Fate Therapeutics (FATE) 10-K17 Mar 142013 FY Annual reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Mar. 13, 2014
Document and Entity Information	'	'
Entity Registrant Name	'FATE THERAPEUTICS INC	'
Entity Central Index Key	'0001434316	'
Document Type	'10-K	'
Document Period End Date	31-Dec-13	'
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	'Smaller Reporting Company	'
Entity Public Float	$0	'
Entity Common Stock, Shares Outstanding	'	20,435,676
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'FY	'

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current assets:	'	'
Cash and cash equivalents	$54,036	$9,087
Prepaid expenses and other current assets	615	706
Total current assets	54,651	9,793
Property and equipment, net	810	1,161
Restricted cash	122	122
Total assets	55,583	11,076
Current liabilities:	'	'
Accounts payable	682	1,228
Accrued expenses	2,039	1,040
Current portion of deferred revenue	'	63
Current portion of deferred rent	53	251
Repurchase liability for unvested equity awards	94	143
Preferred stock warrant liability	'	184
Long-term debt, current portion	1,732	1,941
Total current liabilities	4,600	4,850
Deferred rent	135	132
Accrued expenses	'	110
Exchangeable share liability	'	551
Long-term debt, less current portion	'	1,732
Commitments and contingencies (Note 4)	'	'
Convertible Preferred Stock, $0.001 par value; authorized shares - zero at December 31, 2013 and 62,200,000 at December 31, 2012; issued and outstanding shares - zero at December 31, 2013 and 44,967,690 at December 31, 2012	'	56,526
Stockholders' Equity (Deficit):	'	'
Preferred stock, $0.001 par value; authorized shares - 5,000,000 at December 31, 2013 and zero at December 31, 2012; no shares issued or outstanding	'	'
Common stock, $0.001 par value; authorized shares - 150,000,000 at December 31, 2013 and 100,000,000 at December 31, 2012; issued and outstanding - 20,434,080 at December 31, 2013 and 1,334,115 at December 31, 2012	20	1
Additional paid-in capital	137,337	12,789
Deficit accumulated during the development stage	-86,509	-65,615
Total stockholders' equity (deficit)	50,848	-52,825
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	$55,583	$11,076

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Consolidated Balance Sheets	'	'
Convertible preferred stock, par value (in dollars per share)	$0.00	$0.00
Convertible preferred, shares authorized	0	62,200,000
Convertible preferred stock, share sold (in shares)	0	44,967,690
Convertible preferred stock, shares outstanding	0	44,967,690
Preferred stock, par value (in dollars per share)	$0.00	$0.00
Preferred stock, authorized shares	5,000,000	0
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value (in dollars per share)	$0.00	$0.00
Common stock, authorized shares	150,000,000	100,000,000
Common stock, issued shares	20,434,080	1,334,115
Common stock, outstanding shares	20,434,080	1,334,115

Consolidated_Statements_of_Ope

Consolidated Statements of Operations and Comprehensive Loss (USD $)	12 Months Ended			80 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Revenue:	'	'	'	'
Collaboration revenue	$626	$1,268	$833	$2,927
Grant revenue	345	1,402	337	2,084
Total revenue	971	2,670	1,170	5,011
Operating expenses:	'	'	'	'
Research and development	12,007	11,999	9,858	56,986
General and administrative	6,639	4,228	4,605	30,710
Total operating expenses	18,646	16,227	14,463	87,696
Loss from operations	-17,675	-13,557	-13,293	-82,685
Other income (expense):	'	'	'	'
Interest income	6	1	2	192
Interest expense	-796	-487	-127	-2,641
Income from 48D tax credit	'	'	'	1,231
Loss on extinguishment of debt	'	-323	-9	-332
Change in fair value of warrant liability	-8	37	5	35
Change in fair value of exchangeable shares	-2,421	90	-5	-2,309
Total other income (expense), net	-3,219	-682	-134	-3,824
Net loss and comprehensive loss	($20,894)	($14,239)	($13,427)	($86,509)
Net loss per common share, basic and diluted (in dollars per share)	($3.54)	($13.06)	($16.16)	'
Weighted-average common shares used to compute basic and diluted net loss per share (in shares)	5,896,171	1,090,317	830,959	'

Consolidated_Statements_of_Con

Consolidated Statements of Convertible Preferred Stock and Stockholders (Deficit) (USD $)	Total	Common stock	Additional Paid-in Capital	Deficit Accumulated During Development Stage
In Thousands, except Share data, unless otherwise specified	Total	Common stock	Additional Paid-in Capital	Deficit Accumulated During Development Stage
Balance at Apr. 26, 2007	'	'	'	'
Increase (Decrease) in Shareholders' Equity	'	'	'	'
Issuance of common stock to founders and consultants for cash	$5	$1	$4	'
Issuance of common stock to founders and consultants for cash (in shares)	'	801,250	'	'
Net loss	-1,224	'	'	-1,224
Balance at Dec. 31, 2007	-1,219	1	4	-1,224
Balance (in shares) at Dec. 31, 2007	'	801,250	'	'
Increase (Decrease) in Shareholders' Equity	'	'	'	'
Issuance of common stock to founders and consultants for cash	18	'	18	'
Issuance of common stock to founders and consultants for cash (in shares)	'	420,323	'	'
Repurchase of founders stock	-2	'	-2	'
Repurchase of founders stock (in shares)	'	-235,897	'	'
Net loss	-7,169	'	'	-7,169
Exercise of stock options	1	'	1	'
Exercise of stock options (in shares)	'	20,924	'	'
Issuance of common stock for technology	1	'	1	'
Issuance of common stock for technology (in shares)	18,462	18,462	'	'
Stock-based compensation	17	'	17	'
Balance at Dec. 31, 2008	-8,353	1	39	-8,393
Balance (in shares) at Dec. 31, 2008	'	1,025,062	'	'
Increase (Decrease) in Shareholders' Equity	'	'	'	'
Net loss	-13,334	'	'	-13,334
Exercise of stock options	21	'	21	'
Exercise of stock options (in shares)	'	205,926	'	'
Issuance of common stock for technology	17	'	17	'
Issuance of common stock for technology (in shares)	46,923	46,923	'	'
Stock-based compensation	196	'	196	'
Repurchase of common stock	-4	'	-4	'
Repurchase of common stock (in shares)	'	-64,866	'	'
Balance at Dec. 31, 2009	-21,457	1	269	-21,727
Balance (in shares) at Dec. 31, 2009	'	1,213,045	'	'
Increase (Decrease) in Shareholders' Equity	'	'	'	'
Net loss	-16,222	'	'	-16,222
Exercise of stock options	10	'	10	'
Exercise of stock options (in shares)	'	21,602	'	'
Issuance of common stock for technology	5	'	5	'
Issuance of common stock for technology (in shares)	3,077	3,077	'	'
Stock-based compensation	229	'	229	'
Repurchase of common stock (in shares)	'	-4,808	'	'
Balance at Dec. 31, 2010	-37,435	1	513	-37,949
Balance (in shares) at Dec. 31, 2010	'	1,232,916	'	'
Increase (Decrease) in Shareholders' Equity	'	'	'	'
Net loss	-13,427	'	'	-13,427
Exercise of stock options	14	'	14	'
Exercise of stock options (in shares)	'	18,645	'	'
Stock-based compensation	172	'	172	'
Repurchase of common stock	-7	'	-7	'
Repurchase of common stock (in shares)	'	-126,872	'	'
Balance at Dec. 31, 2011	-50,683	1	692	-51,376
Balance (in shares) at Dec. 31, 2011	'	1,124,689	'	'
Increase (Decrease) in Shareholders' Equity	'	'	'	'
Net loss	-14,239	'	'	-14,239
Exercise of stock options	15	'	15	'
Exercise of stock options (in shares)	'	11,154	'	'
Issuance of common stock for technology	21	'	21	'
Issuance of common stock for technology (in shares)	15,385	15,385	'	'
Stock-based compensation	155	'	155	'
Issuance of common stock at $0.25 per share for cash	192	'	192	'
Issuance of common stock at $0.25 per share for cash (in shares)	'	118,360	'	'
Exchange of debt and common stock for Series B-1 preferred stock	-32	'	-32	'
Exchange of debt and common stock for Series B-1 preferred stock (in shares)	'	-23,077	'	'
Repurchase liability for unvested equity awards	-143	'	-143	'
Impact of initial public offering:	'	'	'	'
Conversion of convertible preferred stock into common stock	11,889	'	11,889	'
Conversion of convertible preferred stock into common stock (in shares)	'	87,604	'	'
Balance at Dec. 31, 2012	-52,825	1	12,789	-65,615
Balance (in shares) at Dec. 31, 2012	'	1,334,115	'	'
Increase (Decrease) in Shareholders' Equity	'	'	'	'
Net loss	-20,894	'	'	-20,894
Exercise of stock options	23	'	23	'
Exercise of stock options (in shares)	'	35,852	'	'
Issuance of common stock for technology	13	'	13	'
Issuance of common stock for technology (in shares)	7,692	7,692	'	'
Stock-based compensation	1,554	'	1,554	'
Repurchase liability for unvested equity awards	49	'	49	'
Beneficial conversion feature related to convertible notes	336	'	336	'
Impact of initial public offering:	'	'	'	'
Initial public offering of common stock, net of $5,520 of offering costs	40,480	8	40,472	'
Initial public offering of common stock, net of $5,520 of offering costs (in shares)	'	7,666,667	'	'
Conversion of convertible preferred stock into common stock	56,526	7	56,519	'
Conversion of convertible preferred stock into common stock (in shares)	'	7,229,590	'	'
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	'	'
Warrant liability reclassification	192	'	192	'
Balance at Dec. 31, 2013	$50,848	$20	$137,337	($86,509)
Balance (in shares) at Dec. 31, 2013	'	20,434,080	'	'

