Document and Entity Information
Document and Entity Information - USD ($) | 12 Months Ended | ||
Dec. 31, 2015 | Feb. 15, 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 | ATRA | ||
Entity Registrant Name | Atara Biotherapeutics, Inc. | ||
Entity Central Index Key | 1,604,464 | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Current Reporting Status | Yes | ||
Entity Voluntary Filers | No | ||
Entity Filer Category | Accelerated Filer | ||
Entity Common Stock, Shares Outstanding | 28,692,220 | ||
Entity Public Float | $ 698,303,925 |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) $ in Thousands | Dec. 31, 2015 | Dec. 31, 2014 |
Current assets: | ||
Cash and cash equivalents | $ 23,746 | $ 21,897 |
Short-term investments | 296,736 | 82,219 |
Restricted cash | 194 | |
Prepaid expenses and other current assets | 3,921 | 1,910 |
Total current assets | 324,597 | 106,026 |
Property and equipment, net | 270 | 48 |
Other assets | 108 | 48 |
Total assets | 324,975 | 106,122 |
Current liabilities: | ||
Accounts payable | 1,445 | 440 |
Accrued compensation | 2,624 | 1,225 |
Accrued research and development expenses | 5,112 | 824 |
Other accrued liabilities | 528 | 235 |
Total current liabilities | 9,709 | 2,724 |
Long-term liabilities | 166 | 216 |
Total liabilities | $ 9,875 | $ 2,940 |
Commitments and contingencies (Note 7) | ||
Stockholders’ equity: | ||
Common stock—$0.0001 par value, 500,000,000 shares authorized as of December 31, 2015 and 2014; 28,458,807 and 19,692,937 shares issued and outstanding as of December 31, 2015 and 2014, respectively | $ 3 | $ 2 |
Additional paid-in capital | 413,725 | 144,169 |
Accumulated other comprehensive loss | (518) | (100) |
Accumulated deficit | (98,110) | (40,889) |
Total stockholders’ equity | 315,100 | 103,182 |
Total liabilities and stockholders’ equity | $ 324,975 | $ 106,122 |
Consolidated Balance Sheets (Pa
Consolidated Balance Sheets (Parenthetical) - $ / shares | Dec. 31, 2015 | Dec. 31, 2014 |
Statement Of Financial Position [Abstract] | ||
Common stock, par value | $ 0.0001 | $ 0.0001 |
Common stock, shares authorized | 500,000,000 | 500,000,000 |
Common stock, shares issued | 28,458,807 | 19,692,937 |
Common stock, shares outstanding | 28,458,807 | 19,692,937 |
Consolidated and Combined State
Consolidated and Combined Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Operating expenses: | |||
Research and development | $ 41,618 | $ 14,380 | $ 4,306 |
Research and development costs paid to Amgen | 1,066 | 553 | |
General and administrative | 16,830 | 12,710 | 3,756 |
Total operating expenses | 58,448 | 28,156 | 8,615 |
Loss from operations | (58,448) | (28,156) | (8,615) |
Interest and other income, net | 1,218 | 125 | 12 |
Loss before provision for income taxes | (57,230) | (28,031) | (8,603) |
Provision (benefit) for income taxes | (9) | (25) | 170 |
Net loss | (57,221) | (28,006) | (8,773) |
Other comprehensive loss: | |||
Unrealized loss on available-for-sale securities | (418) | (100) | |
Comprehensive loss | $ (57,639) | $ (28,106) | $ (8,773) |
Net loss per common share: | |||
Basic and diluted net loss per common share | $ (2.24) | $ (5.62) | $ (9.08) |
Weighted-average common shares outstanding used to calculate basic and diluted net loss per common share | 25,583,334 | 4,985,540 | 965,825 |
Consolidated and Combined Stat5
Consolidated and Combined Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands | Total | February 2,015 | July 2,015 | Preferred StockSeries A Convertible Preferred Stock | Preferred StockSeries A 1 Convertible Preferred Stock | Preferred StockSeries B Convertible Preferred Stock | Common Stock | Common StockFebruary 2015 | Common StockJuly 2015 | Additional Paid-in Capital [Member] | Additional Paid-in Capital [Member]February 2015 | Additional Paid-in Capital [Member]July 2015 | Receivables from Stockholder [Member] | Accumulated Other Comprehensive Income (Loss) [Member] | Accumulated Deficit [Member] |
Beginning balance, temporary equity at Dec. 31, 2012 | $ 4,946 | $ 1,765 | |||||||||||||
Beginning balance at Dec. 31, 2012 | $ (3,727) | $ 1 | $ 382 | $ (4,110) | |||||||||||
Beginning balance, temporary equity (in shares) at Dec. 31, 2012 | 11,538,000 | 3,532,000 | |||||||||||||
Beginning balance (in shares) at Dec. 31, 2012 | 7,462,000 | ||||||||||||||
Issuance of common stock, net of discounts and offering costs, shares | 615,000 | ||||||||||||||
Issuance of preferred stock | $ 14,963 | ||||||||||||||
Issuance of preferred stock, shares | 34,818,000 | ||||||||||||||
Issuance of preferred stock for license fee to Amgen, Value | $ 1,003 | $ 38,414 | |||||||||||||
Issuance of preferred stock for license fee to Amgen, shares | 2,006,000 | 43,529,000 | |||||||||||||
Notes receivable from stockholder | (331) | $ (331) | |||||||||||||
Interest income accrued on notes receivable from stockholder | (4) | (4) | |||||||||||||
Issuance of common stock upon vesting of restricted stock awards | $ 105 | 105 | |||||||||||||
Issuance of common stock upon vesting of restricted stock awards, shares | 3,927,000 | ||||||||||||||
Issuance of common stock pursuant to stock option exercises, shares | 0 | ||||||||||||||
Stock-based compensation expense | $ 1,713 | 1,713 | |||||||||||||
Net loss | (8,773) | (8,773) | |||||||||||||
Ending balance, temporary equity at Dec. 31, 2013 | $ 19,909 | $ 2,768 | $ 38,414 | ||||||||||||
Ending balance at Dec. 31, 2013 | (11,017) | $ 1 | 2,200 | (335) | (12,883) | ||||||||||
Ending balance, temporary equity (in shares) at Dec. 31, 2013 | 46,356,000 | 5,538,000 | 43,529,000 | ||||||||||||
Ending balance (in shares) at Dec. 31, 2013 | 12,004,000 | ||||||||||||||
Issuance of common stock, net of discounts and offering costs, Value | 56,456 | $ 1 | 56,455 | ||||||||||||
Issuance of common stock, net of discounts and offering costs, shares | 5,750,000 | ||||||||||||||
Issuance of preferred stock | $ 13,481 | ||||||||||||||
Issuance of preferred stock, shares | 15,263,000 | ||||||||||||||
Interest income accrued on notes receivable from stockholder | (2) | (2) | |||||||||||||
Repayment of notes receivable from stockholder | 337 | $ 337 | |||||||||||||
Issuance of common stock upon vesting of restricted stock awards | 20 | 20 | |||||||||||||
Issuance of common stock upon vesting of restricted stock awards, shares | 645,000 | ||||||||||||||
Recapitalization (Note 2) | $ (1) | 1 | |||||||||||||
Recapitalization, shares (Note 2) | (41,205,000) | (4,923,000) | (52,260,000) | (11,346,000) | |||||||||||
Issuance of common stock upon vesting of stock awards—post Recapitalization | 70 | 70 | |||||||||||||
Issuance of common stock upon vesting of stock awards—post Recapitalization, shares | 282,000 | ||||||||||||||
Issuance of common stock for research and development expenses related to technology licensing option | 750 | 750 | |||||||||||||
Issuance of common stock for research and development expenses related to technology licensing option, shares | 60,000 | ||||||||||||||
Conversion of preferred stock | $ 74,573 | $ (19,909) | $ (2,768) | $ (51,895) | $ 1 | 74,572 | |||||||||
Conversion of preferred stock, shares | (5,151,000) | (615,000) | (6,532,000) | 12,298,000 | |||||||||||
Issuance of common stock pursuant to stock option exercises, shares | 0 | ||||||||||||||
Stock-based compensation expense | $ 10,101 | 10,101 | |||||||||||||
Net loss | (28,006) | (28,006) | |||||||||||||
Ending balance at Dec. 31, 2014 | 103,182 | $ 2 | 144,169 | $ (100) | (40,889) | ||||||||||
Ending balance (in shares) at Dec. 31, 2014 | 19,693,000 | ||||||||||||||
Unrealized loss on available-for-sale securities | $ (100) | (100) | |||||||||||||
Issuance of common stock, net of discounts and offering costs, Value | $ 69,487 | $ 193,947 | $ 1 | $ 69,486 | $ 193,947 | ||||||||||
Issuance of common stock, net of discounts and offering costs, shares | 4,147,000 | 3,981,000 | |||||||||||||
Issuance of preferred stock for license fee to Amgen, shares | 59,761 | ||||||||||||||
Issuance of common stock upon vesting of restricted stock awards | $ 80 | 80 | |||||||||||||
Issuance of common stock upon vesting of restricted stock awards, shares | 287,000 | ||||||||||||||
RSU settlements, net of shares withheld | (4,647) | (4,647) | |||||||||||||
RSU settlements, net of shares withheld, shares | 327,000 | ||||||||||||||
Issuance of common stock pursuant to stock option exercises | $ 439 | 439 | |||||||||||||
Issuance of common stock pursuant to stock option exercises, shares | 23,822 | 24,000 | |||||||||||||
Stock-based compensation expense | $ 10,251 | 10,251 | |||||||||||||
Net loss | (57,221) | (57,221) | |||||||||||||
Ending balance at Dec. 31, 2015 | 315,100 | $ 3 | $ 413,725 | (518) | $ (98,110) | ||||||||||
Ending balance (in shares) at Dec. 31, 2015 | 28,459,000 | ||||||||||||||
Unrealized loss on available-for-sale securities | $ (418) | $ (418) |
Consolidated and Combined Stat6
Consolidated and Combined Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Common Stock | |||
Stock issuance, discounts and costs | $ 6,794 | $ 1 | |
February 2015 | Common Stock | |||
Stock issuance, discounts and costs | $ 5,166 | ||
July 2015 | Common Stock | |||
Stock issuance, discounts and costs | $ 13,053 | ||
Series A Convertible Preferred Stock | Preferred Stock | |||
Stock issuance, discounts and costs | 124 | ||
Series B Convertible Preferred Stock | Preferred Stock | |||
Stock issuance, discounts and costs | $ 19 | $ 86 |
Consolidated and Combined Stat7
Consolidated and Combined Statements of Cash Flows - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Operating activities | |||
Net loss | $ (57,221) | $ (28,006) | $ (8,773) |
Adjustments to reconcile net loss to net cash used in operating activities: | |||
Stock-based compensation expense | 10,251 | 10,101 | 1,713 |
Amortization of investment premiums and discounts | 3,465 | 526 | |
Non-cash research and development expenses | 750 | ||
Depreciation expense | 48 | 6 | 4 |
Write off of property and equipment | 21 | ||
Loss on foreign exchange | 94 | ||
Interest accrued on notes receivable from stockholder | (2) | (4) | |
Changes in operating assets and liabilities: | |||
Prepaid expenses and other current assets | (767) | (1,246) | (158) |
Other assets | (61) | (37) | 27 |
Accounts payable | 1,005 | (164) | 485 |
Accrued compensation | 1,399 | 894 | 280 |
Accrued research and development expenses | 4,288 | 468 | 356 |
Other accrued liabilities | 293 | 4 | 104 |
Long-term liabilities | 29 | 78 | |
Net cash used in operating activities | (37,156) | (16,628) | (5,966) |
Investing activities | |||
Purchase of short-term investments | (379,776) | (95,525) | |
Sales and maturities of short-term investments | 160,133 | 12,208 | |
Transfer to restricted cash | (194) | ||
Purchase of property and equipment | (290) | (46) | (3) |
Net cash used in investing activities | (220,127) | (83,363) | (3) |
Financing activities | |||
Proceeds from sale of common stock, net of offering costs | 263,434 | 56,455 | |
Taxes paid related to net share settlement of restricted stock units | (4,647) | ||
Proceeds from exercise of stock options | 439 | ||
Proceeds from sale of convertible preferred stock, net of offering costs | 13,481 | 53,377 | |
Repayment of notes receivable from stockholder | 337 | ||
Net cash provided by financing activities | 259,226 | 70,273 | 53,377 |
Effect of exchange rates on cash | (94) | ||
Increase (decrease) in cash and cash equivalents | 1,849 | (29,718) | 47,408 |
Cash and cash equivalents-beginning of period | 21,897 | 51,615 | 4,207 |
Cash and cash equivalents-end of period | 23,746 | 21,897 | 51,615 |
Non-cash financing activities | |||
Issuance of common stock related to technology licensing option | 750 | 750 | |
Issuance of Series A-1 convertible preferred stock to Amgen in exchange for license | 1,003 | ||
Change in obligation to issue Series A-1 convertible preferred stock to Amgen | (1,003) | ||
Issuance of common stock upon vesting of stock awards | 80 | 90 | 105 |
Change in other long-term liabilities related to non-vested stock awards | (80) | (90) | 226 |
Restricted stock issued to related party in exchange for notes receivable | 331 | ||
Supplemental cash flow disclosure | |||
Cash paid for taxes | $ 3 | $ 70 | $ 22 |
Description of Business
Description of Business | 12 Months Ended |
Dec. 31, 2015 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Description of Business | 1. Description of Business Atara Biotherapeutics, Inc. (“Atara”, “we”, “our” or “the Company”) was incorporated in August 2012 in Delaware. Atara is a clinical-stage biopharmaceutical company focused on developing meaningful therapies for patients with . Our T-cell programs were acquired through licensing arrangements with Memorial Sloan Kettering Cancer Center (“MSK”). Our molecularly targeted biologics programs were acquired through licensing arrangements with Amgen Inc. (“Amgen”). In December 2015, we announced that we were suspending our PINTA 745 program, which was originally licensed from Amgen. See Note 6 for further information. In October 2014, we completed our initial public offering (“IPO”) of 5,750,000 shares of common stock at an offering price to the public of $11.00 per share. We received net proceeds of $56.5 million, after deducting underwriting discounts and commissions and offering expenses. In connection with the IPO, our outstanding shares of convertible preferred stock were automatically converted into 12,298,515 shares of common stock, resulting in the reclassification of $74.6 million from mezzanine equity to additional paid-in capital. In February 2015, we completed a follow-on offering of 4,147,358 shares of common stock at an offering price to the public of $18.00 per share. We received net proceeds of $69.5 million, after deducting underwriting discounts and commissions and offering expenses. In July 2015, we completed a follow-on offering of 3,980,768 shares of common stock at an offering price to the public of $52.00 per share. We received net proceeds of $193.9 million, after deducting underwriting discounts and commissions and offering expenses. |
