Document_and_Entity_Informatio
Document and Entity Information | 3 Months Ended | |
Mar. 31, 2014 | 5-May-14 | |
Document And Entity Information [Abstract] | ' | ' |
Document Type | '10-Q | ' |
Amendment Flag | 'false | ' |
Document Period End Date | 31-Mar-14 | ' |
Document Fiscal Year Focus | '2014 | ' |
Document Fiscal Period Focus | 'Q1 | ' |
Entity Registrant Name | 'ATHERSYS, INC / NEW | ' |
Entity Central Index Key | '0001368148 | ' |
Current Fiscal Year End Date | '--12-31 | ' |
Entity Filer Category | 'Accelerated Filer | ' |
Entity Common Stock, Shares Outstanding | ' | 77,046,136 |
Condensed_Consolidated_Balance
Condensed Consolidated Balance Sheets (Unaudited) (USD $) | Mar. 31, 2014 | Dec. 31, 2013 |
In Thousands, unless otherwise specified | ||
Current assets: | ' | ' |
Cash and cash equivalents | $44,981 | $31,948 |
Accounts receivable | 894 | 520 |
Prepaid expenses and other | 319 | 387 |
Total current assets | 46,194 | 32,855 |
Equipment, net | 1,394 | 1,333 |
Total assets | 47,588 | 34,188 |
Current liabilities: | ' | ' |
Accounts payable | 2,454 | 2,243 |
Accrued compensation and related benefits | 601 | 1,067 |
Accrued clinical trial costs | 96 | 88 |
Accrued expenses | 890 | 884 |
Deferred revenue | 46 | 86 |
Note payable | 178 | ' |
Total current liabilities | 4,265 | 4,368 |
Note payable | ' | 176 |
Warrant liabilities | 13,663 | 9,823 |
Stockholders' equity: | ' | ' |
Preferred stock, at stated value; 10,000,000 shares authorized, and no shares issued and outstanding at March 31, 2014 and December 31, 2013 | ' | ' |
Common stock, $0.001 par value; 150,000,000 shares authorized and 77,121,743 and 70,749,212 shares issued at March 31, 2014 and December 31, 2013, respectively, and 77,046,136 and 70,683,480 shares outstanding at March 31, 2014 and December 31, 2013, respectively | 77 | 71 |
Additional paid-in capital | 305,784 | 284,323 |
Treasury stock, at cost; 75,607 and 65,732 shares at March 31, 2014 and December 31, 2013, respectively | -279 | -135 |
Accumulated deficit | -275,922 | -264,438 |
Total stockholders' equity | 29,660 | 19,821 |
Total liabilities and stockholders' equity | $47,588 | $34,188 |
Condensed_Consolidated_Balance1
Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) | Mar. 31, 2014 | Dec. 31, 2013 |
Statement Of Financial Position [Abstract] | ' | ' |
Preferred stock, shares authorized | 10,000,000 | 10,000,000 |
Preferred stock, shares issued | ' | ' |
Preferred stock, shares outstanding | ' | ' |
Common stock, par value | $0.00 | $0.00 |
Common stock, shares authorized | 150,000,000 | 150,000,000 |
Common stock, shares issued | 77,121,743 | 70,749,212 |
Common stock, shares outstanding | 77,046,136 | 70,683,480 |
Treasury stock, shares outstanding | 75,607 | 65,732 |
Condensed_Consolidated_Stateme
Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) (USD $) | 3 Months Ended | |
In Thousands, except Share data, unless otherwise specified | Mar. 31, 2014 | Mar. 31, 2013 |
Revenues | ' | ' |
Contract revenue | $44 | $84 |
Grant revenue | 663 | 242 |
Total revenues | 707 | 326 |
Costs and expenses | ' | ' |
Research and development | 6,226 | 5,576 |
General and administrative | 1,781 | 1,507 |
Depreciation | 89 | 85 |
Total costs and expenses | 8,096 | 7,168 |
Loss from operations | -7,389 | -6,842 |
Other income, net | 29 | 17 |
Expense from change in fair value of warrants, net | -4,124 | -2,563 |
Net loss and comprehensive loss | ($11,484) | ($9,388) |
Basic and diluted net loss per common share | ($0.15) | ($0.18) |
Weighted average shares outstanding, basic and diluted | 75,852,753 | 53,455,779 |
Condensed_Consolidated_Stateme1
Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) | 3 Months Ended | |
In Thousands, unless otherwise specified | Mar. 31, 2014 | Mar. 31, 2013 |
Operating activities | ' | ' |
Net loss | ($11,484) | ($9,388) |
Adjustments to reconcile net loss to net cash used in operating activities: | ' | ' |