Consolidated_Statements_of_Con1

Consolidated Statements of Convertible Preferred Stock and Stockholders (Deficit) (Details 2) (USD $)	Total	Convertible Preferred Stock
In Thousands, except Share data, unless otherwise specified	Total	Convertible Preferred Stock
Balance at Apr. 26, 2007	'	'
Increase (Decrease) in Stockholders' Equity	'	'
Issuance of stock for cash, net of issuance costs	'	$1,541
Issuance of stock for cash, net of issuance costs (in shares)	'	1,655,435
Balance at Dec. 31, 2007	'	1,541
Balance (in shares) at Dec. 31, 2007	'	1,655,435
Increase (Decrease) in Stockholders' Equity	'	'
Issuance of stock for cash, net of issuance costs	'	12,914
Issuance of stock for cash, net of issuance costs (in shares)	'	12,953,751
Balance at Dec. 31, 2008	'	14,455
Balance (in shares) at Dec. 31, 2008	'	14,609,186
Increase (Decrease) in Stockholders' Equity	'	'
Issuance of stock for cash, net of issuance costs	'	32,354
Issuance of stock for cash, net of issuance costs (in shares)	'	16,244,180
Balance at Dec. 31, 2009	'	46,809
Balance (in shares) at Dec. 31, 2009	'	30,853,366
Balance at Dec. 31, 2010	'	46,809
Balance (in shares) at Dec. 31, 2010	'	30,853,366
Increase (Decrease) in Stockholders' Equity	'	'
Issuance of stock for cash, net of issuance costs	'	3,500
Issuance of stock for cash, net of issuance costs (in shares)	'	1,500,000
Balance at Dec. 31, 2011	'	50,309
Balance (in shares) at Dec. 31, 2011	'	32,353,366
Increase (Decrease) in Stockholders' Equity	'	'
Issuance of stock for cash, net of issuance costs	'	16,726
Issuance of stock for cash, net of issuance costs (in shares)	'	16,808,504
Conversion of convertible preferred stock into common stock	11,889	-11,889
Conversion of convertible preferred stock into common stock (in shares)	'	-5,694,180
Exchange of debt and common stock for Series B-1 preferred stock	'	1,380
Exchange of debt and common stock for Series B-1 preferred stock (in shares)	'	1,500,000
Balance at Dec. 31, 2012	56,526	56,526
Balance (in shares) at Dec. 31, 2012	44,967,690	44,967,690
Increase (Decrease) in Stockholders' Equity	'	'
Conversion of convertible preferred stock into common stock	$56,526	($56,526)
Conversion of convertible preferred stock into common stock (in shares)	'	-44,967,690
Balance (in shares) at Dec. 31, 2013	0	'

Consolidated_Statements_of_Con2

Consolidated Statements of Convertible Preferred Stock and Stockholders (Deficit) (Parenthetical) (USD $)	12 Months Ended		8 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2007	Dec. 31, 2008	Dec. 31, 2011	Dec. 31, 2009	Dec. 31, 2012
	Common stock	Common stock	Series A	Series A	Series B preferred stock	Series B preferred stock	Series C preferred stock
Share price (in dollars per share)	'	$0.25	$1	$1	$2.33	$2	$1
Stock issuance costs	$5,520	'	$115	$40	'	$134	$84

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended			80 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Cash flows from operating activities	'	'	'	'
Net loss	($20,894)	($14,239)	($13,427)	($86,509)
Adjustments to reconcile net loss to net cash used in operating activities	'	'	'	'
Depreciation and amortization	571	590	672	2,508
Issuances of common stock for technology	13	21	'	57
Stock-based compensation	1,554	155	172	2,323
Amortization of discounts	394	84	23	535
Noncash interest expense	147	121	13	1,169
Deferred rent	-195	-197	228	188
Deferred revenue	-63	-83	-646	'
Initial fair value and change in fair value of exchangeable shares	2,767	-12	356	3,318
Change in fair value of preferred stock warrants	8	-37	-5	-35
Loss on disposal of assets	18	'	117	135
Loss on extinguishment of debt	'	323	9	332
Changes in assets and liabilities:	'	'	'	'
Prepaid expenses and other assets	-1,271	-405	209	-1,977
Accounts payable and accrued expenses	1,578	405	134	3,847
Net cash used in operating activities	-15,373	-13,274	-12,145	-74,109
Cash flows from investing activities	'	'	'	'
Purchase of property and equipment	-244	-709	-2	-3,661
Proceeds from sale of property and equipment	6	'	202	208
Restricted cash	'	'	'	-122
Net cash (used in) provided by investing activities	-238	-709	200	-3,575
Cash flows from financing activities	'	'	'	'
Issuance of common stock for cash	23	207	14	294
Repurchase of common stock for cash	'	'	-7	-7
Proceeds from initial public offering, net of offering costs	40,480	'	'	40,480
Issuance of convertible promissory notes	23,736	'	1,000	32,236
Proceeds from long-term debt	'	'	3,400	6,400
Payments on long-term debt	-2,000	-250	-800	-4,650
Payment on convertible promissory note	-1,679	'	'	-1,679
Issuance of preferred stock for cash, net of offering costs	'	16,726	3,500	58,646
Net cash provided by financing activities	60,560	16,683	7,107	131,720
Net increase (decrease) in cash and cash equivalents	44,949	2,700	-4,838	54,036
Cash and cash equivalents, beginning of period	9,087	6,387	11,225	'
Cash and cash equivalents, end of period	54,036	9,087	6,387	54,036
Supplemental disclosure of cash flow information	'	'	'	'
Interest paid	250	282	90	930
Supplemental schedule of noncash investing and financing activities	'	'	'	'
Conversion of notes payable for Series B preferred stock	'	'	'	8,388
Issuance of warrants in connection with long-term debt	'	'	172	226
Beneficial conversion feature related to convertible notes	336	'	'	336
Conversion of convertible preferred stock into common stock	56,526	11,889	'	56,526
Conversion of convertible notes into common stock	22,076	'	'	22,076
Exchange of exchangeable shares into common stock	3,318	'	'	3,318
Warrant liability reclassification to equity	$192	'	'	$192

Organization_and_Summary_of_Si

Organization and Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2013

Organization and Summary of Significant Accounting Policies

1. Organization and Summary of Significant Accounting Policies

Organization and Basis of Presentation

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 clinical-stage biopharmaceutical company engaged in the discovery and development of pharmacologic modulators of adult stem cells. Based on the Company's understanding of key biological mechanisms that guide the fate of adult stem cells, the Company has built two platforms that optimize the activity and enhance the therapeutic potential of adult stem cells: its HSC modulation platform and its Satellite Cell modulation platform.

