presentation of its results of operations, financial position or disclosures. In August 2014, the FASB issued guidance that requires management to assess an entity’s ability to continue as a going concern every reporting period, and provide certain disclosures if management has substantial doubt about the entity’s ability to operate as a going concern, or an express statement if not, by incorporating and expanding upon certain principles that are currently in U.S. auditing standards. This guidance is effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. Early application is permitted. The adoption of this guidance is not expected to have an impact on the Company’s financial position or results of operations. In June 2014, the FASB issued guidance requiring when there is a performance target that affects vesting of equity awards granted and could be achieved after the requisite service period to be treated as a performance condition. A reporting entity should apply existing guidance on stock-based compensation, as it relates to such awards. This guidance is effective for annual periods and interim periods within those annual periods beginning after December 15, 2015 with early adoption permitted using either of two methods: (i) prospective to all awards granted or modified after the effective date; or (ii) retrospective to all awards with performance targets that are outstanding as of the beginning of the earliest annual period presented in the financial statements and to all new or modified awards thereafter, with the cumulative effect of applying this guidance as an adjustment to the opening retained earnings balance as of the beginning of the earliest annual period presented in the financial statements. The Company issued performance-based awards during the year ended December 31, 2015. The Company’s adoption of this guidance is not expected to have a material impact on the consolidated financial statements. In May 2014, the FASB issued guidance that affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (e.g., insurance contracts or lease contracts). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The amendments are effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early application is not permitted. The Company has not had any revenue from contracts with customers from its inception through December 31, 2015. The Company’s adoption of this guidance is not expected to have a material impact on the consolidated financial statements.

Summary of Significant Accoun25

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of Operations in Different Geographic Regions	Information about the Company’s operations in different geographic regions is presented in the tables below: As of December 31, 2015 2014 Long-lived assets: United States $ 5,204 $ 4,866 Israel 9 12 Total long-lived assets $ 5,213 $ 4,878
Summary of Cash Equivalents Measured at Fair Value on Recurring Basis	The Company’s cash equivalents, which consist of money market funds, are measured at fair value on a recurring basis. As of December 31, 2015 and 2014, the carrying amount of cash and cash equivalents was $30,915 and $58,591, respectively, which approximates fair value and was determined based upon Level 1 inputs. Money market funds are valued using quoted market prices with no valuation adjustments applied. Accordingly, these securities are categorized as Level 1 and had a balance of $25,764 and $49,750 as of December 31, 2015 and 2014, respectively, shown in the table below. Description Total Quoted prices in active markets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) December 31, 2015 Money market $ 25,764 $ 25,764 $ — $ — $ 25,764 $ 25,764 $ — $ — Description Total Quoted prices in active markets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) December 31, 2014 Money market $ 49,750 $ 49,750 $ — $ — $ 49,750 $ 49,750 $ — $ —
Schedule of Depreciation and Amortization using Straight-line Method over Estimated Useful Lives of Assets	The Company provides for depreciation and amortization using the straight-line method over the estimated useful lives of the assets, which are as follows: Asset Category Estimated Useful Lives Office equipment 3 to 5 years Laboratory equipment 3 to 5 years Leasehold improvements Shorter of the remaining lease term or useful life
Summary of Intangible Asset, Net of Accumulated Impairment Charges	Intangible asset, net of accumulated impairment charges, are summarized as follows: As of December 31, 2015 As of December 31, 2014 Cost Accumulated Impairment Net Book Value Cost Accumulated Impairment Net Book Value IPR&D $ 630 $ (430 ) $ 200 $ 630 $ (120 ) $ 510 $ 630 $ (430 ) $ 200 $ 630 $ (120 ) $ 510

Earnings (Loss) Per Common Sh26

Earnings (Loss) Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Earnings (Loss) Per Common Share	Basic and diluted earnings (loss) per common share are calculated as follows: Year Ended December 31, 2015 2014 Numerator: Net loss $ (32,024 ) $ (22,793 ) Extinguishment of Net Sales Distribution Payment Liability redemption provision — 15,803 Adjustment to fair value of Series A-1 Preferred Stock (Note 11) — (3,520 ) Earnings (loss) attributable to common stockholders—basic and diluted $ (32,024 ) $ (10,510 ) Denominator: Weighted-average number of common shares used in earnings (loss) per share—basic and diluted 13,231,126 1,534,108 Earnings (loss) per share—basic and diluted $ (2.42 ) $ (6.85 )
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following potentially dilutive securities have been excluded from the computation of diluted weighted-average shares outstanding, as they would be anti-dilutive (in common stock equivalent shares): As of December 31, 2015 2014 Restricted stock and options to purchase common stock 1,227,957 546,176 Warrants exercisable into common stock 166,403 162,704

Prepaid Expenses and Other Cu27

Prepaid Expenses and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Text Block [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following: As of December 31, 2015 2014 Deposits $ 67 $ 505 Undelivered laboratory and office equipment 17 78 Insurance 42 67 Other current assets 195 146 Prepaid expenses and other current assets $ 321 $ 796

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment consisted of the following: As of December 31, 2015 2014 Office equipment $ 539 $ 467 Laboratory equipment 4,337 2,978 Leasehold improvements 7,683 7,503 Construction in progress 547 270 Software 96 35 Total property and equipment 13,202 11,253 less: accumulated depreciation (7,989 ) (6,375 ) Property and equipment, net $ 5,213 $ 4,878

