Athersys, Inc / New (ATHXQ) 10-Q 6 Aug 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Aug. 01, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Trading Symbol	ATHX
Entity Registrant Name	ATHERSYS, INC / NEW
Entity Central Index Key	1,368,148
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		83,116,504

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 32,346	$ 26,127
Accounts and other receivables	2,382	694
Prepaid expenses and other	341	427
Total current assets	35,069	27,248
Equipment, net	1,207	1,270
Deferred tax assets	203	200
Total assets	36,479	28,718
Current liabilities:
Accounts payable	2,255	2,767
Accrued compensation and related benefits	723	1,060
Accrued clinical trial costs	165	126
Accrued expenses	705	664
Deferred revenue	10,000	75
Note payable	187
Total current liabilities	14,035	4,692
Note payable		183
Warrant liabilities	$ 1,068	$ 2,948
Stockholders' equity:
Preferred stock, at stated value; 10,000,000 shares authorized, and no shares issued and outstanding at June 30, 2015 and December 31, 2014
Common stock, $0.001 par value; 150,000,000 shares authorized, and 83,082,183 and 77,706,816 shares issued and outstanding at June 30, 2015 and December 31, 2014, respectively	$ 83	$ 78
Additional paid-in capital	321,330	307,337
Accumulated deficit	(300,037)	(286,520)
Total stockholders' equity	21,376	20,895
Total liabilities and stockholders' equity	$ 36,479	$ 28,718

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	83,082,183	77,706,816
Common stock, shares outstanding	83,082,183	77,706,816

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues
Contract revenue	$ 49	$ 36	$ 155	$ 80
Grant revenue	167	352	792	1,015
Total revenues	216	388	947	1,095
Costs and expenses
Research and development	5,261	5,754	10,928	11,981
General and administrative	1,924	1,827	3,810	3,607
Depreciation	65	93	136	182
Total costs and expenses	7,250	7,674	14,874	15,770
Loss from operations	(7,034)	(7,286)	(13,927)	(14,675)
Other income, net	42	42	56	71
Income from change in fair value of warrants, net	5,957	7,919	354	3,795
Net (loss) income and comprehensive (loss) income	$ (1,035)	$ 675	$ (13,517)	$ (10,809)
Net (loss) income per share - Basic	$ (0.01)	$ 0.01	$ (0.17)	$ (0.14)
Weighted average shares outstanding, basic	82,843,739	77,077,492	81,022,337	76,468,506
Net loss per share - Diluted	$ (0.05)	$ (0.04)	$ (0.17)	$ (0.16)
Weighted average shares outstanding, diluted	83,562,405	78,778,181	81,022,337	78,407,380

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Operating activities
Net loss	$ (13,517,000)	$ (10,809,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	136,000	182,000
Stock-based compensation	1,456,000	1,180,000
Change in fair value of warrant liabilities	(354,000)	(3,795,000)
Changes in operating assets and liabilities:
Accounts receivable	(1,688,000)	(195,000)
Prepaid expenses and other	87,000	80,000
Accounts payable and accrued expenses	(769,000)	11,000
Deferred revenue	9,925,000	(62,000)
Net cash used in operating activities	(4,724,000)	(13,408,000)
Investing activities
Purchases of equipment	(73,000)	(192,000)
Net cash used in investing activities	(73,000)	(192,000)
Financing activities
Proceeds from issuance of common stock and warrants, net	10,371,000	19,756,000
Purchase of treasury stock	(331,000)	(292,000)
Proceeds from exercise of warrants	976,000	938,000
Net cash provided by financing activities	11,016,000	20,402,000
Increase in cash and cash equivalents	6,219,000	6,802,000
Cash and cash equivalents at beginning of the period	26,127,000	31,948,000
Cash and cash equivalents at end of the period	$ 32,346,000	$ 38,750,000