Depreciation | 89 | 85 |
Stock-based compensation | 579 | 116 |
Change in fair value of warrant liabilities | 4,124 | 2,563 |
Changes in operating assets and liabilities: | ' | ' |
Accounts receivable | -374 | 17 |
Prepaid expenses and other assets | 68 | -7 |
Accounts payable and accrued expenses | -239 | 501 |
Deferred revenue | -40 | ' |
Net cash used in operating activities | -7,277 | -6,113 |
Investing activities | ' | ' |
Purchases of equipment | -150 | -101 |
Net cash used in investing activities | -150 | -101 |
Financing activities | ' | ' |
Proceeds from issuance of common stock and warrants, net | 19,814 | 2,026 |
Purchase of treasury stock | -292 | ' |
Proceeds from exercise of warrants | 938 | ' |
Net cash provided by financing activities | 20,460 | 2,026 |
Increase (decrease) in cash and cash equivalents | 13,033 | -4,188 |
Cash and cash equivalents at beginning of the period | 31,948 | 25,533 |
Cash and cash equivalents at end of the period | $44,981 | $21,345 |
Background_and_Basis_of_Presen
Background and Basis of Presentation | 3 Months Ended |
Mar. 31, 2014 | |
Accounting Policies [Abstract] | ' |
Background and Basis of Presentation | ' |
1. Background and Basis of Presentation | |
We are an international biopharmaceutical company that is focused primarily on 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, 2013. 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. |
Net_Loss_per_Share
Net Loss per Share | 3 Months Ended | ||||||||
Mar. 31, 2014 | |||||||||
Earnings Per Share [Abstract] | ' | ||||||||
Net Loss per Share | ' | ||||||||
2. Net Loss per Share | |||||||||
Basic and diluted net loss per share has been computed using the weighted-average number of shares of common stock outstanding during the period. 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 | |||||||||
March 31, | |||||||||
2014 | 2013 | ||||||||
Outstanding options | 5,088,973 | 4,005,601 | |||||||
Restricted stock units | 2,224,096 | 70,814 | |||||||
Outstanding warrants | 9,480,103 | 5,806,853 | |||||||
Total | 16,793,172 | 9,883,268 | |||||||
Financial_Instruments
Financial Instruments | 3 Months Ended | ||||||||||||||||||||||||||
Mar. 31, 2014 | |||||||||||||||||||||||||||
Investments All Other Investments [Abstract] | ' | ||||||||||||||||||||||||||
Financial Instruments | ' | ||||||||||||||||||||||||||
3. 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 financial assets and liabilities measured at fair value on a recurring basis as of March 31, 2014 (in thousands): | |||||||||||||||||||||||||||
Fair Value Measurements at March 31, 2014 Using | |||||||||||||||||||||||||||
Description | Balance as of | Quoted Prices in Active | Significant Other | Significant Unobservable | |||||||||||||||||||||||
March 31, 2014 | Markets for | Observable Inputs | Inputs (Level 3) | ||||||||||||||||||||||||
Identical Assets | (Level 2) | ||||||||||||||||||||||||||
(Level 1) | |||||||||||||||||||||||||||
Warrant liabilities | $ | 13,663 | $ | — | $ | — | $ | 13,663 | |||||||||||||||||||
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 warrants issued in our December 2013 offering were issued in two series, since 1,401,218 of the total 3,500,000 warrants issued are not exercisable until June 3, 2014. The following inputs were used at March 31, 2014: | |||||||||||||||||||||||||||
Expected Volatility | Risk-Free Interest Rate | Expected Life | |||||||||||||||||||||||||
Warrants with one year or less remaining term | 58.28% - 58.71% | 0.13% | 0.82 – 1.00 year | ||||||||||||||||||||||||
Warrants with greater than one year remaining term | 55.35% - 72.00% | 0.44% - 0.90% | 1.84 – 2.96 years | ||||||||||||||||||||||||
A roll-forward of fair value measurements using significant unobservable inputs (Level 3) for the warrants is as follows (in thousands): | |||||||||||||||||||||||||||
Three months ended | |||||||||||||||||||||||||||