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 Basis of Presentation and Recapitalization The accompanying consolidated and combined financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and the rules and regulations of the US Securities and Exchange Commission (the “SEC”). All share and per-share amounts presented in the consolidated and combined financial statements for the years ended December 31, 2015, 2014 and 2013 and in the notes hereto have been revised to reflect a 1.3-to-1 reverse stock split which became effective July 9, 2014. Certain items in the balance sheets and statements of cash flows have been reclassified from their presentation in prior years. Atara was originally formed as a management company with the sole purpose of providing management, financial and administrative services for Nina Biotherapeutics, Inc. (“Nina”), Santa Maria Biotherapeutics, Inc. (“Santa Maria”) and Pinta Biotherapeutics, Inc. (“Pinta”). Prior to March 31, 2014, the accompanying financial statements include the operations of Atara, Nina, Pinta and Santa Maria on a combined basis as the four individual companies were under common ownership and common management. All intercompany transactions have been eliminated. On March 31, 2014, we implemented a recapitalization (the “Recapitalization”) in which (a) all the outstanding shares of common stock of Atara were cancelled and forfeited by existing stockholders and (b) the stockholders of Nina, Pinta and Santa Maria exchanged their existing common and convertible preferred stock for newly-issued shares of Atara, with the same rights and privileges as the outstanding capital stock of Nina, Pinta and Santa Maria. The shares were exchanged on a collective nine-for-one basis. The Recapitalization lacked economic substance as the newly-issued shares have the same rights and privileges as the previously outstanding capital stock of Nina, Pinta and Santa Maria and there was no change in ownership percentages of the individual stockholders. As a result of the Recapitalization, Nina, Pinta and Santa Maria became wholly owned subsidiaries of Atara effective March 31, 2014. The Recapitalization is considered a tax-free exchange for US federal income tax purposes. Because the four individual companies were under common ownership and the Recapitalization lacked economic substance, we accounted for the Recapitalization as a combination of businesses under common control. The assets and liabilities of Nina, Pinta and Santa Maria were recorded by Atara at their historical carrying amounts on March 31, 2014 and beginning March 31, 2014, the financial statements of Atara are presented on a consolidated basis. Principles of Consolidation The consolidated and combined financial statements include the accounts of Atara and its wholly owned subsidiaries, Nina, Pinta, Santa Maria Islands Segment and Geographic Information We operate and manage our business as one reporting and one operating segment, which is the business of developing and commercializing therapeutics. Our Chief Executive Officer, who is our chief operating decision maker, reviews financial information on an aggregate basis for purposes of allocating resources and evaluating financial performance. All of our assets are located in the United States. Significant Risks and Uncertainties We have incurred significant operating losses since inception and have relied on public and private equity financings to fund our operations. As of December 31, 2015, we had an accumulated deficit of $98.1 million. As we continue to incur losses, our transition to profitability will depend on the successful development, approval and commercialization of product candidates and on the achievement of sufficient revenues to support our cost structure. We may never achieve profitability, and unless and until we do, we will need to continue to raise additional capital. Management expects that our cash, cash equivalents and short-term investments as of December 31, 2015 will be sufficient to fund our planned operations through 2018. Concentration of Credit Risk and Other Uncertainties We place cash and cash equivalents in the custody of financial institutions that management believes are of high credit quality, which at times, may be in excess of the amount insured by the Federal Deposit Insurance Corporation. We also have short-term investments in money market funds, U.S. Treasury, government agency and corporate debt obligations, commercial paper and asset-backed securities, which can be subject to certain credit risk. However, we mitigate the risks by investing in high-grade instruments, limiting our exposure to any one issuer, and monitoring the ongoing creditworthiness of the financial institutions and issuers. We are subject to certain risks and uncertainties and believe that changes in any of the following areas could have a material adverse effect on future financial position or results of operations: ability to obtain future financing; regulatory approval and market acceptance of, and reimbursement for, our product candidates; performance of third-party clinical research organizations and manufacturers upon which we rely; development of sales channels; protection of our intellectual property; litigation or claims against us based on intellectual property, patent, product, regulatory or other factors; and our ability to attract and retain employees necessary to support our growth. Use of Estimates 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. Significant estimates relied upon in preparing these financial statements include the fair value of common stock and the fair value of preferred stock prior to our IPO and estimates related to clinical trial accruals and stock-based compensation expense. Actual results could differ materially from those estimates. Foreign Currency Transactions and foreign currency-denominated monetary assets and liabilities that are denominated in a foreign currency are translated into U.S. dollars at the current exchange rate on the transaction date and as of each balance sheet date, respectively, with gains or losses on foreign exchange changes recognized in interest and other income (expense), net in the statements of operations and comprehensive loss. As of December 31, 2015, we held British pounds valued at $1.5 million. There were no foreign currency transactions in prior periods. Cash Equivalents and Short-Term Investments Cash equivalents are defined as short-term, highly liquid investments with original maturities of 90 days or less at the date of purchase, and generally consist of money market funds, U.S. Treasury, government agency and corporate debt obligations, and commercial paper. Investments with original maturities of greater than 90 days are classified as short-term investments on the balance sheet, and consist primarily of U.S. Treasury, government agency and corporate debt obligations, commercial paper and asset-backed securities. As our entire investment portfolio is considered available for use in current operations, we classify all investments as available-for-sale and as current assets, even though the stated maturity may be more than one year from the current balance sheet date. Available-for-sale securities are carried at fair value, with unrealized gains and losses reported in accumulated other comprehensive loss, which is a separate component of stockholders’ equity in the balance sheet. The amortized cost of securities is adjusted for amortization of premiums and accretion of discounts to maturity, which are both recorded to interest and other income (expense), net in the statements of operations and comprehensive loss. Changes in the fair value of available-for-sale securities impact the statements of operations only when such securities are sold or if an other-than-temporary impairment is recognized. Realized gains and losses on the sale of securities are determined by specific identification of each security’s cost basis. We regularly review our investment portfolio to determine if any security is other-than-temporarily impaired, which would require us to record an impairment charge in the period any such determination is made. In making this judgment, we evaluate, among other things, the duration and extent to which the fair value of a security is less than its cost, the financial condition of the issuer and any changes thereto, our intent to sell, or whether it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis. Our assessment on whether a security is other-than-temporarily impaired could change in the future due to new developments or changes in assumptions related to any particular security. Realized gains and losses and declines in value judged to be other-than-temporary on available-for-sale securities, if any, are recorded to interest and other income (expense), net in the statements of operations and comprehensive loss. Fair Value Measurement The carrying amounts of certain of our financial instruments including cash equivalents, prepaid expenses, accounts payable and accrued liabilities approximate fair value due to their short maturities. Short-term investments are comprised of available-for-sale securities, which are carried at fair value. Fair Value of Financial Instruments Our financial assets and liabilities are measured at fair value on a recurring basis using the following hierarchy to prioritize valuation inputs, Level 1: Quoted prices in active markets for identical assets or liabilities that we have the ability to access Level 2: Observable market based inputs or unobservable inputs that are corroborated by market data such as quoted prices, interest rates and yield curves Level 3: Inputs that are unobservable data points that are not corroborated by market data We review the fair value hierarchy classification on a quarterly basis. Changes in the ability to observe valuation inputs may result in a reclassification of levels of certain securities within the fair value hierarchy. We recognize transfers into and out of levels within the fair value hierarchy in the period in which the actual event or change in circumstances that caused the transfer occurs. There have been no transfers between Level 1, Level 2, and Level 3 in any periods presented. Financial assets and liabilities are considered Level 2 when their fair values are determined using inputs that are observable in the market or can be derived principally from or corroborated by observable market data such as pricing for similar securities, recently executed transactions, cash flow models with yield curves, and benchmark securities. In addition, Level 2 financial instruments are valued using comparisons to like-kind financial instruments and models that use readily observable market data as their basis. U.S. Treasury, government agency and corporate debt obligations, and commercial paper and asset-backed securities are valued primarily using market prices of comparable securities, bid/ask quotes, interest rate yields and prepayment spreads and are included in Level 2. Financial assets and liabilities are considered Level 3 when their fair values are determined using pricing models, discounted cash flow methodologies, or similar techniques, and at least one significant model assumption or input is unobservable. We have no Level 3 financial assets or liabilities. Property and Equipment, net Property and equipment are stated at cost and depreciated using the straight-line method over the estimated useful lives of the assets, ranging from three to five years. Maintenance and repairs are charged to operations as incurred. Long-lived Assets We evaluate the carrying amount of our long-lived assets whenever events or changes in circumstances indicate that the assets may not be recoverable. An impairment loss would be recognized when estimated future cash flows expected to result from the use of the asset and its eventual disposition are less than the carrying amount of the asset. To date, there have been no such impairment losses. Stock-Based Compensation Expense We account for stock-based compensation expense, including the expense of restricted common stock awards (“RSAs”) and grants of restricted stock units (“RSUs”) and stock options that may be settled in shares of our common stock, based on the fair values of the equity instruments issued. The fair value is determined on the measurement date, which is generally the date of grant for employee awards and the date when the service performance is completed for non-employees. The fair value for our RSAs is their intrinsic value, which is the difference between the fair value of the underlying stock at the measurement date and the purchase price. The fair value of our RSUs is the fair value of the underlying stock at the measurement date. The fair value for our stock option awards is determined at the grant date using the Black-Scholes valuation model. For employees’ awards with performance-based vesting criteria, we assess the probability of the achievement of the performance conditions at the end of each reporting period and recognize the share-based compensation costs when it becomes probable that the performance conditions will be met. For non-employees’ awards with performance-based vesting criteria, we assess all possible outcomes at the end of each reporting period and recognize the lowest aggregate fair value in the range of possible outcomes. The lowest value in the range of possible outcomes may be zero. For awards that are subject to both service and performance conditions, no expense is recognized until it is probable that performance conditions will be met. Stock-based compensation expense for awards with time-based vesting criteria is recognized as expense on a straight-line basis over the requisite service period. Stock-based compensation expense for awards with performance and other vesting criteria is recognized as expense under an accelerated graded vesting model. Key assumptions used in the Black-Scholes valuation model used for employee stock awards include: Expected term – The expected term assumption represents the period that our stock-based awards are expected to be outstanding and is determined using the simplified method. Expected volatility – Expected volatility is estimated using comparable public companies’ volatility for similar terms. Expected dividend – We have not historically declared or paid dividends to our stockholders and have no plans to pay dividends; therefore we assumed an expected dividend yield of 0%. Risk-free interest rate – The risk-free interest rate is based on the yield on U.S. Treasury securities with the expected term of the associated award. The fair value of non-employee stock options is estimated using the Black-Scholes valuation model with assumptions generally consistent with those used for employee stock options, with the exception of the expected term, which is the remaining contractual life at each measurement date. Prior to our IPO in October 2014, due to the absence of an active market for our common stock, we estimated the fair value of our common stock in accordance with the framework of the American Institute of Certified Public Accountants Technical Practice Aid, Valuation of Privately-Held Company Equity Securities Issued as Compensation. Each valuation included estimates and assumptions that required management’s judgment, including assumptions regarding the probability and estimated time to completion of our IPO. Subsequent to the completion of our IPO, the fair value of our