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2015
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following: As of December 31, 2015 2014 Accrued compensation $ 758 $ 814 Accrued clinical expenses 138 384 Accrued fees for technology transfer agreement — 350 Accrued other 548 128 Accrued expenses due to Intrexon 1,546 7 Total accrued expenses $ 2,990 $ 1,683

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Minimum Annual Lease Commitments Under Non-Cancellable Operating Leases	Aggregate minimum annual lease commitments of the Company under its non-cancellable operating leases as of December 31, 2015 are as follows: For the Year Ended December 31, 2016 $ 2,272 2017 2,266 2018 754 2019 586 2020 596 Thereafter 1,534 Total minimum lease payments $ 8,008

Warrants, Other Liability and31

Warrants, Other Liability and Net Sales Distribution Payment Liability (Tables)	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Schedule of Reconciliation of Liabilities Measured at Fair Value	The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs at December 31, 2014: Year Ended 2014 Beginning balance $ 26,912 Change in fair value of Net Sales Distribution Payment Liability (10,007 ) Extinguishment of liabilities (16,905 ) Ending balance $ —

Capital and Convertible Redee32

Capital and Convertible Redeemable Preferred Stock (Tables)	12 Months Ended
	Dec. 31, 2015
Text Block [Abstract]
Schedule of Common Stock Reserved For Future Issuance	The Company has reserved for future issuance the following number of shares of common stock: As of December 31, Vesting of restricted stock 5,191 Options to purchase common stock 1,222,767 Common stock warrants (equity) 166,403 Total 1,394,361

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Activity Under the 2012 and 2013 Plans	Stock option activity under the 2012 and 2013 plans is summarized as follows: Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Outstanding at December 31, 2014 537,683 $ 6.19 8.9 $ 2,488 Granted 914,722 7.74 Exercised (53,458 ) 0.76 Cancelled (176,180 ) 8.13 Outstanding at December 31, 2015 1,222,767 $ 7.31 9.0 $ (4,679 ) Vested and expected to vest at December 31, 2014 451,153 $ 5.83 8.9 $ 2,247 Vested and expected to vest at December 31, 2015 1,133,925 $ 7.29 9.0 $ (4,293 ) Exercisable at December 31, 2014 139,798 $ 1.84 8.1 $ 1,239 Exercisable at December 31, 2015 318,733 $ 4.60 7.6 $ (351 )
Additional Information about Stock Option Activity	Additional information about the Company’s stock option activity is as follows: Years Ended December 31, 2015 2014 Weighted-average grant date fair value per share of employee option grants within the year $ 4.08 $ 6.70 Cash received upon exercise of options 39 26
Schedule of Restricted Stock Awards Under the 2012 and 2013 Plans	Restricted stock awards under the 2012 and 2013 plans are summarized as follows: Number of Shares Weighted Average Grant Date Fair Value Unvested at December 31, 2014 8,493 $ 1.04 Vesting of restricted stock (3,303 ) 1.00 Unvested at December 31, 2015 5,190 $ 1.07
Summary of Stock-Based Compensation	Stock-based compensation is as follows: Years Ended December 31, 2015 2014 Research and development $ 451 $ 181 General and administrative 777 366 Total stock-based compensation expense $ 1,228 $ 547
Summary of Weighted-Average Assumptions Used in the Black-Scholes Option Pricing Model to Determine the Fair Value of the Employee Stock Option Grants	The weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of the employee stock option grants were as follows: Years Ended December 31, 2015 2014 Risk-free interest rate 1.68 % 1.83 % Expected volatility 62.6 % 104.5 % Expected term (in years) 6.04 6.08 Expected dividend yield 0.0 % 0.0 %
Summary of Weighted-Average Assumptions Used in the Black-Scholes Option Pricing Model to Determine the Fair Value of the Non-Employee Stock Option Grants	The weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of the non-employee stock option grants were as follows: Years Ended December 31, 2015 2014 Risk-free interest rate 1.79 % 0.89 % Expected volatility 63.2 % 99.4 % Expected term (in years) 6.16 2.47 Expected dividend yield 0.0 % 0.0 %

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Components of Loss Before Income Taxes	The components of loss before income taxes were as follows: As of December 31, 2015 2014 U.S. $ (31,332 ) $ (22,240 ) Foreign (692 ) (553 ) Total $ (32,024 ) $ (22,793 )
Schedule of Reconciliation of Income Tax Expense (Benefit) Computed at Statutory Federal Income Tax Rate	A reconciliation of income tax expense (benefit) computed at the statutory federal income tax rate to income taxes as reflected in the financial statements is as follows: As of December 31, 2015 2014 Federal income tax (benefit) at statutory rate 34.0 % 34.0 % Increase income tax benefit resulting from: Permanent differences (1.2 )% (4.8 )% Change in valuation allowance (31.7 )% (29.2 )% Other (1.1 )% 0.0 % Income tax expense (benefit) 0.0 % 0.0 %
Components of Deferred Tax Assets and Liabilities	Deferred taxes are recognized for temporary differences between the basis of assets and liabilities for financial statement and income tax purposes. The significant components of the Company’s deferred tax assets and liabilities are comprised of the following: As of December 31, 2015 2014 Deferred tax assets: Net operating loss carryforwards $ 28,200 $ 18,933 Depreciation and amortization 6,688 7,235 Accrued expenses 1,183 698 Capitalized start-up costs 8,531 7,276 Capitalized R&D — 27 Other 259 67 Deferred tax assets before valuation allowance 44,861 34,236 Valuation allowance (43,751 ) (31,966 ) 1,110 2,270 Deferred tax liabilities IPR&D (36 ) (121 ) Change in accounting method (1,074 ) (2,149 ) (1,110 ) (2,270 ) Net deferred tax assets $ — $ —
Summary of Changes In Unrecognized Tax Benefits	The changes in the Company’s unrecognized tax benefits are summarized as follows: As of December 31, 2015 2014 Unrecognized tax benefit, beginning of year $ 811 $ 935 Increase (decrease) related to current year positions (124 ) (124 ) Unrecognized tax benefit, end of year $ 687 $ 811