March 31, 2014 | |||||||||||||||||||||||||||
Balance January 1, 2014 | $ | 9,823 | |||||||||||||||||||||||||
Issuance of warrants January 2014 | 2,012 | ||||||||||||||||||||||||||
Settlements | (2,296 | ) | |||||||||||||||||||||||||
Loss included in expense from change in fair value of warrants | 4,124 | ||||||||||||||||||||||||||
Balance March 31, 2014 | $ | 13,663 | |||||||||||||||||||||||||
Collaborations_and_Revenue_Rec
Collaborations and Revenue Recognition | 3 Months Ended |
Mar. 31, 2014 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | ' |
Collaborations and Revenue Recognition | ' |
4. Collaborations and Revenue Recognition | |
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. We are eligible to receive milestone payments upon the successful achievement of certain development, regulatory and commercial milestones, for which we evaluated the nature of the events triggering these contingent payments and concluded that these events constituted substantive milestones that will be recognized as revenue in the period in which the underlying triggering event occurs. No significant milestone revenue has been recognized to date. | |
Pfizer pays us for manufacturing product for clinical development and commercialization purposes, which is recognized in the period that the manufacturing services are performed. Pfizer would have responsibility for development, regulatory and commercialization and would pay us tiered royalties on worldwide commercial sales of MultiStem IBD products. Alternatively, in lieu of royalties and certain commercialization milestones, we may elect to co-develop with Pfizer and the parties would share development and commercialization expenses and profits/losses on an agreed basis beginning at Phase 3 clinical development. | |
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. 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. In addition, we receive royalties on worldwide commercial sales of implants using our technologies. No milestone revenue has been recognized to date. |
Stockbased_Compensation
Stock-based Compensation | 3 Months Ended |
Mar. 31, 2014 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | ' |
Stock-based Compensation | ' |
5. 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 March 31, 2014, a total of 762,972 shares of common stock have been issued under our equity incentive plans. | |
As of March 31, 2014, a total of 3,423,959 shares were available for issuance under our equity compensation plans and stock-based awards to purchase 7,313,069 shares of common stock were outstanding. For the three-month periods ended March 31, 2014 and 2013, stock-based compensation expense was approximately $579,000 and $116,000, respectively. At March 31, 2014, total unrecognized estimated compensation cost related to unvested stock-based awards was approximately $5,124,000, which is expected to be recognized by the end of 2017 using the straight-line method. |
Issuance_of_Common_Stock_and_W
Issuance of Common Stock and Warrants | 3 Months Ended | ||||||||||
Mar. 31, 2014 | |||||||||||
Equity [Abstract] | ' | ||||||||||
Issuance of Common Stock and Warrants | ' | ||||||||||
6. 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 first quarter of 2014, we sold 250,000 shares to Aspire Capital Fund, LLC under our equity purchase agreement at an average price of $3.78 per share. | |||||||||||
As of March 31, 2014, we had the following outstanding warrants to purchase shares of common stock: | |||||||||||
Number of | Exercise Price | Expiration | |||||||||
Underlying Shares | |||||||||||
149,026 | $ | 5 | June 8, 2014 | ||||||||
1,310,000 | $ | 3.55 | February 2, 2016 | ||||||||
3,021,077 | $ | 1.01 | 14-Mar-17 | ||||||||
3,500,000 | $ | 2.5 | 31-Mar-15 | ||||||||
1,500,000 | $ | 4.5 | 15-Jul-16 | ||||||||
9,480,103 | |||||||||||