common stock is based on observable market prices. Research and Development Expense Research and development expense consists of costs incurred in performing research and development activities, including compensation and benefits for research and development employees, expenses incurred under agreements with contract research organizations and investigative sites that conduct clinical trials and preclinical studies, the costs of acquiring and manufacturing clinical trial materials, other supplies and costs associated with product development efforts, preclinical activities and regulatory operations, and an allocation of facility and overhead expenses. Research and development costs are expensed as incurred. Clinical Trial Accruals Costs for preclinical study and clinical trial activities are recognized based on an evaluation of our vendors’ progress towards completion of specific tasks, using data such as patient enrollment, clinical site activations or information provided to us by our vendors regarding their actual costs incurred. Payments for these activities are based on the terms of individual contracts and payment timing may differ significantly from the period in which the services are performed. We determine accrual estimates through reports from and discussions with applicable personnel and outside service providers as to the progress or state of completion of trials, or the services completed. Our estimates of accrued expenses as of each balance sheet date are based on the facts and circumstances known at the time. Costs that are paid in advance of performance are deferred as a prepaid expense and amortized over the service period as the services are provided. Income Taxes We use the assets and liabilities method to account for income taxes. We record deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statement carrying amounts and the tax basis of assets and liabilities using enacted tax rates expected to be in effect when the differences are expected to reverse. Valuation allowances are provided when necessary to reduce net deferred tax assets to the amount that is more likely than not to be realized. Based on the available evidence, we are unable, at this time, to support the determination that it is more likely than not that our deferred tax assets will be utilized in the future. Accordingly, we recorded a full valuation allowance as of December 31, 2015 and 2014. We intend to maintain valuation allowances until sufficient evidence exists to support their reversal. Tax benefits related to uncertain tax positions are recognized when it is more likely than not that a tax position will be sustained during an audit. Interest and penalties related to unrecognized tax benefits are included within the provision for income tax. Comprehensive Loss Comprehensive loss is defined as a change in equity of a business enterprise during a period resulting from transactions from non-owner sources. Our other comprehensive loss is comprised solely of unrealized gains (losses) on available-for-sale securities, and is presented net of taxes. We have not recorded any reclassifications from other comprehensive loss to net loss during any period presented. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers In August Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern which will require a reporting entity to evaluate, at each annual and interim reporting period, whether there are conditions or events that raise substantial doubt about the reporting entity's ability to continue as a going concern within one year after the date the financial statements are issued and provide related disclosures. In April 2015, the FASB issued ASU Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement , Entities may apply the new guidance either prospectively to all arrangements entered into or materially modified after the effective date or retrospectively. of this standard did not have a material impact on our consolidated financial statements. In November 2015, the FASB issued ASU Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes of this standard did not have a material impact on our consolidated financial statements. On January 5, 2016, the FASB issued ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities |
Net Loss per Common Share
Net Loss per Common Share | 12 Months Ended |
Dec. 31, 2015 | |
Earnings Per Share [Abstract] | |
Net Loss per Common Share | 3. Net Loss per Common Share Basic and diluted net loss per common share is presented, giving effect to the Recapitalization, including cancellation of existing Atara common stock and a nine-for-one share exchange. Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, without consideration of common stock equivalents. Diluted net loss per common share is computed by dividing the net loss by the weighted-average number of shares of common stock and common share equivalents outstanding for the period. Common share equivalents are only included in the calculation of diluted net loss per common share when their effect is dilutive. Prior to the date of our IPO, we considered all series of our convertible preferred stock to be participating securities as they were entitled to participate in undistributed earnings with shares of common stock. Due to net losses, there is no impact on the net loss per common share calculation in applying the two-class method since the participating securities had no legal requirement to share in any losses. Potential dilutive securities, which include convertible preferred stock prior to our IPO, unvested RSAs, unvested RSUs and vested and unvested options have been excluded from the computation of diluted net loss per share as the effect is antidilutive. Therefore, the denominator used to calculate both basic and diluted net loss per common share is the same in all periods presented. The following table represents the potential common shares issuable pursuant to outstanding securities as of the related period end dates that were excluded from the computation of diluted net loss per common share as their inclusion would have an antidilutive effect: As of December 31, 2015 2014 2013 Unvested restricted common stock awards 233,413 666,091 790,216 Unvested restricted stock units 427,605 721,293 — Vested and unvested options 3,137,529 313,565 — Additionally, convertible preferred stock that was outstanding prior to our IPO in October 2014 has been excluded from the computation of diluted net loss per common share, as these securities would have been antidilutive during 2014 and 2013. |
Financial Instruments
Financial Instruments | 12 Months Ended |
Dec. 31, 2015 | |
Financial Instruments Disclosure [Abstract] | |
Financial Instruments | 4. Financial Instruments The following tables summarize the estimated fair value and related valuation input hierarchy of our financial assets measured on a recurring basis, which were comprised solely of available-for-sale securities as of each period end: Total Total Total Total Amortized Unrealized Unrealized Estimated As of December 31, 2015: Input Level Cost Gain Loss Fair Value (in thousands) Money market funds Level 1 $ 16,364 $ — $ — $ 16,364 U.S. Treasury obligations Level 2 599 — (1 ) 598 Government agency obligations Level 2 36,480 1 (88 ) 36,393 Corporate debt obligations Level 2 203,767 8 (339 ) 203,436 Commercial paper Level 2 999 — — 999 Asset-backed securities Level 2 61,304 2 (102 ) 61,204 Total available-for-sale securities 319,513 11 (530 ) 318,994 Less amounts classified as cash equivalents (22,259 ) — 1 (22,258 ) Amounts classified as short-term investments $ 297,254 $ 11 $ (529 ) $ 296,736 Total Total Total Total Amortized Unrealized Unrealized Estimated As of December 31, 2014: Input Level Cost Gain Loss Fair Value (in thousands) Money market funds Level 1 $ 18,141 $ — $ — $ 18,141 U.S. Treasury obligations Level 2 466 — (1 ) 465 Government agency obligations Level 2 12,519 — (5 ) 12,514 Corporate debt obligations Level 2 60,052 1 (89 ) 59,964 Commercial paper Level 2 1,200 — — 1,200 Asset-backed securities Level 2 11,838 2 (8 ) 11,832 Total available-for-sale securities 104,216 3 (103 ) 104,116 Less amounts classified as cash equivalents (21,897 ) — — (21,897 ) Amounts classified as short-term investments $ 82,319 $ 3 $ (103 ) $ 82,219 The amortized cost and fair value of our available-for-sale securities by contractual maturity were as follows: As of December 31, 2015 As of December 31, 2014 Amortized Estimated Amortized Estimated Cost Fair Value Cost Fair Value (in thousands) (in thousands) Maturing within one year $ 211,311 $ 211,059 $ 78,649 $ 78,611 Maturing in one to five years 108,202 107,935 25,567 25,505 Total available-for-sale securities $ 319,513 $ 318,994 $ 104,216 $ 104,116 As of December 31, 2015, certain available-for-sale securities had been in a continuous unrealized loss position, each for less than twelve months. As of this date, no significant facts or circumstances were present to indicate a deterioration in the creditworthiness of the respective issuers, and the Company had no requirement or intention to sell these securities before maturity or recovery of their amortized cost basis. During the years ended December 31, 2015, 2014, and 2013, we did not recognize any other-than-temporary impairment loss. |
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 consists of lab equipment, furniture and fixtures, computer equipment and software, which is depreciated over the estimated useful lives of the assets, ranging from three to five years. Depreciation expense was not material for all periods presented. |
License and Collaboration Agree
License and Collaboration Agreements | 12 Months Ended |
Dec. 31, 2015 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
License and Collaboration Agreements | 6. License and Collaboration Agreements MSK Agreements – In September 2014, we entered into an exclusive option agreement with MSK under which we had the right to acquire the exclusive worldwide license rights to three clinical stage T-cell therapies from MSK. In exchange for the option, we paid $1.25 million in cash and issued 59,761 shares of our common stock to MSK. At the time of issuance, we estimated the fair value of the stock issued to MSK to be $0.75 million. The total of $2.0 million was recorded as research and development expense in our statements of operations and comprehensive loss. In June 2015, we exercised our option and entered into an exclusive license agreement with MSK. In connection with the execution of the license agreement, we paid was recorded as research and development expense in our statement of operations and comprehensive loss. We are required to make as well as future sales of products resulting from the development of the licensed product candidates, if any. In addition, under certain circumstances, we are required to make certain minimum annual royalty payments to MSK, which are creditable against earned royalties owed for the same annual period. We are also required to pay a low double-digit percentage of any consideration we receive for sublicensing the licensed rights. The license agreement expires on a product-by-product and country-by-country basis on the later of: (i) expiration of the last licensed patent rights related to each licensed product, (ii) expiration of any market exclusivity period granted by law with respect to each licensed product, and (iii) a specified number of years after the first commercial sale of the licensed product in each country. Upon expiration of the license agreement, Atara will retain non-exclusive rights to the licensed products. Amgen License - In September 2012, we entered into three license agreements with Amgen, which at the time was, but is no longer considered, a related party, for the development, manufacturing, use and distribution of products using certain proprietary compounds. Under the terms of these agreements, we paid $0.25 million in cash and issued 5,538,462 shares of Series A-1 convertible preferred stock (615,384 shares after giving effect to the Recapitalization) to Amgen, for which we estimated the fair value to be $2.8 million. Both amounts were recorded as research and development expense paid to Amgen in our combined statements of operations and comprehensive loss in 2012. Of the total Series A-1 convertible preferred stock, 2,006,688 and 3,531,774 shares were issued in 2013 and 2012, respectively. During the year ended December 31, 2014, we purchased clinical services totaling $0.1 million and made a $1.0 million milestone payment to Amgen. During the year ended December 31, 2013, we purchased clinical supplies totaling $0.6 million from Amgen. There were no payments to Amgen in 2015. The above payments to Amgen have been recorded as research and development costs paid to Amgen in our statements of operations and comprehensive loss. In accordance with terms of the agreements with Amgen, we use commercially reasonable efforts to prepare, file, prosecute, defend and maintain the patents covered by the license agreements. During the years ended December 31, 2015, 2014 and 2013, we incurred expenses of $1.5 million, $1.2 million and $0.8 million, respectively, related to these activities. We are required to make payments to Amgen of up to $86.0 million upon the achievement of certain development and regulatory approval milestones, of which $1.0 million has been paid to date. Of these milestone payments, $14.0 million relate to milestones for clinical trials. The remaining $72.0 million relate to milestones for regulatory approvals in various territories and are anticipated to be made no earlier than 2018. Thereafter, we are required to make tiered payments based on achievement of commercial milestones based upon net sales levels. The maximum payments would be $206.0 million based on sales of over $1.0 billion for each of three products in a calendar year. In December 2015, we announced that we would be suspending further development of PINTA 745. Consequently, we expect payments upon the achievement of development and regulatory approval milestones to be no more than $59.0 million in total and sales-based payments to be no more than $104.0 million in total. We are also required to pay mid-single-digit percentage tiered royalties on future net sales of products which are developed and approved as defined by the agreements, if any. Our royalty obligations as to a particular licensed product will be payable, on a country-by-country and product-by-product basis, until the later of (a) the date of expiration of the last to expire valid claim within the licensed patents that covers the manufacture, use or sale, offer to sell, or import of such licensed product by us or a sublicense in such country, (b) loss of regulatory exclusivity, or (c) 10 years after the first commercial sale of the applicable licensed product in the applicable country. These agreements expire at the end of all royalty obligations to Amgen and, upon expiration, the licenses will be fully paid, royalty-free, irrevocable and non-exclusive. As of December 31, 2015, Amgen owned 5.1% of our outstanding common stock. Amgen does not have any rights to participate in our product candidates’ development and is not represented on our board of directors. QIMR Berghofer Agreements – In October 2015, we entered into an exclusive license agreement and a research and development collaboration agreement with QIMR Berghofer Medical Research Institute (“QIMR Berghofer”). Under the terms of the license agreement, we obtained an exclusive, worldwide license to develop and commercialize allogeneic cytotoxic T-lymphocytes (“CTL”) therapy programs utilizing technology and know-how developed by QIMR Berghofer. In consideration for the exclusive license, we paid $3.0 million in cash to QIMR Berghofer, which was recorded as research and development expense in our statement of operations and comprehensive loss. Under the research and development collaboration agreement, we are required to reimburse the cost of agreed upon development activities. These payments are expensed as incurred and resulted in research and development expense of $0.2 million for the year ended December 31, 2015. The agreement also provides for various milestone and royalty payments to QIMR Berghofer based on achievement of certain developmental milestones and future product sales, if any. Milestones and royalties under each of the above agreements are contingent upon future events and will be recorded as expense when it is probable that the milestones will be achieved or royalties are due. As of December 31, 2015 and 2014, there were no outstanding obligations for milestones and royalties to MSK, Amgen and QIMR Berghofer. |