Nature of Business - Additional

Nature of Business - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Dec. 08, 2015	Dec. 03, 2014	May. 13, 2011	Dec. 31, 2015	Dec. 31, 2014	Mar. 31, 2015	Dec. 08, 2014	Jul. 09, 2014	Jul. 20, 2012
Nature Of Business And Basis Of Presentation [Line Items]
Gross proceeds from initial public offering					$ 60,450
Net proceeds from initial public offering		$ 56,539
Conversion of redeemable preferred stock and accrued dividends	5,158,407	5,158,407			4,558,483
Net exercise of warrants, shares		44,531		156,138	156,138	7,398	44,531	6,566	161,977
Surrender of warrant to satisfy other liability		5,839
Additional paid-in capital				$ 193,631	$ 187,620
Common stock, shares authorized		100,000,000		100,000,000	100,000,000
Preferred stock shares authorized		10,000,000
ProChon [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Business acquisition date				May 13, 2011
Consideration paid to acquisition			$ 2,224
IPO [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Sale of common stock shares		5,909,091
Initial public offering price per share		$ 11
Gross proceeds from initial public offering		$ 65,000
Convertible notes payable to common stock		$ 11,100			$ 11,100
Accrued interest to common stock		1,009,115
Warrant Liability [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Additional paid-in capital		$ 490
Other Liability [Member]
Nature Of Business And Basis Of Presentation [Line Items]
Additional paid-in capital		$ 612

Summary of Significant Accoun36

Summary of Significant Accounting Policies - Additional Information (Detail)	Dec. 31, 2014USD ($)	Dec. 03, 2014USD ($)	Nov. 14, 2014	Dec. 31, 2015USD ($)Segment	Dec. 31, 2014USD ($)	Sep. 30, 2014USD ($)	Dec. 31, 2013USD ($)
Summary Of Significant Accounting Policies [Line Items]
Reverse stock split, number of shares converted to one share			10.804
Number of operating segments | Segment				2
Number of reporting segment | Segment				1
Transfers between Levels 1, 2 and 3				$ 0	$ 0
Cash and cash equivalents, carrying amount	$ 58,527,000			30,915,000	58,527,000		$ 8,734,000
Cash and cash equivalents, fair value	49,750,000			25,764,000	49,750,000
Impairment of intangible assets				$ 310,000	60,000
Discount rate				13.00%
IPO costs reclassified to additional paid-in capital		$ 3,911,000		$ 377,000	8,461,000
Payments related to IPO					73,000
Maximum percentage of recognition of tax benefits from uncertain tax positions				50.00%
IPO [Member]
Summary Of Significant Accounting Policies [Line Items]
Payments related to IPO	2,897,000
Remaining amount of IPO costs included in accounts payable	1,014,000				1,014,000
IPR&D [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment of intangible assets				$ 310,000	60,000
Intrexon [Member] | Promissory Note [Member]
Summary Of Significant Accounting Policies [Line Items]
Promissory note, face amount						$ 10,000,000
Quoted Prices in Active Markets (Level 1) [Member]
Summary Of Significant Accounting Policies [Line Items]
Assets, fair value disclosure, recurring	0			0	0
Liabilities, fair value disclosure, recurring	0			0	0
Cash and cash equivalents, fair value	49,750,000			25,764,000	49,750,000
Significant Other Observable Inputs (Level 2) [Member]
Summary Of Significant Accounting Policies [Line Items]
Assets, fair value disclosure, recurring	0			0	0
Liabilities, fair value disclosure, recurring	0			0	0
Significant Unobservable Inputs (Level 3) [Member]
Summary Of Significant Accounting Policies [Line Items]
Assets, fair value disclosure, recurring	0			0	0
Liabilities, fair value disclosure, recurring	0			0	0
Money Market [Member]
Summary Of Significant Accounting Policies [Line Items]
Cash and cash equivalents, fair value	49,750,000			25,764,000	49,750,000
Money Market [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Summary Of Significant Accounting Policies [Line Items]
Cash and cash equivalents, fair value	$ 49,750,000			$ 25,764,000	$ 49,750,000

Summary of Significant Accoun37

Summary of Significant Accounting Policies - Summary of Operations in Different Geographic Regions (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Long-lived assets	$ 5,213	$ 4,878
United States [Member]
Segment Reporting Information [Line Items]
Long-lived assets	5,204	4,866
Israel [Member]
Segment Reporting Information [Line Items]
Long-lived assets	$ 9	$ 12