Background and Basis of Present

Background and Basis of Presentation	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background and Basis of Presentation	1. Background and Basis of Presentation We are an international biotechnology company that is focused primarily in the field of regenerative medicine and operate in one business segment. Our operations consist primarily of research and product development activities. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2014. The accompanying financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and Article 10 of Regulation S-X. Accordingly, since they are interim statements, the accompanying financial statements do not include all of the information and notes required by GAAP for complete financial statements. The accompanying financial statements reflect all adjustments, consisting of normal recurring adjustments, that are, in the opinion of management, necessary for a fair presentation of financial position and results of operations for the interim periods presented. Interim results are not necessarily indicative of results for a full year. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Our critical accounting policies, estimates and assumptions are described in “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” which is included below in this Quarterly Report on Form 10-Q.

Recently Issued Accounting Stan

Recently Issued Accounting Standards	6 Months Ended
	Jun. 30, 2015
Accounting Changes and Error Corrections [Abstract]
Recently Issued Accounting Standards	2. Recently Issued Accounting Standards In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 requires an entity to recognize revenue in a manner that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve that core principle, the amendment provides five steps that an entity should apply when recognizing revenue. The amendment also specifies the accounting of some costs to obtain or fulfill a contract with a customer and expands the disclosure requirements around contracts with customers. An entity can either adopt this amendment retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying the update recognized at the date of initial application. In April 2015, FASB announced that the effective date of ASU 2014-09 will be for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Early adoption is permitted for annual reporting periods beginning after December 15, 2016. We are in the process of evaluating, but have not determined, the impact that the adoption of ASU 2014-09 will have on our consolidated financial statements. In August 2014, the FASB issued ASU 2014-15, “Presentation of Financial Statements - Going Concern, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern,” which establishes management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and, if so, to provide related footnote disclosures. ASU 2014-15 ASU 2014-15

Net Loss per Share

Net Loss per Share	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Net Loss per Share	3. Net Loss per Share Basic and diluted net (loss) income per share have been computed using the weighted-average number of shares of common stock outstanding during the period. The table below reconciles the net (loss) income and the number of shares used to calculate basic and diluted net (loss) income per share for the three and six month periods ended June 30, 2015 and 2014, in thousands. Three months ended Six months ended June 30, 2015 2014 2015 2014 Numerator: Net (loss) income attributable to common stockholders - Basic $ (1,035 ) $ 675 $ (13,517 ) $ (10,809 ) Less: income from change in fair value of warrants (3,074 ) (4,042 ) — (1,344 ) Net loss attributable to common stockholders used to calculate diluted net loss per share $ (4,109 ) $ (3,367 ) $ (13,517 ) $ (12,153 ) Denominator: Weighted-average shares outstanding - Basic 82,844 77,077 81,022 76,469 Potentially dilutive common shares outstanding: Warrants 718 1,472 — 1,938 Stock-based awards — 229 — — Weighted-average shares used to calculate diluted net loss per share 83,562 78,778 81,022 78,407 Basic earnings per share $ (0.01 ) $ 0.01 $ (0.17 ) $ (0.14 ) Dilutive earnings per share $ (0.05 ) $ (0.04 ) $ (0.17 ) $ (0.16 ) We have outstanding options, restricted stock units and warrants that are not used in the calculation of diluted net loss per share because to do so would be antidilutive. The following instruments were excluded from the calculation of diluted net loss per share because their effects would be antidilutive: Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Stock options 7,465,064 6,075,165 7,465,064 6,296,165 Restricted stock units 1,830,567 7,578 1,830,567 2,451,634 Warrants 2,810,000 6,310,000 4,864,893 6,310,000 Total 12,105,631 12,392,743 14,160,524 15,057,799

