Fate Therapeutics (FATE) 10-K 3 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Mar. 02, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Entity Registrant Name	FATE THERAPEUTICS INC
Entity Central Index Key	1,434,316
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 166,230,000
Entity Common Stock, Shares Outstanding		28,861,711
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 64,809	$ 49,101
Prepaid expenses and other current assets	843	760
Total current assets	65,652	49,861
Property and equipment, net	2,160	1,200
Restricted cash	122	122
Other assets	24
Total assets	67,958	51,183
Current liabilities:
Accounts payable	996	645
Accrued expenses	2,439	2,260
Current portion of deferred rent	54	85
Current portion of deferred revenue	2,401
Repurchase liability for unvested equity awards	1	45
Long–term debt, current portion	7,550	1,535
Total current liabilities	13,441	4,570
Deferred rent	58	51
Deferred revenue	4,934
Accrued expenses	799	149
Long–term debt, net of current portion	$ 10,688	$ 18,073
Commitments and contingencies (Note 5)
Stockholders’ Equity:
Preferred stock, $0.001 par value; authorized shares—5,000,000 at December 31, 2015 and December 31, 2014; no shares issued or outstanding
Common stock, $0.001 par value; authorized shares—150,000,000 at December 31, 2015 and December 31, 2014; issued and outstanding—28,716,570 at December 31, 2015 and 20,569,399 at December 31, 2014	$ 29	$ 21
Additional paid–in capital	180,393	140,711
Accumulated deficit	(142,384)	(112,392)
Total stockholders’ equity	38,038	28,340
Total liabilities and stockholders’ equity	$ 67,958	$ 51,183

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement Of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized shares	150,000,000	150,000,000
Common stock issued	28,716,570	20,569,399
Common stock, outstanding shares	28,716,570	20,569,399

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue:
Collaboration revenue	$ 2,431		$ 626
Grant revenue			345
Total revenue	2,431		971
Operating expenses:
Research and development	19,861	$ 16,435	12,007
General and administrative	10,352	8,469	6,639
Total operating expenses	30,213	24,904	18,646
Loss from operations	(27,782)	(24,904)	(17,675)
Other income (expense):
Interest income	10	2	6
Interest expense	(2,220)	(549)	(796)
Loss on extinguishment of debt		(432)
Change in fair value of exchangeable shares			(2,421)
Change in fair value of warrant liability			(8)
Total other expense, net	(2,210)	(979)	(3,219)
Net loss and comprehensive loss	$ (29,992)	$ (25,883)	$ (20,894)
Net loss per common share, basic and diluted (in dollars per share)	$ (1.18)	$ (1.27)	$ (3.54)
Weighted-average common shares used to compute basic and diluted net loss per share (in shares)	25,484,262	20,451,840	5,896,171

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid In Capital [Member]	Accumulated Deficit [Member]	Convertible Preferred Stock
Balance at Dec. 31, 2012	$ (52,825)	$ 1	$ 12,789	$ (65,615)	$ 56,526
Balance (in shares) at Dec. 31, 2012		1,334,115			44,967,690
Increase (Decrease) in Shareholders' Equity
Exercise of stock options	23		23
Exercise of stock options (in shares)		35,852
Repurchase liability for unvested equity awards	49		49
Stock–based compensation	1,554		1,554
Issuance of common stock for technology	13		13
Issuance of common stock for technology (in shares)		7,692
Beneficial conversion feature related to convertible notes	336		336
Initial public offering of common stock	40,480	$ 8	40,472
Initial public offering of common stock (in shares)		7,666,667
Conversion of convertible preferred stock into common stock	56,526	$ 7	56,519		$ (56,526)
Conversion of convertible preferred stock into common stock (in shares)		7,229,590			(44,967,690)
Conversion of convertible notes into common stock	22,076	$ 4	22,072
Conversion of convertible notes into common stock (in shares)		3,679,401
Exchange of exchangeable shares into common stock	3,318		3,318
Exchange of exchangeable shares into common stock (in shares)		480,763
Issuance of warrants for common stock	192		192
Net loss	(20,894)			(20,894)
Balance at Dec. 31, 2013	50,848	$ 20	137,337	(86,509)
Balance (in shares) at Dec. 31, 2013		20,434,080
Increase (Decrease) in Shareholders' Equity
Exercise of stock options	142	$ 1	141
Exercise of stock options (in shares)		96,856
Repurchase liability for unvested equity awards	49		49
Stock–based compensation	2,434		2,434
Issuance of warrants for common stock	375		375
Issuance of stock on achievement of milestone	375		375
Issuance of stock on achievement of milestone (in shares)		38,463
Net loss	(25,883)			(25,883)
Balance at Dec. 31, 2014	28,340	$ 21	140,711	(112,392)
Balance (in shares) at Dec. 31, 2014		20,569,399
Increase (Decrease) in Shareholders' Equity
Exercise of stock options	420		420
Exercise of stock options (in shares)		227,215
Repurchase liability for unvested equity awards	44		44
Stock–based compensation	2,400		2,400
Senior executive incentive bonuses paid in common stock	97		97
Senior executive incentive bonuses paid in common stock (in Shares)		19,956
Initial public offering of common stock	32,149	$ 7	32,142
Initial public offering of common stock (in shares)		6,900,000
Issuance of common stock to collaboration partner	$ 4,580	$ 1	4,579
Issuance of common stock to collaboration partner (in Shares)		1,000,000
Issuance of stock on achievement of milestone (in shares)	19,956
Net loss	$ (29,992)			(29,992)
Balance at Dec. 31, 2015	$ 38,038	$ 29	$ 180,393	$ (142,384)
Balance (in shares) at Dec. 31, 2015		20,569,399

Consolidated Statements of Con6

Consolidated Statements of Convertible Preferred Stock and Stockholders'Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2013
Common Stock [Member]
Deferred Offering Costs	$ 2,353	$ 5,520

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities
Net loss	$ (29,992)	$ (25,883)	$ (20,894)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization	687	496	571
Issuances of common stock for technology			13
Stock–based compensation	2,400	2,434	1,554
Amortization of discounts	176	24	394
Noncash interest expense	651	167	147
Deferred rent	(24)	(52)	(195)
Deferred revenue	7,335		(63)
Stock–based milestone charges and change in fair value of exchangeable shares		375	2,767
Change in fair value of preferred stock warrants			8
Loss on disposal of assets			18
Loss on extinguishment of debt		3
Changes in assets and liabilities:
Prepaid expenses and other assets	(107)	(146)	(1,271)
Accounts payable and accrued expenses	477	163	1,578
Net cash used in operating activities	(18,397)	(22,419)	(15,373)
Cash flows from investing activities
Purchase of property and equipment	(1,498)	(882)	(244)
Proceeds from sale of property and equipment			6
Net cash used in investing activities	(1,498)	(882)	(238)
Cash flows from financing activities
Issuance of common stock, net of repurchases and issuance cost	420	142	23
Proceeds from public offering of common stock, net of issuance costs	32,149		40,480
Issuance of convertible promissory notes			23,736
Proceeds from sale of common stock to collaboration partner	4,580
Proceeds from long–term debt		20,000
Payments on long–term debt	(1,546)	(1,750)	(2,000)
Payment on convertible promissory note			(1,679)
Payments for the issuance of debt		(26)
Net cash provided by financing activities	35,603	18,366	60,560
Net change in cash and cash equivalents	15,708	(4,935)	44,949
Cash and cash equivalents at beginning of the period	49,101	54,036	9,087
Cash and cash equivalents at end of the period	64,809	49,101	54,036
Supplemental disclosure of cash flow information
Interest paid	$ 1,353	494	250
Supplemental schedule of noncash investing and financing activities
Issuance of warrants for common stock in connection with long–term debt		$ 375
Beneficial conversion feature related to convertible notes			336
Conversion of convertible preferred stock into common stock			56,526
Conversion of convertible notes into common stock			22,076
Exchange of exchangeable shares into common stock			3,318
Warrant liability reclassification to equity			$ 192