Summary of Significant Accoun38

Summary of Significant Accounting Policies - Summary of Cash Equivalents Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents, fair value	$ 25,764	$ 49,750
Money Market [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents, fair value	25,764	49,750
Quoted Prices in Active Markets (Level 1) [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents, fair value	25,764	49,750
Quoted Prices in Active Markets (Level 1) [Member] | Money Market [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents, fair value	$ 25,764	$ 49,750

Summary of Significant Accoun39

Summary of Significant Accounting Policies - Schedule of Depreciation and Amortization using Straight-line Method over Estimated Useful Lives of Assets (Detail)	12 Months Ended
	Dec. 31, 2015
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	Shorter of the remaining lease term or useful life
Minimum [Member] | Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	3 years
Minimum [Member] | Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	3 years
Maximum [Member] | Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	5 years
Maximum [Member] | Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	5 years

Summary of Significant Accoun40

Summary of Significant Accounting Policies - Summary of Intangible Asset, Net of Accumulated Impairment Charges (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Cost	$ 630	$ 630
Accumulated Impairment	(430)	(120)
Net Book Value	200	510
IPR&D [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	630	630
Accumulated Impairment	(430)	(120)
Net Book Value	$ 200	$ 510

Earnings (Loss) Per Common Sh41

Earnings (Loss) Per Common Share - Schedule of Basic and Diluted Earnings (Loss) Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Numerator:
Net loss	$ (32,024)	$ (22,793)
Extinguishment of Net Sales Distribution Payment Liability redemption provision		15,803
Earnings (loss) attributable to common stockholders-basic and diluted	$ (32,024)	$ (10,510)
Denominator:
Weighted-average number of common shares used in earnings (loss) per share-basic and diluted	13,231,126	1,534,108
Earnings (loss) per share-basic and diluted	$ (2.42)	$ (6.85)
Series A-1 Convertible Redeemable Preferred Stock [Member]
Numerator:
Adjustment to fair value of Series A-1 Preferred Stock		$ (3,520)

Earnings (Loss) Per Common Sh42

Earnings (Loss) Per Common Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Restricted Stock and Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share	1,227,957	546,176
Warrants Exercisable into Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share	166,403	162,704

Earnings (Loss) Per Common Sh43

Earnings (Loss) Per Common Share - Additional Information (Detail) - $ / shares	Dec. 31, 2015	Dec. 21, 2015	Dec. 08, 2015	Dec. 03, 2014	Jul. 20, 2012	Mar. 31, 2015	Dec. 31, 2014	Dec. 08, 2014	Jul. 09, 2014
Earnings Per Share [Abstract]
Common stock warrant issued as compensation to the consulting firm	156,138			44,531	161,977	7,398	156,138	44,531	6,566
Conversion of redeemable preferred stock and accrued dividends			5,158,407	5,158,407			4,558,483
Net exercise of warrants, shares					47,828		47,898
Common stock warrant, exercise price	$ 0.01					$ 9.75	$ 0.01
Warrants exercisable period						24 months
Warrants expiry period					10 years	10 years
Warrants, forfeiture		3,699
Warrants vested and exercisable	3,699
Warrants, percentage of forfeiture		50.00%
Surrender of warrant to satisfy other liability				5,839
Warrants outstanding	156,138

Prepaid Expenses and Other Cu44

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Prepaid Expense and Other Assets, Current [Abstract]
Deposits	$ 67	$ 505
Undelivered laboratory and office equipment	17	78
Insurance	42	67
Other current assets	195	146
Prepaid expenses and other current assets	$ 321	$ 796

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 13,202	$ 11,253
less: accumulated depreciation	(7,989)	(6,375)
Property and equipment, net	5,213	4,878
Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	539	467
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	4,337	2,978
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	7,683	7,503
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	547	270
Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 96	$ 35

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 1,614	$ 726

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Apr. 15, 2014
Payables and Accruals [Abstract]
Accrued compensation	$ 758	$ 814
Accrued clinical expenses	138	384
Accrued fees for technology transfer agreement		350	$ 350
Accrued other	548	128
Accrued expenses due to Intrexon	1,546	7
Total accrued expenses	$ 2,990	$ 1,683

Accrued Expenses - Additional I

Accrued Expenses - Additional Information (Detail) - USD ($) $ in Thousands	Apr. 15, 2014	Dec. 31, 2014
Payables and Accruals [Abstract]
Technology transfer agreement, fees paid	$ 400
Technology transfer agreement, additional fees payable	$ 350	$ 350

Commitments and Contingencies -

Commitments and Contingencies - Schedule of Minimum Annual Lease Commitments Under Non-Cancellable Operating Leases (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2,016	$ 2,272
2,017	2,266
2,018	754
2,019	586
2,020	596
Thereafter	1,534
Total minimum lease payments	$ 8,008