As of December 31, 2013, the Company has devoted substantially all of its efforts to product development, raising capital and building infrastructure and has not generated revenues from its planned principal operations. Accordingly, the Company is considered to be in the development stage.

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 (see Note 5);

•

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 (see Note 4);

•

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"), 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 (see Note 2);

•

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 (as discussed below in Note 1); 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 (see Note 5).

Use of Estimates

The Company's consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States ("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 the valuation of equity awards and clinical trial accruals. 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. ("Fate Canada"), Fate Therapeutics Ltd, incorporated in the United Kingdom, and Destin Therapeutics Inc., incorporated in Canada. 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 December 31, 2013 and 2012, the carrying amount of cash equivalents was $52.3 million and $1.3 million, respectively, which approximates fair value and was determined based upon Level 1 inputs. Cash equivalents primarily consisted of money market funds. As of December 31, 2013 and 2012, the Company did not hold any Level 2 or Level 3 financial assets that are recorded at fair value on a recurring basis.

Financial liabilities that were measured at fair value on a recurring basis include the preferred stock warrant liability and exchangeable shares for the period the liabilities were outstanding (see Note 2). 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.

As of December 31, 2013, the Company had no liabilities measured at fair value on a recurring basis. Liabilities measured at fair value on a recurring basis as of December 31, 2012 are as follows (in thousands):

Fair Value Measurements

at Reporting Date Using

Total

Quoted Prices in

Significant

Active Markets for

Other

Unobservable

Identical

Observable

Inputs

Assets

Inputs

(Level 3)

(Level 1)

(Level 2)

As of December 31, 2012:

Warrant liability

184

—

184

Exchangeable share liability

551

—

551

735

—

735

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.

The following assumptions were used in the Black-Scholes option pricing model to determine the fair value of the preferred stock warrant liability:

As of

October 4, 2013

December 31, 2012

Risk-free interest rate

2.1

1.2

Expected volatility

85.9

93.5

Remaining contractual term (in years)

7.55

8.31

Expected dividend yield

The following fair values per share of the Company's underlying convertible preferred stock and common stock were used to determine the fair value of the preferred stock warrant liability and the Exchangeable Shares (as defined in Note 2):

As of

October 4, 2013

December 31, 2012

Series B convertible preferred stock

6.9

0.92

Series C convertible preferred stock

6.9

0.99

Common stock

6.9

1.37

The fair value of the convertible preferred stock and common stock, prior to it being actively traded subsequent to the Company' IPO, was determined using a probability weighted expected return model. The key inputs into the model included the probability and timing of expected liquidity event dates, discount rates and the selection of appropriate market comparable transactions and multiples to apply to the Company's various historical and forecasted operational metrics.

The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs (in thousands):

Warrant

Exchangeable

Liability

Balance at December 31, 2011

221

563

Issuance of exchangeable shares

—

Change in fair value

(37

)

(90

)

Balance at December 31, 2012

184

551

Issuance of exchangeable shares

—

346

Change in fair value

2,421

Transfer to stockholders' equity at fair value upon closing of IPO

(192

)

(3,318

)

Balance at December 31, 2013

—

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.

Other Assets

Other assets capitalized during 2013 consisted of the Company's deferred IPO costs prior to the closing of the IPO on October 4, 2013. These costs represent legal, accounting and other direct costs related to the Company's efforts to raise capital through a public sale of its common stock. Upon closing of the IPO, the costs were reclassified to additional paid-in capital as a reduction of the IPO proceeds.

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 lease for its facilities provides for fixed increases in minimum annual rental payments. The total amount of rental payments due over the lease term is being charged to rent expense ratably over the life of the lease.

Preferred Stock Warrant Liability

The Company historically issued freestanding warrants to purchase shares of its convertible preferred stock. The fair value of these warrants was classified as a current liability in the accompanying consolidated balance sheets since the underlying convertible preferred stock was classified as temporary equity in the accompanying consolidated balance sheets instead of in stockholders' equity (deficit) in accordance with authoritative guidance for the classification and measurement of potentially redeemable securities. Upon certain change in control events outside of the Company's control, including liquidation, sale or transfer of control of the Company, holders of the convertible preferred stock could have caused its redemption. The warrants were recorded at fair value using the Black-Scholes option pricing model with any changes in fair value being recognized as a component of other income (expense) in the accompanying consolidated statements of operations and comprehensive loss. Both the convertible preferred stock and the warrant liability were reclassified into stockholders' equity (deficit) as a result of the Company's IPO on October 4, 2013.

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) collectibility 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 is 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. The Company has not entered into or materially modified any multiple element arrangements subsequent to 2010.

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. The receivable for reimbursable amounts that have not been collected is reflected in prepaid and other current assets.

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 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 with performance-based milestones, the expense is recorded over the remaining service period after the point when the achievement of the milestone is probable or the performance condition has been achieved. For stock option grants with both performance-based milestones and market conditions, expense is recorded over the derived service period after the point when the achievement of the performance-based milestone is probable or the performance condition has been achieved. The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model, with the exception of option grants with both performance-based milestones and market conditions, which are valued using a lattice based model.

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 with performance-based milestones, the expense is recorded over the remaining service period after the point when the performance condition 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 107,570 shares, 173,772 shares, and 303,253 shares for the years ended December 31, 2013, 2012, and 2011, 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, exchangeable shares and 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,

2013

2012

2011

Convertible preferred stock outstanding

—

7,229,590

5,385,353

Warrants for convertible preferred stock

—

36,074

Warrants for common stock

36,074

—

Exchangeable shares

—

403,841

346,147

Common stock options

1,726,991

1,432,369

305,192

1,763,065

9,101,874

6,072,766

The convertible preferred stock and exchangeable shares were converted into shares of the Company's stock as a result of the completion of the Company's IPO on October 4, 2013.

Asset_Acquisition_of_Verio_The

Asset Acquisition of Verio Therapeutics Inc.	12 Months Ended
Asset Acquisition of Verio Therapeutics Inc.	Dec. 31, 2013
Asset Acquisition of Verio Therapeutics Inc.	'
Asset Acquisition of Verio Therapeutics Inc.	'

	2. 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 common stock of the Company, subject to increase upon the occurrence of certain events as described below, and 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





	These 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 was 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.

	As of December 31, 2013, the Company may issue an additional 403,842 shares of the Company's common stock based on the achievement of additional contractual milestones as follows: (i) 76,923 shares for the achievement of certain pre-clinical milestones, (ii) 211,538 shares for the achievement of certain clinical milestones and (iii) 115,381 shares for the achievement of certain commercialization milestones, such that the maximum aggregate number of shares of the Company's common stock that may be issued related to the Verio acquisition is 884,605.

	At the date of the achievement of a milestone, the fair value of the additional shares is charged to research and development expense. Prior to the Company's IPO, at the end of each reporting period, any changes in the fair value of Exchangeable Shares resulting from changes in the fair value of the underlying common stock of the Company were recorded as a component of other income (expense). The Company recorded a non-cash charge of $0.4 million in other income (expense) 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 Company recorded a non-cash charge of $2.4 million, $0.1 million and $(5,000) for the years ended December 31, 2013, 2012, and 2011, respectively, in other income (expense) related to the change in fair value of the exchangeable shares. Upon any future achievement of a milestone, the fair value will be recorded in additional paid-in capital.