Commitment and Contingencies
Commitment and Contingencies | 12 Months Ended |
Dec. 31, 2015 | |
Commitments And Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | 7. Commitments and Contingencies License and Collaboration Agreements Potential payments related to our license and collaboration agreements, including milestone and royalty payments, are detailed in Note 6. As the achievement of these milestones and royalties are currently not fixed and determinable, such commitments have not been included in our balance sheets. Other Research and Development Agreements We may also enter into contracts in the normal course of business with clinical research organizations for clinical trials, with contract manufacturing clinical supplies, and with other vendors for pre-clinical studies, supplies and other services and products for operating purposes. These contracts generally provide for termination on Operating Leases We lease our corporate headquarters in South San Francisco, California under a non-cancellable sublease agreement that expires in January 2017. In December Operating Leases (in thousands) 2016 $ 967 2017 969 2018 981 2019 734 2020 614 Thereafter 207 Total operating lease commitments $ 4,472 Rent expense for the years ended December 31, 2015, 2014 and 2013 were $0.4 million, $0.1 million and $0.1 million, respectively. Indemnification Agreements In the normal course of business, we enter into contracts and agreements that contain a variety of representations and warranties and provide for indemnification for certain liabilities. The exposure under these agreements is unknown because it involves claims that may be made against us in the future but have not yet been made. To date, we have not paid any claims or been required to defend any action related to our indemnification obligations. However, we may record charges in the future as a result of these indemnification obligations. We also have indemnification obligations to our directors and executive officers for specified events or occurrences, subject to some limits, while they are serving at our request in such capacities. There have been no claims to date and we believe the fair value of these indemnification agreements is minimal. Accordingly, we have not recorded any liabilities for these agreements as of December 31, 2015 and 2014. Contingencies From time to time, we may be involved in legal proceedings, as well as demands, claims and threatened litigation, which arise in the normal course of our business or otherwise. The ultimate outcome of any litigation is uncertain and unfavorable outcomes could have a negative impact on our results of operations and financial condition. Regardless of outcome, litigation can have an adverse impact on us because of the defense costs, diversion of management resources and other factors. We are not currently involved in any material legal proceedings. |
Stockholders' Equity
Stockholders' Equity | 12 Months Ended |
Dec. 31, 2015 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Stockholders' Equity | 8. Stockholders’ Equity Our authorized capital stock consists of 520,000,000 shares, all with a par value of $0.0001 per share, of which 500,000,000 shares are designated as common stock and 20,000,000 shares are designated as preferred stock. There were no shares of preferred stock outstanding as of December 31, 2015 and 2014. The following shares of common stock were reserved for future issuance as of December 31, 2015: Total Shares Reserved 2014 Equity Incentive Plan 3,916,362 2014 Employee Stock Purchase Plan 432,898 Total reserved shares of common stock 4,349,260 Restricted Stock Awards In August 2012, in connection with our formation, our CEO purchased 9,595,384 shares of restricted common stock at a nominal per share purchase price. The shares were issued subject to certain vesting conditions, restrictions on transfer and a Company right of repurchase of any unvested share at their original purchase price. These shares are placed in escrow until vested, and have rights to vote and participate in dividends and distributions. The combined grant date intrinsic value for this award was $1.7 million, and 7,996,153 of the shares had service and fundraising vesting conditions. Under the service vesting condition, shares vest monthly over 48 months, commencing from the first closing of Series A convertible preferred stock financing on October 22, 2012. The remaining 1,599,231 of these shares were subject to performance milestones and fundraising vesting conditions. The fundraising vesting conditions for all shares were satisfied as of December 31, 2013. All shares subject to service vesting conditions are subject to accelerated vesting in the event of certain change of control transactions. In March 2013, an Atara employee purchased 2,423,074 shares of restricted common stock for $0.3 million. The shares were issued under our 2012 Equity Incentive Plan and are subject to certain vesting conditions, restrictions on transfer and a Company right of repurchase of any unvested shares at their original purchase price. These shares are placed in escrow until vested, and have rights to vote and participate in dividends and distributions. Under these agreements, the shares vest as follows: 2,319,228 shares vest over four years, with one-quarter vesting after one year of service and the remainder vesting in equal installments over the subsequent thirty-six months, and 103,846 shares vest upon achievement of certain performance milestones. Vesting of all shares is subject to acceleration of vesting in the event of certain change of control transactions. The amounts paid for both RSAs were initially recorded as other long-term liabilities. As the shares vest, we reclassify liabilities to equity and report shares as outstanding in the financial statements. On March 31, 2014, these shares were exchanged for 1,335,384 shares of Atara common stock. As of December 31, 2015, 1,101,972 of these shares had vested and are reported as shares outstanding in the financial statements. The remaining 233,413 shares are expected to fully vest in 2016. As both the Chief Executive Officer and the Atara employee were consultants of Nina, Pinta and Santa Maria through the Recapitalization date, we accounted for these RSAs as non-employee stock-based awards. Following the Recapitalization, these RSAs were accounted for as employee awards based upon the fair market value of common stock on March 31, 2014. The weighted average grant date fair value of RSAs granted during the year ended December 31, 2013 was $0.40. There were no grants of RSAs in the years ended December 31, 2015 and 2014. Stock-based compensation expense related to the RSAs is recorded using accelerated graded vesting model and was $0.8 million, $5.2 million and $1.7 million for the years ended December 31, 2015, 2014 and 2013, respectively. The unrecognized stock-based compensation expense related to unvested RSAs was $0.2 million as of December 31, 2015 and this expense is expected to be recognized in 2016. The aggregate intrinsic value of unvested RSAs was $6.1 million as of December 31, 2015. Equity Incentive Plan In March 2014, we adopted the 2014 Equity Incentive Plan (the “2014 EIP”) as part of our Recapitalization. In connection with the Recapitalization, Atara assumed the plans of Nina, Pinta and Santa Maria and all outstanding RSAs and RSUs granted under such plans. At the date of Recapitalization, RSAs and RSUs issued by Nina, Pinta and Santa Maria to Atara employees became employee awards and the awards’ grant dates were established as the Recapitalization date. In May 2014, our board of directors amended and restated our 2014 EIP and the amended plan became effective on October 15, 2014 upon the pricing of our IPO. The 2014 EIP provides for annual increases in the number of shares available for issuance thereunder on the first business day of each fiscal year, beginning with 2015 and ending in 2024, equal to five percent of the number of shares of the Company’s common stock outstanding as of such date or a lesser number of shares as determined by our board of directors. As of December 31, 2015, a total of 3,916,362 shares of common stock were reserved for issuance under the 2014 Plan, of which 326,393 shares were available for future grant and 3,589,969 were subject to outstanding options and RSUs. Under the terms of the 2014 EIP, we may grant options, RSAs and RSUs to employees, directors, consultants and other service providers. RSUs typically require settlement by the earlier of seven years from the date of grant or the service termination (or, for RSUs granted prior to February 2014, two years following the service termination date). Stock options are granted at prices no less than 100% of the estimated fair value of the shares on the date of grant as determined by the board of directors, provided, however, that the exercise price of an option granted to a 10% shareholder cannot be less than 110% of the estimated fair value of the shares on the date of grant. Options granted to employees and non-employees generally vest over four years and expire in seven years. Restricted Stock Units and Awards The RSUs granted prior to our October 2014 IPO had a time-based service condition and a liquidity-based performance condition, and vest when both conditions are met. Prior to our IPO, we determined that the liquidity-based performance condition was not probable of occurring and recorded no stock-based compensation expense related to these RSUs. Upon the closing of our IPO, we recorded $3.8 million of stock-based compensation expense in our statement of operations and comprehensive loss. The weighted average grant date fair value of RSUs granted during the year ended December 31, 2015, 2014 and 2013 was $25.15, $6.53 and $1.99, respectively. As of December 31, 2015, there was $1.9 million of unrecognized stock-based compensation expense related to RSUs that is expected to be recognized over a weighted average period of 1.1 years. The aggregate intrinsic value of the RSUs outstanding as of December 31, 2015 was $11.9 million. The following is a summary of RSAs and RSUs activity under our 2014 EIP: RSAs RSUs Shares Weighted Average Grant Date Fair Value Shares Weighted Average Grant Date Fair Value Unvested as of December 31, 2014 112,740 $ 0.40 619,303 $ 4.64 Granted — — 87,600 $ 25.15 Forfeited — — (2,645 ) $ 8.59 Vested (64,423 ) $ 0.40 (276,653 ) $ 6.12 Unvested as of December 31, 2015 48,317 $ 0.40 427,605 $ 7.86 Vested and unreleased 24,835 Outstanding as of December 31, 2015 — — 452,440 Under our RSU net settlement procedures, we withhold shares at settlement to cover the minimum payroll withholding tax obligations. During 2015, we settled 451,306 RSUs, of which 327,383 RSUs were net settled by withholding 123,923 shares. The value of the RSUs withheld was $4.6 million, based on the closing price of our common stock on the settlement date. This amount was remitted to the appropriate taxing authorities and has been reflected as a financing activity in our statements of cash flows. Stock Options The following is a summary of option activity under our 2014 EIP: Number of shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding as of December 31, 2014 623,936 $ 13.69 Granted 2,610,174 $ 28.95 Exercised (23,822 ) $ 18.44 Forfeited or expired (72,759 ) $ 37.11 Outstanding as of December 31, 2015 3,137,529 $ 25.81 6.42 $ 12,978 Vested and expected to vest as of December 31, 2015 3,137,529 $ 25.81 6.42 $ 12,978 Exercisable as of December 31, 2015 276,909 $ 17.75 5.75 $ 2,470 Aggregate intrinsic value represents the difference between the closing stock price of our common stock on December 31, 2015 and the exercise price of outstanding, in-the-money options. As of December 31, 2015, there was $40.4 million of unrecognized stock-based compensation expense related to stock options that is expected to be recognized over a weighted average period of 3.4 years. Options for 23,822 shares of our common stock were exercised during the year ended December 31, 2015, with an intrinsic value of $0.6 million. No options were exercised during 2014 and 2013. As we believe it is more likely than not that no stock option related tax benefits will be realized, we do not record any net tax benefits related to exercised options. The fair value of each option issued was estimated at the date of grant using the Black-Scholes valuation model. The following table summarizes the weighted-average assumptions used as inputs to the Black-Scholes model, and resulting weighted-average grant date fair values of employee and consultant stock options granted during the periods indicated: Year Ended December 31, 2015 Year Ended December 31, 2014 Employees Consultants Employees Consultants Assumptions: Expected term (years) 4.5 7.0 4.5 7.0 Expected volatility 72.4 % 71.5 % 65.7 % 65.8 % Risk-free interest rate 1.6 % 2.0 % 1.6 % 2.2 % Expected dividend yield 0.0 % 0.0 % 0.0 % 0.0 % Weighted-average estimated grant date fair value per share $ 16.63 $ 27.82 $ 7.29 $ 8.61 The estimated fair value of stock options that vested in the years ended December 31, 2015, 2014 and 2013 was $2.9 million, $0.1 million and zero, respectively. Employee Stock Purchase Plan In May 2014, we adopted the 2014 Employee Stock Purchase Plan (“2014 ESPP”), which became effective on October 15, 2014 upon the pricing of our IPO. The 2014 ESPP permits eligible employees to purchase common stock at a discount through payroll deductions during defined offering periods. No offerings commenced and there were no purchases of shares under the 2014 ESPP in the year ended December 31, 2015. The 2014 ESPP provides for annual increases in the number of shares available for issuance thereunder on the first business day of each fiscal year, beginning with 2015 and ending in 2024, equal to the lower of (i) one percent of the number of shares of our common stock outstanding as of such date, (ii) 230,769 shares of our common stock, or (iii) a lesser number of shares as determined by our board of directors. As of December 31, 2015, there were 432,898 shares authorized for issuance under the 2014 ESPP. Stock-based Compensation Expense Total stock-based compensation expense related to all employee and non-employee awards was as follows: Year ended December 31, 2015 2014 2013 (in thousands) Research and development $ 4,822 $ 3,258 $ 251 General and administrative 5,429 6,843 1,462 Total stock-based compensation $ 10,251 $ 10,101 $ 1,713 |