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Summary of Significant Accounting Policies	1. Organization and Summary of Significant Accounting Policies Organization Fate Therapeutics, Inc. (the “Company”) was incorporated in the state of Delaware on April 27, 2007 and has its principal operations in San Diego, California. The Company is a biopharmaceutical company dedicated to the development of programmed cellular immunotherapies for cancer and immune disorders. The Company’s cell therapy pipeline is comprised of immuno-oncology programs, including off-the-shelf NK- and T-cell cancer immunotherapies derived from engineered induced pluripotent cells, and immuno-regulatory programs, including hematopoietic cell immunotherapies for protecting the immune system of patients undergoing hematopoietic cell transplantation and for suppressing autoimmunity. Its adoptive cell therapy programs are based on the Company’s novel ex vivo As of December 31, 2015, the Company has devoted substantially all of its efforts to product development, raising capital and building infrastructure and has not generated any revenues from any sales of its therapeutic products. To date, the Company’s revenues have been derived from collaboration agreements and government grants. Initial Public Offering On October 4, 2013, the Company completed its initial public offering (the “IPO”) whereby it sold 7,666,667 shares of common stock at a public offering price of $6.00 per share. Gross proceeds from the offering were $46.0 million. After giving effect to underwriting discounts, commissions and other cash costs related to the offering, net proceeds were $40.5 million. In addition, each of the following occurred in connection with the completion of the IPO on October 4, 2013: · the conversion of all outstanding shares of the Company’s convertible preferred stock into 7,229,590 shares of the Company’s common stock; · the conversion of the Company’s $22.1 million of outstanding principal and accrued interest on its convertible notes into 3,679,401 shares of common stock, the write‑off of $0.3 million of unamortized debt discount and the related cash repayment of $1.7 million of outstanding principal and accrued interest on the convertible notes; · the issuance of 480,763 shares of the Company’s common stock pursuant to the redemption of an aggregate of 900,000 exchangeable shares of Fate Therapeutics (Canada) Inc. (“Fate Canada”), a subsidiary of the Company incorporated in Canada, resulting in a final fair value adjustment charge of $0.4 million on the exchangeable shares, and the resultant reclassification of the exchangeable share liability to additional paid‑in capital; · the conversion of warrants to purchase 230,000 shares of convertible preferred stock into warrants to purchase 36,074 shares of the Company’s common stock, and the resultant reclassification of the warrant liability to additional paid‑in capital; and · the filing of an amended and restated certificate of incorporation on October 3, 2013, authorizing 150,000,000 shares of common stock and 5,000,000 shares of undesignated preferred stock. Follow-on Public Equity Offering In May 2015, the Company completed a public offering of common stock in which the Company sold 6,900,000 shares of its common stock at an offering price of $5.00 per share. Gross proceeds from the offering were $34.5 million. Total underwriting discounts, commissions, and other cash costs related to the offering were $2.4 million. After giving effect to all such costs, total net proceeds from the offering were $32.1 million. Use of Estimates The Company’s consolidated financial statements are prepared in accordance with United States generally accepted accounting principles (“GAAP”). The preparation of the Company’s consolidated financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s consolidated financial statements and accompanying notes. The most significant estimates in the Company’s consolidated financial statements relate to accrued expenses. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions. Principles of Consolidation The consolidated financial statements include the accounts of the Company and its subsidiaries, Fate Therapeutics (Canada), Inc. or “Fate Canada”, incorporated in Canada, Fate Therapeutics Ltd., incorporated in the United Kingdom, and Destin Therapeutics Inc., incorporated in Canada, which was dissolved in June 2014. To date, the aggregate operations of these subsidiaries have not been significant and all intercompany transactions and balances have been eliminated in consolidation. Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision‑maker in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment. Fair Value of Financial Instruments The carrying amounts of accounts payable and accrued liabilities are considered to be representative of their respective fair values because of the short‑term nature of those instruments. Based on the borrowing rates currently available to the Company for loans with similar terms, which is considered a Level 2 input, the Company believes that the fair value of long‑term debt approximates its carrying value. The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market‑based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three‑ tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets; Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. As of each of December 31, 2015 and 2014, the carrying amount of cash equivalents was $35.3 million, which approximates fair value and was determined based upon Level 1 inputs. Cash equivalents primarily consisted of money market funds. As of December 31, 2015 and 2014, the Company did not hold any Level 2 or Level 3 financial assets that are recorded at fair value on a recurring basis. As of December 31, 2015 and 2014, the Company had no liabilities measured at fair value on a recurring basis. Financial liabilities that were previously measured at fair value on a recurring basis include the preferred stock warrant liability and exchangeable shares for the period the liabilities were outstanding. The preferred stock warrant liability was recorded at fair value using the Black‑Scholes option pricing model and the exchangeable share liability was recorded at fair value based on the fair value of the underlying common stock. These liabilities were reclassified from liabilities to stockholders’ equity as a result of the completion of the Company’s IPO on October 4, 2013, which was the final fair value measurement date for each. None of the Company’s non‑financial assets or liabilities is recorded at fair value on a non‑recurring basis. No transfers between levels have occurred during the periods presented. Cash and Cash Equivalents Cash and cash equivalents include cash in readily available checking and savings accounts, money market accounts and money market funds. The Company considers all highly liquid investments with an original maturity of three months or less from the date of purchase to be cash equivalents. Concentration of Credit Risk Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. Property and Equipment Property and equipment are recorded at cost and depreciated using the straight‑line method over the estimated useful lives of the assets (generally two to five years) and generally consist of furniture and fixtures, computers, scientific and office equipment. Repairs and maintenance costs are charged to expense as incurred. Impairment of Long‑Lived Assets Long‑lived assets consist primarily of property and equipment. An impairment loss is recorded if and when events and circumstances indicate that assets might be impaired and the undiscounted cash flows estimated to be generated by those assets are less than the carrying amount of those assets. While the Company’s current and historical operating losses and negative cash flows are indicators of impairment, management believes that future cash flows to be received support the carrying value of its long‑lived assets and, accordingly, has not recognized any impairment losses since inception. Deferred Rent Deferred rent consists of the difference between cash payments and the recognition of rent expense on a straight‑line basis for the facilities the Company occupies. The Company’s leases for its facilities provide for fixed increases in minimum annual rental payments. The total amount of rental payments due over the lease terms are charged to rent expense ratably over the life of the leases. Revenue Recognition The Company recognizes revenues when all four of the following criteria are met: (i) persuasive evidence that an agreement exists; (ii) delivery of the products and/or services has occurred; (iii) the selling price is fixed or determinable; and (iv) collectability is reasonably assured. Revenue arrangements with multiple elements are analyzed to determine whether the elements can be divided into separate units of accounting or whether the elements must be accounted for as a single unit of accounting. The Company divides the elements into separate units of accounting and applies the applicable revenue recognition criteria to each of the elements, if the delivered elements have value to the customer on a stand-alone basis, if the arrangement includes a general right of return relative to the delivered elements, and if the delivery or performance of the undelivered elements is considered probable and substantially within the Company’s control. For transactions entered into prior to 2011, revenue was allocated to each element based on its relative fair value when objective and reliable evidence of fair value existed for all elements in an arrangement. If an element was sold on a stand-alone basis, the fair value of the element was the price charged for the element. When the Company was unable to establish fair value for delivered elements or when fair value of undelivered elements had not been established, revenue was deferred until all elements were delivered or until fair value could be objectively determined for any undelivered elements. Beginning in 2011, revenue has been allocated to each element at the inception of the arrangement using the relative selling price method that is based on a three-tier hierarchy. The relative selling price method requires that the estimated selling price for each element be based on vendor-specific objective evidence (“VSOE”) of fair value, which represents the price charged for each element when it is sold separately or, for an element not yet being sold separately, the price established by management. When VSOE of fair value is not available, third-party evidence (“TPE”) of fair value is acceptable, or a best estimate of selling price is used if neither VSOE nor TPE is available. A best estimate of selling price should be consistent with the objective of determining the price at which the Company would transact if the element were sold regularly on a stand-alone basis and should also take into account market conditions and company-specific factors. Revenue arrangements with multiple elements may include license fees, research and development payments, milestone payments, other contingent payments, and royalties on any product sales derived from collaborations. The Company recognizes nonrefundable license fees with stand-alone value as revenue at the time that the Company has satisfied all performance obligations, and recognizes license fees without stand-alone value as revenue in combination with any undelivered performance obligations. The Company recognizes a research and development payment as revenue over the term of the collaboration agreement as contracted amounts are earned, or reimbursable costs are incurred, under the agreement, where contracted amounts are considered to be earned in relative proportion to the performance required under the applicable agreement. The Company recognizes a milestone payment, which is contingent upon the achievement of a milestone in its entirety, as revenue in the period in which the milestone is achieved only if the milestone meets all criteria to be considered substantive. These criteria include the following: (i) the consideration being earned should be commensurate with either the Company’s performance to achieve the milestone or the enhancement of the value of the item delivered as a result of a specific outcome resulting from the Company’s performance to achieve the milestone; (ii) the consideration being earned should relate solely to past performance; (iii) the consideration being earned should be reasonable relative to all deliverables and payment terms in the arrangement; and (iv) the milestone should be considered in its entirety and cannot be bifurcated into substantive and nonsubstantive components. Any amounts received pursuant to revenue arrangements with multiple elements prior to satisfying the Company’s revenue recognition criteria are recorded as deferred revenue on the Company’s consolidated balance sheets. Revenue from government grants is recorded when reimbursable expenses are incurred under the grant in accordance with the terms of the grant award. Research and Development Costs All research and development costs are expensed as incurred. Patent Costs Costs related to filing and pursuing patent applications are recorded as general and administrative expense and expensed as incurred since recoverability of such expenditures is uncertain. Stock‑Based Compensation Stock-based compensation expense represents the cost of the grant date fair value of employee stock option and restricted stock unit grants recognized over the requisite service period of the awards (usually the vesting period) on a straight-line basis, net of estimated forfeitures. For stock option grants for which vesting is subject to performance-based milestones, the expense is recorded over the remaining service period after the point when the achievement of the milestone is probable or the performance condition has been achieved. For stock option grants for which vesting is subject to both performance-based milestones and market conditions, expense is recorded over the derived service period after the point when the achievement of the performance-based milestone is probable or the performance condition has been achieved. The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model, with the exception of option grants for which vesting is subject to both performance-based milestones and market conditions, which are valued using a lattice-based model. The fair value of restricted stock units is based on the closing price of the Company’s common stock as reported on The NASDAQ Global Market on the date of grant. The Company accounts for stock options and restricted stock awards to non-employees using the fair value approach. Stock options and restricted stock awards to non-employees are subject to periodic revaluation over their vesting terms. For stock option grants for which vesting is subject to performance-based milestones, the expense is recorded over the remaining service period after the point when the performance condition is determined to be probable of achievement or when it has been achieved. Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax‑planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions on the basis of a two‑step process whereby (1) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more‑ likely‑than‑not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability. Comprehensive Loss Comprehensive loss is defined as a change in equity during a period from transactions and other events and circumstances from non‑owner sources. Net loss and comprehensive loss were the same for all periods presented. Net Loss Per Common Share Basic net loss per common share is calculated by dividing the net loss by the weighted‑average number of common shares outstanding for the period, without consideration for common stock equivalents. Excluded from the weighted‑average number of shares outstanding are shares which have been issued upon the early exercise of stock options and are subject to future vesting and unvested restricted stock totaling 44,381 shares, 76,947 shares, and 107,570 shares for the years ended December 31, 2015, 2014, and 2013, respectively. Diluted net loss per common share is calculated by dividing the net loss by the weighted‑average number of common share equivalents outstanding for the period determined using the treasury‑stock method. Dilutive common stock equivalents are comprised of convertible preferred stock, warrants for the purchase of convertible preferred stock and common stock, exchangeable shares and common stock options outstanding under the Company’s stock option plans. For all periods presented, there is no difference in the number of common shares used to calculate basic and diluted common shares outstanding due to the Company’s net loss position. Potentially dilutive securities not included in the calculation of diluted net loss per common share because to do so would be anti‑dilutive are as follows (in common stock equivalent shares): As of December 31, 2015 2014 2013 Warrants for common stock 134,113 134,113 36,074 Common stock options 2,587,474 2,425,969 1,726,991 2,721,587 2,560,082 1,763,065 Recent Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update No. 2016-02 (ASU 2016-02) . In November 2015, the FASB issued ASU 2015-17, which requires that all deferred tax assets and liabilities be classified as noncurrent on the balance sheet, instead of separating deferred taxes into current and noncurrent amounts. The update is effective for financial statements issued for fiscal years beginning after December 15, 2016. As early adoption of this amendment is permitted, the Company has adopted the update prospectively during the year ended December 31, 2015. The adoption of this guidance did not have a material impact on the Company’s Consolidated Financial Statements. In April 2015, the FASB issued ASU 2015-03, which requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The update is effective for financial statements issued for fiscal years beginning after December 15, 2015. As early adoption of this amendment is permitted, the Company has implemented the update accordingly by reclassifying prior period and current period amounts from assets to liabilities. The adoption of this guidance did not have a material impact on the Company’s Consolidated Financial Statements. In August 2014, the FASB issued ASU 2014-15, which defined management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related disclosure. ASU 2014-15 defined the term substantial doubt and requires an assessment for a period of one year after the date of the issuance of the financial statements. It requires certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans and requires an express statement and other disclosures when substantial doubt is not alleviated. The guidance becomes effective for reporting periods ending after December 15, 2016, with early adoption permitted. The Company does not believe that the adoption of this guidance will have a material impact on its Consolidated Financial Statements. In May 2014, the FASB issued ASU 2014-09, which created a single, principle-based revenue recognition model that will supersede and replace nearly all existing U.S. GAAP revenue recognition guidance. Entities will recognize revenue in a manner that depicts the transfer of goods or services to customers at an amount that reflects the consideration to which the entity expects to be entitled to receive in exchange for those goods or services. The model provides that entities follow five steps: (i) identify the contract with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations, and (v) recognize revenue. For public business entities, the guidance becomes effective for annual reporting periods beginning after December 15, 2017, and interim periods therein. The Company is currently evaluating the impact the adoption of this guidance will have on its Consolidated Financial Statements.

Collaboration and License Agree

Collaboration and License Agreements	12 Months Ended
	Dec. 31, 2015
Collaboration And License Agreements Disclosure [Abstract]
Collaboration and License Agreements	2. Collaboration and License Agreements Juno Collaboration Agreement On May 4, 2015, the Company entered into a strategic research collaboration and license agreement (the “Agreement”) with Juno Therapeutics, Inc. (“Juno”) to screen for and identify small molecules that enhance the therapeutic properties of Juno’s genetically-engineered T-cell immunotherapies. Pursuant to the terms of the Agreement, Juno paid the Company a non-refundable upfront payment of $5.0 million and purchased 1,000,000 shares of the Company’s common stock at a price of $8.00 per share. Additionally, Juno agreed to fund all of the Company’s collaboration research activities for an initial four-year research term beginning on the effective date of the Agreement, with minimum annual research payments of $2.0 million to the Company. Juno has the option to extend the exclusive research term for an additional two years beyond the initial four-year term, subject to the payment of an extension fee of $3.0 million and the continued funding of the Company’s activities under the collaboration during the extended term, with minimum annual research payments of $4.0 million to the Company during the two-year extension period. Upon exercise of the research term extension, the Company has the option to require Juno to purchase up to $10.0 million of the Company’s common stock at a premium equal to 120% of the then thirty-day trailing volume weighted average trading price of the Company’s common stock. The Company applied Accounting Standards Codification (“ASC”) 605-25, Revenue Recognition — Multiple Element Arrangements, Pursuant to the collaboration’s research plan under the Agreement, the Company is responsible for screening and identifying small molecule modulators of immunological cells, while Juno will be responsible for the development and commercialization of engineered T-cell immunotherapies incorporating the Company’s modulators. As the Company is principally responsible for the performance of the research services under the Agreement, revenue is recognized on a gross basis for such services when earned. Billings for research services will be recognized as deferred revenue until earned. Total revenue recognized under the Agreement for year ended December 31, 2015 was $2.4 million. As of December 31, 2015, aggregate deferred revenue related to the Agreement was $7.3 million. Under the Agreement, the Company has granted Juno an exclusive worldwide license to certain of its intellectual property, including its intellectual property arising under the collaboration, to make, use, sell and otherwise exploit genetically-engineered T-cell immunotherapies using or incorporating small molecule modulators directed against certain designated tumor-associated antigen targets, subject to the selection of a target by Juno. The Company has retained exclusive rights to such intellectual property, including its intellectual property arising under the collaboration, for all other purposes, including its use outside of those targets selected by Juno. The Company is eligible under the Agreement to receive selection fees for each tumor-associated antigen target selected by Juno and bonus selection fees based on the aggregate number of tumor-associated antigen targets selected by Juno. In accordance with ASC 605-28, Revenue Recognition — Milestone Method In connection with each Juno therapy that uses or incorporates the Company’s small molecule modulators, Juno has agreed to pay the Company non-refundable, non-creditable milestone payments totaling up to approximately $51.0 million in the aggregate per therapy upon the achievement of various clinical, regulatory and commercial milestones. Additionally, in connection with the third Juno therapy and the fifth Juno therapy that uses or incorporates the Company’s small molecule modulators, Juno has agreed to pay the Company additional non-refundable, non-creditable bonus milestone payments totaling up to approximately $116.0 million and $137.5 million, respectively, in the aggregate, per therapy upon the achievement of various clinical, regulatory, and commercial milestones. In accordance with ASU 2010-17, the Company determined that these contingent payments meet the definition of a milestone under ASU 2010-17, and that the milestones are substantive given that the milestones are commensurate with the Company’s performance, relate solely to the Company’s past performance, and are reasonable relative to other deliverables and payments under the Agreement. Accordingly, the milestones under the Agreement will be accounted for as revenue on the achievement date, if any. Beginning on the date of the first commercial sale (in each country) for each Juno therapy that uses or incorporates the Company’s small molecule modulators, and continuing until the later of: i) the expiration of the last valid patent claim, ii) ten years after such first commercial sale, or iii) the expiration of all data and other regulatory exclusivity periods afforded each therapy, Juno has agreed to pay the Company royalties in the low single-digits on net sales of each Juno therapy that uses or incorporates the Company’s small molecule modulators. The Agreement will end on the date that no further payments are due under the Agreement. Becton, Dickinson and Company Collaboration Agreement On September 30, 2010, the Company entered into a worldwide exclusive collaboration and license agreement with Becton, Dickinson and Company (“BD”) for the joint development and worldwide commercialization of certain induced pluripotent stem cell (“iPSC”) tools and technologies for use in drug discovery and development. In connection with the agreement, the Company received a $0.3 million upfront, nonrefundable license payment and received research funding of $0.8 million per year, during a three‑year joint development period, for the conduct of its development activities. In addition, the Company is eligible to receive: (i) milestone payments in the amount of $0.5 million, $0.7 million and $0.8 million in connection with the first commercial sale of up to three different iPSC products developed under the agreement, (ii) milestone payments of up to an aggregate amount of $4.0 million in connection with the achievement of certain annual net sales of iPSC products and (iii) royalties on the sale of such iPSC products. In 2012, the Company received a milestone payment of $0.5 million in connection with the first commercial sale of an iPSC product. The Company does not believe it is probable that it will receive any future milestone payments in connection with the first commercial sale of an iPSC product or the achievement of certain annual net sales of iPSC products, or any material royalties, under the agreement. License payments under the BD agreement were recorded as deferred revenue upon receipt and recognized ratably as revenue over the three‑year program period as a result of the Company’s continuing involvement with the collaboration. Funding received for the Company’s research efforts under the program was recognized as revenue as costs were incurred, which approximated the level of effort over the three year period of the program. The Company recognized revenue from milestone payments when earned, provided that (i) the milestone event is substantive in that it can only be achieved based in whole or in part on either the Company’s performance or on the occurrence of a specific outcome resulting from the Company’s performance and its achievability was not reasonably assured at the inception of the agreement, (ii) the Company does not have ongoing performance obligations related to the achievement of the milestone and (iii) it would result in the receipt of additional payments. A milestone payment is considered substantive if all of the following conditions are met: (i) the milestone payment is non‑refundable; (ii) achievement of the milestone was not reasonably assured at the inception of the arrangement; (iii) substantive effort is involved to achieve the milestone; and (iv) the amount of the milestone payment appears reasonable in relation to the effort expended, the other milestones in the arrangement and the related risk associated with the achievement of the milestone. Royalties received under the agreement will generally be recognized as revenue upon receipt of the related royalty payment. In connection with the BD agreement for the year ended December 31, 2013 the Company recognized $0.6 million as revenue in its consolidated statements of operations.