Commitments and Contingencies50

Commitments and Contingencies - Additional Information (Detail) - USD ($)	1 Months Ended		12 Months Ended
	Sep. 30, 2015	Jun. 30, 2012	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2004
Loss Contingencies [Line Items]
Rent expense under operating lease agreements			$ 1,116,000	$ 900,000
Research and development expense			23,243,000	$ 26,037,000
Tissue Regeneration License Agreement [Member]
Loss Contingencies [Line Items]
Research and development expense			709,000
One-time payment amount			$ 300,000
Percentage of royalty offsetting			50.00%
Hydrogel License Agreement [Member]
Loss Contingencies [Line Items]
Research and development expense			$ 3,200,000
One-time payment amount			3,000,000
Plasmid License Agreement [Member]
Loss Contingencies [Line Items]
Non-refundable license fee			2,000
Minimum [Member] | Tissue Regeneration License Agreement [Member]
Loss Contingencies [Line Items]
Non-refundable royalty fee			10,000
Maximum [Member] | Waltham [Member]
Loss Contingencies [Line Items]
Construction allowance to total cost of tenant improvements			3,184,000
Maximum [Member] | Lexington [Member]
Loss Contingencies [Line Items]
Construction allowance to total cost of tenant improvements			996,000
Tissue Processor Sub License Agreement [Member]
Loss Contingencies [Line Items]
Research and development expense			941,000
Reimbursement for development cost		$ 250,000
Potential milestone payments			200,000
Tissue Processor Sub License Agreement [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Non-refundable royalty fee			$ 20,000
OCS Agreement [Member]
Loss Contingencies [Line Items]
Accrued and received grants, aggregate					$ 1,100,000
OCS Agreement [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Royalties payment, rate			3.00%
OCS Agreement [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Royalties payment, rate			5.00%
Royalty payment percentage as percentage of grant received			300.00%
Engineering Agreement [Member]
Loss Contingencies [Line Items]
Purchase amount required to pay			$ 377,000
Purchase amount, remaining to be paid			190,000
Collagen Supply Agreement [Member]
Loss Contingencies [Line Items]
Purchase amount, remaining to be paid			30,000
Minimum amount of material and/or services	$ 150,000
Non-refundable payment			121,000
Amount paid to suppliers			$ 93,000
Initial term of the agreement	3 years
Supplier agreement description			The initial term of the agreement is three years and will automatically renew from year to year thereafter unless otherwise terminated with at least 180 days' notice by either party.
Operating lease expiration year			2,016

Related Party Convertible Pro51

Related Party Convertible Promissory Notes - Additional Information (Detail) - USD ($)	Dec. 03, 2014	Nov. 06, 2014	Nov. 30, 2014	Sep. 30, 2014
Convertible Promissory Notes [Member]
Debt Instrument [Line Items]
Promissory note, face amount		$ 1,000,000
Promissory note, interest rate			6.00%
Shares issued upon conversion		90,909
Promissory notes, amount authorized			$ 2,500,000
Intrexon [Member]
Debt Instrument [Line Items]
Shares issued upon conversion	918,206
Intrexon [Member] | Promissory Note [Member]
Debt Instrument [Line Items]
Promissory note, face amount				$ 10,000,000
Promissory note, interest rate				6.00%
Shares issued upon conversion	918,206

Warrants, Other Liability and52

Warrants, Other Liability and Net Sales Distribution Payment Liability - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 03, 2014	Oct. 14, 2014	Dec. 18, 2013	Jul. 20, 2012	Dec. 31, 2015	Dec. 31, 2014	Mar. 31, 2015	Dec. 08, 2014	Jul. 09, 2014
Class of Warrant or Right [Line Items]
Common stock issued upon common stock warrants exercisable				47,828		47,898
Net exercise of warrants, shares	44,531			161,977	156,138	156,138	7,398	44,531	6,566
Percentage of net sales in net sales distribution payment			2.00%
Percentage of net sales of entitled distribution payment under new royalty agreement			3.00%
Amount payable for each net sales percentage point redeemed					$ 10,000
Extinguishment of Net Sales Distribution Payment Liability redemption provision						$ 15,803
New Royalty Agreement [Member]
Class of Warrant or Right [Line Items]
Percentage of net sales of entitled distribution payment under new royalty agreement	3.00%
Extinguishment of Net Sales Distribution Payment Liability redemption provision		$ 15,803
Series A Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Net exercise of warrants, shares				161,977
Series A Preferred Stock [Member] | New Royalty Agreement [Member]
Class of Warrant or Right [Line Items]
Percentage of net sales in net sales distribution payment					2.00%
Percentage of net sales of entitled distribution payment under new royalty agreement					3.00%
Amount payable for each net sales percentage point redeemed					$ 10,000

Warrants, Other Liability and53

Warrants, Other Liability and Net Sales Distribution Payment Liability - Schedule of Reconciliation of Liabilities Measured at Fair Value (Detail) - Significant Unobservable Inputs (Level 3) [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2014USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 26,912
Change in fair value of Net Sales Distribution Payment Liability	(10,007)
Extinguishment of liabilities	(16,905)
Ending balance	$ 0