Income Taxes
Income Taxes | 12 Months Ended |
Dec. 31, 2015 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | 9. Income Taxes For the years ended December 31, 2015, 2014 and 2013, all of the loss before provision for income taxes was domestic, and we recorded the following income tax provision: Year Ended December 31, 2015 2014 2013 Current provision (benefit) for: (in thousands) Federal income taxes $ (1 ) $ (36 ) $ 153 State income taxes (8 ) 11 17 Total current provision (benefit) $ (9 ) $ (25 ) $ 170 A reconciliation of statutory tax rates to effective tax rates for the years ended December 31, 2015, 2014 and 2013 is as follows: Year Ended December 31, 2015 2014 2013 Federal income taxes at statutory rate 34.0 % 34.0 % 34.0 % Non-deductible stock compensation (0.6 %) (7.3 %) (6.8 %) State income tax, net of federal benefit — — (0.3 %) Other — 0.1 % (0.1 %) Valuation allowance (33.4 %) (26.7 %) (28.8 %) Effective tax rate 0.0 % 0.1 % (2.0 %) Deferred tax assets and liabilities reflect the net tax effect of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of our deferred tax assets and liabilities were as follows as of the dates indicated: As of December 31, 2015 2014 Deferred tax assets: (in thousands) Net operating losses $ 24,219 $ 8,220 License fees 5,122 2,279 Stock-based compensation 4,999 1,964 Legal fees 1,436 757 Other 1,249 494 Total deferred tax assets 37,025 13,714 Valuation allowance (37,025 ) (13,714 ) Net deferred tax assets $ — $ — We recognize deferred income taxes for temporary differences between the basis of assets and liabilities for financial statement and income tax purposes, as well as for tax attribute carryforwards. We regularly evaluate the positive and negative evidence in determining the realizability of our deferred tax assets. Based upon the weight of available evidence, which includes our historical operating performance and reported cumulative net losses since inception, we maintained a full valuation allowance on the net deferred tax assets as of December 31, 2015 and 2014. We intend to maintain a full valuation allowance on our deferred tax assets until sufficient positive evidence exists to support reversal of the valuation allowance. The valuation allowance increased by $23.3 million, $9.2 million and $2.9 million for the years ended December 31, 2015, 2014 and 2013, respectively. As of December 31, 2015, we had federal and state net operating loss carryforwards for tax return purposes of $68.8 million and $68.7 million, respectively. The federal and state net operating loss carryforwards begin to expire in 2032 in various amounts if not utilized. Under Section 382 of the Internal Revenue Code of 1986, as amended (the “Code”), our ability to utilize net operating loss carryforwards or other tax attributes in any taxable year may be limited if we have experienced an “ownership change.” Generally, a Section 382 “ownership change” occurs if one or more stockholders or groups of stockholders who owns at least 5% of a corporation’s stock increases its ownership by more than 50% over its lowest ownership percentage within a specified testing period. Similar rules may apply under state tax laws. We have completed a Section 382 study of transactions in our stock through December 31, 2015. The study concluded that we have experienced at least one ownership change since inception and that our utilization of net operating loss carryforwards will be subject to annual limitations. Further, other provisions of the Code may limit our ability to utilize federal net operating losses incurred before our Recapitalization to offset income or gain realized after the Recapitalization unless such income or gain is realized by the same entity that originally incurred such losses. However, it is not expected that these limitations will result in the expiration of tax attribute carryforwards prior to utilization. A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows: (In thousands) Balance as of December 31, 2013 $ - Gross increases for tax positions related to current year 1,014 Gross increases for tax positions related to prior years 629 Balance as of December 31, 2014 1,643 Gross increases for tax positions related to current year 2,671 Balance as of December 31, 2015 $ 4,314 Of the $4.3 million total unrecognized tax benefits, $0.1 million, if recognized, would affect the effective tax rate due to the valuation allowance that currently offsets deferred tax assets. We recognize interest and penalties related to uncertain tax positions as part of the income tax provision and, to date, such interest and penalties have not been material. We are not aware of any items that will significantly increase or decrease our unrecognized tax benefits in the next 12 months. We file income tax returns in the US federal jurisdiction and California. All of our tax years remain open to examination by the US federal and California tax authorities. |
Summary of Significant Accoun17
Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2015 | |
Accounting Policies [Abstract] | |
Basis of Presentation and Recapitalization | Basis of Presentation and Recapitalization The accompanying consolidated and combined financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and the rules and regulations of the US Securities and Exchange Commission (the “SEC”). All share and per-share amounts presented in the consolidated and combined financial statements for the years ended December 31, 2015, 2014 and 2013 and in the notes hereto have been revised to reflect a 1.3-to-1 reverse stock split which became effective July 9, 2014. Certain items in the balance sheets and statements of cash flows have been reclassified from their presentation in prior years. Atara was originally formed as a management company with the sole purpose of providing management, financial and administrative services for Nina Biotherapeutics, Inc. (“Nina”), Santa Maria Biotherapeutics, Inc. (“Santa Maria”) and Pinta Biotherapeutics, Inc. (“Pinta”). Prior to March 31, 2014, the accompanying financial statements include the operations of Atara, Nina, Pinta and Santa Maria on a combined basis as the four individual companies were under common ownership and common management. All intercompany transactions have been eliminated. On March 31, 2014, we implemented a recapitalization (the “Recapitalization”) in which (a) all the outstanding shares of common stock of Atara were cancelled and forfeited by existing stockholders and (b) the stockholders of Nina, Pinta and Santa Maria exchanged their existing common and convertible preferred stock for newly-issued shares of Atara, with the same rights and privileges as the outstanding capital stock of Nina, Pinta and Santa Maria. The shares were exchanged on a collective nine-for-one basis. The Recapitalization lacked economic substance as the newly-issued shares have the same rights and privileges as the previously outstanding capital stock of Nina, Pinta and Santa Maria and there was no change in ownership percentages of the individual stockholders. As a result of the Recapitalization, Nina, Pinta and Santa Maria became wholly owned subsidiaries of Atara effective March 31, 2014. The Recapitalization is considered a tax-free exchange for US federal income tax purposes. Because the four individual companies were under common ownership and the Recapitalization lacked economic substance, we accounted for the Recapitalization as a combination of businesses under common control. The assets and liabilities of Nina, Pinta and Santa Maria were recorded by Atara at their historical carrying amounts on March 31, 2014 and beginning March 31, 2014, the financial statements of Atara are presented on a consolidated basis. |
Principles of Consolidation | Principles of Consolidation The consolidated and combined financial statements include the accounts of Atara and its wholly owned subsidiaries, Nina, Pinta, Santa Maria Islands |
Segment and Geographic Information | Segment and Geographic Information We operate and manage our business as one reporting and one operating segment, which is the business of developing and commercializing therapeutics. Our Chief Executive Officer, who is our chief operating decision maker, reviews financial information on an aggregate basis for purposes of allocating resources and evaluating financial performance. All of our assets are located in the United States. |
Significant Risks and Uncertainties | Significant Risks and Uncertainties We have incurred significant operating losses since inception and have relied on public and private equity financings to fund our operations. As of December 31, 2015, we had an accumulated deficit of $98.1 million. As we continue to incur losses, our transition to profitability will depend on the successful development, approval and commercialization of product candidates and on the achievement of sufficient revenues to support our cost structure. We may never achieve profitability, and unless and until we do, we will need to continue to raise additional capital. Management expects that our cash, cash equivalents and short-term investments as of December 31, 2015 will be sufficient to fund our planned operations through 2018. |
Concentration of Credit Risk and Other Uncertainties | Concentration of Credit Risk and Other Uncertainties We place cash and cash equivalents in the custody of financial institutions that management believes are of high credit quality, which at times, may be in excess of the amount insured by the Federal Deposit Insurance Corporation. We also have short-term investments in money market funds, U.S. Treasury, government agency and corporate debt obligations, commercial paper and asset-backed securities, which can be subject to certain credit risk. However, we mitigate the risks by investing in high-grade instruments, limiting our exposure to any one issuer, and monitoring the ongoing creditworthiness of the financial institutions and issuers. We are subject to certain risks and uncertainties and believe that changes in any of the following areas could have a material adverse effect on future financial position or results of operations: ability to obtain future financing; regulatory approval and market acceptance of, and reimbursement for, our product candidates; performance of third-party clinical research organizations and manufacturers upon which we rely; development of sales channels; protection of our intellectual property; litigation or claims against us based on intellectual property, patent, product, regulatory or other factors; and our ability to attract and retain employees necessary to support our growth. |
Use of Estimates | Use of Estimates 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. Significant estimates relied upon in preparing these financial statements include the fair value of common stock and the fair value of preferred stock prior to our IPO and estimates related to clinical trial accruals and stock-based compensation expense. Actual results could differ materially from those estimates. |
Foreign Currency | Foreign Currency Transactions and foreign currency-denominated monetary assets and liabilities that are denominated in a foreign currency are translated into U.S. dollars at the current exchange rate on the transaction date and as of each balance sheet date, respectively, with gains or losses on foreign exchange changes recognized in interest and other income (expense), net in the statements of operations and comprehensive loss. As of December 31, 2015, we held British pounds valued at $1.5 million. There were no foreign currency transactions in prior periods. |
Cash Equivalents and Short-Term Investments | Cash Equivalents and Short-Term Investments Cash equivalents are defined as short-term, highly liquid investments with original maturities of 90 days or less at the date of purchase, and generally consist of money market funds, U.S. Treasury, government agency and corporate debt obligations, and commercial paper. Investments with original maturities of greater than 90 days are classified as short-term investments on the balance sheet, and consist primarily of U.S. Treasury, government agency and corporate debt obligations, commercial paper and asset-backed securities. As our entire investment portfolio is considered available for use in current operations, we classify all investments as available-for-sale and as current assets, even though the stated maturity may be more than one year from the current balance sheet date. Available-for-sale securities are carried at fair value, with unrealized gains and losses reported in accumulated other comprehensive loss, which is a separate component of stockholders’ equity in the balance sheet. The amortized cost of securities is adjusted for amortization of premiums and accretion of discounts to maturity, which are both recorded to interest and other income (expense), net in the statements of operations and comprehensive loss. Changes in the fair value of available-for-sale securities impact the statements of operations only when such securities are sold or if an other-than-temporary impairment is recognized. Realized gains and losses on the sale of securities are determined by specific identification of each security’s cost basis. We regularly review our investment portfolio to determine if any security is other-than-temporarily impaired, which would require us to record an impairment charge in the period any such determination is made. In making this judgment, we evaluate, among other things, the duration and extent to which the fair value of a security is less than its cost, the financial condition of the issuer and any changes thereto, our intent to sell, or whether it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis. Our assessment on whether a security is other-than-temporarily impaired could change in the future due to new developments or changes in assumptions related to any particular security. Realized gains and losses and declines in value judged to be other-than-temporary on available-for-sale securities, if any, are recorded to interest and other income (expense), net in the statements of operations and comprehensive loss. |