Asset Acquisition of Verio Ther

Asset Acquisition of Verio Therapeutics Inc.	12 Months Ended
	Dec. 31, 2015
Asset Acquisition [Abstract]
Asset Acquisition of Verio Therapeutics Inc.	3. Asset Acquisition of Verio Therapeutics Inc. Acquisitions are analyzed to determine whether an acquired set of activities and assets represents a business. A business is considered to be an integrated set of activities and assets that is capable of being conducted and managed for the purpose of providing a return in the form of dividends, lower costs, or other economic benefits directly to investors or other owners, members, or participants. A business commonly has three elements: inputs, processes applied to those inputs, and outputs. A set of activities and assets is required to have only the first two of those three elements, which together are or will be used to create outputs, to be considered a business. If an acquired set of activities and assets does not represent a business, the acquired set of activities and assets represents an asset. On April 7, 2010, the Company acquired Verio Therapeutics Inc. (“Verio”), a development stage company headquartered in Ottawa, Ontario to gain access to its exclusively licensed intellectual property. Based on its evaluation of the set of activities and assets of Verio, the Company determined that Verio did not meet the definition of a business. Based on its assessment, the Company determined that Verio was a development stage enterprise without any material inputs; without any processes that create, or have the ability to create, outputs; and without any outputs. As such, the Company accounted for the acquisition of Verio as an asset acquisition and charged the associated consideration paid for the assets to research and development expense. In connection with the asset acquisition of Verio, the stockholders of Verio received 900,000 non‑voting shares of Fate Canada (the “Exchangeable Shares”) that were initially exchangeable into 138,462 shares of the Company’s common stock and, subject to the validation of certain scientific data and the achievement of certain preclinical, clinical, commercial and financial milestones, were exchangeable for up to 884,605 shares of the Company’s common stock. Additionally, the Company assumed $212,090 of net liabilities of Verio. The purchase price of the Verio asset acquisition is summarized as follows (in thousands): Net liabilities $ 212 Initial fair value of Exchangeable Shares 234 $ 446 The amounts in the table above represent an estimate of the fair value of purchased in‑process technology for projects that, as of the acquisition date, had not yet reached technological feasibility and had no alternative future use. As a result of the Company’s IPO on October 4, 2013, 480,763 shares of the Company’s common stock were issued during the fourth quarter of 2013 pursuant to the redemption of the Exchangeable Shares. The total number of shares of the Company’s common stock issued upon the exchange of the Exchangeable Shares as a result of the IPO had increased from 138,462 shares of the Company’s common stock to a total of 480,763 shares of the Company’s common stock based upon the achievement of certain contractual milestones. During the year ended December 31, 2014, based on the achievement of certain preclinical milestones, an additional 38,463 shares of the Company’s common stock were earned and issued, resulting in a $0.4 million charge to research and development expense. In April 2015, the contractual earn-out period during which milestones were eligible to be earned and achieved expired under the Verio agreement and, as such, there are no additional contractual milestones that remain eligible for achievement. Accordingly, no additional shares of the Company’s common stock remain issuable under the Verio agreement. Prior to the Company’s IPO, on the date of achievement of a milestone, the fair value of the related increase in the number of shares of common stock of the Company into which the Exchangeable Shares were exchangeable was charged to research and development expense. Additionally, the fair value of the Exchangeable Shares was re‑measured at each reporting date, with any changes in fair value being recognized in the change in fair value of the exchangeable share liability, a component of other income (expense), in the accompanying consolidated statements of operations. The fair value of the exchangeable share liability was equal to the fair value of the number of shares of common stock of the Company into which the Exchangeable Shares were exchangeable. For the year ended December 31, 2013, the Company recorded other expense related to the change in fair value of the Exchangeable Shares of $2.4 million. For the fourth quarter of 2013, the Company recorded other expense of $0.4 million related to the final fair value adjustment of the exchangeable share liability as of the IPO date, and reclassified the then‑corresponding $3.3 million exchangeable share liability into additional paid‑in capital. The changes in the number of shares of the Company’s common stock issuable, and the initial fair value of the issuable shares, are summarized as follows (in thousands, except share and per share amounts): Shares of Common Stock Fair Value Per Share of Underlying Common Stock Initial Fair Value of Common Stock April 2010 138,462 $ 1.69 $ 234 March 2011 92,308 1.69 156 May 2011 115,380 1.69 195 April 2012 57,691 1.37 78 July 2013 76,922 4.49 346 March 2014 38,463 9.74 375 519,226 $ 1,384

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Property and Equipment	4. Property and Equipment Property and equipment consist of the following (in thousands): December 31, 2015 2014 Furniture and fixtures $ 324 $ 265 Computer and office equipment 300 169 Software 103 103 Leasehold improvements—building 180 66 Scientific equipment 4,725 3,384 Property and equipment, gross 5,632 3,987 Less accumulated depreciation and amortization (3,472 ) (2,787 ) Property and equipment, net $ 2,160 $ 1,200 Depreciation expense related to property and equipment was $0.7 million, $0.5 million, and $0.6 million, for the years ended December 31, 2015, 2014, and 2013, respectively. No material gains or losses on the disposal of property and equipment have been recorded for the years ended December 31, 2015, 2014, and 2013.

Accrued Expenses, Long-Term Deb

Accrued Expenses, Long-Term Debt, Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Accrued Expenses Long Term Debt Commitments And Contingencies Disclosure [Abstract]
Accrued Expenses, Long-Term Debt, Commitments and Contingencies	5. Accrued Expenses, Long-Term Debt, Commitments and Contingencies Accrued Expenses Current accrued expenses consist of the following (in thousands): December 31, 2015 December 31, 2014 Accrued payroll and other employee benefits $ 993 $ 1,234 Accrued clinical trial costs 446 415 Accrued other 1,000 611 Accrued expenses $ 2,439 $ 2,260 During the year ended December 31, 2015, the Company issued 19,956 shares of its common stock to certain senior executives of the Company as consideration for a portion of their 2014 annual bonuses. During January 2016, the Company issued 37,641 shares of its common stock to certain senior executives of the Company as consideration for a portion of their 2015 annual bonuses. All related amounts were accrued for as liabilities as of December 31, 2015 and 2014. Future senior executive bonus amounts, timing, and method of payment are at the sole discretion of the Board of Directors of the Company. As such, all relevant bonus estimates are accrued for as liabilities. Long-term accrued expenses consist primarily of accruals for the final payment fees associated with our long-term debt. Long‑Term Debt Long‑term debt and unamortized discount balances are as follows (in thousands): December 31, 2015 December 31, 2014 Long-term debt $ 18,454 $ 20,000 Less debt issuance costs and discount, net of current portion (77 ) (381 ) Long-term debt, net of long-term portion of debt issuance costs and discount 18,377 19,619 Less current portion of long-term debt (7,689 ) (1,546 ) Long-term debt, net $ 10,688 $ 18,073 Current portion of long-term debt $ 7,689 $ 1,546 Less current portion of debt issuance costs and discount (139 ) (11 ) Current portion of long-term debt, net $ 7,550 $ 1,535 In July 30, 2014, the Company entered into an Amended and Restated Loan and Security Agreement (the “Restated LSA”) with Silicon Valley Bank (the “Bank”), collateralized by substantially all of the Company’s assets, excluding certain intellectual property. The Restated LSA amends and restates the Loan and Security Agreement, dated as of January 5, 2009, as amended, by and between the Company and the Bank (the “Loan Agreement”). Pursuant to the Restated LSA, the Bank agreed to make loans to the Company in an aggregate principal amount of up to $20.0 million, comprised of (i) a $10.0 million term loan, funded at the closing date (the “Term A Loan”) and (ii) subject to the achievement of a specified clinical milestone relating to the Company’s Phase 2 clinical trial of ProHema, additional term loans totaling up to $10.0 million in the aggregate, which were available until December 31, 2014 (each, a “Term B Loan”). On December 24, 2014, the Company elected to draw on the full $10.0 million under a Term B Loan. The Term A Loan and the Term B Loan mature on January 1, 2018 and June 1, 2018, respectively and bear interest at a fixed annual rate of 6.94% and 7.07%, respectively. Interest became payable in cash on a monthly basis beginning the first day of each month following the month in which the funding date of each loan occurred. The Company is required to make a monthly payment of interest only during the first twelve months following the funding date of each loan, and thereafter is required to repay the principal and interest under each loan in thirty equal monthly installments based on a thirty‑month amortization schedule. During the year ended December 31, 2015, the Company made principal payments totaling $1.5 million on the Term A Loan. The Company is required to make a final payment fee of 7.5%, equaling $0.8 million, of the funded amount for each of the Term A Loan and Term B Loan on the respective maturity dates. The final payment fees are accrued as interest expense over the terms of the loans and recorded in long‑term accrued expenses. A portion of the proceeds from the Term A Loan were used to repay loans outstanding under the Loan Agreement and to pay for transaction fees related to the Restated LSA, including a commitment fee of $0.4 million paid by the Company to the Bank. Net proceeds from the Term A Loan, after repayment of loans outstanding under the Loan Agreement and transaction fees, were $8.8 million. The Company determined the repayment of the Loan Agreement was a debt extinguishment, and accounted for the Term A Loan at fair value as of the issuance date accordingly. During the year ended December 31, 2014, the Company recorded a loss on debt extinguishment of $0.4 million, primarily related to the commitment fee paid to the Bank. Proceeds from the Term B Loan were $10.0 million. In connection with the funding of the Term B Loan, the Company issued the Bank and one of its affiliates fully‑exercisable warrants to purchase an aggregate of 98,039 shares of the Company’s common stock (the “Warrants”) at an exercise price of $4.08 per share. The Warrants expire in December 2021. The aggregate fair value of the Warrants was determined to be $0.4 million using the Black‑Scholes option pricing model (see Note 6 of the Notes to the Consolidated Financial Statements for additional information) and was recorded as a debt discount on the Term B Loan and is amortized to interest expense over the term of the Term B Loan using the effective interest method. The Company determined the effective interest rates of the Term A Loan and Term B Loan to be 10.3% and 12.0%, respectively. For the years ended December 31, 2015 and 2014 the Company recorded $2.2 million and $0.5 million, respectively, in aggregate interest expense related to the Term A and Term B Loans. For the years ended December 31, 2014 and 2013, the Company recorded aggregate interest expense related to the Loan Agreement of $0.1 million and $0.3 million, respectively. Warrants to purchase 36,074 shares of the Company’s common stock at a weighted average exercise price of $7.21 per share issued in connection with the Loan Agreement remain outstanding as of December 31, 2015, with 5,305 and 30,769 of such warrants having expiration dates in January 2019 and August 2021, respectively. June and July 2013 Convertible Note Financing In June and July 2013, the Company issued convertible promissory notes in an aggregate principal amount of $3.7 million to certain existing stockholders. The notes accrued interest at 2% per year and were due on June 24, 2014. The outstanding principal and all accrued and unpaid interest due on the notes were converted into 625,828 shares of the Company’s common stock as a result of the Company’s IPO on October 4, 2013. In connection with the issuance of the convertible notes, the Company recorded a debt discount of $0.3 million related to a beneficial conversion feature that was recorded as the proceeds allocated to the debt instrument were less than the gross fair value of the shares of Series C convertible preferred stock into which the notes could convert. This debt discount was amortized as interest expense utilizing the effective interest method over the one‑year term of the notes. For the year ended December 31, 2013, the entire $0.3 million debt discount was charged to interest expense in connection with its amortization during the period for which the notes were outstanding and the conversion of the notes into common stock pursuant to the Company’s IPO on October 4, 2013. August 2013 Convertible Note Financing In August 2013, the Company issued convertible promissory notes in an aggregate principal amount of $20.0 million to certain new investors. The notes accrued interest at 2% per year and were due on August 8, 2016. In connection with the completion of the Company’s IPO on October 4, 2013, the Company repaid $1.7 million of then‑outstanding principal and unpaid accrued interest on the notes in cash, with the remaining outstanding principal converting to 3,053,573 shares of the Company’s common stock. For the year ended December 31, 2013, the Company recorded aggregate interest expense of $0.1 million on the stated interest rate of the notes issued in August 2013. Facility Lease The Company leases certain office and laboratory space from a stockholder of the Company under a non-cancelable operating lease. In March 2015, the Company extended the term of the lease on this facility an additional 15 months through September 2017. The lease is subject to additional charges for common area maintenance and other costs. In connection with the lease, the Company entered into a cash-collateralized irrevocable standby letter of credit in the amount of $0.1 million. As of December 31, 2015, future minimum payments under the operating lease are $1.8 million. In January 2015, the Company entered into a sublease for additional laboratory space. The sublease is accounted for as an operating lease and expires in September 2017. Under the sublease, total future minimum payments as of December 31, 2015 are $0.5 million. Aggregate contractual rent expense for both leases was $1.2 million, $0.9 million, and $0.9 million for the years ended December 31, 2015, 2014, and 2013, respectively. License Agreements The Company has entered into exclusive license agreements with certain academic institutions and universities pursuant to which the Company acquired certain intellectual property. Pursuant to each agreement, as consideration for an exclusive license to the intellectual property, the Company paid a license fee, reimbursed the institution for historical patent costs and, in certain instances, issued the institution shares of restricted common stock. Additionally, under each agreement, the institution is generally eligible to receive future consideration including, but not limited to, annual maintenance fees, royalties, milestone payments and sublicensing fees. Each of the license agreements is generally cancelable by the Company, given appropriate prior written notice. Minimum annual payments to maintain these cancelable licenses total an aggregate of $0.3 million. Commitments Future minimum payments under the long‑term debt and the non‑cancelable operating leases as of December 31, 2015 are as follows (in thousands): Long–Term Debt Operating Leases Total Years Ending December 31, 2016 $ 8,757 1,270 10,027 2017 8,757 1,088 9,845 2018 4,055 — 4,055 Total $ 21,569 $ 2,358 $ 23,927 Less interest (1,615 ) Less additional payments due upon maturity (1,500 ) Less unamortized debt discount and debt issuance costs (216 ) Less current portion of long–term debt (7,550 ) Long–term debt, net of current portion $ 10,688