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2015
Investments, All Other Investments [Abstract]
Fair Value of Financial Instruments	4. Fair Value of Financial Instruments Fair Value Measurements We classify the inputs used to measure fair value into the following hierarchy: Level 1 Unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 Unadjusted quoted prices in active markets for similar assets or liabilities, or unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or inputs other than quoted prices that are observable for the asset or liability. Level 3 Unobservable inputs for the asset or liability. The following table provides a summary of the fair values of our assets and liabilities measured at fair value on a recurring basis as of June 30, 2015 (in thousands): Fair Value Measurements at June 30, 2015 Using Description Balance as of Quoted Prices in Active Significant Other Significant Unobservable Warrant liabilities $ 1,068 $ — $ — $ 1,068 We review and reassess the fair value hierarchy classifications on a quarterly basis. Changes from one quarter to the next related to the observability of inputs in a fair value measurement may result in a reclassification between fair value hierarchy levels. There were no reclassifications for all periods presented. The estimated fair value of warrants accounted for as liabilities, representing a level 3 fair value measure, was determined on the issuance date and subsequently marked to market at each financial reporting date. We use the Black-Scholes valuation model to value the warrant liabilities at fair value. The fair value is estimated using the expected volatility based on our historical volatility for warrants issued after January 1, 2013, or for warrants issued prior to 2013, using the historical volatilities of comparable companies from a representative peer group selected based on industry and market capitalization. The fair value of the warrants is determined using probability weighted-average assumptions, when appropriate. The following inputs were used at June 30, 2015: Expected Volatility Risk-Free Interest Rate Expected Life Warrants with one year or less remaining term 69.46% 0.28% 0.59 year Warrants with greater than one year remaining term 67.33% - 76.72% 0.28% - 0.64% 1.04 - 1.71 years A roll-forward of fair value measurements using significant unobservable inputs (Level 3) for the warrants is as follows (in thousands): Three months Six months ended Balance April 1, 2015 $ 7,025 Balance January 1, 2015 $ 2,948 Settlements from exercise — Settlements from exercise (1,526 ) Income for the period (5,957 ) Income for the period (354 ) Balance June 30, 2015 $ 1,068 Balance June 30, 2015 $ 1,068