Non-Recurring Fair Value Meas54

Non-Recurring Fair Value Measurements - Additional Information (Detail) - USD ($)	Dec. 03, 2014	Jul. 09, 2014	Jul. 20, 2012	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 08, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Class of Warrants or right to purchase common stock	44,531	6,566	161,977	7,398	156,138	156,138	44,531
Class of Warrants or right to purchase common stock, exercise price				$ 9.75	$ 0.01	$ 0.01
Warrants expiry period			10 years	10 years
Fair value of the warrants, risk free interest rate			0.22%
Fair value of the warrants, implied volatility			99.00%
Fair value of the warrants, expected term to liquidity			1 year 8 months 12 days
Fair value of warrants			$ 117,000
Surrender of warrant to satisfy other liability	5,839
Warrants outstanding					156,138
Silicon Valley Bank [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Class of Warrants or right to purchase common stock					6,566
Class of Warrants or right to purchase common stock, exercise price					$ 7.99
Warrants expiry period					10 years
Fair value of the warrants, risk free interest rate		2.58%
Fair value of the warrants, implied volatility		87.00%
Fair value of the warrants, expected term to liquidity		10 years
Fair value of warrants		$ 51,000
Amount of loan to purchase equipment		$ 1,750,000
Amount of loan, interest rate stated percentage						6.00%
Bank loan and security agreement, repayment period		36 months
Warrants outstanding					6,566
Silicon Valley Bank [Member] | Prime Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amount of loan bears interest basis spread on variable rate		2.75%
Series A Preferred Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Class of Warrants or right to purchase common stock			161,977
Class of Warrants or right to purchase common stock, exercise price			$ 0.01

Capital and Convertible Redee55

Capital and Convertible Redeemable Preferred Stock - Additional Information (Detail) - USD ($)	Dec. 03, 2014	Oct. 14, 2014	May. 27, 2014	Dec. 18, 2013	Nov. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Mar. 31, 2015	Dec. 08, 2014	Jul. 09, 2014	Dec. 31, 2013	Dec. 17, 2013	Jul. 20, 2012
Class of Stock [Line Items]
Warrants to purchase shares of common stock	44,531					156,138	156,138	7,398	44,531	6,566			161,977
Percentage of right to receive net sales distribution payment				2.00%
Percentage of net sales of entitled distribution payment under new royalty agreement				3.00%
Liability for sales distribution payment				$ 13,100,000
Reduction of additional paid-in capital							$ 3,520,000
Extinguishment of Net Sales Distribution Payment Liability redemption provision							15,803,000
Issuance cost incurred							73,000
Net proceeds from issuance							$ 10,314,000
Stock issued, reverse stock split					10.804
Amount payable for each net sales percentage point redeemed						$ 10,000,000
Fair value of common stock election period						10 days
Product Concentration Risk [Member] | Sales Revenue, Net [Member]
Class of Stock [Line Items]
Royalty Recipients payment of net sales						3.00%
Investor [Member]
Class of Stock [Line Items]
Warrants to purchase shares of common stock													47,828
Common Stock [Member]
Class of Stock [Line Items]
Shares Issued							5,909,091
Stock issued upon conversion of convertible redeemable preferred stock	5,158,407						5,158,407
Advisor [Member]
Class of Stock [Line Items]
Warrants to purchase shares of common stock													161,977
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Stock purchase agreement, shares authorized													4,535,357
Warrants to purchase shares of common stock													161,977
Shares issued and sold													2,647,350
Price per share													$ 10.80
Investors commitment to purchase preferred shares													$ 20,648,000
Extinguishment of outstanding shares				2,647,350
Carrying value/Fair value of preferred shares												$ 31,910,000
Reduction of additional paid-in capital				$ 28,000,000
Shares fair value				$ 59,910,000
Series A-1 Convertible Redeemable Preferred Stock [Member]
Class of Stock [Line Items]
Shares issued and sold				955,568
Price per share			$ 10.80	$ 10.80
Investors commitment to purchase preferred shares				$ 10,324,000
Preferred stock par value				$ 0.01		$ 0.01	$ 0.01
Aggregate proceeds from sale of preferred stock			$ 10,324,000	$ 10,324,000
Extinguishment of outstanding shares							1,911,133
Carrying value/Fair value of preferred shares				$ 14,454,000							$ 14,454,000
Fair value per share of preferred shares			$ 14.48	$ 15.13
Reduction of additional paid-in capital			$ 3,520,000
Shares Issued				955,568
Share par value, per share			$ 0.01	$ 0.01
Issuance cost incurred			$ 10,000
Net proceeds from issuance			10,314,000
Shares fair value			$ 13,834,000				$ 13,834,000
Share issued price, per share			$ 10.80	$ 10.80
Preferred shares issue			955,565	955,568
Series A Convertible Redeemable Preferred Stock [Member]
Class of Stock [Line Items]
Price per share				$ 16.10
Preferred stock par value						$ 0.01	$ 0.01
Extinguishment of outstanding shares							2,647,350
Carrying value/Fair value of preferred shares				$ 42,617,000							$ 42,617,000
Share par value, per share													$ 0.01
Shares Issued													49,000,000
Share issued price, per share													$ 10.80
Preferred shares issue													2,647,350
Aggregate purchase price													$ 26,500,000
Stock Purchase Agreement [Member] | Convertible Redeemable Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, dividends rate						8.00%
Dividends declared or paid							$ 0
Cumulative dividends for preferred stock							$ 3,307,000
New Royalty Agreement [Member]
Class of Stock [Line Items]
Percentage of net sales of entitled distribution payment under new royalty agreement	3.00%
Extinguishment of Net Sales Distribution Payment Liability redemption provision		$ 15,803,000
New Royalty Agreement [Member] | Series A Preferred Stock [Member]
Class of Stock [Line Items]
Percentage of right to receive net sales distribution payment						2.00%
Percentage of net sales of entitled distribution payment under new royalty agreement						3.00%
Amount payable for each net sales percentage point redeemed						$ 10,000,000