Convertible Preferred Stock and

Convertible Preferred Stock and Stockholders' Equity	12 Months Ended
	Dec. 31, 2015
Convertible Preferred Stock And Stockholders Deficit Disclosure [Abstract]
Convertible Preferred Stock and Stockholders' Equity (Deficit)	6. Convertible Preferred Stock and Stockholders’ Equity Convertible Preferred Stock The authorized, issued and outstanding shares of convertible preferred stock by series immediately prior to October 4, 2013 (the date each outstanding share of convertible preferred stock was converted to common stock as a result of the Company’s IPO) is as follows: Shares Authorized Shares Outstanding Series A 14,609,186 14,609,186 Series B 12,080,000 12,050,000 Series B–1 1,500,000 1,500,000 Series C 29,000,000 16,808,504 Series C–1 11,171,000 — 68,360,186 44,967,690 In connection with the completion of the Company’s IPO on October 4, 2013, all of the outstanding shares of convertible preferred stock converted into 7,229,590 shares of the Company’s common stock. Each outstanding share of Series A and Series C convertible preferred stock converted into approximately 0.1538 shares of common stock, or 4,833,490 common shares, and each outstanding share of Series B and Series B‑1 convertible preferred stock converted into approximately 0.1768 shares of common stock, or 2,396,100 common shares. Description of Securities Dividends As of December 31, 2015, the Board of Directors of the Company has not declared any dividends. 2007 Equity Incentive Plan and 2013 Stock Option and Incentive Plan The Company adopted an Equity Incentive Plan in 2007 (the 2007 Plan) under which, as amended in August 2013, 2,423,072 shares of common stock were reserved for issuance to employees, nonemployee directors and consultants of the Company. The 2007 Plan provides for the grant of incentive stock options, non‑statutory stock options, rights to purchase restricted stock, stock appreciation rights, dividend equivalents, stock payments, and restricted stock units to eligible recipients. In connection with the issuance of restricted common stock, the Company maintains a repurchase right where shares of restricted common stock are released from such repurchase right over a period of time of continued service by the recipient. Effective upon the completion of the Company’s IPO, the board of directors determined not to grant any further awards under the 2007 Plan. On August 28, 2013, the Company’s board of directors and stockholders approved and adopted the 2013 Stock Option and Incentive Plan (the “2013 Plan” and collectively with the 2007 Plan “the Plans”). The 2013 Plan became effective immediately prior to the Company’s IPO. Under the 2013 Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units and other awards to individuals who are then employees, officers, directors or consultants of the Company or its subsidiaries. A total of 1,020,000 shares of common stock were initially reserved for issuance under the 2013 Plan. The shares issuable pursuant to awards granted under the 2013 Plan will be authorized, but unissued shares. The shares of common stock underlying any awards from the 2013 Plan and the 2007 Plan that are forfeited, cancelled, held back upon exercise or settlement of an award to satisfy the exercise price or tax withholding, reacquired by us prior to vesting, satisfied without any issuance of common stock, expire or are otherwise terminated (other than by exercise) under the 2013 Plan and the 2007 Plan will be added back to the shares of common stock available for issuance under the 2013 Plan. In addition, the number of shares of stock available for issuance under the 2013 Plan will be automatically increased each January 1 by 4% of the outstanding number of shares of the Company’s common stock on the immediately preceding December 31 or such lesser number as determined by the compensation committee of the Company’s board of directors. Recipients of incentive stock options under the Plans shall be eligible to purchase shares of the Company’s common stock at an exercise price equal to no less than the estimated fair value of such stock on the date of grant. Under the Plans, stock options generally vest 25% on the first anniversary of the original vesting date, with the balance vesting monthly over the remaining three years, or vest monthly over four years, unless they contain specific performance and/or market‑based vesting provisions. The maximum term of stock options granted under the Plans is ten years. Restricted stock units under the 2013 Plan generally vest 50% on the second anniversary of the grant date, and 50% on the fourth anniversary of the grant date. Employee Stock Purchase Plan On September 13, 2013, the Company’s board of directors approved and adopted the 2013 Employee Stock Purchase Plan (the “ESPP”). The ESPP became effective immediately prior to the completion of the IPO. A total of 729,000 shares of common stock were initially reserved for issuance under the ESPP. In addition, the number of shares of stock available for issuance under the ESPP will be automatically increased each January 1, beginning on January 1, 2015, by the lesser of (i) 2% of the outstanding number of shares of the Company’s common stock on the immediately preceding December 31, (ii) 450,000 shares, or (iii) such lesser number as determined by the compensation committee of the Company’s board of directors. No purchases have been made to date under the ESPP. Stock Options and Restricted Stock Awards Stock Options. The following table summarizes stock option activity and related information under the Plans for the year ended December 31, 2015: Options Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (in 000s) Outstanding at December 31, 2014 2,425,969 $ 3.83 8.06 $ 4,839 Granted 1,345,744 5.23 Exercised (227,215 ) 1.85 Cancelled (957,024 ) 4.20 Outstanding at December 31, 2015 2,587,474 $ 4.59 6.92 $ 1,486 Options vested and expected to vest at December 31, 2015 2,478,573 $ 4.54 8.01 $ 1,481 Options exercisable at December 31, 2015 1,309,010 $ 3.71 4.99 $ 1,330 As of December 31, 2015 and 2014, the outstanding options included 14,769 and 138,649, respectively, of performance‑based options for which the achievement of the performance‑based vesting provisions was determined not to be probable. The aggregate grant date fair value of these options at December 31, 2015 and December 31, 2014 was $0.1 million and $0.6 million, respectively. For the years ended December 31, 2015, 2014 and 2013, the Company granted its employees 1.2 million, 0.9 million and 0.3 million stock options, respectively, at a weighted‑average grant date fair value per share equal to $3.54, $5.10 and $4.40, respectively. As of December 31, 2015 and 2014, the unrecognized compensation cost related to outstanding options (excluding those with unachieved performance‑ based conditions) was $3.8 million and $4.1 million, respectively, which is expected to be recognized as expense over approximately 2.8 years and 2.6 years, respectively. The total intrinsic value, which is the amount by which the exercise price was exceeded by the price of the Company’s common stock on the date of exercise, of stock options exercised during the year ended December 31, 2015 was $1.0 million. Total cash received upon the exercise of stock options was $0.4 million for the year ended December 31, 2015. Restricted Stock Units. For the year ended December 31, 2015, the Company granted its employees 0.5 million restricted stock units at a weighted‑average grant date price per share equal to $4.89. As of December 31, 2015, 0.5 million restricted stock units were outstanding. As of December 31, 2015 the unrecognized compensation cost related to outstanding restricted stock units was $2.4 million which is expected to be recognized as expense over approximately 3.8 years. Restricted Stock Awards. Unvested outstanding restricted stock awards, issued under the 2007 Plan, as of December 31, 2015 and 2014 were 26,270 and 62,150 shares, respectively. As of December 31, 2015, these awards consist entirely of shares that cliff vest in April 2018 or earlier upon the achievement of specified milestones. Stock‑Based Compensation Expense The allocation of stock‑based compensation for all stock awards is as follows (in thousands): Years Ended December 31, 2015 2014 2013 Research and development $ 1,241 $ 1,416 $ 912 General and administrative 1,159 1,018 642 Total stock-based compensation expense $ 2,400 $ 2,434 $ 1,554 Employee Stock Option Grants. The weighted‑average assumptions used in the Black‑Scholes option pricing model to determine the fair value of the employee stock option grants were as follows: Years Ended December 31, 2015 2014 2013 Risk–free interest rate 1.6 % 1.9 % 1.6 % Expected volatility 81 % 94 % 90 % Expected term (in years) 6.0 6.0 5.9 Expected dividend yield 0.0 % 0.0 % 0.0 % Risk‑free interest rate. The Company bases the risk‑free interest rate assumption on observed interest rates appropriate for the expected term of the stock option grants. Expected dividend yield. The Company bases the expected dividend yield assumption on the fact that it has never paid cash dividends and has no present intention to pay cash dividends. Expected volatility. Due to the Company’s limited operating history and lack of company‑specific historical or implied volatility, the expected volatility assumption is based on historical volatilities of a peer group of similar companies whose share prices are publicly available. The peer group was developed based on companies in the biotechnology industry. Expected term. The expected term represents the period of time that options are expected to be outstanding. As the Company does not have historical exercise behavior, it determines the expected life assumption using the simplified method, which is an average of the contractual term of the option and its vesting period. Based on historical employee turnover experience, pre‑vesting forfeitures for all employee stock option grants was at estimated at 0% for each of the years ended December 31, 2015, 2014, and 2013. Non‑Employee Stock Option Grants. The weighted‑average assumptions used in the Black‑Scholes option pricing model to determine the fair value of the non‑employee stock option grants were as follows: Years Ended December 31, 2015 2014 2013 Risk–free interest rate 0.8 % 2.1 % 2.1 % Expected volatility 72 % 87 % 91 % Expected term (in years) 2.7 6.5 7.3 Expected dividend yield 0.0 % 0.0 % 0.0 % Warrants to Purchase Common Stock in Connection with Debt Issuance As a result of the financing of the Term B Loan on December 24, 2014, the Company issued the Bank and one of its affiliates fully‑exercisable warrants to purchase an aggregate of 98,039 shares of the Company’s common stock at an exercise price of $4.08 per share. The warrants expire in December 2021. See Note 5 of the Notes to the Consolidated Financial Statements for additional information on the debt issuance. The fair value of the warrants was determined to be $0.4 million, which was recorded to additional paid‑in capital as a debt discount. The weighted‑ average assumptions used in the Black‑Scholes option pricing model to determine the fair value of the warrants issued were as follows: As of December 24, 2014 Risk–free interest rate 2.1 % Expected volatility 85 % Expected term (in years) 7.0 Expected dividend yield 0.0 % Common Stock Reserved for Future Issuance Common stock reserved for future issuance is as follows: December 31, 2015 2014 Common stock warrants 134,113 134,113 Common stock options 2,587,474 2,425,969 Awards available under the 2013 Plan 908,288 999,482 Exchangeable shares — 365,379 Employee stock purchase plan 729,000 729,000 4,358,875 4,653,943