Fair Value Measurement | Fair Value Measurement The carrying amounts of certain of our financial instruments including cash equivalents, prepaid expenses, accounts payable and accrued liabilities approximate fair value due to their short maturities. Short-term investments are comprised of available-for-sale securities, which are carried at fair value. |
Fair Value of Financial Instruments | Fair Value of Financial Instruments Our financial assets and liabilities are measured at fair value on a recurring basis using the following hierarchy to prioritize valuation inputs, Level 1: Quoted prices in active markets for identical assets or liabilities that we have the ability to access Level 2: Observable market based inputs or unobservable inputs that are corroborated by market data such as quoted prices, interest rates and yield curves Level 3: Inputs that are unobservable data points that are not corroborated by market data We review the fair value hierarchy classification on a quarterly basis. Changes in the ability to observe valuation inputs may result in a reclassification of levels of certain securities within the fair value hierarchy. We recognize transfers into and out of levels within the fair value hierarchy in the period in which the actual event or change in circumstances that caused the transfer occurs. There have been no transfers between Level 1, Level 2, and Level 3 in any periods presented. Financial assets and liabilities are considered Level 2 when their fair values are determined using inputs that are observable in the market or can be derived principally from or corroborated by observable market data such as pricing for similar securities, recently executed transactions, cash flow models with yield curves, and benchmark securities. In addition, Level 2 financial instruments are valued using comparisons to like-kind financial instruments and models that use readily observable market data as their basis. U.S. Treasury, government agency and corporate debt obligations, and commercial paper and asset-backed securities are valued primarily using market prices of comparable securities, bid/ask quotes, interest rate yields and prepayment spreads and are included in Level 2. Financial assets and liabilities are considered Level 3 when their fair values are determined using pricing models, discounted cash flow methodologies, or similar techniques, and at least one significant model assumption or input is unobservable. We have no Level 3 financial assets or liabilities. |
Property and Equipment, Net | Property and Equipment, net Property and equipment are stated at cost and depreciated using the straight-line method over the estimated useful lives of the assets, ranging from three to five years. Maintenance and repairs are charged to operations as incurred. |
Long-lived Assets | Long-lived Assets We evaluate the carrying amount of our long-lived assets whenever events or changes in circumstances indicate that the assets may not be recoverable. An impairment loss would be recognized when estimated future cash flows expected to result from the use of the asset and its eventual disposition are less than the carrying amount of the asset. To date, there have been no such impairment losses. |
Stock-Based Compensation Expense | Stock-Based Compensation Expense We account for stock-based compensation expense, including the expense of restricted common stock awards (“RSAs”) and grants of restricted stock units (“RSUs”) and stock options that may be settled in shares of our common stock, based on the fair values of the equity instruments issued. The fair value is determined on the measurement date, which is generally the date of grant for employee awards and the date when the service performance is completed for non-employees. The fair value for our RSAs is their intrinsic value, which is the difference between the fair value of the underlying stock at the measurement date and the purchase price. The fair value of our RSUs is the fair value of the underlying stock at the measurement date. The fair value for our stock option awards is determined at the grant date using the Black-Scholes valuation model. For employees’ awards with performance-based vesting criteria, we assess the probability of the achievement of the performance conditions at the end of each reporting period and recognize the share-based compensation costs when it becomes probable that the performance conditions will be met. For non-employees’ awards with performance-based vesting criteria, we assess all possible outcomes at the end of each reporting period and recognize the lowest aggregate fair value in the range of possible outcomes. The lowest value in the range of possible outcomes may be zero. For awards that are subject to both service and performance conditions, no expense is recognized until it is probable that performance conditions will be met. Stock-based compensation expense for awards with time-based vesting criteria is recognized as expense on a straight-line basis over the requisite service period. Stock-based compensation expense for awards with performance and other vesting criteria is recognized as expense under an accelerated graded vesting model. Key assumptions used in the Black-Scholes valuation model used for employee stock awards include: Expected term – The expected term assumption represents the period that our stock-based awards are expected to be outstanding and is determined using the simplified method. Expected volatility – Expected volatility is estimated using comparable public companies’ volatility for similar terms. Expected dividend – We have not historically declared or paid dividends to our stockholders and have no plans to pay dividends; therefore we assumed an expected dividend yield of 0%. Risk-free interest rate – The risk-free interest rate is based on the yield on U.S. Treasury securities with the expected term of the associated award. The fair value of non-employee stock options is estimated using the Black-Scholes valuation model with assumptions generally consistent with those used for employee stock options, with the exception of the expected term, which is the remaining contractual life at each measurement date. Prior to our IPO in October 2014, due to the absence of an active market for our common stock, we estimated the fair value of our common stock in accordance with the framework of the American Institute of Certified Public Accountants Technical Practice Aid, Valuation of Privately-Held Company Equity Securities Issued as Compensation. Each valuation included estimates and assumptions that required management’s judgment, including assumptions regarding the probability and estimated time to completion of our IPO. Subsequent to the completion of our IPO, the fair value of our common stock is based on observable market prices. |
Research and Development Expense | Research and Development Expense Research and development expense consists of costs incurred in performing research and development activities, including compensation and benefits for research and development employees, expenses incurred under agreements with contract research organizations and investigative sites that conduct clinical trials and preclinical studies, the costs of acquiring and manufacturing clinical trial materials, other supplies and costs associated with product development efforts, preclinical activities and regulatory operations, and an allocation of facility and overhead expenses. Research and development costs are expensed as incurred. |
Clinical Trial Accruals | Clinical Trial Accruals Costs for preclinical study and clinical trial activities are recognized based on an evaluation of our vendors’ progress towards completion of specific tasks, using data such as patient enrollment, clinical site activations or information provided to us by our vendors regarding their actual costs incurred. Payments for these activities are based on the terms of individual contracts and payment timing may differ significantly from the period in which the services are performed. We determine accrual estimates through reports from and discussions with applicable personnel and outside service providers as to the progress or state of completion of trials, or the services completed. Our estimates of accrued expenses as of each balance sheet date are based on the facts and circumstances known at the time. Costs that are paid in advance of performance are deferred as a prepaid expense and amortized over the service period as the services are provided. |
Income Taxes | Income Taxes We use the assets and liabilities method to account for income taxes. We record deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial statement carrying amounts and the tax basis of assets and liabilities using enacted tax rates expected to be in effect when the differences are expected to reverse. Valuation allowances are provided when necessary to reduce net deferred tax assets to the amount that is more likely than not to be realized. Based on the available evidence, we are unable, at this time, to support the determination that it is more likely than not that our deferred tax assets will be utilized in the future. Accordingly, we recorded a full valuation allowance as of December 31, 2015 and 2014. We intend to maintain valuation allowances until sufficient evidence exists to support their reversal. Tax benefits related to uncertain tax positions are recognized when it is more likely than not that a tax position will be sustained during an audit. Interest and penalties related to unrecognized tax benefits are included within the provision for income tax. |
Comprehensive Loss | Comprehensive Loss Comprehensive loss is defined as a change in equity of a business enterprise during a period resulting from transactions from non-owner sources. Our other comprehensive loss is comprised solely of unrealized gains (losses) on available-for-sale securities, and is presented net of taxes. We have not recorded any reclassifications from other comprehensive loss to net loss during any period presented. |
Recent Accounting Pronouncements | Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers In August Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern which will require a reporting entity to evaluate, at each annual and interim reporting period, whether there are conditions or events that raise substantial doubt about the reporting entity's ability to continue as a going concern within one year after the date the financial statements are issued and provide related disclosures. In April 2015, the FASB issued ASU Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement , Entities may apply the new guidance either prospectively to all arrangements entered into or materially modified after the effective date or retrospectively. of this standard did not have a material impact on our consolidated financial statements. In November 2015, the FASB issued ASU Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes of this standard did not have a material impact on our consolidated financial statements. On January 5, 2016, the FASB issued ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities |
Net Loss per Common Share (Tabl
Net Loss per Common Share (Tables) | 12 Months Ended |
Dec. 31, 2015 | |
Earnings Per Share [Abstract] | |
Antidilutive Securities Excluded From Computation of Diluted Net Loss per Common Share | The following table represents the potential common shares issuable pursuant to outstanding securities as of the related period end dates that were excluded from the computation of diluted net loss per common share as their inclusion would have an antidilutive effect: As of December 31, 2015 2014 2013 Unvested restricted common stock awards 233,413 666,091 790,216 Unvested restricted stock units 427,605 721,293 — Vested and unvested options 3,137,529 313,565 — |
Financial Instruments (Tables)
Financial Instruments (Tables) | 12 Months Ended |
Dec. 31, 2015 | |
Financial Instruments Disclosure [Abstract] | |
Fair Value, Assets Measured on Recurring Basis [Table Text Block] | The following tables summarize the estimated fair value and related valuation input hierarchy of our financial assets measured on a recurring basis, which were comprised solely of available-for-sale securities as of each period end: Total Total Total Total Amortized Unrealized Unrealized Estimated As of December 31, 2015: Input Level Cost Gain Loss Fair Value (in thousands) Money market funds Level 1 $ 16,364 $ — $ — $ 16,364 U.S. Treasury obligations Level 2 599 — (1 ) 598 Government agency obligations Level 2 36,480 1 (88 ) 36,393 Corporate debt obligations Level 2 203,767 8 (339 ) 203,436 Commercial paper Level 2 999 — — 999 Asset-backed securities Level 2 61,304 2 (102 ) 61,204 Total available-for-sale securities 319,513 11 (530 ) 318,994 Less amounts classified as cash equivalents (22,259 ) — 1 (22,258 ) Amounts classified as short-term investments $ 297,254 $ 11 $ (529 ) $ 296,736 Total Total Total Total Amortized Unrealized Unrealized Estimated As of December 31, 2014: Input Level Cost Gain Loss Fair Value (in thousands) Money market funds Level 1 $ 18,141 $ — $ — $ 18,141 U.S. Treasury obligations Level 2 466 — (1 ) 465 Government agency obligations Level 2 12,519 — (5 ) 12,514 Corporate debt obligations Level 2 60,052 1 (89 ) 59,964 Commercial paper Level 2 1,200 — — 1,200 Asset-backed securities Level 2 11,838 2 (8 ) 11,832 Total available-for-sale securities 104,216 3 (103 ) 104,116 Less amounts classified as cash equivalents (21,897 ) — — (21,897 ) Amounts classified as short-term investments $ 82,319 $ 3 $ (103 ) $ 82,219 |