Capital and Convertible Redee56

Capital and Convertible Redeemable Preferred Stock - Schedule of Common Stock Reserved For Future Issuance (Detail)	Dec. 31, 2015shares
Class of Stock [Line Items]
Common stock reserved for future issuance	1,394,361
Warrants Exercisable into Common Stock [Member]
Class of Stock [Line Items]
Common stock reserved for future issuance	166,403
Restricted Stock [Member]
Class of Stock [Line Items]
Common stock reserved for future issuance	5,191
Stock Options [Member]
Class of Stock [Line Items]
Common stock reserved for future issuance	1,222,767

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Dec. 03, 2014	Oct. 31, 2014	Jul. 31, 2012	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jan. 16, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards granted					914,722
Stock-based compensation expense					$ 1,228	$ 547
2012 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance						609,389
Stock options vesting period			3 years
Term of stock options granted			10 years
2012 Equity Incentive Plan [Member] | First Anniversary of Original Vesting Date [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting percentage			25.00%
2013 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance	103,665						155,497
Increase in authorized shares of common stock amount	51,832
Increase in authorized shares, percentage of common stock outstanding	1.00%
2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance						518,327
Stock options vesting period		3 years
Term of stock options granted		10 years
Number of awards granted						0
Increase in authorized shares of common stock amount		181,414
Increase in authorized shares, percentage of common stock outstanding		3.50%
2013 Equity Incentive Plan [Member] | First Anniversary of Original Vesting Date [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting percentage		25.00%
Research And Development And General And Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense					1,228	$ 547
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense					777	366
Restricted stock-based compensation expense					$ 4	$ 3
Scenario, Forecast [Member] | 2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in authorized shares of common stock amount				181,414
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, recognition period					1 year 2 months 5 days	2 years 1 month 24 days
Unrecognized compensation cost related to restricted stock awards					$ 4	$ 7
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to outstanding options					3,959	2,373
Intrinsic value of options exercised					$ 301	$ 196
Unrecognized compensation cost, recognition period					2 years 8 months 5 days	2 years 8 months 1 day
Weighted average grant date fair value of vested options					$ 3.80
Weighted average grant date fair value of shares outstanding					$ 4.49

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity Under the 2012 and 2013 Plans (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Options, Outstanding Beginning Balance	537,683
Number of Options, Granted	914,722
Number of Options, Exercised	(53,458)
Number of Options, Cancelled	(176,180)
Number of Options, Outstanding Ending Balance	1,222,767	537,683
Number of Options, Vested and expected to vest outstanding	1,133,925	451,153
Number of Options, Exercisable	318,733	139,798
Weighted Average Exercise Price, Outstanding Beginning Balance	$ 6.19
Weighted Average Exercise Price, Granted	7.74
Weighted Average Exercise Price, Exercised	0.76
Weighted Average Exercise Price, Cancelled	8.13
Weighted Average Exercise Price, Outstanding Ending Balance	7.31	$ 6.19
Weighted Average Exercise Price, Vested and expected to vest outstanding	7.29	5.83
Weighted Average Exercise Price, Exercisable	$ 4.60	$ 1.84
Weighted Average Remaining Contractual Term, Outstanding	9 years	8 years 10 months 24 days
Weighted Average Remaining Contractual Term, Vested and expected to vest outstanding	9 years	8 years 10 months 24 days
Weighted Average Remaining Contractual Term, Exercisable	7 years 7 months 6 days	8 years 1 month 6 days
Aggregate Intrinsic Value, Outstanding	$ 4,679	$ 2,488
Aggregate Intrinsic Value, Vested and expected to vest outstanding	4,293	2,247
Aggregate Intrinsic Value, Exercisable	$ 351	$ 1,239

Stock-Based Compensation - Ad59

Stock-Based Compensation - Additional Information about Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted-average grant date fair value per share of employee option grants within the year	$ 4.08	$ 6.70
Cash received upon exercise of options	$ 39	$ 26

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Restricted Stock Awards Under the 2012 and 2013 Plans (Detail) - Restricted Stock [Member]	12 Months Ended
	Dec. 31, 2015$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, Unvested beginning balance | shares	8,493
Vesting of restricted stock | shares	(3,303)
Number of shares, Unvested ending balance | shares	5,190
Weighted-average grant date fair value, Unvested beginning balance | $ / shares	$ 1.04
Vesting of restricted stock | $ / shares	1
Weighted-average grant date fair value, Unvested ending balance | $ / shares	$ 1.07

Stock-Based Compensation - Su61

Stock-Based Compensation - Summary of Stock-Based Compensation by Award (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 1,228	$ 547
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	451	181
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 777	$ 366

Stock-Based Compensation - Su62

Stock-Based Compensation - Summary of Weighted-Average Assumptions Used in the Black-Scholes Option Pricing Model to Determine the Fair Value of the Employee Stock Option Grants (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Risk-free interest rate	1.68%	1.83%
Expected volatility	62.60%	104.50%
Expected term (in years)	6 years 15 days	6 years 29 days
Expected dividend yield	0.00%	0.00%