During the three months ended March 31, 2014, we received proceeds of approximately $938,000 from the exercise of warrants, resulting in the issuance of 928,924 shares of common stock in the aggregate. |
Warrant_Liabilities
Warrant Liabilities | 3 Months Ended |
Mar. 31, 2014 | |
Text Block [Abstract] | ' |
Warrant Liabilities | ' |
7. 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 and December 2013 registered direct offerings 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 | 3 Months Ended |
Mar. 31, 2014 | |
Income Tax Disclosure [Abstract] | ' |
Income Taxes | ' |
8. Income Taxes | |
We have net operating loss and research and development tax credit carryforwards that may be used to reduce future taxable income and tax liabilities. 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, our net operating loss carryforwards are significantly limited for use under Section 382 of the Internal Revenue Code. |
Net_Loss_per_Share_Tables
Net Loss per Share (Tables) | 3 Months Ended | ||||||||
Mar. 31, 2014 | |||||||||
Earnings Per Share [Abstract] | ' | ||||||||
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 | |||||||||
March 31, | |||||||||
2014 | 2013 | ||||||||
Outstanding options | 5,088,973 | 4,005,601 | |||||||
Restricted stock units | 2,224,096 | 70,814 | |||||||
Outstanding warrants | 9,480,103 | 5,806,853 | |||||||
Total | 16,793,172 | 9,883,268 | |||||||
Financial_Instruments_Tables
Financial Instruments (Tables) | 3 Months Ended | ||||||||||||||||||||||||||
Mar. 31, 2014 | |||||||||||||||||||||||||||
Investments All Other Investments [Abstract] | ' | ||||||||||||||||||||||||||
Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis | ' | ||||||||||||||||||||||||||
The following table provides a summary of the financial assets and liabilities measured at fair value on a recurring basis as of March 31, 2014 (in thousands): | |||||||||||||||||||||||||||
Fair Value Measurements at March 31, 2014 Using | |||||||||||||||||||||||||||
Description | Balance as of | Quoted Prices in Active | Significant Other | Significant Unobservable | |||||||||||||||||||||||
March 31, 2014 | Markets for | Observable Inputs | Inputs (Level 3) | ||||||||||||||||||||||||
Identical Assets | (Level 2) | ||||||||||||||||||||||||||
(Level 1) | |||||||||||||||||||||||||||
Warrant liabilities | $ | 13,663 | $ | — | $ | — | $ | 13,663 | |||||||||||||||||||
Fair Value of Warrants Based on Historical Volatilities | ' | ||||||||||||||||||||||||||
The following inputs were used at March 31, 2014: | |||||||||||||||||||||||||||
Expected Volatility | Risk-Free Interest Rate | Expected Life | |||||||||||||||||||||||||
Warrants with one year or less remaining term | 58.28% - 58.71% | 0.13% | 0.82 – 1.00 year | ||||||||||||||||||||||||
Warrants with greater than one year remaining term | 55.35% - 72.00% | 0.44% - 0.90% | 1.84 – 2.96 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 ended | |||||||||||||||||||||||||||
March 31, 2014 | |||||||||||||||||||||||||||
Balance January 1, 2014 | $ | 9,823 | |||||||||||||||||||||||||
Issuance of warrants January 2014 | 2,012 | ||||||||||||||||||||||||||
Settlements | (2,296 | ) | |||||||||||||||||||||||||
Loss included in expense from change in fair value of warrants | 4,124 | ||||||||||||||||||||||||||
Balance March 31, 2014 | $ | 13,663 | |||||||||||||||||||||||||
Issuance_of_Common_Stock_and_W1
Issuance of Common Stock and Warrants (Tables) | 3 Months Ended | ||||||||||
Mar. 31, 2014 | |||||||||||
Equity [Abstract] | ' | ||||||||||
Outstanding Warrants to Purchase Shares of Common Stock | ' | ||||||||||
As of March 31, 2014, we had the following outstanding warrants to purchase shares of common stock: | |||||||||||
Number of | Exercise Price | Expiration | |||||||||
Underlying Shares | |||||||||||
149,026 | $ | 5 | June 8, 2014 | ||||||||
1,310,000 | $ | 3.55 | February 2, 2016 | ||||||||
3,021,077 | $ | 1.01 | 14-Mar-17 | ||||||||
3,500,000 | $ | 2.5 | 31-Mar-15 | ||||||||
1,500,000 | $ | 4.5 | 15-Jul-16 | ||||||||