Collaborative Arrangements and

Collaborative Arrangements and Revenue Recognition	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaborative Arrangements and Revenue Recognition	5. Collaborative Arrangements and Revenue Recognition Chugai In February 2015, we entered into an exclusive license agreement (the “Chugai Agreement”) with Chugai Pharmaceutical Co., Ltd. (“Chugai”) to develop and commercialize MultiStem for the treatment of ischemic stroke in Japan. Chugai has the exclusive rights for the development, regulatory activities and commercialization of MultiStem for ischemic stroke in Japan and will pay us for supplying clinical and commercial product. Chugai will pay us royalties on net sales, starting in the low double digits and increasing incrementally to the high teens depending on net sales levels. We received a non-refundable, up-front cash payment of $10 million from Chugai, of which $2.0 million was temporarily withheld by Japan taxing authorities. The withholdings are expected to be refunded to us in August 2015 and were recorded as a receivable at June 30, 2015. Under the terms of the Chugai Agreement, we may terminate the Chugai Agreement in the event that Chugai does not pay us a $7 million milestone payment following its review of the interim results from our Phase 2 ischemic stroke study. In the event that Chugai does not make the $7 million milestone payment within the required time and we terminate the Chugai Agreement, all rights would revert to us and we would retain the up-front $10 million cash payment. Under the Chugai Agreement, the payment is due during the third quarter of 2015. To determine the appropriate accounting for the Chugai Agreement, we evaluated its terms, considering our specific facts and circumstances, to assess the rights and obligations and determined that our obligations under the Chugai Agreement represent multiple deliverables. In the period prior to Chugai’s decision to continue the collaboration and make the $7 million payment to us, the deliverables include the license grant and access to our technology, and importantly, the interim results of our stroke Phase 2 clinical study. For deliverables with standalone value, our policy is to account for these as separate units of accounting We allocate the overall consideration of the arrangement that is fixed and determinable, excluding consideration that is contingent upon future deliverables, to the separate units of accounting based on estimated selling prices (as defined in ASC 605-25) of each deliverable. We considered the deliverables and concluded that the license grant, for example, did not have standalone value (as defined in ASC 605-25) at the inception of the arrangement. At the time, the Phase 2 ischemic stroke study results were not yet available to Chugai and, once available, Chugai has several months to review the results before making the $7 million milestone payment required for it to retain its license. Thus, the effective use of the license by Chugai would not take place until after Chugai makes the $7 million payment to us. Accordingly, we have recorded the $10 million up-front payment as deferred revenue at June 30, 2015. Pfizer In 2009, we entered into a collaboration with Pfizer Inc. (“Pfizer”) to develop and commercialize our MultiStem product candidate to treat inflammatory bowel disease (“IBD”) for the worldwide market on an exclusive basis. Under the terms of the agreement, we received a $6 million non-refundable, up-front payment from Pfizer and research funding and support, totaling $6.25 million, through June 2012. In addition, Pfizer conducted a Phase 2 clinical study exploring the potential of MultiStem cell therapy to treat advanced and severe ulcerative colitis, and would be responsible for any subsequent development. Overall, the study results were disappointing, even though a single administration of the cell therapy may have had some short-term effects. Taking these results into account, following an internal portfolio review, Pfizer determined that it would not invest further in this program targeting IBD, as would be required by the collaboration, and in May 2015, notified us of this decision and its intent to terminate the license agreement effective in the third quarter of 2015. In connection with the termination, all rights that Pfizer had to the program revert to us, and intellectual property generated through the collaboration will be owned by us. Pfizer will transfer to us all preclinical and clinical data relating to the program in its possession, all reports, records and other information relating to preclinical and clinical development, and ownership of all investigator brochures, regulatory filings and approvals related to the program. We will be free to use such information, data, filings and approvals for subsequent analyses and development in this area, and such research findings to support development in other areas, including immunology and inflammatory conditions. RTI Surgical, Inc. In 2010, we entered into an agreement with RTI Surgical, Inc. (“RTI”) to develop and commercialize biologic implants using our technology for certain orthopedic applications in the bone graft substitutes market on an exclusive basis. Under the terms of the agreement, we received a non-refundable license fee in installments and performed certain services that were concluded in 2012. We are eligible to receive cash payments upon the successful achievement of certain commercial milestones. We evaluated the nature of the events triggering these contingent payments and concluded that these events are substantive and that revenue will be recognized in the period in which each underlying triggering event occurs. No milestone revenue has been recognized to date. In addition, we began receiving in 2014 tiered royalties on worldwide commercial sales of implants using our technologies based on a royalty rate starting in the mid-single digits and increasing into the mid-teens. Any royalties may be subject to a reduction if third-party payments for intellectual property rights are necessary or commercially desirable to permit the manufacture or sale of the product.

Stock-based Compensation

Stock-based Compensation	6 Months Ended
	Jun. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation	6. Stock-based Compensation We have two incentive plans that authorized an aggregate of 11,500,000 shares of common stock for awards to employees, directors and consultants. These equity incentive plans authorize the issuance of equity-based compensation in the form of stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares and units, and other stock-based awards. As of June 30, 2015, a total of 2,143,332 shares of common stock have been issued under our equity incentive plans. In the three-month period ended June 30, 2015, we granted 1,187,296 stock options and 455,776 restricted stock units to our employees and directors pursuant to our annual incentive programs. As of June 30, 2015, a total of 61,037 shares were available for issuance under our equity compensation plans and stock-based awards to purchase 9,295,631 shares of common stock were outstanding. For the three-month periods ended June 30, 2015 and 2014, stock-based compensation expense was approximately $705,000 and $601,000, respectively. At June 30, 2015, total unrecognized estimated compensation cost related to unvested stock-based awards was approximately $5.8 million, which is expected to be recognized by the end of 2019 using the straight-line method.