	The changes in the number of shares of the Company's common stock issuable upon the exchange of the Exchangeable Shares and the initial fair value of the shares are summarized as follows (in thousands, except share and per share amounts):


		Exchangeable		Fair Value Per		Initial Fair
		Shares		Share of		Value of
				Underlying		Exchangeable
				Common Stock		Shares
	Apr-10		138,462	$	1.69	$	234
	Mar-11		92,308		1.69		156
	May-11		115,380		1.69		195
	Apr-12		57,691		1.37		78
	Jul-13		76,922		4.49		346


	Total		480,763			$	1,009

Property_and_Equipment

Property and Equipment	12 Months Ended
Property and Equipment	Dec. 31, 2013
Property and Equipment	'
Property and Equipment	'

	3. Property and Equipment

	Property and equipment consist of the following (in thousands):


		December 31,
		2013			2012
	Furniture and fixtures	$	247		$	242
	Computer and office equipment		123			129
	Software		103			103
	Leasehold improvements—building		60			—
	Scientific equipment		2,573			2,436


	Property and equipment, gross		3,106			2,910
	Less accumulated depreciation and amortization		(2,296	)		(1,749	)


	Property and equipment, net	$	810		$	1,161





	Depreciation expense related to property and equipment was $0.6 million, $0.6 million, and $0.7 million, for the years ended December 31, 2013, 2012, and 2011, respectively, and $2.5 million for the period from April 27, 2007 (inception) to December 31, 2013. In connection with the renovation of its laboratory space, the Company sold certain equipment that was no longer relevant to its operations. The Company recognized a loss on the disposal of $0.1 million for the year ended December 31, 2011, which is included in general and administrative expense. No material gains or losses on the disposal of property and equipment have been recorded for the years ended December 31, 2013 and 2012.

LongTerm_Debt_Commitments_and_

Long-Term Debt, Commitments and Contingencies	12 Months Ended
Long-Term Debt, Commitments and Contingencies	Dec. 31, 2013
Long-Term Debt, Commitments and Contingencies	'
Long-Term Debt, Commitments and Contingencies	'

	4. Long-Term Debt, Commitments and Contingencies

	Long-Term Debt

	Long-term debt and unamortized discount balances (excluding convertible debt) are as follows (in thousands):


			December 31,
			2013			2012
	Long-term debt		$	1,750		$	3,750
	Less debt discount, net of current portion			—			(18	)


	Long-term debt, net of discount			1,750			3,732
	Less current portion of long-term debt			(1,750	)		(2,000	)


	Long-term debt, net of current portion		$	—		$	1,732




	Current portion of long-term debt		$	1,750		$	2,000
	Current portion of debt discount			(18	)		(59	)


	Current portion of long-term debt, net		$	1,732		$	1,941





	In 2009, the Company entered into a $3.0 million loan and security agreement collateralized by substantially all of the Company's assets, excluding certain intellectual property. The Company drew the full $3.0 million available under the loan and security agreement in 2009 and issued a fully exercisable warrant for 30,000 shares of the Company's Series B convertible preferred stock at an exercise price of $2.00 per share.

	In August 2011, the loan and security agreement was amended to: (i) increase the available credit under the loan and security agreement to $4.0 million, (ii) add an additional payment upon maturity equal to 5% of the maximum loan amount and (iii) repay the remaining $0.6 million of outstanding principal related to the original $3.0 million loan. In August 2011, the Company issued the lender a warrant that provided $0.2 million of warrant coverage for either (i) 100,000 shares of Series B convertible preferred stock at an exercise price of $2.00 per share or (ii) a number of shares and exercise price to be determined based on the pricing of a subsequent qualified financing. In May 2012, as a result of the Company's Series C qualified financing, the warrant became exercisable for 200,000 shares of the Company's Series C convertible preferred stock at an exercise price of $1.00 per share.

	The Company accessed the full $4.0 million of available credit under the amended loan and security agreement by taking a term advance of $2.0 million in August 2011 and a term advance of $2.0 million in December 2011 (together, the "Term Advances"), each of which are scheduled to be fully paid by August 2014 and December 2014, respectively. The Term Advances require interest-only payments during the first 12 months from access and equal monthly principal and interest payments during the final 24 months from access. The interest rate on the Term Advances is fixed at 7.0% for their entire 36-month term of the debt. As of December 31, 2013, the aggregate outstanding principal was $1.8 million.

	The initial fair values of the warrants issued in 2009 and 2011 were $0.1 million and $0.2 million, respectively, and recorded as a debt discount and amortized to interest expense over the term of the related loans on the effective interest method. The initial fair values of the warrants were estimated using the Black-Scholes option pricing model.

	Upon closing of the Company's IPO on October 4, 2013, the warrants to purchase convertible preferred stock converted into warrants to purchase 36,074 shares of the Company's common stock, and the then fair value of $0.2 million of the warrant liability was reclassified to additional paid-in capital. The weighted average exercise price of the warrants is $7.21 per share. Warrants to purchase 5,305 and 30,769 shares of the Company's common stock expire in January 2019 and August 2021, respectively, or earlier upon the acquisition of the Company.

	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 principal balance 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. During 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 our IPO on October 4, 2013, the Company repaid $1.7 million of then-outstanding principal and unpaid accrued interest in cash, with the remaining outstanding principal converting to 3,053,573 shares of the Company's common stock. During 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 September 2013, the Company exercised its option to extend the lease for two years. The lease expires in June 2016. 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. Rent expense was $0.9 million, $0.7 million, $0.7 million, and $3.8 million for the years ended December 31, 2013, 2012, and 2011 and the period from April 27, 2007 (inception) to December 31, 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.

	In connection with the above license agreements, the Company has issued an aggregate of 91,539 shares of common stock and recorded the aggregate fair value of $57,000 as research and development expense. The share issuances are summarized as follows (in thousands, except share amounts):


		Shares of			Fair Value of
		Common Stock			Common Shares
2008			18,462		$	1
2009			46,923			17
2010			3,077			5
2012			15,385			21
2013			7,692			13


Total			91,539		$	57





Commitments

Future minimum payments under the long-term debt and the non-cancelable operating lease as of December 31, 2013 are as follows (in thousands):


		Long-Term			Operating Lease			Total
		Debt			Operating Lease			Total
Years Ending December 31,
2014		$	2,011		$	911		$	2,922
2015			—			943			943
2016			—			480			480


Total			2,011		$	2,334		$	4,345




Less interest			(61	)
Less additional payments due upon maturity			(200	)
Less current portion of long-term debt			(1,750	)


Long-term debt, net of current portion		$	—

Convertible_Preferred_Stock_an

Convertible Preferred Stock and Stockholders' Equity (Deficit)	12 Months Ended
	Dec. 31, 2013
Convertible Preferred Stock and Stockholders' Equity (Deficit)	'
Convertible Preferred Stock and Stockholders' Equity (Deficit)	'

	5. Convertible Preferred Stock and Stockholders' Equity (Deficit)

	Reverse Stock Split

	On September 12, 2013, the Company filed an amendment to its amended and restated certificate of incorporation, effecting a one-for-6.5 reverse stock split of the Company's issued and outstanding shares of common stock. All issued and outstanding common stock and per share amounts contained in the Company's consolidated financial statements have been retroactively adjusted to reflect this reverse stock split for all periods presented.

	Convertible Preferred Stock

	The authorized, issued and outstanding shares of convertible preferred stock by series immediately prior to October 4, 2013 (the date each convertible preferred outstanding share 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, 2013, the Board of Directors of the Company has not declared any dividends.

	Convertible Preferred Stock and Related Transactions

	The Company sold 1,655,435 shares and 12,953,751 shares of Series A convertible preferred stock at $1.00 per share in 2007 and 2008, respectively.

	In 2009, the Company sold 12,050,000 shares of Series B convertible preferred stock at $2.00 per share for $24.1 million in cash and sold 4,194,180 shares of Series B convertible preferred stock in exchange for the conversion of $7.5 million of convertible notes payable and $0.9 million of related accrued interest. The convertible notes payable were originally issued in April 2008 and accrued interest at a rate of 7.5% per annum.

	In March 2011, the Company sold Takeda Ventures, Inc. ("Takeda") 1,500,000 shares of Series B convertible preferred stock at $2.33 per share for $3,500,000 in cash. Also in March 2011, the Company entered into a subordinated note purchase agreement (the "Note Purchase Agreement") with Takeda. Pursuant to such Note Purchase Agreement, the Company sold and issued Takeda one general, unsecured, subordinated note (the "Subordinated Note"). Such Subordinated Note had a principal amount of $1,000,000 and accrued interest at a rate of 2.0% per annum.