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	7. Income Taxes The following is a reconciliation of the Company’s expected federal income tax provision (benefit) to the actual income tax provision (in thousands): Years Ended December 31, 2015 2014 2013 Tax computed at federal statutory rate $ (10,198 ) $ (8,800 ) $ (7,104 ) State tax, net of federal tax benefit 2,226 (1,311 ) (1,011 ) Permanent differences 43 159 755 Stock compensation 213 426 161 R&D tax credits (594 ) (596 ) (373 ) Reserve for uncertain tax positions 1,733 — — Tax attribute limitation 2,727 — — Other (37 ) (256 ) (8 ) Valuation allowance 3,887 10,378 7,580 Income tax expense $ — $ — $ — Significant components of the Company’s deferred tax assets are summarized as follows (in thousands): As of December 31, 2015 2014 Deferred tax assets: Section 59e amortization $ 13,042 $ 13,905 Net operating losses 28,963 25,620 R&D tax credits 1,274 2,221 Depreciation and amortization 921 1,050 Deferred revenue 2,494 — Other 950 961 Deferred tax assets 47,644 43,757 Valuation allowance (47,644 ) (43,757 ) Net deferred tax assets $ — $ — A valuation allowance of $47.6 million and $43.8 million at December 31, 2015 and 2014, respectively, has been established to offset the deferred tax assets, as realization of such assets is uncertain. At December 31, 2015, the Company had federal, California and Canadian net operating loss (“NOL”) carryforwards of approximately $79.8 million, $61.9 million and $0.3 million, respectively, which may be available to offset future taxable income. The federal, California and Canadian NOL carryforwards begin to expire in 2027, 2028 and 2030, respectively, unless previously utilized. At December 31, 2015, the Company had federal and California research and development (“R&D”) credit carryforwards of approximately $0.4 million and $2.7 million, respectively. The federal R&D tax credit carryforwards will begin to expire in 2035 unless previously utilized. The California R&D credit carryforwards will carry forward indefinitely. Under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, or the Code, substantial changes in our ownership may limit the amount of net operating loss and research and development credit carryforwards that could be used annually in the future to offset taxable income. The tax benefits related to future utilization of federal and state net operating loss carryforwards, credit carryforwards, and other deferred tax assets may be limited or lost if cumulative changes in ownership exceeds 50% within any three-year period. The Company completed a study to assess whether an ownership change, as defined by Section 382 of the Internal Revenue Code of 1986, had occurred from the Company’s formation through December 31, 2015. Based upon this study, the Company determined that multiple ownership changes had occurred. Accordingly, the Company reduced its deferred tax assets related to the federal NOL carryforwards and the federal R&D credit carryforwards that are anticipated to expire unused as a result of these ownership changes. These tax attributes were excluded from deferred tax assets with a corresponding reduction of the valuation allowance with no net effect on income tax expense or the effective tax rate. Future ownership changes may further limit the Company’s ability to utilize its remaining tax attributes. The Company files income tax returns in the United States, California and Canada. The Company currently has no years under examination by any jurisdiction; however, the Company is subject to income tax examination by federal, state and Canadian tax authorities for years beginning in 2012, 2011, and 2011, respectively. However, to the extent allowed by law, the taxing authorities may have the right to examine prior periods where NOLs and tax credits were generated and carried forward, and make adjustments up to the amount of the carryforwards. The change in the Company’s unrecognized tax benefits is summarized as follows (in thousands): Balance at December 31, 2012 $ 1,034 Increase related to current year tax positions 295 Balance at December 31, 2013 $ 1,329 Increase related to current year tax positions 491 Balance at December 31, 2014 $ 1,820 Increase related to current year tax positions 374 Increase related to prior year tax positions 2,624 Decrease related to prior year tax positions (949 ) Balance at December 31, 2015 $ 3,869 The Company does not anticipate that the amount of unrecognized tax benefits as of December 31, 2015 will significantly change within the next twelve months. Due to the valuation allowance recorded against the Company’s deferred tax assets, none of the total unrecognized tax benefits as of December 31, 2015 would reduce the effective tax rate if recognized. The Company has not recognized interest or penalties in its consolidated statements of operations and comprehensive loss since inception. During the year ended December 31, 2015, the Company adopted ASU 2015-17 and applied the standard prospectively (prior period amounts were not retrospectively adjusted). With this adoption our deferred tax assets and liabilities are no longer classified between current and non-current. All deferred tax assets and liabilities are now classified as non-current regardless of their classification on the balance sheet and the timing of their anticipated reversal. The Company’s deferred tax assets are fully offset by a valuation allowance, and therefore, the non-current deferred tax asset balance as of December 31, 2015 is zero.

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2015
Compensation And Retirement Disclosure [Abstract]
Employee Benefits	8. Employee Benefits Effective January 1, 2009, the Company adopted a defined contribution 401(k) plan for employees who are at least 21 years of age. Employees are eligible to participate in the plan beginning on the first day of the calendar quarter following date of hire. Under the terms of the plan, employees may make voluntary contributions as a percent of compensation. No matching contributions have been made by the Company since the adoption of the 401(k) plan.

Selected Quarterly Financial Da

Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data	9. Selected Quarterly Financial Data (in thousands, except per share data) (unaudited) First Quarter Second Quarter Third Quarter Fourth Quarter 2015 Revenues $ — $ 329 $ 1,026 $ 1,076 Total operating expenses 7,324 7,547 7,354 7,988 Net loss (7,881 ) (7,779 ) (6,886 ) (7,446 ) Basic and diluted net loss per common share $ (0.38 ) $ (0.33 ) $ (0.24 ) $ (0.26 ) 2014 Revenues $ — $ — $ — $ — Total operating expenses 6,937 6,040 5,984 5,943 Net loss (6,980 ) (6,067 ) (6,603 ) (6,233 ) Basic and diluted net loss per common share $ (0.34 ) $ (0.30 ) $ (0.32 ) $ (0.30 )

Organization and Summary of S17

Organization and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Initial Public Offering	Initial Public Offering On October 4, 2013, the Company completed its initial public offering (the “IPO”) whereby it sold 7,666,667 shares of common stock at a public offering price of $6.00 per share. Gross proceeds from the offering were $46.0 million. After giving effect to underwriting discounts, commissions and other cash costs related to the offering, net proceeds were $40.5 million. In addition, each of the following occurred in connection with the completion of the IPO on October 4, 2013: · the conversion of all outstanding shares of the Company’s convertible preferred stock into 7,229,590 shares of the Company’s common stock; · the conversion of the Company’s $22.1 million of outstanding principal and accrued interest on its convertible notes into 3,679,401 shares of common stock, the write‑off of $0.3 million of unamortized debt discount and the related cash repayment of $1.7 million of outstanding principal and accrued interest on the convertible notes; · the issuance of 480,763 shares of the Company’s common stock pursuant to the redemption of an aggregate of 900,000 exchangeable shares of Fate Therapeutics (Canada) Inc. (“Fate Canada”), a subsidiary of the Company incorporated in Canada, resulting in a final fair value adjustment charge of $0.4 million on the exchangeable shares, and the resultant reclassification of the exchangeable share liability to additional paid‑in capital; · the conversion of warrants to purchase 230,000 shares of convertible preferred stock into warrants to purchase 36,074 shares of the Company’s common stock, and the resultant reclassification of the warrant liability to additional paid‑in capital; and · the filing of an amended and restated certificate of incorporation on October 3, 2013, authorizing 150,000,000 shares of common stock and 5,000,000 shares of undesignated preferred stock.
Follow-on Public Equity Offering	Follow-on Public Equity Offering In May 2015, the Company completed a public offering of common stock in which the Company sold 6,900,000 shares of its common stock at an offering price of $5.00 per share. Gross proceeds from the offering were $34.5 million. Total underwriting discounts, commissions, and other cash costs related to the offering were $2.4 million. After giving effect to all such costs, total net proceeds from the offering were $32.1 million.
Use of Estimates	Use of Estimates The Company’s consolidated financial statements are prepared in accordance with United States generally accepted accounting principles (“GAAP”). The preparation of the Company’s consolidated financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s consolidated financial statements and accompanying notes. The most significant estimates in the Company’s consolidated financial statements relate to accrued expenses. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its subsidiaries, Fate Therapeutics (Canada), Inc. or “Fate Canada”, incorporated in Canada, Fate Therapeutics Ltd., incorporated in the United Kingdom, and Destin Therapeutics Inc., incorporated in Canada, which was dissolved in June 2014. To date, the aggregate operations of these subsidiaries have not been significant and all intercompany transactions and balances have been eliminated in consolidation.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision‑maker in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of accounts payable and accrued liabilities are considered to be representative of their respective fair values because of the short‑term nature of those instruments. Based on the borrowing rates currently available to the Company for loans with similar terms, which is considered a Level 2 input, the Company believes that the fair value of long‑term debt approximates its carrying value. The accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market‑based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three‑ tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets; Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. As of each of December 31, 2015 and 2014, the carrying amount of cash equivalents was $35.3 million, which approximates fair value and was determined based upon Level 1 inputs. Cash equivalents primarily consisted of money market funds. As of December 31, 2015 and 2014, the Company did not hold any Level 2 or Level 3 financial assets that are recorded at fair value on a recurring basis. As of December 31, 2015 and 2014, the Company had no liabilities measured at fair value on a recurring basis. Financial liabilities that were previously measured at fair value on a recurring basis include the preferred stock warrant liability and exchangeable shares for the period the liabilities were outstanding. The preferred stock warrant liability was recorded at fair value using the Black‑Scholes option pricing model and the exchangeable share liability was recorded at fair value based on the fair value of the underlying common stock. These liabilities were reclassified from liabilities to stockholders’ equity as a result of the completion of the Company’s IPO on October 4, 2013, which was the final fair value measurement date for each. None of the Company’s non‑financial assets or liabilities is recorded at fair value on a non‑recurring basis. No transfers between levels have occurred during the periods presented.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include cash in readily available checking and savings accounts, money market accounts and money market funds. The Company considers all highly liquid investments with an original maturity of three months or less from the date of purchase to be cash equivalents.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially subject the Company to significant concentration of credit risk, consist primarily of cash and cash equivalents. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost and depreciated using the straight‑line method over the estimated useful lives of the assets (generally two to five years) and generally consist of furniture and fixtures, computers, scientific and office equipment. Repairs and maintenance costs are charged to expense as incurred.
Impairment of Long-Lived Assets	Impairment of Long‑Lived Assets Long‑lived assets consist primarily of property and equipment. An impairment loss is recorded if and when events and circumstances indicate that assets might be impaired and the undiscounted cash flows estimated to be generated by those assets are less than the carrying amount of those assets. While the Company’s current and historical operating losses and negative cash flows are indicators of impairment, management believes that future cash flows to be received support the carrying value of its long‑lived assets and, accordingly, has not recognized any impairment losses since inception.
Deferred Rent	Deferred Rent Deferred rent consists of the difference between cash payments and the recognition of rent expense on a straight‑line basis for the facilities the Company occupies. The Company’s leases for its facilities provide for fixed increases in minimum annual rental payments. The total amount of rental payments due over the lease terms are charged to rent expense ratably over the life of the leases.
Revenue Recognition	Revenue Recognition The Company recognizes revenues when all four of the following criteria are met: (i) persuasive evidence that an agreement exists; (ii) delivery of the products and/or services has occurred; (iii) the selling price is fixed or determinable; and (iv) collectability is reasonably assured. Revenue arrangements with multiple elements are analyzed to determine whether the elements can be divided into separate units of accounting or whether the elements must be accounted for as a single unit of accounting. The Company divides the elements into separate units of accounting and applies the applicable revenue recognition criteria to each of the elements, if the delivered elements have value to the customer on a stand-alone basis, if the arrangement includes a general right of return relative to the delivered elements, and if the delivery or performance of the undelivered elements is considered probable and substantially within the Company’s control. For transactions entered into prior to 2011, revenue was allocated to each element based on its relative fair value when objective and reliable evidence of fair value existed for all elements in an arrangement. If an element was sold on a stand-alone basis, the fair value of the element was the price charged for the element. When the Company was unable to establish fair value for delivered elements or when fair value of undelivered elements had not been established, revenue was deferred until all elements were delivered or until fair value could be objectively determined for any undelivered elements. Beginning in 2011, revenue has been allocated to each element at the inception of the arrangement using the relative selling price method that is based on a three-tier hierarchy. The relative selling price method requires that the estimated selling price for each element be based on vendor-specific objective evidence (“VSOE”) of fair value, which represents the price charged for each element when it is sold separately or, for an element not yet being sold separately, the price established by management. When VSOE of fair value is not available, third-party evidence (“TPE”) of fair value is acceptable, or a best estimate of selling price is used if neither VSOE nor TPE is available. A best estimate of selling price should be consistent with the objective of determining the price at which the Company would transact if the element were sold regularly on a stand-alone basis and should also take into account market conditions and company-specific factors. Revenue arrangements with multiple elements may include license fees, research and development payments, milestone payments, other contingent payments, and royalties on any product sales derived from collaborations. The Company recognizes nonrefundable license fees with stand-alone value as revenue at the time that the Company has satisfied all performance obligations, and recognizes license fees without stand-alone value as revenue in combination with any undelivered performance obligations. The Company recognizes a research and development payment as revenue over the term of the collaboration agreement as contracted amounts are earned, or reimbursable costs are incurred, under the agreement, where contracted amounts are considered to be earned in relative proportion to the performance required under the applicable agreement. The Company recognizes a milestone payment, which is contingent upon the achievement of a milestone in its entirety, as revenue in the period in which the milestone is achieved only if the milestone meets all criteria to be considered substantive. These criteria include the following: (i) the consideration being earned should be commensurate with either the Company’s performance to achieve the milestone or the enhancement of the value of the item delivered as a result of a specific outcome resulting from the Company’s performance to achieve the milestone; (ii) the consideration being earned should relate solely to past performance; (iii) the consideration being earned should be reasonable relative to all deliverables and payment terms in the arrangement; and (iv) the milestone should be considered in its entirety and cannot be bifurcated into substantive and nonsubstantive components. Any amounts received pursuant to revenue arrangements with multiple elements prior to satisfying the Company’s revenue recognition criteria are recorded as deferred revenue on the Company’s consolidated balance sheets. Revenue from government grants is recorded when reimbursable expenses are incurred under the grant in accordance with the terms of the grant award.
Research and Development Costs	Research and Development Costs All research and development costs are expensed as incurred.
Patent Costs	Patent Costs Costs related to filing and pursuing patent applications are recorded as general and administrative expense and expensed as incurred since recoverability of such expenditures is uncertain.
Stock-Based Compensation	Stock‑Based Compensation Stock-based compensation expense represents the cost of the grant date fair value of employee stock option and restricted stock unit grants recognized over the requisite service period of the awards (usually the vesting period) on a straight-line basis, net of estimated forfeitures. For stock option grants for which vesting is subject to performance-based milestones, the expense is recorded over the remaining service period after the point when the achievement of the milestone is probable or the performance condition has been achieved. For stock option grants for which vesting is subject to both performance-based milestones and market conditions, expense is recorded over the derived service period after the point when the achievement of the performance-based milestone is probable or the performance condition has been achieved. The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model, with the exception of option grants for which vesting is subject to both performance-based milestones and market conditions, which are valued using a lattice-based model. The fair value of restricted stock units is based on the closing price of the Company’s common stock as reported on The NASDAQ Global Market on the date of grant. The Company accounts for stock options and restricted stock awards to non-employees using the fair value approach. Stock options and restricted stock awards to non-employees are subject to periodic revaluation over their vesting terms. For stock option grants for which vesting is subject to performance-based milestones, the expense is recorded over the remaining service period after the point when the performance condition is determined to be probable of achievement or when it has been achieved.
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax‑planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions on the basis of a two‑step process whereby (1) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more‑ likely‑than‑not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability.
Comprehensive Loss	Comprehensive Loss Comprehensive loss is defined as a change in equity during a period from transactions and other events and circumstances from non‑owner sources. Net loss and comprehensive loss were the same for all periods presented.
Net Loss Per Common Share	Net Loss Per Common Share Basic net loss per common share is calculated by dividing the net loss by the weighted‑average number of common shares outstanding for the period, without consideration for common stock equivalents. Excluded from the weighted‑average number of shares outstanding are shares which have been issued upon the early exercise of stock options and are subject to future vesting and unvested restricted stock totaling 44,381 shares, 76,947 shares, and 107,570 shares for the years ended December 31, 2015, 2014, and 2013, respectively. Diluted net loss per common share is calculated by dividing the net loss by the weighted‑average number of common share equivalents outstanding for the period determined using the treasury‑stock method. Dilutive common stock equivalents are comprised of convertible preferred stock, warrants for the purchase of convertible preferred stock and common stock, exchangeable shares and common stock options outstanding under the Company’s stock option plans. For all periods presented, there is no difference in the number of common shares used to calculate basic and diluted common shares outstanding due to the Company’s net loss position. Potentially dilutive securities not included in the calculation of diluted net loss per common share because to do so would be anti‑dilutive are as follows (in common stock equivalent shares): As of December 31, 2015 2014 2013 Warrants for common stock 134,113 134,113 36,074 Common stock options 2,587,474 2,425,969 1,726,991 2,721,587 2,560,082 1,763,065
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update No. 2016-02 (ASU 2016-02) . In November 2015, the FASB issued ASU 2015-17, which requires that all deferred tax assets and liabilities be classified as noncurrent on the balance sheet, instead of separating deferred taxes into current and noncurrent amounts. The update is effective for financial statements issued for fiscal years beginning after December 15, 2016. As early adoption of this amendment is permitted, the Company has adopted the update prospectively during the year ended December 31, 2015. The adoption of this guidance did not have a material impact on the Company’s Consolidated Financial Statements. In April 2015, the FASB issued ASU 2015-03, which requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The update is effective for financial statements issued for fiscal years beginning after December 15, 2015. As early adoption of this amendment is permitted, the Company has implemented the update accordingly by reclassifying prior period and current period amounts from assets to liabilities. The adoption of this guidance did not have a material impact on the Company’s Consolidated Financial Statements. In August 2014, the FASB issued ASU 2014-15, which defined management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related disclosure. ASU 2014-15 defined the term substantial doubt and requires an assessment for a period of one year after the date of the issuance of the financial statements. It requires certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans and requires an express statement and other disclosures when substantial doubt is not alleviated. The guidance becomes effective for reporting periods ending after December 15, 2016, with early adoption permitted. The Company does not believe that the adoption of this guidance will have a material impact on its Consolidated Financial Statements. In May 2014, the FASB issued ASU 2014-09, which created a single, principle-based revenue recognition model that will supersede and replace nearly all existing U.S. GAAP revenue recognition guidance. Entities will recognize revenue in a manner that depicts the transfer of goods or services to customers at an amount that reflects the consideration to which the entity expects to be entitled to receive in exchange for those goods or services. The model provides that entities follow five steps: (i) identify the contract with a customer, (ii) identify the performance obligations in the contract, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations, and (v) recognize revenue. For public business entities, the guidance becomes effective for annual reporting periods beginning after December 15, 2017, and interim periods therein. The Company is currently evaluating the impact the adoption of this guidance will have on its Consolidated Financial Statements.