Issuance of Common Stock and Wa

Issuance of Common Stock and Warrants	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Issuance of Common Stock and Warrants	7. Issuance of Common Stock and Warrants In January 2014, we completed a registered direct offering generating net proceeds of approximately $18.8 million through the issuance of 5,000,000 shares of common stock and immediately exercisable warrants to purchase 1,500,000 shares of common stock with an exercise price of $4.50 per share that expire on July 15, 2016. The securities were sold in multiples of a fixed combination of one share of common stock and a warrant to purchase 0.30 shares of common stock at an offering price of $4.10 per fixed combination. In the second quarter of 2015, we sold 974,959 shares to Aspire Capital Fund, LLC (“Aspire Capital”) under our equity purchase agreement at an average price of $2.84 per share, generating aggregate proceeds of $2.8 million. As of June 30, 2015, we had the following outstanding warrants to purchase shares of common stock: Number of Underlying Shares Exercise Price Expiration 1,310,000 $ 3.55 February 2, 2016 1,500,000 $ 4.50 July 15, 2016 2,054,893 $ 1.01 March 14, 2017 4,864,893 In January 2015, we amended the warrants we issued in December 2013 to purchase 3,500,000 shares of common stock to increase the exercise price from $2.50 to $2.75 per share and to extend the expiration date from March 31, 2015 to May 31, 2015. Any outstanding warrants expired unexercised on May 31, 2015.

Warrant Liabilities

Warrant Liabilities	6 Months Ended
	Jun. 30, 2015
Text Block [Abstract]
Warrant Liabilities	8. Warrant Liabilities We account for common stock warrants as either liabilities or as equity instruments depending on the specific terms of the warrant agreement. Registered common stock warrants that could require cash settlement are accounted for as liabilities. We classify these warrant liabilities on the consolidated balance sheet as a non-current liability. The warrant liabilities are revalued at fair value at each balance sheet date subsequent to the initial issuance. Changes in the fair market value of the warrant are reflected in the consolidated statement of operations as income (expense) from change in fair value of warrants. The warrants we issued in the January 2014 registered direct offering contain a provision for a cash payment in the event that the shares are not delivered to the holder within two trading days. The cash payment equals $10 per day per $2,000 of warrant shares for each day late. The warrants issued in the March 2012 private placement and the February 2011 registered direct offering each contain a provision for net cash settlement in the event that there is a fundamental transaction (e.g., merger, sale of substantially all assets, tender offer, or share exchange). If a fundamental transaction occurs in which the consideration issued consists of all cash or stock in a non-public company, then the warrant holder has the option to receive cash equal to a Black Scholes value of the remaining unexercised portion of the warrant. Further, the March 2012 warrants include price protection in the event we sell stock below the exercise price, as defined, and the exercise price as reduced in February 2013 to $1.01 per share as a result of the October 2012 public offering. The warrants have been classified as liabilities, as opposed to equity, due to the potential adjustment to the exercise price that could result upon late delivery of the shares or potential cash settlement upon the occurrence of certain events as described above, and are recorded at their fair values at each balance sheet date.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes We have U.S. federal, state and foreign net operating loss, research and development tax credit and foreign tax credit carryforwards that may be used to reduce future taxable income and tax liabilities. Substantially all of our deferred tax assets have been fully offset by a valuation allowance due to our cumulative losses. As a result of our October 2012 equity offering, the utilization of our net operating loss and tax credit carryforwards generated prior to October 2012 is substantially limited under Section 382 of the Internal Revenue Code. U.S. federal net operating loss carryforwards, research and development tax credits, and state and local net operating loss carryforwards generated after October 2012, as well as foreign net operating loss carryforwards and foreign tax credits, are not subject to annual limitations. In 2014, we recognized a refundable tax benefit related to research and development credits associated with our foreign subsidiary.