	Pursuant to the terms of the Series C financing described below, the 1,500,000 shares of Series B convertible preferred stock purchased by Takeda in March 2011 were converted into 150,000 shares of common stock in July 2012. In May 2012, the Company and Takeda entered into a letter agreement pursuant to which, effective in July 2012, Takeda forfeited all of its rights and forgave all of the obligations of the Company under the Note Purchase Agreement in exchange for the Company converting Takeda's 23,077 shares of common stock into 1,500,000 shares of Series B-1 convertible preferred stock. As a result of the exchange of: (i) $1.0 million of debt and related $25,000 of accrued interest and (ii) 23,077 shares of common stock with a fair value of approximately $32,000 for 1,500,000 shares of Series B-1 convertible preferred stock with a fair value of approximately $1.4 million, the Company recorded a loss on exchange of approximately $0.3 million.

	On May 4, 2012, the Company entered into a Series C stock purchase agreement pursuant to which it sold 6,120,369 shares of Series C convertible preferred stock for cash at $1.00 per share in May 2012 and sold 3,124,310 shares of Series C convertible preferred stock for cash at $1.00 per share in July 2012 (together, the "First Closing"). The Company sold an additional 7,563,825 shares of Series C convertible preferred stock for cash at $1.00 per share in a second closing in October 2012.

	Pursuant to the Series C stock purchase agreement, certain non-participating stockholders' holdings of preferred stock were converted into common stock on a basis of one share of common stock for each 65 shares of preferred stock. As a result, in addition to Takeda, one investor had its 4,194,180 shares of Series B convertible preferred stock converted into 64,527 shares of common stock upon the First Closing.

	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, nonstatutory 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 or shares that we reacquire. 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, beginning on January 1, 2014, 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.

	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 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 were made under the ESPP during the year ended December 31, 2013.

Stock Options and Restricted Stock Awards

The following table summarizes stock option activity and related information under the Plans for the year ended December 31, 2013:


		Options			Weighted			Weighted			Aggregate
					Average			Average			Intrinsic Value
					Exercise			Remaining			(in 000s)
					Price Per Share			Contractual
								Term
Outstanding at December 31, 2012			1,432,369		$	1.43			9.14		$	51
Granted			355,780			5.6
Exercised			(35,853	)		0.65
Cancelled			(25,305	)		2.24


Outstanding at December 31, 2013			1,726,991		$	2.3			8.47		$	7,203




Options vested and expected to vest at December 31, 2013			1,555,091		$	1.92			8.37		$	6,935




Options exercisable at December 31, 2013			668,667		$	1.52			7.89		$	3,190





As of December 31, 2013 and 2012, the outstanding options included 174,730 and 272,001, respectively, of performance-based options for which the achievement of the performance-based vesting provisions was not determined to be probable. The aggregate grant date fair value of these unvested options at December 31, 2013 and December 31, 2012 was $0.8 million and $0.2 million, respectively.

As of December 31 2012, the outstanding options included 163,573 options, with both performance-based milestones and market conditions that were not determined to be probable of achievement. The aggregate grant date fair value of these unvested options at December 31, 2012 was $0.2 million. As of December 31, 2013, the performance-based milestone components of these options had been achieved, and such options are therefore being expensed over the derived service period. As of December 31, 2013, the market conditions of these options have not been achieved.

As of December 31, 2013 and 2012, the unrecognized compensation cost related to outstanding options (excluding those with unachieved performance-based and/or market conditions), was $1.9 million and $0.8 million, respectively, and is expected to be recognized as expense over approximately 2.9 years and 3.4 years, respectively.

Information about the Company's stock option activity is as follows (in thousands, except share and per share data):


		Years Ended December 31,
		2013			2012			2011
Weighted-average grant date fair value per share of employee options granted		$	4.4		$	1.11		$	1.24




Cash received upon exercise of options		$	23		$	15		$	14





During the year ended December 31, 2012, the Company received $0.2 million from the issuance of restricted common stock.

Outstanding restricted stock awards both inside and outside of the 2007 Plan are summarized as follows:


		Inside the Plan						Outside the Plan
		Number of			Weighted-Average			Number of			Weighted-Average
		Shares			Price			Shares			Price
Balance at December 31, 2013 and December 31, 2012			434,884		$	0.468			564,904		$	0.007

Unvested outstanding restricted stock awards, issued inside the 2007 Plan, as of December 31, 2013 and 2012 were 91,740 and 121,332 shares, respectively. Unvested restricted stock awards as of December 31, 2013 consists of 56,713 shares that vest monthly over a four year period and 35,027 shares that cliff vest in April 2018 or earlier upon the achievement of specified milestones. All restricted stock awards outside the 2007 Plan were fully vested as of December 31, 2013 and 2012.

Stock-Based Compensation Expense

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,
		2013			2012			2011
Risk-free interest rate			1.6	%		1	%		1.1	%
Expected volatility			90	%		94	%		90	%
Expected term (in years)			5.9			6.1			6.1
Expected dividend yield			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. Because 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.

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,
		2013			2012			2011
Risk-free interest rate			2.1	%		1.2	%		1.1	%
Expected volatility			91	%		94	%		90	%
Expected term (in years)			7.3			7.5			6.1
Expected dividend yield			0	%		0	%		0	%

The allocation of stock-based compensation for all options granted and restricted stock awards are as follows (in thousands):


		Years Ended
		December 31,									Period from April 27,
											2007 (inception) to
		2013			2012			2011			December 31, 2013
Research and development		$	912		$	97		$	156		$	1,569
General and administrative			642			58			16			754


Total stock-based compensation expense		$	1,554		$	155		$	172		$	2,323





Common Stock Reserved for Future Issuance

Common stock reserved for future issuance is as follows:


		December 31,
		2013			2012
Conversion of convertible preferred stock			—			7,229,590
Stock warrants			36,074			36,074
Common stock options			1,726,991			1,432,369
Awards available under the 2013 Plan			1,003,526			154,448
Exchangeable shares			403,842			884,605
Employee stock purchase plan			729,000			—


			3,899,433			9,737,086

Collaboration_Agreement

Collaboration Agreement	12 Months Ended
Collaboration Agreement	Dec. 31, 2013
Collaboration Agreement	'
Collaboration Agreement	'

	6. 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 years ended December 31, 2013, 2012, and 2011 and the period from April 27, 2007 (inception) to December 31, 2013, the Company recognized $0.6 million, $1.3 million, $0.8 million, and $2.9 million, respectively, as revenue in its consolidated statements of operations.

Income_Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2013
Income Taxes	'
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,
			2013			2012			2011
	Tax computed at federal statutory rate		$	(7,104	)	$	(4,842	)	$	(4,540	)
	State tax, net of federal tax benefit			(1,011	)		(777	)		(742	)
	Permanent differences			755			113			135
	Stock compensation			161			36			—
	R&D tax credits			(621	)		(243	)		(515	)
	Other			(8	)		207			5
	Valuation allowance			7,828			5,506			5,657


	Income tax expense		$	—		$	—		$	—





	Significant components of the Company's deferred tax assets are summarized as follows (in thousands):


			December 31,
			2013			2012
	Deferred tax assets:
	Section 59e amortization		$	12,070		$	9,766
	Foreign net operating losses			72			101
	Depreciation and amortization			880			787
	Other			845			495


	Deferred tax assets			13,867			11,149
	Valuation allowance			(13,867	)		(11,149	)


	Net deferred tax assets		$	—		$	—





	A valuation allowance of $13.9 million and $11.1 million at December 31, 2013 and 2012, respectively, has been established to offset the deferred tax assets, as realization of such assets is uncertain.

	At December 31, 2013, the Company had federal, California and Canadian net operating loss ("NOL") carryforwards of approximately $45.2 million, $42.7 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 2029, respectively, unless previously utilized. At December 31, 2013, the Company had federal and California research and development ("R&D") credit carryforwards of approximately $1.7 million and $1.6 million, respectively. The federal R&D tax credit carryforwards will begin to expire in 2027 unless previously utilized. The California R&D credit carryforwards will carry forward indefinitely.