Stock-Based Compensation - Su63

Stock-Based Compensation - Summary of Weighted-Average Assumptions Used in the Black-Scholes Option Pricing Model to Determine the Fair Value of the Non-Employee Stock Option Grants (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Share-based Goods and Nonemployee Services Transaction [Abstract]
Risk-free interest rate	1.79%	0.89%
Expected volatility	63.20%	99.40%
Expected term (in years)	6 years 1 month 28 days	2 years 5 months 19 days
Expected dividend yield	0.00%	0.00%

Income Taxes - Components of Lo

Income Taxes - Components of Loss Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
U.S.	$ (31,332)	$ (22,240)
Foreign	(692)	(553)
Total	$ (32,024)	$ (22,793)

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Income Tax Expense (Benefit) Computed at Statutory Federal Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Federal income tax (benefit) at statutory rate	34.00%	34.00%
Increase income tax benefit resulting from:
Permanent differences	(1.20%)	(4.80%)
Change in valuation allowance	(31.70%)	(29.20%)
Other	(1.10%)	0.00%
Income tax expense (benefit)	0.00%	0.00%

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Net operating loss carryforwards	$ 28,200	$ 18,933
Depreciation and amortization	6,688	7,235
Accrued expenses	1,183	698
Capitalized start-up costs	8,531	7,276
Capitalized R&D		27
Other	259	67
Deferred tax assets before valuation allowance	44,861	34,236
Valuation allowance	(43,751)	(31,966)
Deferred tax assets, net	1,110	2,270
Deferred tax liabilities
IPR&D	(36)	(121)
Change in accounting method	(1,074)	(2,149)
Total deferred tax liabilities	(1,110)	(2,270)
Net deferred tax assets	$ 0	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes Disclosure [Line Items]
Increase in valuation allowance	$ 11,785,000	$ 7,710,000
Net deferred tax liability, current		651,000
Net deferred tax liability, non-current		651,000
NOL carry forwards, net of limitations	47,170,000	47,170,000
Unrecognized tax benefits	687,000	811,000	$ 935,000
Unrecognized tax benefits may be recognized by the end of 2016	124,000
Accrued interest or penalties related to uncertain tax positions	0	0
Interest or penalties related to uncertain tax positions	0	0
U.S. Federal [Member]
Income Taxes Disclosure [Line Items]
NOL carryforwards	$ 55,662,000	31,230,000
NOL carryforwards, expiration date	Dec. 31, 2035
U.S. State [Member]
Income Taxes Disclosure [Line Items]
NOL carryforwards	$ 55,502,000	31,176,000
NOL carryforwards, expiration date	Dec. 31, 2035
Foreign [Member]
Income Taxes Disclosure [Line Items]
NOL carryforwards	$ 25,627,000	$ 25,128,000

Income Taxes - Summary of Chang

Income Taxes - Summary of Changes In Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Unrecognized tax benefit, beginning of year	$ 811	$ 935
Increase (decrease) related to current year positions	(124)	(124)
Unrecognized tax benefit, end of year	$ 687	$ 811

Employee Benefits - Additional

Employee Benefits - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015USD ($)
Defined Contribution Plan Disclosure [Line Items]
Defined benefit plan contribution by employer	$ 0
Minimum [Member]
Defined Contribution Plan Disclosure [Line Items]
Defined contribution plan eligibility years of age for employees	21 years

Related Parties - Additional In

Related Parties - Additional Information (Detail) - USD ($)	Dec. 03, 2014	Sep. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Jun. 30, 2012
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Net sales			$ 0	$ 0
IPO Stock purchased, value				56,539,000
Accrued expenses due to Intrexon			$ 1,546,000	7,000
Intrexon [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration Agreement cancellation notification			90 days
Collaboration Agreement cancellation with material breach that cannot be remedied			60 days
Common stock to be purchased under equity purchase commitment		$ 15,000,000
Shares issued upon conversion	918,206
IPO Stock purchased, value	$ 19,496,000
IPO Stock purchased, shares	1,772,364
Accrued expenses due to Intrexon			$ 1,546,000
Intrexon [Member] | Investigational New Drug (IND) Filing Milestone Event [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payable		500,000
Intrexon [Member] | IND Acceptance Milestone Event [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payable		2,500,000
Intrexon [Member] | Phase III Milestone Event [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payable		3,000,000
Intrexon [Member] | Approval Milestone Event [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payable		5,000,000
Intrexon [Member] | Approval Amendment Milestone Event [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payable		1,000,000
Intrexon [Member] | Cumulative Sales Milestones One [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payable		5,000,000
Net sales		300,000,000
Intrexon [Member] | Cumulative Sales Milestones Two [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payable		7,500,000
Net sales		650,000,000
Intrexon [Member] | Cumulative Sales Milestones Three [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Milestone payable		10,000,000
Net sales		1,000,000,000
Intrexon [Member] | Promissory Note [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Promissory note issued as up-front fee		$ 10,000,000
Shares issued upon conversion	918,206
Purpose, Co. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Reimbursement for development cost, amount					$ 250,000
Reimbursement for development cost, paid			187,000	173,000
Research and Development [Member] | Intrexon [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Research and development expense from transaction with Intrexon			$ 3,100,000	$ 14,000