Recently Issued Accounting St15

Recently Issued Accounting Standards (Policies)	6 Months Ended
	Jun. 30, 2015
Accounting Changes and Error Corrections [Abstract]
Revenue from Contracts with Customers	In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 requires an entity to recognize revenue in a manner that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve that core principle, the amendment provides five steps that an entity should apply when recognizing revenue. The amendment also specifies the accounting of some costs to obtain or fulfill a contract with a customer and expands the disclosure requirements around contracts with customers. An entity can either adopt this amendment retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying the update recognized at the date of initial application. In April 2015, FASB announced that the effective date of ASU 2014-09 will be for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Early adoption is permitted for annual reporting periods beginning after December 15, 2016. We are in the process of evaluating, but have not determined, the impact that the adoption of ASU 2014-09 will have on our consolidated financial statements.
Presentation of Financial Statements	In August 2014, the FASB issued ASU 2014-15, “Presentation of Financial Statements - Going Concern, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern,” which establishes management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and, if so, to provide related footnote disclosures. ASU 2014-15 ASU 2014-15

Net Loss per Share (Tables)

Net Loss per Share (Tables)	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Net (Loss) Income and Number of Shares Used to Calculate Basic and Diluted Net (Loss) Income Per Share	The table below reconciles the net (loss) income and the number of shares used to calculate basic and diluted net (loss) income per share for the three and six month periods ended June 30, 2015 and 2014, in thousands. Three months ended Six months ended June 30, 2015 2014 2015 2014 Numerator: Net (loss) income attributable to common stockholders - Basic $ (1,035 ) $ 675 $ (13,517 ) $ (10,809 ) Less: income from change in fair value of warrants (3,074 ) (4,042 ) — (1,344 ) Net loss attributable to common stockholders used to calculate diluted net loss per share $ (4,109 ) $ (3,367 ) $ (13,517 ) $ (12,153 ) Denominator: Weighted-average shares outstanding - Basic 82,844 77,077 81,022 76,469 Potentially dilutive common shares outstanding: Warrants 718 1,472 — 1,938 Stock-based awards — 229 — — Weighted-average shares used to calculate diluted net loss per share 83,562 78,778 81,022 78,407 Basic earnings per share $ (0.01 ) $ 0.01 $ (0.17 ) $ (0.14 ) Dilutive earnings per share $ (0.05 ) $ (0.04 ) $ (0.17 ) $ (0.16 )
Instruments Excluded from Calculation of Diluted Net Loss Per Share	The following instruments were excluded from the calculation of diluted net loss per share because their effects would be antidilutive: Three months ended June 30, Six months ended June 30, 2015 2014 2015 2014 Stock options 7,465,064 6,075,165 7,465,064 6,296,165 Restricted stock units 1,830,567 7,578 1,830,567 2,451,634 Warrants 2,810,000 6,310,000 4,864,893 6,310,000 Total 12,105,631 12,392,743 14,160,524 15,057,799

Fair Value of Financial Instr17

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2015
Investments, All Other Investments [Abstract]
Summary of Fair Values of Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table provides a summary of the fair values of our assets and liabilities measured at fair value on a recurring basis as of June 30, 2015 (in thousands): Fair Value Measurements at June 30, 2015 Using Description Balance as of Quoted Prices in Active Significant Other Significant Unobservable Warrant liabilities $ 1,068 $ — $ — $ 1,068
Fair Value of Warrants Based on Historical Volatilities	The fair value of the warrants is determined using probability weighted-average assumptions, when appropriate. The following inputs were used at June 30, 2015: Expected Volatility Risk-Free Interest Rate Expected Life Warrants with one year or less remaining term 69.46% 0.28% 0.59 year Warrants with greater than one year remaining term 67.33% - 76.72% 0.28% - 0.64% 1.04 - 1.71 years
Roll-Forward of Fair Value Measurements Using Significant Unobservable Inputs (Level 3) for Warrants	A roll-forward of fair value measurements using significant unobservable inputs (Level 3) for the warrants is as follows (in thousands): Three months Six months ended Balance April 1, 2015 $ 7,025 Balance January 1, 2015 $ 2,948 Settlements from exercise — Settlements from exercise (1,526 ) Income for the period (5,957 ) Income for the period (354 ) Balance June 30, 2015 $ 1,068 Balance June 30, 2015 $ 1,068