	Utilization of the NOL and R&D credit carryforwards may be subject to a substantial annual limitation due to ownership change limitations that may have occurred or that could occur in the future, as required by Section 382 of the Internal Revenue Code of 1986, as amended (the "Code"), as well as similar state and foreign provisions. These ownership changes may limit the amount of NOL and R&D credit carryforwards that can be utilized annually to offset future taxable income and tax, respectively. In general, an "ownership change" as defined by Section 382 of the Code results from a transaction or series of transactions over a three-year period resulting in an ownership change of more than 50 percentage points of the outstanding stock of a company by certain stockholders. Since the Company's formation, the Company has raised capital through the issuance of capital stock on several occasions, including the IPO in 2013, which on their own or combined with the purchasing stockholders' subsequent disposition of those shares, may have resulted in such an ownership change, or could result in an ownership change in the future.

	The Company has not completed a study to assess whether an ownership change has occurred or whether there have been multiple ownership changes since the Company's formation due to the complexity and cost associated with such a study and the fact that there may be additional such ownership changes in the future. If the Company has experienced an ownership change at any time since its formation, utilization of the NOL or R&D credit carryforwards would be subject to an annual limitation under Section 382 of the Code, which is determined by first multiplying the value of the Company's stock at the time of the ownership change by the applicable long-term, tax-exempt rate, and then could be subject to additional adjustments, as required. Any limitation may result in expiration of a portion of the NOL or R&D credit carryforwards before utilization. Further, until a study is completed and any limitation known, no amounts are being considered as an uncertain tax position or disclosed as an unrecognized tax benefit. Due to the existence of the valuation allowance, future changes in the Company's unrecognized tax benefits will not impact its effective tax rate. Any carryforwards that will expire prior to utilization as a result of such limitations will be removed from deferred tax assets, with a corresponding reduction of the valuation allowance.

	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 2010, 2009, and 2010, 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 adjustment 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, 2011		$	—
	Increase related to prior year positions			11


	Balance at December 31, 2012		$	11
Increase related to prior year positions			5


Balance at December 31, 2013		$	16





The Company does not anticipate that the amount of unrecognized tax benefits as of December 31, 2013 will change within the next twelve months. The Company has not recognized interest or penalties in its consolidated statements of operations and comprehensive loss since inception.

Employee_Benefits

Employee Benefits	12 Months Ended
Employee Benefits	Dec. 31, 2013
Employee Benefits	'
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_D

Selected Quarterly Financial Data	12 Months Ended
Selected Quarterly Financial Data	Dec. 31, 2013
Selected Quarterly Financial Data	'
Selected Quarterly Financial Data	'

	9. Selected Quarterly Financial Data


	(in thousands, except per share data) (unaudited)	First			Second			Third			Fourth
	(in thousands, except per share data) (unaudited)	Quarter			Quarter			Quarter			Quarter
	2013
	Revenues	$	472		$	290		$	209		$	—
	Total operating expenses		3,828			4,559			5,357			4,902
	Net loss		(3,548	)		(5,534	)		(6,073	)		(5,739	)
	Basic and diluted net loss per common share	$	(2.92	)	$	(4.46	)	$	(4.81	)	$	(0.29	)
	2012
	Revenues	$	418		$	1,081		$	528		$	643
	Total operating expense		3,538			3,824			4,178			4,687
	Net loss		(3,234	)		(2,737	)		(4,113	)		(4,155	)
	Basic and diluted net loss per common share	$	(3.43	)	$	(2.58	)	$	(3.51	)	$	(3.51	)

Subsequent_Events

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2013
Subsequent Events	'
Subsequent Events	'

	10. Subsequent Events

	The Company evaluates transactions and events that occur after the balance sheet date as potential subsequent events that may require disclosure and or adjustments to the consolidated financial statements as of the balance sheet date. We have completed this evaluation of all events through the issuance date of these financial statements and determined that no subsequent transactions or events require disclosure.

Organization_and_Summary_of_Si1

Organization and Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2013

Organization and Summary of Significant Accounting Policies

Initial Public Offering

•

the conversion of all outstanding shares of the Company's convertible preferred stock into 7,229,590 shares of the Company's common stock (see Note 5);

•

Use of Estimates

Principles of Consolidation

Segment Reporting

Fair Value of Financial Instruments

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

Fair Value Measurements

at Reporting Date Using

Total

Quoted Prices in

Significant

Active Markets for

Other

Unobservable

Identical

Observable

Inputs

Assets

Inputs

(Level 3)

(Level 1)

(Level 2)

As of December 31, 2012:

Warrant liability

184

—

184

Exchangeable share liability

551

—

551

735

—

735

The following assumptions were used in the Black-Scholes option pricing model to determine the fair value of the preferred stock warrant liability:

As of

October 4, 2013

December 31, 2012

Risk-free interest rate

2.1

1.2

Expected volatility

85.9

93.5

Remaining contractual term (in years)

7.55

8.31

Expected dividend yield

As of

October 4, 2013

December 31, 2012

Series B convertible preferred stock

6.9

0.92

Series C convertible preferred stock

6.9

0.99

Common stock

6.9

1.37

The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs (in thousands):

Warrant

Exchangeable

Liability

Balance at December 31, 2011

221

563

Issuance of exchangeable shares

—

Change in fair value

(37

)

(90

)

Balance at December 31, 2012

184

551

Issuance of exchangeable shares

—

346

Change in fair value

2,421

Transfer to stockholders' equity at fair value upon closing of IPO

(192

)

(3,318

)

Balance at December 31, 2013

—

Cash and Cash Equivalents

Concentration of Credit Risk

Property and Equipment

Impairment of Long-Lived Assets

Other Assets

Deferred Rent

Preferred Stock Warrant Liability

Revenue Recognition

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

Income Taxes

Comprehensive Loss

Net Loss Per Common Share

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,

2013

2012

2011

Convertible preferred stock outstanding

—

7,229,590

5,385,353

Warrants for convertible preferred stock

—

36,074

Warrants for common stock

36,074

—

Exchangeable shares

—

403,841

346,147

Common stock options

1,726,991

1,432,369

305,192

1,763,065

9,101,874

6,072,766

The convertible preferred stock and exchangeable shares were converted into shares of the Company's stock as a result of the completion of the Company's IPO on October 4, 2013.

Organization_and_Summary_of_Si2

Organization and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
Organization and Summary of Significant Accounting Policies	'
Schedule of liabilities measured at fair value on a recurring basis	'

	Liabilities measured at fair value on a recurring basis as of December 31, 2012 are as follows (in thousands):


					Fair Value Measurements
					at Reporting Date Using
		Total			Quoted Prices in			Significant		Significant
					Active Markets for			Other		Unobservable
					Identical			Observable		Inputs
					Assets			Inputs		(Level 3)
					(Level 1)			(Level 2)
	As of December 31, 2012:
	Warrant liability	$	184		$	—		$	—	$	184
	Exchangeable share liability		551			—			—		551


		$	735		$	—		$	—	$	735




Schedule of assumptions used to determine fair value of preferred stock warrant liability	'




		As of			As of
		4-Oct-13			31-Dec-12
	Risk-free interest rate		2.1	%		1.2	%
	Expected volatility		85.9	%		93.5	%
	Remaining contractual term (in years)		7.55			8.31
	Expected dividend yield		0	%		0	%
Schedule of fair values per share of the Company's underlying convertible preferred stock and common stock	'




		As of			As of
		4-Oct-13			31-Dec-12
	Series B convertible preferred stock	$	6.9		$	0.92
	Series C convertible preferred stock		6.9			0.99
	Common stock		6.9			1.37
Schedule of reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs	'

	The following table provides a reconciliation of all liabilities measured at fair value using Level 3 significant unobservable inputs (in thousands):


		Warrant			Exchangeable
		Liability			Share
					Liability
	Balance at December 31, 2011	$	221		$	563
	Issuance of exchangeable shares		—			78
	Change in fair value		(37	)		(90	)