9,480,103 | |||||||||||
Background_and_Basis_of_Presen1
Background and Basis of Presentation - Additional Information (Detail) | 3 Months Ended |
Mar. 31, 2014 | |
Segment | |
Accounting Policies [Abstract] | ' |
Number of business segments | 1 |
Net_Loss_Per_Share_Instruments
Net Loss Per Share - Instruments Excluded from the Calculation of Diluted Net Loss Per Share (Detail) | 3 Months Ended | |
Mar. 31, 2014 | Mar. 31, 2013 | |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ' | ' |
Total | 16,793,172 | 9,883,268 |
Outstanding options [Member] | ' | ' |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ' | ' |
Total | 5,088,973 | 4,005,601 |
Restricted stock units [Member] | ' | ' |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ' | ' |
Total | 2,224,096 | 70,814 |
Outstanding Warrants [Member] | ' | ' |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ' | ' |
Total | 9,480,103 | 5,806,853 |
Financial_Instruments_Summary_
Financial Instruments - Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $) | Mar. 31, 2014 | Dec. 31, 2013 |
In Thousands, unless otherwise specified | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Warrant liabilities | $13,663 | $9,823 |
Fair Value Measurements, Recurring Basis [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Warrant liabilities | 13,663 | ' |
Fair Value Measurements, Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Warrant liabilities | ' | ' |
Fair Value Measurements, Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Warrant liabilities | ' | ' |
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 | $13,663 | ' |
Financial_Instruments_Addition
Financial Instruments - Additional Information (Detail) | 3 Months Ended | |
Mar. 31, 2014 | Jan. 31, 2014 | |
Fair Value Disclosures [Abstract] | ' | ' |
Number of warrants issued in two series to purchase common stock | 3,500,000 | 1,500,000 |
Number of warrants not exercisable | 1,401,218 | ' |
Financial_Instruments_Fair_Val
Financial Instruments - Fair Value of Warrants Based on Historical Volatilities (Detail) | 3 Months Ended |
Mar. 31, 2014 | |
Warrants With One Year or Less Remaining Term [Member] | ' |
Class of Warrant or Right [Line Items] | ' |
Risk-free interest rate | 0.13% |
Minimum [Member] | Warrants With One Year or Less Remaining Term [Member] | ' |
Class of Warrant or Right [Line Items] | ' |
Expected volatility | 58.28% |
Expected life | '9 months 26 days |
Minimum [Member] | Warrants With Greater Than One Year Remaining Term [Member] | ' |
Class of Warrant or Right [Line Items] | ' |
Expected volatility | 55.35% |
Risk-free interest rate | 0.44% |
Expected life | '1 year 10 months 2 days |
Maximum [Member] | Warrants With One Year or Less Remaining Term [Member] | ' |
Class of Warrant or Right [Line Items] | ' |
Expected volatility | 58.71% |
Expected life | '1 year |
Maximum [Member] | Warrants With Greater Than One Year Remaining Term [Member] | ' |
Class of Warrant or Right [Line Items] | ' |
Expected volatility | 72.00% |
Risk-free interest rate | 0.90% |
Expected life | '2 years 11 months 16 days |
Financial_Instruments_RollForw
Financial Instruments - Roll-Forward of Fair Value Measurements Using Significant Unobservable Inputs (Level 3) for Warrants (Detail) (Outstanding Warrants [Member], USD $) | 3 Months Ended |
In Thousands, unless otherwise specified | Mar. 31, 2014 |
Outstanding Warrants [Member] | ' |
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] | ' |
Beginning Balance | $9,823 |
Issuance of warrants | 2,012 |
Settlements | -2,296 |
Loss included in expense from change in fair value of warrants | 4,124 |
Ending Balance | $13,663 |
Collaborations_and_Revenue_Rec1
Collaborations and Revenue Recognition - Additional Information (Detail) (USD $) | 3 Months Ended |
Mar. 31, 2014 | |
Pfizer [Member] | ' |
Collaborative Arrangements And Revenue Recognition [Line Items] | ' |
Commercial milestone revenue | $0 |