Issuance of Common Stock and 18

Issuance of Common Stock and Warrants (Tables)	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Outstanding Warrants to Purchase Shares of Common Stock	As of June 30, 2015, we had the following outstanding warrants to purchase shares of common stock: Number of Underlying Shares Exercise Price Expiration 1,310,000 $ 3.55 February 2, 2016 1,500,000 $ 4.50 July 15, 2016 2,054,893 $ 1.01 March 14, 2017 4,864,893

Background and Basis of Prese19

Background and Basis of Presentation - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2015Segment
Accounting Policies [Abstract]
Number of business segments	1

Net Loss per Share - Net (Loss)

Net Loss per Share - Net (Loss) Income and Number of Shares Used to Calculate Basic and Diluted Net (Loss) Income Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Numerator:
Net (loss) income attributable to common stockholders - Basic	$ (1,035)	$ 675	$ (13,517)	$ (10,809)
Less: income from change in fair value of warrants	(3,074)	(4,042)		(1,344)
Net loss attributable to common stockholders used to calculate diluted net loss per share	$ (4,109)	$ (3,367)	$ (13,517)	$ (12,153)
Denominator:
Weighted-average shares outstanding - Basic	82,843,739	77,077,492	81,022,337	76,468,506
Potentially dilutive common shares outstanding:
Warrants	718,000	1,472,000		1,938,000
Stock-based awards		229,000
Weighted-average shares used to calculate diluted net loss per share	83,562,405	78,778,181	81,022,337	78,407,380
Basic earnings per share	$ (0.01)	$ 0.01	$ (0.17)	$ (0.14)
Dilutive earnings per share	$ (0.05)	$ (0.04)	$ (0.17)	$ (0.16)

Net Loss per Share - Instrument

Net Loss per Share - Instruments Excluded from Calculation of Diluted Net Loss Per Share (Detail) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	12,105,631	12,392,743	14,160,524	15,057,799
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	7,465,064	6,075,165	7,465,064	6,296,165
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	1,830,567	7,578	1,830,567	2,451,634
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	2,810,000	6,310,000	4,864,893	6,310,000

Fair Value of Financial Instr22

Fair Value of Financial Instruments - Summary of Fair Values of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liabilities	$ 1,068	$ 2,948
Fair Value Measurements, Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liabilities	1,068
Fair Value Measurements, Recurring Basis [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liabilities	$ 1,068

Fair Value of Financial Instr23

Fair Value of Financial Instruments - Fair Value of Warrants Based on Historical Volatilities (Detail) - 6 months ended Jun. 30, 2015	Total
Warrants With Greater Than One Year Remaining Term [Member] | Minimum [Member]
Class of Warrant or Right [Line Items]
Expected Volatility	67.33%
Risk-Free Interest Rate	0.28%
Expected Life	1 year 15 days
Warrants With Greater Than One Year Remaining Term [Member] | Maximum [Member]
Class of Warrant or Right [Line Items]
Expected Volatility	76.72%
Risk-Free Interest Rate	0.64%
Expected Life	1 year 8 months 16 days
Warrants With One Year or Less Remaining Term [Member]
Class of Warrant or Right [Line Items]
Expected Volatility	69.46%
Risk-Free Interest Rate	0.28%
Expected Life	7 months 2 days

Fair Value of Financial Instr24

Fair Value of Financial Instruments - Roll-Forward of Fair Value Measurements Using Significant Unobservable Inputs (Level 3) for Warrants (Detail) - Jun. 30, 2015 - Outstanding Warrants [Member] - USD ($) $ in Thousands	Total	Total
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Beginning Balance	$ 7,025	$ 2,948
Settlements from exercise		(1,526)
Income for the period	(5,957)	(354)
Ending Balance	$ 1,068	$ 1,068