	Balance at December 31, 2012		184			551
	Issuance of exchangeable shares		—			346
	Change in fair value		8			2,421
	Transfer to stockholders' equity at fair value upon closing of IPO		(192	)		(3,318	)


	Balance at December 31, 2013	$	—		$	—




Schedule of anti-dilutive securities not included in the calculation of diluted net loss per common share	'




		As of December 31,
		2013			2012			2011
	Convertible preferred stock outstanding		—			7,229,590			5,385,353
	Warrants for convertible preferred stock		—			36,074			36,074
	Warrants for common stock		36,074			—			—
	Exchangeable shares		—			403,841			346,147
	Common stock options		1,726,991			1,432,369			305,192


			1,763,065			9,101,874			6,072,766

Asset_Acquisition_of_Verio_The1

Asset Acquisition of Verio Therapeutics Inc. (Tables)	12 Months Ended
Asset Acquisition of Verio Therapeutics Inc. (Tables)	Dec. 31, 2013
Asset Acquisition of Verio Therapeutics Inc.	'
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 upon the exchange of the Exchangeable Shares and the initial fair value of the shares are summarized as follows (in thousands, except share and per share amounts):


		Exchangeable		Fair Value Per		Initial Fair
		Shares		Share of		Value of
				Underlying		Exchangeable
				Common Stock		Shares
	Apr-10		138,462	$	1.69	$	234
	Mar-11		92,308		1.69		156
	May-11		115,380		1.69		195
	Apr-12		57,691		1.37		78
	Jul-13		76,922		4.49		346


	Total		480,763			$	1,009

Property_and_Equipment_Tables

Property and Equipment (Tables)	12 Months Ended
Property and Equipment (Tables)	Dec. 31, 2013
Property and Equipment	'
Schedule of property and equipment	'

	Property and equipment consist of the following (in thousands):


		December 31,
		2013			2012
	Furniture and fixtures	$	247		$	242
	Computer and office equipment		123			129
	Software		103			103
	Leasehold improvements—building		60			—
	Scientific equipment		2,573			2,436


	Property and equipment, gross		3,106			2,910
	Less accumulated depreciation and amortization		(2,296	)		(1,749	)


	Property and equipment, net	$	810		$	1,161

LongTerm_Debt_Commitments_and_1

Long-Term Debt, Commitments and Contingencies (Tables)	12 Months Ended
Long-Term Debt, Commitments and Contingencies (Tables)	Dec. 31, 2013
Long-Term Debt, Commitments and Contingencies	'
Schedule of long-term debt and unamortized discount balances (excluding convertible debt)	'

	Long-term debt and unamortized discount balances (excluding convertible debt) are as follows (in thousands):


		December 31,
		2013			2012
	Long-term debt	$	1,750		$	3,750
	Less debt discount, net of current portion		—			(18	)


	Long-term debt, net of discount		1,750			3,732
	Less current portion of long-term debt		(1,750	)		(2,000	)


	Long-term debt, net of current portion	$	—		$	1,732




	Current portion of long-term debt	$	1,750		$	2,000
	Current portion of debt discount		(18	)		(59	)


	Current portion of long-term debt, net	$	1,732		$	1,941




Summary of share issuances	'

	The share issuances are summarized as follows (in thousands, except share amounts):


		Shares of			Fair Value of
		Common Stock			Common Shares
	2008		18,462		$	1
	2009		46,923			17
	2010		3,077			5
	2012		15,385			21
	2013		7,692			13


	Total		91,539		$	57




Schedule of future minimum payments under the long-term debt and the non-cancelable operating lease	'

	Future minimum payments under the long-term debt and the non-cancelable operating lease as of December 31, 2013 are as follows (in thousands):


		Long-Term			Operating Lease			Total
		Debt			Operating Lease			Total
	Years Ending December 31,
	2014	$	2,011		$	911		$	2,922
	2015		—			943			943
	2016		—			480			480


	Total		2,011		$	2,334		$	4,345




	Less interest		(61	)
	Less additional payments due upon maturity		(200	)
	Less current portion of long-term debt		(1,750	)


	Long-term debt, net of current portion	$	—

Convertible_Preferred_Stock_an1

Convertible Preferred Stock and Stockholders' Equity (Deficit) (Tables)	12 Months Ended
	Dec. 31, 2013
Convertible Preferred Stock and Stockholders' Equity (Deficit)	'
Schedule of the authorized, issued and outstanding shares of convertible preferred stock by series	'

	The authorized, issued and outstanding shares of convertible preferred stock by series immediately prior to October 4, 2013 (the date each convertible preferred outstanding share 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




Summary of information about the Company's stock option activity	'

	Information about the Company's stock option activity is as follows (in thousands, except share and per share data):


		Years Ended December 31,
		2013			2012			2011
	Weighted-average grant date fair value per share of employee options granted	$	4.4		$	1.11		$	1.24




	Cash received upon exercise of options	$	23		$	15		$	14




Schedule of allocation of stock-based compensation for all options and restricted stock awards	'

	The allocation of stock-based compensation for all options granted and restricted stock awards are as follows (in thousands):


		Years Ended
		December 31,									Period from April 27,
											2007 (inception) to
		2013			2012			2011			December 31, 2013
	Research and development	$	912		$	97		$	156		$	1,569
	General and administrative		642			58			16			754


	Total stock-based compensation expense	$	1,554		$	155		$	172		$	2,323




Schedule of common stock reserved for future issuance	'




		December 31,
		2013			2012
	Conversion of convertible preferred stock		—			7,229,590
	Stock warrants		36,074			36,074
	Common stock options		1,726,991			1,432,369
	Awards available under the 2013 Plan		1,003,526			154,448
	Exchangeable shares		403,842			884,605
	Employee stock purchase plan		729,000			—


			3,899,433			9,737,086




Employee stock option	'
Convertible Preferred Stock and Stockholders' Equity (Deficit)	'
Schedule of weighted-average assumptions used to determine the fair value of stock option grants	'




		Years Ended
		December 31,
		2013			2012			2011
	Risk-free interest rate		1.6	%		1	%		1.1	%
	Expected volatility		90	%		94	%		90	%
	Expected term (in years)		5.9			6.1			6.1
	Expected dividend yield		0	%		0	%		0	%
Non-employee stock option	'
Convertible Preferred Stock and Stockholders' Equity (Deficit)	'
Schedule of weighted-average assumptions used to determine the fair value of stock option grants	'




		Years Ended
		December 31,
		2013			2012			2011
	Risk-free interest rate		2.1	%		1.2	%		1.1	%
	Expected volatility		91	%		94	%		90	%
	Expected term (in years)		7.3			7.5			6.1
	Expected dividend yield		0	%		0	%		0	%
Combined plans	'
Convertible Preferred Stock and Stockholders' Equity (Deficit)	'
Summary of stock option activity under the Plan	'




		Options			Weighted			Weighted			Aggregate
					Average			Average			Intrinsic Value
					Exercise			Remaining			(in 000s)
					Price Per Share			Contractual
								Term
	Outstanding at December 31, 2012		1,432,369		$	1.43			9.14		$	51
	Granted		355,780			5.6
	Exercised		(35,853	)		0.65
	Cancelled		(25,305	)		2.24


	Outstanding at December 31, 2013		1,726,991		$	2.3			8.47		$	7,203




	Options vested and expected to vest at December 31, 2013		1,555,091		$	1.92			8.37		$	6,935




	Options exercisable at December 31, 2013		668,667		$	1.52			7.89		$	3,190




Summary of outstanding restricted stock awards under the plan	'




		Inside the Plan						Outside the Plan
		Number of			Weighted-Average			Number of			Weighted-Average
		Shares			Price			Shares			Price
	Balance at December 31, 2013 and December 31, 2012		434,884		$	0.468			564,904		$	0.007