Amortized Cost and Fair Value of Available for Sale Securities by Contractual Maturity | The amortized cost and fair value of our available-for-sale securities by contractual maturity were as follows: As of December 31, 2015 As of December 31, 2014 Amortized Estimated Amortized Estimated Cost Fair Value Cost Fair Value (in thousands) (in thousands) Maturing within one year $ 211,311 $ 211,059 $ 78,649 $ 78,611 Maturing in one to five years 108,202 107,935 25,567 25,505 Total available-for-sale securities $ 319,513 $ 318,994 $ 104,216 $ 104,116 |
Commitment and Contingencies (T
Commitment and Contingencies (Tables) | 12 Months Ended |
Dec. 31, 2015 | |
Commitments And Contingencies Disclosure [Abstract] | |
Future Operating Lease Commitments | Future minimum commitments for these operating leases are as follows: Operating Leases (in thousands) 2016 $ 967 2017 969 2018 981 2019 734 2020 614 Thereafter 207 Total operating lease commitments $ 4,472 |
Stockholders' Equity (Tables)
Stockholders' Equity (Tables) | 12 Months Ended |
Dec. 31, 2015 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Schedule of Common Stock Reserved for Future Issuance | The following shares of common stock were reserved for future issuance as of December 31, 2015: Total Shares Reserved 2014 Equity Incentive Plan 3,916,362 2014 Employee Stock Purchase Plan 432,898 Total reserved shares of common stock 4,349,260 |
Summary of RSU Activity and Restricted Stock Award | The following is a summary of RSAs and RSUs activity under our 2014 EIP: RSAs RSUs Shares Weighted Average Grant Date Fair Value Shares Weighted Average Grant Date Fair Value Unvested as of December 31, 2014 112,740 $ 0.40 619,303 $ 4.64 Granted — — 87,600 $ 25.15 Forfeited — — (2,645 ) $ 8.59 Vested (64,423 ) $ 0.40 (276,653 ) $ 6.12 Unvested as of December 31, 2015 48,317 $ 0.40 427,605 $ 7.86 Vested and unreleased 24,835 Outstanding as of December 31, 2015 — — 452,440 |
Summary of Stock Option Activity | The following is a summary of option activity under our 2014 EIP: Number of shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding as of December 31, 2014 623,936 $ 13.69 Granted 2,610,174 $ 28.95 Exercised (23,822 ) $ 18.44 Forfeited or expired (72,759 ) $ 37.11 Outstanding as of December 31, 2015 3,137,529 $ 25.81 6.42 $ 12,978 Vested and expected to vest as of December 31, 2015 3,137,529 $ 25.81 6.42 $ 12,978 Exercisable as of December 31, 2015 276,909 $ 17.75 5.75 $ 2,470 |
Summary of Options Estimated with Weighted Average | The fair value of each option issued was estimated at the date of grant using the Black-Scholes valuation model. The following table summarizes the weighted-average assumptions Year Ended December 31, 2015 Year Ended December 31, 2014 Employees Consultants Employees Consultants Assumptions: Expected term (years) 4.5 7.0 4.5 7.0 Expected volatility 72.4 % 71.5 % 65.7 % 65.8 % Risk-free interest rate 1.6 % 2.0 % 1.6 % 2.2 % Expected dividend yield 0.0 % 0.0 % 0.0 % 0.0 % Weighted-average estimated grant date fair value per share $ 16.63 $ 27.82 $ 7.29 $ 8.61 |
Schedule of Stock-based Compensation, Related to Employee and Nonemployee Awards | Total stock-based compensation expense related to all employee and non-employee awards was as follows: Year ended December 31, 2015 2014 2013 (in thousands) Research and development $ 4,822 $ 3,258 $ 251 General and administrative 5,429 6,843 1,462 Total stock-based compensation $ 10,251 $ 10,101 $ 1,713 |
Income Taxes (Tables)
Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2015 | |
Income Tax Disclosure [Abstract] | |
Income Tax Provision | For the years ended December 31, 2015, 2014 and 2013, all of the loss before provision for income taxes was domestic, and we recorded the following income tax provision: Year Ended December 31, 2015 2014 2013 Current provision (benefit) for: (in thousands) Federal income taxes $ (1 ) $ (36 ) $ 153 State income taxes (8 ) 11 17 Total current provision (benefit) $ (9 ) $ (25 ) $ 170 |
Reconciliation of Statutory Tax Rates to Effective Tax Rates | A reconciliation of statutory tax rates to effective tax rates for the years ended December 31, 2015, 2014 and 2013 is as follows: Year Ended December 31, 2015 2014 2013 Federal income taxes at statutory rate 34.0 % 34.0 % 34.0 % Non-deductible stock compensation (0.6 %) (7.3 %) (6.8 %) State income tax, net of federal benefit — — (0.3 %) Other — 0.1 % (0.1 %) Valuation allowance (33.4 %) (26.7 %) (28.8 %) Effective tax rate 0.0 % 0.1 % (2.0 %) |
Components of Deferred Tax Assets and Liabilities | Significant components of our deferred tax assets and liabilities were as follows as of the dates indicated: As of December 31, 2015 2014 Deferred tax assets: (in thousands) Net operating losses $ 24,219 $ 8,220 License fees 5,122 2,279 Stock-based compensation 4,999 1,964 Legal fees 1,436 757 Other 1,249 494 Total deferred tax assets 37,025 13,714 Valuation allowance (37,025 ) (13,714 ) Net deferred tax assets $ — $ — |
Reconciliation of Beginning and Ending Amount of Gross Unrecognized Tax Benefits | A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows: (In thousands) Balance as of December 31, 2013 $ - Gross increases for tax positions related to current year 1,014 Gross increases for tax positions related to prior years 629 Balance as of December 31, 2014 1,643 Gross increases for tax positions related to current year 2,671 Balance as of December 31, 2015 $ 4,314 |
Description of Business (Detail
Description of Business (Detail) - USD ($) $ / shares in Units, $ in Thousands | 1 Months Ended | 12 Months Ended | |||
Jul. 31, 2015 | Feb. 28, 2015 | Oct. 31, 2014 | Dec. 31, 2015 | Dec. 31, 2014 | |
Organization And Description Of Business [Line Items] | |||||
Entity incorporation state | Delaware | ||||
Entity incorporation date | Aug. 1, 2012 | ||||
Net proceeds from sale of common stock | $ 263,434 | $ 56,455 | |||
Additional paid-in capital | $ 413,725 | $ 144,169 | |||
IPO | |||||
Organization And Description Of Business [Line Items] | |||||
Common stock, shares issued | 5,750,000 | ||||
Shares issued, price per share | $ 11 | ||||
Net proceeds from sale of common stock | $ 56,500 | ||||
Preferred stock conversion into common stock | 12,298,515 | ||||
Additional paid-in capital | $ 74,600 | ||||
Follow-on Offering | |||||
Organization And Description Of Business [Line Items] | |||||
Common stock, shares issued | 3,980,768 | 4,147,358 | |||
Shares issued, price per share | $ 52 | $ 18 | |||
Net proceeds from sale of common stock | $ 193,900 | $ 69,500 |
Summary of Significant Accoun24
Summary of Significant Accounting Policies - Additional Information (Detail) £ in Millions | Jul. 09, 2014 | Dec. 31, 2015USD ($)Segment | Dec. 31, 2015GBP (£) | Dec. 31, 2014USD ($) |
Significant Accounting Policies [Line Items] | ||||
Stockholders' equity, stock split conversion ratio | 0.7692 | |||
Stock conversion ratio | Nine-for-one basis | |||
Number of reportable segments | Segment | 1 | |||
Number of operating segments | Segment | 1 | |||
Accumulated deficit | $ | $ 98,110,000 | $ 40,889,000 | ||
Foreign currency value held | £ | £ 1.5 | |||
Cash and cash equivalents maturity period | 90 days | |||
Investment maturity period | 90 days | |||
Impairment of long-lived assets | $ | $ 0 | |||
Expected dividend yield | 0.00% | |||
Minimum | ||||
Significant Accounting Policies [Line Items] | ||||
Property, plant and equipment, useful life | 3 years | |||
Maximum | ||||
Significant Accounting Policies [Line Items] | ||||
Property, plant and equipment, useful life | 5 years |
Net Loss per Common Share - Ant
Net Loss per Common Share - Antidilutive Securities Excluded From Computation of Diluted Net Loss per Common Share (Detail) - shares | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Unvested Restricted Common Stock Awards | |||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 233,413 | 666,091 | 790,216 |
Unvested Restricted Stock Units | |||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 427,605 | 721,293 | |
Vested and Unvested Options | |||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 3,137,529 | 313,565 |
Financial Instruments - Estimat
Financial Instruments - Estimated Fair Value and Related Valuation Input Hierarchy of Financial Assets Comprised Solely of Available-for-Sale Securities Measured on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands | Dec. 31, 2015 | Dec. 31, 2014 |
Schedule of Available-for-sale Securities [Line Items] | ||
Total Amortized Cost | $ 319,513 | $ 104,216 |
Total Unrealized Gain | 11 | 3 |
Total Unrealized Loss | (530) | (103) |
Total Fair Value | 318,994 | 104,116 |
Money Market Funds | Level 1 | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Total Amortized Cost | 16,364 | 18,141 |
Total Fair Value | 16,364 | 18,141 |
U.S. Treasury Obligations | Level 2 | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Total Amortized Cost | 599 | 466 |
Total Unrealized Loss | (1) | (1) |
Total Fair Value | 598 | 465 |
Government Agency Obligations | Level 2 | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Total Amortized Cost | 36,480 | 12,519 |
Total Unrealized Gain | 1 | |
Total Unrealized Loss | (88) | (5) |
Total Fair Value | 36,393 | 12,514 |
Corporate Debt Obligations | Level 2 | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Total Amortized Cost | 203,767 | 60,052 |
Total Unrealized Gain | 8 | 1 |
Total Unrealized Loss | (339) | (89) |
Total Fair Value | 203,436 | 59,964 |
Commercial Paper | Level 2 | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Total Amortized Cost | 999 | 1,200 |
Total Fair Value | 999 | 1,200 |
Asset-Backed Securities | Level 2 | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Total Amortized Cost | 61,304 | 11,838 |
Total Unrealized Gain | 2 | 2 |
Total Unrealized Loss | (102) | (8) |
Total Fair Value | 61,204 | 11,832 |
Amounts Classified As Cash Equivalents | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Total Amortized Cost | 22,259 | 21,897 |
Total Unrealized Loss | (1) | |
Total Fair Value | 22,258 | 21,897 |
Amounts Classified As Short-Term Investments | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Total Amortized Cost | 297,254 | 82,319 |
Total Unrealized Gain | 11 | 3 |
Total Unrealized Loss | (529) | (103) |
Total Fair Value | $ 296,736 | $ 82,219 |
Financial Instruments - Amortiz
Financial Instruments - Amortized Cost and Fair Value of Available-for-Sale Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands | Dec. 31, 2015 | Dec. 31, 2014 |
Amortized cost | ||
Maturing within one year, Amortized cost | $ 211,311 | $ 78,649 |
Maturing in one to five years, Amortized cost | 108,202 | 25,567 |
Total available-for-sale securities, Amortized cost | 319,513 | 104,216 |
Estimated Fair value | ||
Maturing within one year, Estimated fair value | 211,059 | 78,611 |
Maturing in one to five years, Estimated fair value | 107,935 | 25,505 |
Total available-for-sale securities, Estimated fair value | $ 318,994 | $ 104,116 |
Property and Equipment - Additi
Property and Equipment - Additional Information (Detail) | 12 Months Ended |
Dec. 31, 2015 | |
Minimum | |
Property Plant And Equipment [Line Items] | |
Property, plant and equipment, useful life | 3 years |
Maximum | |
Property Plant And Equipment [Line Items] | |
Property, plant and equipment, useful life | 5 years |
License and Collaboration Agr29
License and Collaboration Agreements - Additional Information (Detail) - USD ($) | Sep. 30, 2012 | Oct. 31, 2015 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 |
Related Party Transaction [Line Items] | ||||||
Payments under exclusive option license agreement | $ 1,250,000 | |||||
Share issued under the agreements | 59,761 | |||||
Issuance of common stock related to technology licensing option | $ 750,000 | $ 750,000 | ||||
Research and development expense | 2,000,000 | |||||
Payments under license agreement | 4,500,000 | |||||
Potential milestone payments payable | 33,000,000 | |||||
Contractual obligations due MSK, Amgen and QIMR | 0 | 0 | ||||
Maximum | ||||||
Related Party Transaction [Line Items] | ||||||
Potential milestone payments related to sales | 104,000,000 | |||||
Potential milestone payments upon achievement of milestone | 59,000,000 | |||||
Clinical Services | ||||||
Related Party Transaction [Line Items] | ||||||
Payments under license agreement | $ 100,000 | |||||
Clinical supplies | ||||||
Related Party Transaction [Line Items] | ||||||
Payments under license agreement | $ 600,000 | |||||
Amgen | ||||||
Related Party Transaction [Line Items] | ||||||
Payments under license agreement | 0 | |||||
QIMR Berghofer Medical Research Institute | ||||||
Related Party Transaction [Line Items] | ||||||
Research and development expense | 200,000 | |||||
License fee | $ 3,000,000 | |||||
License Agreements | Amgen | ||||||
Related Party Transaction [Line Items] | ||||||
Payments under license agreement | $ 250,000 | |||||
Potential milestone payments payable | 86,000,000 | |||||
Payment under development and regulatory approval milestones | 1,000,000 | |||||
Sales revenue threshold for maximum milestone payment | 1,000,000,000 | |||||
Percentage of common stock | 5.10% | |||||
License Agreements | Amgen | Milestone For Clinical Trials | ||||||
Related Party Transaction [Line Items] | ||||||
Potential milestone payments payable | 14,000,000 | |||||
License Agreements | Amgen | Favorable Regulatory Action | ||||||
Related Party Transaction [Line Items] | ||||||
Potential milestone payments payable | 72,000,000 | |||||
License Agreements | Amgen | Maximum | ||||||
Related Party Transaction [Line Items] | ||||||
Potential milestone payments related to sales | 206,000,000 | |||||
License Agreements | Amgen | Series A 1 Convertible Preferred Stock | ||||||
Related Party Transaction [Line Items] | ||||||
Share issued under the agreements | 2,006,688 | 3,531,774 | ||||
Estimated fair value of stock upon issuance | $ 2,800,000 | |||||
License Agreements | Prior to Recapitalization | Amgen | Series A 1 Convertible Preferred Stock | ||||||
Related Party Transaction [Line Items] | ||||||
Share issued under the agreements | 5,538,462 | |||||
License Agreements | After Recapitalization | Amgen | Series A 1 Convertible Preferred Stock | ||||||
Related Party Transaction [Line Items] | ||||||
Share issued under the agreements | 615,384 | |||||
License Agreement With Amgen | ||||||
Related Party Transaction [Line Items] | ||||||
Payments under license agreement | $ 1,500,000 | $ 1,200,000 | $ 800,000 | |||
Milestone payments paid | $ 1,000,000 |
Commitments and Contingencies -
Commitments and Contingencies - Additional Information (Detail) - USD ($) | 1 Months Ended | 12 Months Ended | |||
Dec. 31, 2015 | Jan. 31, 2015 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Loss Contingencies [Line Items] | |||||
Rental expense | $ 400,000 | $ 100,000 | $ 100,000 | ||
Liabilities related to indemnification agreements | $ 0 | $ 0 | $ 0 | ||