RTI Surgical Inc [Member] | ' |
Collaborative Arrangements And Revenue Recognition [Line Items] | ' |
Commercial milestone revenue | $0 |
Stockbased_Compensation_Additi
Stock-based Compensation - Additional Information (Detail) (USD $) | 3 Months Ended | |
Mar. 31, 2014 | Mar. 31, 2013 | |
Plans | ||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' | ' |
Number of incentive plans | 2 | ' |
Common stock authorized for equity incentive plans | 11,500,000 | ' |
Number of shares issued under equity incentive plan | 762,972 | ' |
Shares of common stock outstanding | 7,313,069 | ' |
Stock-based compensation expense | $579,000 | $116,000 |
Total unrecognized estimated compensation cost | $5,124,000 | ' |
Compensation cost related to unvested stock-based awards not yet recognized, expected year for recognition | '2017 | ' |
Equity compensation plans & stock-based awards [Member] | ' | ' |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' | ' |
Shares available for issuance | 3,423,959 | ' |
Issuance_of_Common_Stock_and_W2
Issuance of Common Stock and Warrants - Additional Information (Detail) (USD $) | 1 Months Ended | 3 Months Ended | ||
In Thousands, except Share data, unless otherwise specified | Jan. 31, 2014 | Mar. 31, 2014 | Mar. 31, 2013 | Feb. 28, 2013 |
Class of Warrant or Right [Line Items] | ' | ' | ' | ' |
Proceeds from issuance of common stock, net | $18,800 | $19,814 | $2,026 | ' |
Issuance of common stock, new issues | 5,000,000 | ' | ' | ' |
Warrants issued to purchase common stock | 1,500,000 | 3,500,000 | ' | ' |
Warrant exercise price per share | 4.5 | ' | ' | 1.01 |
Warrants exercise expiration date | 15-Jul-16 | ' | ' | ' |
Common stock per warrant conversion ratio | 0.3 | ' | ' | ' |
Common stock and warrant combined offering price | $4.10 | ' | ' | ' |
Proceeds from warrants exercise | ' | $938 | ' | ' |
Issuance of common stock from warrant exercises | ' | 928,924 | ' | ' |
Aspire [Member] | ' | ' | ' | ' |
Class of Warrant or Right [Line Items] | ' | ' | ' | ' |
Issuance of common stock, new issues | ' | 250,000 | ' | ' |
Sale of shares at an average price | ' | $3.78 | ' | ' |
Issuance_of_Common_Stock_and_W3
Issuance of Common Stock and Warrants - Outstanding Warrants to Purchase Shares of Common Stock (Detail) | Mar. 31, 2014 | Jan. 31, 2014 | Feb. 28, 2013 |
Class of Warrant or Right [Line Items] | ' | ' | ' |
Number of Underlying Shares | 9,480,103 | ' | ' |
Exercise Price | ' | 4.5 | 1.01 |
June 8, 2014 [Member] | ' | ' | ' |
Class of Warrant or Right [Line Items] | ' | ' | ' |
Number of Underlying Shares | 149,026 | ' | ' |
Exercise Price | 5 | ' | ' |
Expiration | 8-Jun-14 | ' | ' |
February 2, 2016 [Member] | ' | ' | ' |
Class of Warrant or Right [Line Items] | ' | ' | ' |
Number of Underlying Shares | 1,310,000 | ' | ' |
Exercise Price | 3.55 | ' | ' |
Expiration | 2-Feb-16 | ' | ' |
March 14, 2017 [Member] | ' | ' | ' |
Class of Warrant or Right [Line Items] | ' | ' | ' |
Number of Underlying Shares | 3,021,077 | ' | ' |
Exercise Price | 1.01 | ' | ' |
Expiration | 14-Mar-17 | ' | ' |
March 31, 2015 [Member] | ' | ' | ' |
Class of Warrant or Right [Line Items] | ' | ' | ' |
Number of Underlying Shares | 3,500,000 | ' | ' |
Exercise Price | 2.5 | ' | ' |
Expiration | 31-Mar-15 | ' | ' |
July 15, 2016 [Member] | ' | ' | ' |
Class of Warrant or Right [Line Items] | ' | ' | ' |
Number of Underlying Shares | 1,500,000 | ' | ' |
Exercise Price | 4.5 | ' | ' |
Expiration | 15-Jul-16 | ' | ' |
Warrant_Liability_Additional_I
Warrant Liability - Additional Information (Detail) (USD $) | 3 Months Ended | ||
Mar. 31, 2014 | Jan. 31, 2014 | Feb. 28, 2013 | |
Equity [Abstract] | ' | ' | ' |
Terms of issuance of warrant demanding cash payments | 'The warrants we issued in the January 2014 and December 2013 registered direct offerings 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 | ' | ' |
Exercise Price | ' | 4.5 | 1.01 |