Organization and Summary of S18

Organization and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Schedule of anti-dilutive securities not included in the calculation of diluted net loss per common share	As of December 31, 2015 2014 2013 Warrants for common stock 134,113 134,113 36,074 Common stock options 2,587,474 2,425,969 1,726,991 2,721,587 2,560,082 1,763,065

Asset Acquisition of Verio Th19

Asset Acquisition of Verio Therapeutics Inc. (Tables)	12 Months Ended
	Dec. 31, 2015
Asset Acquisition [Abstract]
Summary of the purchase price of the asset acquisition	The purchase price of the Verio asset acquisition is summarized as follows (in thousands): Net liabilities $ 212 Initial fair value of Exchangeable Shares 234 $ 446
Asset Acquisition of Verio Therapeutics Inc.	The changes in the number of shares of the Company’s common stock issuable, and the initial fair value of the issuable shares, are summarized as follows (in thousands, except share and per share amounts): Shares of Common Stock Fair Value Per Share of Underlying Common Stock Initial Fair Value of Common Stock April 2010 138,462 $ 1.69 $ 234 March 2011 92,308 1.69 156 May 2011 115,380 1.69 195 April 2012 57,691 1.37 78 July 2013 76,922 4.49 346 March 2014 38,463 9.74 375 519,226 $ 1,384

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Schedule of property and equipment	Property and equipment consist of the following (in thousands): December 31, 2015 2014 Furniture and fixtures $ 324 $ 265 Computer and office equipment 300 169 Software 103 103 Leasehold improvements—building 180 66 Scientific equipment 4,725 3,384 Property and equipment, gross 5,632 3,987 Less accumulated depreciation and amortization (3,472 ) (2,787 ) Property and equipment, net $ 2,160 $ 1,200

Accrued Expenses, Long-Term D21

Accrued Expenses, Long-Term Debt, Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Accrued Expenses Long Term Debt Commitments And Contingencies Disclosure [Abstract]
Schedule of accrued expenses	Current accrued expenses consist of the following (in thousands): December 31, 2015 December 31, 2014 Accrued payroll and other employee benefits $ 993 $ 1,234 Accrued clinical trial costs 446 415 Accrued other 1,000 611 Accrued expenses $ 2,439 $ 2,260
Schedule of long-term debt and unamortized discount balances	Long‑term debt and unamortized discount balances are as follows (in thousands): December 31, 2015 December 31, 2014 Long-term debt $ 18,454 $ 20,000 Less debt issuance costs and discount, net of current portion (77 ) (381 ) Long-term debt, net of long-term portion of debt issuance costs and discount 18,377 19,619 Less current portion of long-term debt (7,689 ) (1,546 ) Long-term debt, net $ 10,688 $ 18,073 Current portion of long-term debt $ 7,689 $ 1,546 Less current portion of debt issuance costs and discount (139 ) (11 ) Current portion of long-term debt, net $ 7,550 $ 1,535
Schedule of future minimum payments under the long-term debt and the non-cancelable operating leases	Future minimum payments under the long‑term debt and the non‑cancelable operating leases as of December 31, 2015 are as follows (in thousands): Long–Term Debt Operating Leases Total Years Ending December 31, 2016 $ 8,757 1,270 10,027 2017 8,757 1,088 9,845 2018 4,055 — 4,055 Total $ 21,569 $ 2,358 $ 23,927 Less interest (1,615 ) Less additional payments due upon maturity (1,500 ) Less unamortized debt discount and debt issuance costs (216 ) Less current portion of long–term debt (7,550 ) Long–term debt, net of current portion $ 10,688

Convertible Preferred Stock a22

Convertible Preferred Stock and Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity
Schedule of the authorized, issued and outstanding shares of convertible preferred stock by series	Shares Authorized Shares Outstanding Series A 14,609,186 14,609,186 Series B 12,080,000 12,050,000 Series B–1 1,500,000 1,500,000 Series C 29,000,000 16,808,504 Series C–1 11,171,000 — 68,360,186 44,967,690
Schedule of allocation of stock-based compensation for all options and restricted stock awards	Options Weighted Average Exercise Price Per Share Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (in 000s) Outstanding at December 31, 2014 2,425,969 $ 3.83 8.06 $ 4,839 Granted 1,345,744 5.23 Exercised (227,215 ) 1.85 Cancelled (957,024 ) 4.20 Outstanding at December 31, 2015 2,587,474 $ 4.59 6.92 $ 1,486 Options vested and expected to vest at December 31, 2015 2,478,573 $ 4.54 8.01 $ 1,481 Options exercisable at December 31, 2015 1,309,010 $ 3.71 4.99 $ 1,330
Schedule of common stock reserved for future issuance	December 31, 2015 2014 Common stock warrants 134,113 134,113 Common stock options 2,587,474 2,425,969 Awards available under the 2013 Plan 908,288 999,482 Exchangeable shares — 365,379 Employee stock purchase plan 729,000 729,000 4,358,875 4,653,943
Warrant
Stockholders' Equity
Schedule of weighted-average assumptions used to determine the fair value of stock option grants	As of December 24, 2014 Risk–free interest rate 2.1 % Expected volatility 85 % Expected term (in years) 7.0 Expected dividend yield 0.0 %
Employee Stock Option
Stockholders' Equity
Schedule of weighted-average assumptions used to determine the fair value of stock option grants	Years Ended December 31, 2015 2014 2013 Risk–free interest rate 1.6 % 1.9 % 1.6 % Expected volatility 81 % 94 % 90 % Expected term (in years) 6.0 6.0 5.9 Expected dividend yield 0.0 % 0.0 % 0.0 %
Non Employee Stock Option
Stockholders' Equity
Schedule of weighted-average assumptions used to determine the fair value of stock option grants	Years Ended December 31, 2015 2014 2013 Risk–free interest rate 0.8 % 2.1 % 2.1 % Expected volatility 72 % 87 % 91 % Expected term (in years) 2.7 6.5 7.3 Expected dividend yield 0.0 % 0.0 % 0.0 %
Stock Option And Incentive Plan 2007 And 2013
Stockholders' Equity
Summary of outstanding restricted stock awards granted under the plan	The allocation of stock‑based compensation for all stock awards is as follows (in thousands): Years Ended December 31, 2015 2014 2013 Research and development $ 1,241 $ 1,416 $ 912 General and administrative 1,159 1,018 642 Total stock-based compensation expense $ 2,400 $ 2,434 $ 1,554

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of reconciliation of the Company's expected federal income tax provision (benefit) to the actual income tax provision	The following is a reconciliation of the Company’s expected federal income tax provision (benefit) to the actual income tax provision (in thousands): Years Ended December 31, 2015 2014 2013 Tax computed at federal statutory rate $ (10,198 ) $ (8,800 ) $ (7,104 ) State tax, net of federal tax benefit 2,226 (1,311 ) (1,011 ) Permanent differences 43 159 755 Stock compensation 213 426 161 R&D tax credits (594 ) (596 ) (373 ) Reserve for uncertain tax positions 1,733 — — Tax attribute limitation 2,727 — — Other (37 ) (256 ) (8 ) Valuation allowance 3,887 10,378 7,580 Income tax expense $ — $ — $ —
Summary of significant components of the Company's deferred tax assets	Significant components of the Company’s deferred tax assets are summarized as follows (in thousands): As of December 31, 2015 2014 Deferred tax assets: Section 59e amortization $ 13,042 $ 13,905 Net operating losses 28,963 25,620 R&D tax credits 1,274 2,221 Depreciation and amortization 921 1,050 Deferred revenue 2,494 — Other 950 961 Deferred tax assets 47,644 43,757 Valuation allowance (47,644 ) (43,757 ) Net deferred tax assets $ — $ —
Summary of the change in the Company's unrecognized tax benefits	The change in the Company’s unrecognized tax benefits is summarized as follows (in thousands): Balance at December 31, 2012 $ 1,034 Increase related to current year tax positions 295 Balance at December 31, 2013 $ 1,329 Increase related to current year tax positions 491 Balance at December 31, 2014 $ 1,820 Increase related to current year tax positions 374 Increase related to prior year tax positions 2,624 Decrease related to prior year tax positions (949 ) Balance at December 31, 2015 $ 3,869

Selected Quarterly Financial 24

Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Schedule of selected quarterly financial data	(in thousands, except per share data) (unaudited) First Quarter Second Quarter Third Quarter Fourth Quarter 2015 Revenues $ — $ 329 $ 1,026 $ 1,076 Total operating expenses 7,324 7,547 7,354 7,988 Net loss (7,881 ) (7,779 ) (6,886 ) (7,446 ) Basic and diluted net loss per common share $ (0.38 ) $ (0.33 ) $ (0.24 ) $ (0.26 ) 2014 Revenues $ — $ — $ — $ — Total operating expenses 6,937 6,040 5,984 5,943 Net loss (6,980 ) (6,067 ) (6,603 ) (6,233 ) Basic and diluted net loss per common share $ (0.34 ) $ (0.30 ) $ (0.32 ) $ (0.30 )

Organization and Summary of S25

Organization and Summary of Significant Accounting Policies (Details) $ / shares in Units, $ in Thousands	Sep. 13, 2013USD ($)$ / sharesshares	May. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2015USD ($)itemshares	Dec. 31, 2014USD ($)shares	Dec. 31, 2013USD ($)
Equity transactions
Proceeds from sale of common stock to collaboration partner | $			$ 4,580
Net proceeds from issuance of shares after related cash costs | $			$ 420	$ 142	$ 23
Conversion convertible preferred stock into common stock | shares	7,229,590
Repayment of outstanding principal and unpaid accrued interest in cash | $					1,679
Fair value adjustment charge on the exchangeable shares | $					$ (2,421)
Common stock authorized (in shares) | shares			150,000,000	150,000,000
Preferred stock authorized (in shares) | shares			5,000,000	5,000,000
Segment Reporting
Number of operating segments | item			1
Initial Public Offering
Equity transactions
Shares sold | shares	7,666,667
Share issue price (in dollars per share) | $ / shares	$ 6
Proceeds from sale of common stock to collaboration partner | $	$ 46,000
Net proceeds from issuance of shares after related cash costs | $	$ 40,500
Conversion convertible preferred stock into common stock | shares	7,229,590
Principal amount of convertible debt converted | $	$ 22,100
Number of shares of common stock issued upon conversion of debt | shares	3,679,401
Write-off of unamortized debt discount | $	$ 300
Repayment of outstanding principal and unpaid accrued interest in cash | $	$ 1,700
Common stock issuable upon redemption of exchangeable shares | shares	480,763
Exchangeable shares of Fate Canada for redemption | shares	900,000
Fair value adjustment charge on the exchangeable shares | $	$ 400
Warrants to purchase shares of convertible preferred stock which are converted | shares	230,000
Warrants to purchase shares of common stock issued on conversion | shares	36,074
Common stock authorized (in shares) | shares			150,000,000
Preferred stock authorized (in shares) | shares			5,000,000
Follow on public equity offering
Equity transactions
Shares sold | shares		6,900,000
Share issue price (in dollars per share) | $ / shares		$ 5
Proceeds from sale of common stock to collaboration partner | $		$ 34,500
Net proceeds from issuance of shares after related cash costs | $		32,100
Financing And Stock Issuance Costs | $		$ 2,400