South San Francisco California Sublease | |||||
Loss Contingencies [Line Items] | |||||
Lease expiration date | Jan. 31, 2017 | ||||
South San Francisco California New Lease | |||||
Loss Contingencies [Line Items] | |||||
Lease expiration date | Apr. 30, 2021 | ||||
Letter of credit expiration date | Dec. 31, 2016 | ||||
South San Francisco California New Lease | Restricted Cash | |||||
Loss Contingencies [Line Items] | |||||
Letter of credit issued | $ 200,000 | ||||
Westlake Village California [Member] | |||||
Loss Contingencies [Line Items] | |||||
Lease expiration date | Apr. 30, 2018 | ||||
New York Lease | |||||
Loss Contingencies [Line Items] | |||||
Lease expiration date | Apr. 30, 2016 |
Commitments and Contingencies31
Commitments and Contingencies - Schedule of Future Minimum Commitments for Operating Leases (Detail) $ in Thousands | Dec. 31, 2015USD ($) |
Commitments And Contingencies Disclosure [Abstract] | |
2,016 | $ 967 |
2,017 | 969 |
2,018 | 981 |
2,019 | 734 |
2,020 | 614 |
Thereafter | 207 |
Total operating lease commitments | $ 4,472 |
Stockholders' Equity - Addition
Stockholders' Equity - Additional Information (Detail) - USD ($) | 1 Months Ended | 3 Months Ended | 12 Months Ended | ||||
Oct. 31, 2014 | Mar. 31, 2013 | Aug. 31, 2012 | Mar. 31, 2014 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Authorized capital stock | 520,000,000 | ||||||
Common stock, par value | $ 0.0001 | $ 0.0001 | |||||
Common stock, shares authorized | 500,000,000 | 500,000,000 | |||||
Preferred stock, par value | $ 0.0001 | ||||||
Preferred stock, shares authorized | 20,000,000 | ||||||
Preferred stock, shares outstanding | 0 | 0 | |||||
Common stock, shares issued | 28,458,807 | 19,692,937 | |||||
Proceeds from sale of common stock, net of offering costs | $ 263,434,000 | $ 56,455,000 | |||||
Stock-based compensation expense | 10,251,000 | $ 10,101,000 | $ 1,713,000 | ||||
Aggregate intrinsic value | $ 12,978,000 | ||||||
Total reserved shares of common stock | 4,349,260 | ||||||
Stock option granted description terms | the exercise price of an option granted to a 10% shareholder cannot be less than 110% of the estimated fair value of the shares on the date of grant. Options granted to employees and non-employees generally vest over four years and expire in seven years. | ||||||
Ownership percent | 10.00% | ||||||
Issuance of common stock pursuant to stock option exercises, shares | 23,822 | 0 | 0 | ||||
Option intrinsic value, exercised | $ 600,000 | ||||||
Net tax benefits related to exercised options | 0 | ||||||
Estimated fair value of stock option, vested | $ 2,900,000 | $ 100,000 | $ 0 | ||||
Minimum | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Estimated fair value of the shares on the date of grant | 100.00% | ||||||
Minimum | 10% Shareholder | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Estimated fair value of the shares on the date of grant | 110.00% | ||||||
2014 Equity Incentive Plan | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Annual increase in EIP/ESPP, subject to other limitations | 5.00% | ||||||
Total reserved shares of common stock | 3,916,362 | ||||||
Aggregate number of awards available for grant to be issued | 326,393 | ||||||
Outstanding options and RSUs | 3,589,969 | ||||||
2014 Employee Stock Purchase Plan | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Total reserved shares of common stock | 432,898 | ||||||
Aggregate number of awards available for grant to be issued | 432,898 | ||||||
Employee stock purchase plan effective date | Oct. 15, 2014 | ||||||
Shares purchased | 0 | ||||||
2014 Employee Stock Purchase Plan | Maximum | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Annual increase in EIP/ESPP, subject to other limitations | 1.00% | ||||||
Maximum increase in number of shares available for issuance | 230,769 | ||||||
Unvested Restricted Common Stock Awards | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Combined grant date intrinsic value for award | $ 1,700,000 | ||||||
Vested restricted stock awards | 64,423 | ||||||
Unvested restricted stock awards | 48,317 | 112,740 | |||||
Weighted average grant date fair value per share | $ 0 | $ 0 | $ 0.40 | ||||
Unrecognized stock-based compensation expense | $ 200,000 | ||||||
Aggregate intrinsic value | $ 6,100,000 | ||||||
Unvested Restricted Common Stock Awards | Prior to Recapitalization | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Shares exchanged | 1,335,384 | ||||||
Vested restricted stock awards | 1,101,972 | ||||||
Unvested restricted stock awards | 233,413 | ||||||
Expected vesting date | Dec. 31, 2016 | ||||||
Unvested Restricted Common Stock Awards | 2012 Equity Incentive Plan | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Proceeds from sale of common stock, net of offering costs | $ 300,000 | ||||||
Unvested Restricted Common Stock Awards | Chief Executive Officer | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Common stock, shares issued | 9,595,384 | ||||||
Share based compensation, vesting period | 48 months | ||||||
Unvested Restricted Common Stock Awards | Atara Employee | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Common stock, shares issued | 2,423,074 | ||||||
Unvested Restricted Common Stock Awards | Performance milestones and fundraising vesting conditions | 2012 Equity Incentive Plan | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Share-based compensation, number of shares expected to vest | 103,846 | ||||||
Unvested Restricted Common Stock Awards | Performance milestones and fundraising vesting conditions | Chief Executive Officer | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Common stock, shares issued | 1,599,231 | ||||||
Unvested Restricted Common Stock Awards | Service and fundraising vesting conditions | Chief Executive Officer | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Common stock, shares issued | 7,996,153 | ||||||
Unvested Restricted Common Stock Awards | Service and fundraising vesting conditions | Atara Employee | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Share-based compensation, number of shares expected to vest | 2,319,228 | ||||||
Unvested Restricted Common Stock Awards | Service And Performance Conditions | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Stock-based compensation expense | $ 800,000 | $ 5,200,000 | $ 1,700,000 | ||||
Employees And Non Employees | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Share based compensation, vesting period | 4 years | 4 years | |||||
Share based compensation award expiration period | 7 years | ||||||
Unvested Restricted Stock Units | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Vested restricted stock awards | 276,653 | ||||||
Unvested restricted stock awards | 427,605 | 619,303 | |||||
Weighted average grant date fair value per share | $ 25.15 | $ 6.53 | $ 1.99 | ||||
Stock-based compensation expense | $ 3,800,000 | ||||||
Unrecognized stock-based compensation expense | $ 1,900,000 | ||||||
Aggregate intrinsic value | $ 11,900,000 | ||||||
Unrecognized stock-based compensation weighted average recognition period | 1 year 1 month 6 days | ||||||
Restricted stock units, settled | 451,306 | ||||||
Restricted stock units, issued net of tax withholdings | 327,383 | ||||||
Restricted stock units withheld for tax obligations | 123,923 | ||||||
Restricted stock units withheld for tax obligations, value | $ 4,600,000 | ||||||
Unvested Restricted Stock Units | From Date Of Grant | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Share based compensation award expiration period | 7 years | ||||||
Unvested Restricted Stock Units | Following Service Termination Date | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Share based compensation award expiration period | 2 years | ||||||
Vested and Unvested Options | |||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||||
Unrecognized stock-based compensation weighted average recognition period | 3 years 4 months 24 days | ||||||
Unrecognized stock-based compensation | $ 40,400,000 |
Stockholders' Equity - Schedule
Stockholders' Equity - Schedule of Common Stock Reserved for Future Issuance (Detail) | Dec. 31, 2015shares |
Class Of Stock [Line Items] | |
Total reserved shares of common stock | 4,349,260 |
2014 Equity Incentive Plan | |
Class Of Stock [Line Items] | |
Total reserved shares of common stock | 3,916,362 |
2014 Employee Stock Purchase Plan | |
Class Of Stock [Line Items] | |
Total reserved shares of common stock | 432,898 |
Stockholders' Equity - Summary
Stockholders' Equity - Summary of RSU Activity and Restricted Stock Award (Detail) - $ / shares | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Outstanding as of December 31, 2015 | 3,137,529 | ||
Unvested Restricted Common Stock Awards | |||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Unvested as of December 31, 2014 | 112,740 | ||
Vested | (64,423) | ||
Unvested as of December 31, 2015 | 48,317 | 112,740 | |
Unvested as of December 31, 2014 | $ 0.40 | ||
Granted | 0 | $ 0 | $ 0.40 |
Vested | 0.40 | ||
Unvested as of December 31, 2015 | $ 0.40 | $ 0.40 | |
Unvested Restricted Stock Units | |||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Unvested as of December 31, 2014 | 619,303 | ||
Granted | 87,600 | ||
Forfeited | (2,645) | ||
Vested | (276,653) | ||
Unvested as of December 31, 2015 | 427,605 | 619,303 | |
Vested and unreleased | 24,835 | ||
Outstanding as of December 31, 2015 | 452,440 | ||
Unvested as of December 31, 2014 | $ 4.64 | ||
Granted | 25.15 | $ 6.53 | $ 1.99 |
Forfeited | 8.59 | ||
Vested | 6.12 | ||
Unvested as of December 31, 2015 | $ 7.86 | $ 4.64 |
Stockholders' Equity - Summar35
Stockholders' Equity - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |||
Outstanding, Number of shares, beginning balance | 623,936 | ||
Granted, Number of shares | 2,610,174 | ||
Exercised, Number of share | (23,822) | 0 | 0 |
Forfeited or expired, Number of share | (72,759) | ||
Outstanding, Number of shares, ending balance | 3,137,529 | 623,936 | |
Outstanding as of December 31, 2015 | 3,137,529 | ||
Exercisable, Number of shares | 276,909 | ||
Outstanding, Weighted Average Exercise Price, beginning balance | $ 13.69 | ||
Granted, Weighted Average Exercise Price | 28.95 | ||
Exercised, Weighted Average Exercise Price | 18.44 | ||
Forfeited or expired, Weighted Average Exercise price | 37.11 | ||
Outstanding, Weighted Average Exercise Price, ending balance | 25.81 | $ 13.69 | |
Stock options vested and expected to vest, Weighted Average Exercise Price | 25.81 | ||
Exercisable, Weighted Average Exercise Price | $ 17.75 | ||
Outstanding, Weighted Average Remaining Contractual Term | 6 years 5 months 1 day | ||
Stock options vested and expected to vest, Weighted Average Remaining Contractual Term | 6 years 5 months 1 day | ||
Exercisable, Weighted Average Remaining Contractual Term | 5 years 9 months | ||
Aggregate intrinsic value | $ 12,978 | ||
Vested and expected to vest, Aggregate Intrinsic Value | 12,978 | ||
Exercisable, Aggregate Intrinsic Value | $ 2,470 |
Stockholders' Equity - Summar36
Stockholders' Equity - Summary of Estimated Weighted-Average Assumptions (Detail) - $ / shares | 12 Months Ended | |
Dec. 31, 2015 | Dec. 31, 2014 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
Expected dividend yield | 0.00% | |
Employees | ||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
Expected term (years) | 4 years 6 months | 4 years 6 months |
Expected volatility | 72.40% | 65.70% |
Risk-free interest rate | 1.60% | 1.60% |
Expected dividend yield | 0.00% | 0.00% |
Weighted-average estimated grant date fair value per share | $ 16.63 | $ 7.29 |
Non Employees | ||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
Expected term (years) | 7 years | 7 years |
Expected volatility | 71.50% | 65.80% |
Risk-free interest rate | 2.00% | 2.20% |
Expected dividend yield | 0.00% | 0.00% |
Weighted-average estimated grant date fair value per share | $ 27.82 | $ 8.61 |
Stockholders' Equity - Schedu37
Stockholders' Equity - Schedule of Stock-based Compensation Related to All Employee And Non-employee Awards (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |||
Total stock-based compensation | $ 10,251 | $ 10,101 | $ 1,713 |
Research and development | |||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |||
Total stock-based compensation | 4,822 | 3,258 | 251 |
General and administrative | |||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |||
Total stock-based compensation | $ 5,429 | $ 6,843 | $ 1,462 |
Income Taxes - Income Tax Provi
Income Taxes - Income Tax Provision (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Current provision (benefit) for: | |||
Federal income taxes | $ (1) | $ (36) | $ 153 |
State income taxes | (8) | 11 | 17 |
Total current provision (benefit) | $ (9) | $ (25) | $ 170 |
Income Taxes - Reconciliation o
Income Taxes - Reconciliation of Statutory Tax Rates to Effective Tax Rates (Detail) | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Effective Income Tax Rate Continuing Operations Tax Rate Reconciliation [Abstract] | |||
Federal income taxes at statutory rate | 34.00% | 34.00% | 34.00% |
Non-deductible stock compensation | (0.60%) | (7.30%) | (6.80%) |
State income tax, net of federal benefit | (0.30%) | ||
Other | 0.10% | (0.10%) | |
Valuation allowance | (33.40%) | (26.70%) | (28.80%) |
Effective tax rate | 0.00% | 0.10% | (2.00%) |
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 losses | $ 24,219 | $ 8,220 |
License fees | 5,122 | 2,279 |
Stock-based compensation | 4,999 | 1,964 |
Legal fees | 1,436 | 757 |
Other | 1,249 | 494 |
Total deferred tax assets | 37,025 | 13,714 |
Valuation allowance | (37,025) | (13,714) |
Net deferred tax assets | $ 0 | $ 0 |
Income Taxes - Additional Infor
Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | |
Income Tax Disclosure [Abstract] | |||
Increased in valuation allowance tax | $ 23,300 | $ 9,200 | $ 2,900 |
Net operating loss carryforwards, federal | 68,800 | ||
Net operating loss carryforwards, state | $ 68,700 | ||
Net tax operating losses, expiration | Begin to expire in 2032 in various amounts if not utilized. | ||
Unrealized net operating loss deductions from stock option exercises, federal and state | $ 8,900 | ||
Unrecognized tax benefits | 4,314 | $ 1,643 | |
Unrecognized tax benefits if recognized would affect the effective tax rate | $ 100 |
Income Taxes - Reconciliation42
Income Taxes - Reconciliation of Beginning and Ending Amount of Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2015 | Dec. 31, 2014 | |
Income Tax Disclosure [Abstract] | ||
Balance as of December 31, 2013 | $ 1,643 | |
Gross increases for tax positions related to current year | 2,671 | $ 1,014 |
Gross increases for tax positions related to prior years | 629 | |
Balance as of December 31, 2014 | $ 4,314 | $ 1,643 |