Collaborative Arrangements an25

Collaborative Arrangements and Revenue Recognition - Additional Information (Detail) - Jun. 30, 2015 - USD ($)	Total
Chugai Collaboration [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Up-front cash payment received	$ 10,000,000
Deferred revenue withheld	2,000,000
Deferred revenue recorded as receivable	2,000,000
Potential near-term payment received	7,000,000
Deferred revenue outstanding payment	7,000,000
Revenue retained in up-front	10,000,000
Pfizer [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Up-front cash payment received	6,000,000
Deferred revenue recognized totaling	6,250,000
RTI Surgical Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Commercial milestone revenue	$ 0

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2015USD ($)shares	Jun. 30, 2014USD ($)	Jun. 30, 2015USD ($)Plansshares	Jun. 30, 2014USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of incentive plans | Plans			2
Common stock authorized for equity incentive plans	11,500,000		11,500,000
Common stock shares issued			2,143,332
Stock options granted	1,187,296
Shares available for issuance	61,037		61,037
Shares of common stock outstanding	9,295,631		9,295,631
Stock-based compensation expense | $	$ 705,000	$ 601,000	$ 1,456,000	$ 1,180,000
Total unrecognized estimated compensation cost | $	$ 5,800,000		$ 5,800,000
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units granted	455,776

Issuance of Common Stock and 27

Issuance of Common Stock and Warrants - Additional Information (Detail) $ / shares in Units, $ in Millions	1 Months Ended			3 Months Ended
	Jan. 31, 2015$ / sharesshares	Jan. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2013$ / sharesshares	Jun. 30, 2015USD ($)$ / sharesshares	Feb. 28, 2013$ / shares
Class of Warrant or Right [Line Items]
Proceeds from issuance of common stock, net | $		$ 18.8
Issuance of common stock, new issues | shares		5,000,000
Warrants issued to purchase common stock | shares	3,500,000	1,500,000	3,500,000
Warrant exercise price per share		$ 4.50			$ 1.01
Warrants exercise expiration date	May 31, 2015	Jul. 15, 2016	Mar. 31, 2015
Common stock per warrant conversion ratio		0.30
Common stock and warrant combined offering price		$ 4.10
Aspire [Member] | Common Stock [Member]
Class of Warrant or Right [Line Items]
Issuance of common stock, new issues | shares				974,959
Sale of shares at an average price				$ 2.84
Issuance of common stock, new issues | $				$ 2.8
Minimum [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price per share			$ 2.50
Maximum [Member]
Class of Warrant or Right [Line Items]
Warrant exercise price per share	$ 2.75

Issuance of Common Stock and 28

Issuance of Common Stock and Warrants - Outstanding Warrants to Purchase Shares of Common Stock (Detail) - $ / shares	6 Months Ended
	Jun. 30, 2015	Jan. 31, 2014	Feb. 28, 2013
Class of Warrant or Right [Line Items]
Number of Underlying Shares	4,864,893
Exercise Price		$ 4.50	$ 1.01
February 2, 2016 [Member]
Class of Warrant or Right [Line Items]
Number of Underlying Shares	1,310,000
Exercise Price	$ 3.55
Expiration	Feb. 2, 2016
July 15, 2016 [Member]
Class of Warrant or Right [Line Items]
Number of Underlying Shares	1,500,000
Exercise Price	$ 4.50
Expiration	Jul. 15, 2016
March 14, 2017 [Member]
Class of Warrant or Right [Line Items]
Number of Underlying Shares	2,054,893
Exercise Price	$ 1.01
Expiration	Mar. 14, 2017

Warrant Liabilities - Additiona

Warrant Liabilities - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2015	Jan. 31, 2014	Feb. 28, 2013
Equity [Abstract]
Terms of issuance of warrant demanding cash payments	The warrants we issued in the January 2014 registered direct offering contain a provision for a cash payment in the event that the shares are not delivered to the holder within two trading days. The cash payment equals $10 per day per $2,000 of warrant shares for each day late.
Number of trading days to deliver shares under warrants provision	2 days
Value of warrants considered for cash payment for late delivery of shares	$ 2,000
Cash payment per day for warrants shares not delivered as per provision	$ 10
Warrant exercise price per share		$ 4.50	$ 1.01