Organization and Summary of S26

Organization and Summary of Significant Accounting Policies (Details 2) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair value of financial instruments
Transfer of assets from level 1 to level 2	$ 0
Transfer of assets from level 2 to level 1	0
Transfer of liabilities from level 1 to level 2	0
Transfer of liabilities from level 2 to level 1	0
Fair Value Measurements Recurring
Fair value of financial instruments
Liabilities measured at fair value	0	$ 0
Fair Value Measurements Nonrecurring
Fair value of financial instruments
Non-financial assets	0
Non-financial liabilities	0
Carrying Reported Amount Fair Value Disclosure | Fair Value Measurements Recurring | Fair Value Inputs Level 1
Fair value of financial instruments
Cash equivalents	$ 35,300	$ 35,300

Organization and Summary of S27

Organization and Summary of Significant Accounting Policies (Details 3)	12 Months Ended
	Dec. 31, 2015
Furniture And Fixtures | Minimum
Property and equipment
Estimated useful lives	2 years
Furniture And Fixtures | Maximum
Property and equipment
Estimated useful lives	5 years
Computer Equipment | Minimum
Property and equipment
Estimated useful lives	2 years
Computer Equipment | Maximum
Property and equipment
Estimated useful lives	5 years
Scientific Equipment | Minimum
Property and equipment
Estimated useful lives	2 years
Scientific Equipment | Maximum
Property and equipment
Estimated useful lives	5 years
Office Equipment | Minimum
Property and equipment
Estimated useful lives	2 years
Office Equipment | Maximum
Property and equipment
Estimated useful lives	5 years

Organization and Summary of S28

Organization and Summary of Significant Accounting Policies (Details 4) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue Recognition [Abstract]
Four criteria needed for Company to recognize revenue	(i) persuasive evidence that an agreement exists; (ii) delivery of the products and/or services has occurred; (iii) the selling price is fixed or determinable; and (iv) collectability is reasonably assured.
Uncertain tax position description	more than 50 percent
Anti-dilutive securities (in shares)	2,721,587	2,560,082	1,763,065
Employee Stock Option
Revenue Recognition [Abstract]
Anti-dilutive securities (in shares)	44,381	76,947	107,570
Warrants For Common Stock
Revenue Recognition [Abstract]
Anti-dilutive securities (in shares)	134,113	134,113	36,074
Stock Compensation Plan
Revenue Recognition [Abstract]
Anti-dilutive securities (in shares)	2,587,474	2,425,969	1,726,991

Collaboration and License Agr29

Collaboration and License Agreements (Details)	May. 04, 2015USD ($)$ / sharesshares	Sep. 30, 2010USD ($)Product	Dec. 31, 2015USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2012USD ($)
Collaboration agreement
Issuance of common stock			$ 4,580,000
Contracts Revenue			2,431,000	$ 626,000
Juno Therapeutics, Inc
Collaboration agreement
Common stock issued | shares	1,000,000
Research term	4 years
Minimum annual research payments receivable	$ 2,000,000
Extended term of research	2 years
Extension fee	$ 3,000,000
Minimum annual payments receivable for extended term of research	$ 4,000,000
Common stock premium percentage on trading price upon exercise of extension	120.00%
Trailing trading period considered for premium	30 days
Upfront payments recorded as deferred revenue	$ 5,000,000
recognition period of deferred revenue	4 years
Proceeds from sale of common stock	$ 8,000,000
Premium on share price (in dollars per share) | $ / shares	$ 3.40
Aggregate premium on shares issued recorded as deferred revenue	$ 3,400,000
Issuance of common stock	$ 4,600,000
Term of royalties payable after first commercial sale	10 years
Juno Therapeutics, Inc | Maximum
Collaboration agreement
Common stock issued upon exercise of extension	$ 10,000,000
Aggregate milestone payments	51,000,000
Juno Therapeutics, Inc | Maximum | Third Juno Product
Collaboration agreement
Additional aggregate milestone payments	116,000,000
Juno Therapeutics, Inc | Maximum | Fifth Juno Product
Collaboration agreement
Additional aggregate milestone payments	137,500,000
Juno Therapeutics, Inc | Collaborative Arrangement
Collaboration agreement
Proceeds from non refundable upfront fee	$ 5,000,000
Share Price | $ / shares	$ 8
Revenue recognized			2,400,000
Aggregate deferred revenue			$ 7,300,000
BD | Collaborative And License Agreement
Collaboration agreement
Upfront, nonrefundable license payment received		$ 300,000
Research funding received		800,000
Joint development period			3 years
Period to recognize deferred revenue related to license payments			3 years
Period to recognize revenue related to research funding			3 years
Contracts Revenue				$ 600,000
BD | Collaborative And License Agreement | iPSC one | Achievement of commercial sale goals
Collaboration agreement
Milestone payments received		500,000
BD | Collaborative And License Agreement | iPSC two | Achievement of commercial sale goals
Collaboration agreement
Milestone payments received		700,000
BD | Collaborative And License Agreement | iPSC three | Achievement of commercial sale goals
Collaboration agreement
Milestone payments received		$ 800,000
BD | Collaborative And License Agreement | iPSC | Achievement of commercialization goals
Collaboration agreement
Milestone payments received					$ 500,000
BD | Collaborative And License Agreement | Maximum | iPSC
Collaboration agreement
Number of products developed | Product		3
BD | Collaborative And License Agreement | Maximum | iPSC | Achievement of annual sale goals
Collaboration agreement
Milestone payments received		$ 4,000,000

Asset Acquisition of Verio Th30

Asset Acquisition of Verio Therapeutics Inc. (Details) - USD ($)	Oct. 04, 2013	Apr. 07, 2010	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Asset Acquisition
Common stock issued pursuant to the redemption of the exchangeable shares	480,763
Research and Development Expense				$ 19,861,000	$ 16,435,000	$ 12,007,000
Reclassification of the exchangeable share liability to additional paid-in capital				$ 3,300,000
Verio Therapeutics Inc
Asset Acquisition
Exchangeable Shares issued		900,000
Common stock issuable upon redemption of exchangeable shares		138,462		519,226
Net liabilities		$ 212,090
Initial fair value of Exchangeable Shares		234,000		$ 1,384,000
Total purchase price		$ 446,000
Deemed Earned Common Stock Yet to be Issued					38,463
Research and Development Expense					$ 400,000
Change in fair value of exchangeable shares			$ 400,000			$ 2,400,000
Verio Therapeutics Inc | Period Of April 2010
Asset Acquisition
Common stock issuable upon redemption of exchangeable shares				138,462
Initial fair value of Exchangeable Shares				$ 234,000
Fair value per share of underlying common stock (in dollars per share)				$ 1.69
Verio Therapeutics Inc | Period Of March 2011
Asset Acquisition
Common stock issuable upon redemption of exchangeable shares				92,308
Initial fair value of Exchangeable Shares				$ 156,000
Fair value per share of underlying common stock (in dollars per share)				$ 1.69
Verio Therapeutics Inc | Period Of May 2011
Asset Acquisition
Common stock issuable upon redemption of exchangeable shares				115,380
Initial fair value of Exchangeable Shares				$ 195,000
Fair value per share of underlying common stock (in dollars per share)				$ 1.69
Verio Therapeutics Inc | Period Of April 2012
Asset Acquisition
Common stock issuable upon redemption of exchangeable shares				57,691
Initial fair value of Exchangeable Shares				$ 78,000
Fair value per share of underlying common stock (in dollars per share)				$ 1.37
Verio Therapeutics Inc | Period Of July 2013
Asset Acquisition
Common stock issuable upon redemption of exchangeable shares				76,922
Initial fair value of Exchangeable Shares				$ 346,000
Fair value per share of underlying common stock (in dollars per share)				$ 4.49
Verio Therapeutics Inc | Period Of March 2014
Asset Acquisition
Common stock issuable upon redemption of exchangeable shares				38,463
Initial fair value of Exchangeable Shares				$ 375,000
Fair value per share of underlying common stock (in dollars per share)				$ 9.74
Verio Therapeutics Inc | Maximum
Asset Acquisition
Common stock issuable upon redemption of exchangeable shares				884,605

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property and equipment
Property and equipment, gross	$ 5,632	$ 3,987
Less accumulated depreciation and amortization	(3,472)	(2,787)
Property, Plant and Equipment, Net	2,160	1,200
Depreciation expense	687	496	$ 571
Furniture And Fixtures
Property and equipment
Property and equipment, gross	324	265
Computer And Office Equipment
Property and equipment
Property and equipment, gross	300	169
Software And Software Development Costs
Property and equipment
Property and equipment, gross	103	103
Leasehold Improvements
Property and equipment
Property and equipment, gross	180	66
Scientific Equipment
Property and equipment
Property and equipment, gross	$ 4,725	$ 3,384

Accrued Expenses, Long-Term D32

Accrued Expenses, Long-Term Debt, Commitments and Contingencies (Details) - USD ($)	Dec. 24, 2014	Jul. 30, 2014	Sep. 13, 2013	Jan. 31, 2016	Mar. 31, 2015	Jul. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Aug. 31, 2013
Current accrued expenses
Common stock issued to senior executives							19,956
Principal payment on long-term debt							$ 1,546,000	$ 1,750,000	$ 2,000,000
Net Proceeds after repayment of loans outstanding and transaction fees								20,000,000
Loss on extinguishment of debt								(432,000)
Aggregate interest expense							2,200,000	500,000
Repayment of outstanding principal and unpaid accrued interest in cash									1,679,000
Extended term of lease					15 months
Cash-collateralized irrevocable standby letter of credit							100,000
Future minimum payments							2,358,000
Rent expense							1,200,000	900,000	900,000
Accrued payroll and other employee benefits							993,000	1,234,000
Accrued clinical trial costs							446,000	415,000
Accrued other							1,000,000	611,000
Accrued expenses							2,439,000	2,260,000
Long-term debt							18,454,000	20,000,000
Less debt issuance costs and discount, net of current portion							(77,000)	(381,000)
Long-term debt, net of long-term portion of debt issuance costs and discount							18,377,000	19,619,000
Less current portion of long-term debt							(7,689,000)	(1,546,000)
Long-term debt, net							10,688,000	18,073,000
Current portion of long-term debt							7,689,000	1,546,000
Less current portion of debt issuance costs and discount							(139,000)	(11,000)
Current portion of long-term debt, net							7,550,000	1,535,000
Operating leases member
Current accrued expenses
Future minimum payments							1,800,000
Sublease operating leases member
Current accrued expenses
Future minimum payments							$ 500,000
Sublease Expiration Date							2017-09
Warrant
Current accrued expenses
Warrants to purchase shares of common stock issued on conversion							36,074
Exercise price (in dollars per share)							$ 7.21
Warrant | Warrants Expiration Period January2019 [Member]
Current accrued expenses
Warrants to purchase shares of common stock issued on conversion							5,305
Warrants expiration date							2019-01
Warrant | Warrants Expiration Period August2021 [Member]
Current accrued expenses
Warrants to purchase shares of common stock issued on conversion							30,769
Warrants expiration date							2021-08
Term A Loan
Current accrued expenses
Effective interest rate							10.30%
Term B Loan
Current accrued expenses
Warrants to purchase shares of common stock issued on conversion	98,039
Warrants expiration date							2021-12
Effective interest rate							12.00%
Term B Loan | Warrant
Current accrued expenses
Exercise price (in dollars per share)	$ 4.08						$ 4.08
Fair values of warrants issued	$ 400,000						$ 400,000
Amended And Restated Loan And Security Agreement
Current accrued expenses
Commitment fee		$ 400,000
Aggregate interest expense								100,000	300,000
Amended And Restated Loan And Security Agreement | Maximum
Current accrued expenses
Principal amount		20,000,000
Amended And Restated Loan And Security Agreement | Term A Loan
Current accrued expenses
Principal amount		$ 10,000,000
Debt instrument, maturity date							Jan. 1, 2018
Interest rate (as a percent)		6.94%
Principal payment on long-term debt							$ 1,500,000
Final payment fee (amounts in dollars)							$ 800,000
Final payment fee							7.50%
Net Proceeds after repayment of loans outstanding and transaction fees		$ 8,800,000
Loss on extinguishment of debt								$ (400,000)
Amended And Restated Loan And Security Agreement | Term B Loan
Current accrued expenses
Debt instrument, maturity date							Jun. 1, 2018
Interest rate (as a percent)		7.07%
Final payment fee (amounts in dollars)							$ 800,000
Final payment fee							7.50%
Net Proceeds after repayment of loans outstanding and transaction fees							$ 10,000,000
Warrants to purchase shares of common stock issued on conversion							98,039
Amended And Restated Loan And Security Agreement | Term B Loan | Maximum
Current accrued expenses
Principal amount		$ 10,000,000
Amended And Restated Loan And Security Agreement | Term B Loan Tranche 1 [Member] | Minimum
Current accrued expenses
Principal amount	$ 10,000,000
Amended And Restated Loan And Security Agreement | Secured Debt [Member]
Current accrued expenses
Number of monthly payment of interest		12 months
Number of equal monthly installments to repay principal and accrued interest		30 months
Convertible Promissory Notes Due On 24 June 2014 [Member]
Current accrued expenses
Principal amount						$ 3,700,000
Interest rate (as a percent)						2.00%
Warrants to purchase shares of convertible preferred stock which are converted			625,828
Debt discount related to beneficial conversion feature						$ 300,000
Period of maturity						1 year
Debt discount amortization									300,000
Convertible Promissory Notes Due On 8th of August 2016 [Member]
Current accrued expenses
Principal amount										$ 20,000,000
Debt instrument, maturity date							Aug. 8, 2016
Interest rate (as a percent)										2.00%
Aggregate interest expense									$ 100,000
Warrants to purchase shares of convertible preferred stock which are converted			3,053,573
Repayment of outstanding principal and unpaid accrued interest in cash			$ 1,700,000
Subsequent Event [Member]
Current accrued expenses
Common stock issued to senior executives				37,641

Accrued Expenses, Long-Term D33

Accrued Expenses, Long-Term Debt, Commitments and Contingencies (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Accrued Expenses Long Term Debt Commitments And Contingencies Disclosure [Abstract]
Minimum annual payments to maintain cancelable licenses	$ 300
Long-Term Debt
Years Ending December 31,2016	8,757
Years Ending December 31,2017	8,757
Years Ending December 31,2018	4,055
Long-term debt	21,569
Less interest	(1,615)
Less additional payments due upon maturity	(1,500)
Less unamortized debt discount and debt issuance costs	(216)
Less current portion of long–term debt	(7,550)	$ (1,535)
Long–term debt, net of current portion	10,688	$ 18,073
Operating Lease
Years Ending December 31,2016	1,270
Years Ending December 31,2017	1,088
Total	2,358
Total
Years Ending December 31,2016	10,027
Years Ending December 31,2017	9,845
Years Ending December 31,2018	4,055
Total	$ 23,927

Convertible Preferred Stock a34

Convertible Preferred Stock and Stockholders' Equity (Details)	Sep. 13, 2013shares	Dec. 31, 2015USD ($)
Convertible preferred stock
Shares Authorized	68,360,186
Shares Outstanding (in shares)	44,967,690
Shares issued on conversion of convertible preferred stock	7,229,590
Dividends declared | $		$ 0
Series A Preferred Stock
Convertible preferred stock
Shares Authorized	14,609,186
Shares Outstanding (in shares)	14,609,186
Series B Preferred Stock
Convertible preferred stock
Shares Authorized	12,080,000
Shares Outstanding (in shares)	12,050,000
Series B-1 Preferred Stock
Convertible preferred stock
Shares Authorized	1,500,000
Shares Outstanding (in shares)	1,500,000
Series C Preferred Stock
Convertible preferred stock
Shares Authorized	29,000,000
Shares Outstanding (in shares)	16,808,504
Series C-1 Preferred Stock
Convertible preferred stock
Shares Authorized	11,171,000
Series A And Series C Convertible Preferred Stock
Convertible preferred stock
Shares issued on conversion of convertible preferred stock	4,833,490
Conversion ratio (per share of common stock)	0.1538
Series B And Series B1 Convertible Preferred Stock
Convertible preferred stock
Shares issued on conversion of convertible preferred stock	2,396,100
Conversion ratio (per share of common stock)	0.1768

Convertible Preferred Stock a35

Convertible Preferred Stock and Stockholders' Equity (Details 2) - USD ($) $ / shares in Units, $ in Thousands	Dec. 24, 2014	Sep. 13, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Aug. 31, 2013	Aug. 28, 2013
Weighted-average assumptions to determine fair value of stock options
Shares reserved for issuance			4,358,875	4,653,943		4,358,875
Stock purchases under the plan (in shares)						0
Aggregate Intrinsic Value
Total stock-based compensation expense			$ 2,400	$ 2,434	$ 1,554
Equity Unit Purchase Agreements
Weighted-average assumptions to determine fair value of stock options
Shares reserved for issuance				365,379
Warrant
Weighted-average assumptions to determine fair value of stock options
Shares reserved for issuance			134,113	134,113		134,113
Risk-free interest rate (as a percent)	2.10%
Expected volatility (as a percent)	85.00%
Expected term (in years)	7 years
Expected dividend yield (as a percent)	0.00%
Warrants to purchase shares of common stock issued on conversion			36,074
Exercise price (in dollars per share)			$ 7.21			$ 7.21
Term B Loan
Weighted-average assumptions to determine fair value of stock options
Warrants to purchase shares of common stock issued on conversion	98,039
Term B Loan | Warrant
Weighted-average assumptions to determine fair value of stock options
Exercise price (in dollars per share)	$ 4.08		$ 4.08			$ 4.08
Fair values of warrants issued	$ 400		$ 400			$ 400
Research And Development
Aggregate Intrinsic Value
Total stock-based compensation expense			1,241	$ 1,416	912
General And Administrative
Aggregate Intrinsic Value
Total stock-based compensation expense			1,159	$ 1,018	$ 642
Employee And Non Employee Stock Option
Aggregate Intrinsic Value
Total intrinsic value of stock options exercised			1,000
Cash received upon exercise of options (in dollars per share)			$ 400
Employee Stock
Weighted-average assumptions to determine fair value of stock options
Shares reserved for issuance		729,000	729,000	729,000		729,000
Additional shares authorized (as a percent)		2.00%
Additional shares authorized		450,000
Employee Stock Option
Weighted-average assumptions to determine fair value of stock options
Shares reserved for issuance			2,587,474	2,425,969		2,587,474
Risk-free interest rate (as a percent)			1.60%	1.90%	1.60%
Expected volatility (as a percent)			81.00%	94.00%	90.00%
Expected term (in years)			6 years	6 years	5 years 10 months 24 days
Expected dividend yield (as a percent)			0.00%	0.00%	0.00%
Estimated pre-vesting forfeitures percentage			0.00%	0.00%	0.00%
Restricted Stock Units (RSUs)
Aggregate Intrinsic Value
Expected recognition period of unrecognized compensation cost			3 years 9 months 18 days
Unrecognized compensation cost related to unvested restricted shares			$ 2,400			$ 2,400
Granted (in shares)			500,000
Weighted-average grant date fair value per share of employee other than options granted (in dollars per share)			$ 4.89
Stock units outstanding			500,000			500,000
Non Employee Stock Option
Weighted-average assumptions to determine fair value of stock options
Risk-free interest rate (as a percent)			0.80%	2.10%	2.10%
Expected volatility (as a percent)			72.00%	87.00%	91.00%
Expected term (in years)			2 years 8 months 12 days	6 years 6 months	7 years 3 months 18 days
Expected dividend yield (as a percent)			0.00%	0.00%	0.00%
Stock Compensation Plan
Weighted-average assumptions to determine fair value of stock options
Shares reserved for issuance			908,288	999,482		908,288
Equity Incentive Plan 2007
Stockholders' Equity
Shares authorized							2,423,072
Equity Incentive Plan 2007 | Inside Of Plan
Number of Shares
Unvested shares issued (in shares)			26,270	62,150
Stock Option And Incentive Plan 2013
Weighted-average assumptions to determine fair value of stock options
Shares reserved for issuance								1,020,000
Additional shares authorized (as a percent)								4.00%
Stock Option And Incentive Plan 2013 | Restricted Stock | Second Year Anniversary Vesting Date
Weighted-average assumptions to determine fair value of stock options
Stock options generally vested on anniversary grant date (as a percent)			50.00%
Stock Option And Incentive Plan 2013 | Restricted Stock | Fourth Year Anniversary Vesting Date
Weighted-average assumptions to determine fair value of stock options
Stock options generally vested on anniversary grant date (as a percent)			50.00%
Stock Option And Incentive Plan 2007 And 2013 | Employee And Non Employee Stock Option
Weighted-average assumptions to determine fair value of stock options
Stock options generally vested on anniversary grant date (as a percent)			25.00%
General vesting period after first year			3 years
Monthly vesting period			4 years
Number of Options
Balance at the beginning of the period (in shares)			2,425,969
Granted (in shares)			1,345,744
Exercised (in shares)			(227,215)
Cancelled (in shares)			(957,024)
Balance at the end of the period (in shares)			2,587,474	2,425,969		2,587,474
Vested and expected to vest at the end of the period (in shares)			2,478,573			2,478,573
Exercisable at the end of the period (in shares)			1,309,010			1,309,010
Weighted-Average Price
Balance at the beginning of the period (in dollars per share)			$ 3.83
Granted (in dollars per share)			5.23
Exercised (in dollars per share)			1.85
Cancelled (in dollars per share)			4.20
Balance at the end of the period (in dollars per share)			4.59	$ 3.83		$ 4.59
Vested and expected to vest at the end of the period (in dollars per share)			4.54			4.54
Exercisable at the end of the period (in dollars per share)			$ 3.71			$ 3.71
Weighted Average Remaining Contractual Term
Outstanding at the end of the period			6 years 11 months 1 day	8 years 22 days
Vested and expected to vest at the end of the period			8 years 4 days
Exercisable at the end of the period			4 years 11 months 27 days
Aggregate Intrinsic Value
Outstanding at the end of the period (in dollars)			$ 1,486	$ 4,839		$ 1,486
Vested and expected to vest at the end of the period (in dollars)			1,481			1,481
Exercisable at the end of the period (in dollars)			1,330			1,330
Unrecognized compensation cost related to outstanding options			$ 3,800	$ 4,100		$ 3,800
Expected recognition period of unrecognized compensation cost			2 years 9 months 18 days	2 years 7 months 6 days
Granted (in shares)			1,345,744
Stock Option And Incentive Plan 2007 And 2013 | Employee And Non Employee Stock Option | Vesting Based On Performance
Number of Options
Balance at the beginning of the period (in shares)			138,649
Balance at the end of the period (in shares)			14,769	138,649		14,769
Aggregate Intrinsic Value
Aggregate grant date fair value			$ 100	$ 600
Stock Option And Incentive Plan 2007 And 2013 | Employee And Non Employee Stock Option | Maximum
Weighted-average assumptions to determine fair value of stock options
Term of stock awards			10 years
Stock Option And Incentive Plan 2007 And 2013 | Employee Stock Option
Number of Options
Granted (in shares)			1,200,000	900,000	300,000
Aggregate Intrinsic Value
Granted (in shares)			1,200,000	900,000	300,000
Weighted-average grant date fair value per share of employee options granted (in dollars per share)			$ 3.54	$ 5.10	$ 4.40

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of the Company's expected federal income tax provision (benefit) to the actual income tax provision
Tax computed at federal statutory rate	$ (10,198)	$ (8,800)	$ (7,104)
State tax, net of federal tax benefit	2,226	(1,311)	(1,011)
Permanent differences	43	159	755
Stock compensation	213	426	161
R&D tax credits	(594)	(596)	(373)
Reserve for uncertain tax positions	1,733
Tax attribute limitation	2,727
Other	(37)	(256)	(8)
Valuation allowance	3,887	10,378	$ 7,580
Deferred tax assets:
Section 59e amortization	13,042	13,905
Net operating losses	28,963	25,620
R&D tax credits	1,274	2,221
Depreciation and amortization	921	1,050
Deferred revenue	2,494
Other	950	961
Deferred tax assets	47,644	43,757
Valuation allowance	$ (47,644)	$ (43,757)

Income Taxes (Details 2)

Income Taxes (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Valuation allowance	$ 47,644	$ 43,757
U.S. Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 79,800
Net operating loss carryforward expiration year	2,027
California
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 61,900
Net operating loss carryforward expiration year	2,028
Canadian
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 300
Net operating loss carryforward expiration year	2,030

Income Taxes (Details 3)

Income Taxes (Details 3) - Research and development $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)
U.S. Federal
Tax Credit Carryforward [Line Items]
Tax credit carryforwards	$ 0.4
Tax credit carryforward expiration year	2,035
California
Tax Credit Carryforward [Line Items]
Tax credit carryforwards	$ 2.7

Income Taxes (Details 4)

Income Taxes (Details 4) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Change in the Company's unrecognized tax benefits
Balance at the beginning of the period	$ 1,820,000	$ 1,329,000	$ 1,034,000
Increase related to current year tax positions	374,000	491,000	295,000
Increase related to prior year tax positions	2,624,000
Decrease related to prior year tax positions	(949,000)
Balance at the end of the period	3,869,000	$ 1,820,000	$ 1,329,000
Income Taxes
Unrecognized tax benefit	0
Unrecognized tax benefits that, if recognized, would reduce the effective tax rate	0
Non-current deferred tax asset	$ 0

Employee Benefits (Details)

Employee Benefits (Details) - USD ($)	Jan. 02, 2009	Dec. 31, 2015
Compensation And Retirement Disclosure [Abstract]
Minimum age of employees	21 years
Matching contributions under 401(k) plan		$ 0

Selected Quarterly Financial 41

Selected Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 1,076	$ 1,026	$ 329						$ 2,431		$ 971
Total operating expenses	7,988	7,354	7,547	$ 7,324	$ 5,943	$ 5,984	$ 6,040	$ 6,937	30,213	$ 24,904	18,646
Net loss	$ (7,446)	$ (6,886)	$ (7,779)	$ (7,881)	$ (6,233)	$ (6,603)	$ (6,067)	$ (6,980)	$ (29,992)	$ (25,883)	$ (20,894)
Basic and diluted net loss per common share (in dollars per share)	$ (0.26)	$ (0.24)	$ (0.33)	$ (0.38)	$ (0.30)	$ (0.32)	$ (0.30)	$ (0.34)	$ (1.18)	$ (1.27)	$ (3.54)