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2013
Income Taxes	'
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,
		2013			2012			2011
	Tax computed at federal statutory rate	$	(7,104	)	$	(4,842	)	$	(4,540	)
	State tax, net of federal tax benefit		(1,011	)		(777	)		(742	)
	Permanent differences		755			113			135
	Stock compensation		161			36			—
	R&D tax credits		(621	)		(243	)		(515	)
	Other		(8	)		207			5
	Valuation allowance		7,828			5,506			5,657


	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):


		December 31,
		2013			2012
	Deferred tax assets:
	Section 59e amortization	$	12,070		$	9,766
	Foreign net operating losses		72			101
	Depreciation and amortization		880			787
	Other		845			495


	Deferred tax assets		13,867			11,149
	Valuation allowance		(13,867	)		(11,149	)


	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, 2011	$	—
	Increase related to prior year positions		11


	Balance at December 31, 2012	$	11
	Increase related to prior year positions		5


	Balance at December 31, 2013	$	16

Selected_Quarterly_Financial_D1

Selected Quarterly Financial Data (Tables)	12 Months Ended
Selected Quarterly Financial Data (Tables)	Dec. 31, 2013
Selected Quarterly Financial Data	'
Schedule of selected quarterly financial data	'




	(in thousands, except per share data) (unaudited)	First			Second			Third			Fourth
	(in thousands, except per share data) (unaudited)	Quarter			Quarter			Quarter			Quarter
	2013
	Revenues	$	472		$	290		$	209		$	—
	Total operating expenses		3,828			4,559			5,357			4,902
	Net loss		(3,548	)		(5,534	)		(6,073	)		(5,739	)
	Basic and diluted net loss per common share	$	(2.92	)	$	(4.46	)	$	(4.81	)	$	(0.29	)
	2012
	Revenues	$	418		$	1,081		$	528		$	643
	Total operating expense		3,538			3,824			4,178			4,687
	Net loss		(3,234	)		(2,737	)		(4,113	)		(4,155	)
	Basic and diluted net loss per common share	$	(3.43	)	$	(2.58	)	$	(3.51	)	$	(3.51	)

Organization_and_Summary_of_Si3

Organization and Summary of Significant Accounting Policies (Details) (USD $)	0 Months Ended	3 Months Ended	8 Months Ended	12 Months Ended				80 Months Ended
	Oct. 04, 2013	Dec. 31, 2013	Dec. 31, 2007	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2008	Dec. 31, 2013
	Oct. 04, 2013	Dec. 31, 2013	Dec. 31, 2007	item	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2008	Dec. 31, 2013
Organization and Summary of Significant Accounting Policies	'	'	'	'	'	'	'	'
Number of platforms	'	'	'	2	'	'	'	'
Initial Public Offering	'	'	'	'	'	'	'	'
Shares sold in initial public offering	7,666,667	'	'	'	'	'	'	'
Public offering price (in dollars per share)	$6	'	$0.00	'	'	'	$0.01	'
Gross proceeds from initial public offering	$46,000,000	'	'	$40,480,000	'	'	'	$40,480,000
Net proceeds from initial public offering	40,500,000	'	'	'	'	'	'	'
Conversion convertible preferred stock into common stock	7,229,590	'	'	'	'	'	'	'
Principal amount of convertible debt converted	22,100,000	'	'	'	'	'	'	'
Number of shares of common stock issued upon conversion of debt	3,679,401	'	'	'	'	'	'	'
Write-off of unamortized debt discount	300,000	'	'	'	'	'	'	'
Repayment of outstanding principal and unpaid accrued interest in cash	1,700,000	'	'	1,679,000	'	'	'	1,679,000
Common stock issuable upon redemption of exchangeable shares	480,763	'	'	'	'	'	'	'
Fair value adjustment charge on the exchangeable shares	$400,000	$400,000	'	$2,421,000	($90,000)	$5,000	'	$2,309,000
Warrants to purchase shares of convertible preferred stock which are converted	230,000	'	'	'	'	'	'	'
Warrants to purchase shares of common stock issued on conversion	36,074	'	'	'	'	'	'	'
Common stock authorized (in shares)	150,000,000	150,000,000	'	150,000,000	100,000,000	'	'	150,000,000
Preferred stock authorized (in shares)	5,000,000	5,000,000	'	5,000,000	0	'	'	5,000,000
Segment Reporting	'	'	'	'	'	'	'	'
Number of operating segments	'	'	'	1	'	'	'	'

Organization_and_Summary_of_Si4

Organization and Summary of Significant Accounting Policies (Details 2) (USD $)

Dec. 31, 2013

Oct. 04, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Warrant liability

Recurring

Non-recurring

Carrying amount

Total

Significant Unobservable Inputs (Level 3)

Recurring

Warrant liability

Exchangeable share liability

Warrant liability

Exchangeable share liability

Quoted Prices in Active Markets for Identical Assets (Level 1)

Fair value of financial instruments

Cash equivalents

$52,300,000

$41,300,000

Non-financial assets

Non-financial liabilities

Transfer of assets from level 1 to level 2

Transfer of assets from level 2 to level 1

Transfer of liabilities from level 1 to level 2

Transfer of liabilities from level 2 to level 1

Liabilities measured at fair value

Liabilities

$735,000

$184,000

$551,000

$184,000

$551,000

$735,000

Assumptions used to determine the fair value

Risk-free interest rate (as a percent)

2.10%

1.20%

Expected volatility (as a percent)

85.90%

93.50%

Remaining contractual term

'7 years 6 months 18 days

'8 years 3 months 22 days

Expected dividend yield (as a percent)

0.00%

Organization_and_Summary_of_Si5

Organization and Summary of Significant Accounting Policies (Details 3) (USD $)	Dec. 31, 2013	Oct. 04, 2013	Dec. 31, 2012	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Fair values per share of the Company's underlying stock	'	'	'	'	'	'
Fair values of stock (in dollars per share)	$13	$6	$21	$5	$17	$1
Common stock	'	'	'	'	'	'
Fair values per share of the Company's underlying stock	'	'	'	'	'	'
Fair values of stock (in dollars per share)	'	$6.90	$1.37	'	'	'
Series B convertible preferred stock	'	'	'	'	'	'
Fair values per share of the Company's underlying stock	'	'	'	'	'	'
Fair values of stock (in dollars per share)	'	$6.90	$0.92	'	$2	'
Series C convertible preferred stock	'	'	'	'	'	'
Fair values per share of the Company's underlying stock	'	'	'	'	'	'
Fair values of stock (in dollars per share)	'	$6.90	$0.99	'	'	'

Organization_and_Summary_of_Si6

Organization and Summary of Significant Accounting Policies (Details 4) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Warrant liability	'	'
Reconciliation of liabilities measured at fair value	'	'
Balance at the beginning of the period	$184	$221
Change in fair value	8	-37
Transfer to stockholders' equity at fair value upon closing of IPO	-192	'
Balance at the end of the period	'	184
Exchangeable share liability	'	'
Reconciliation of liabilities measured at fair value	'	'
Balance at the beginning of the period	551	563
Issuance of exchangeable shares	346	78
Change in fair value	2,421	-90
Transfer to stockholders' equity at fair value upon closing of IPO	-3,318	'
Balance at the end of the period	'	$551

Organization_and_Summary_of_Si7

Organization and Summary of Significant Accounting Policies (Details 5)	12 Months Ended
	Dec. 31, 2013
Furniture and fixtures \| Minimum	'
Property and equipment	'
Estimated useful lives	'2 years
Furniture and fixtures \| Maximum	'
Property and equipment	'
Estimated useful lives	'5 years
Computers \| Minimum	'
Property and equipment	'
Estimated useful lives	'2 years
Computers \| Maximum	'
Property and equipment	'
Estimated useful lives	'5 years
Scientific \| Minimum	'
Property and equipment	'
Estimated useful lives	'2 years
Scientific \| 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_Si8

Organization and Summary of Significant Accounting Policies (Details 6)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenue recognition	'	'	'
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) collectibility is reasonably assured	'	'
Shares excluded from weighted average number of shares attributable to share based payments	107,570	173,772	303,253
Net loss per common share	'	'	'
Anti-dilutive securities (in shares)	1,763,065	9,101,874	6,072,766
Convertible preferred stock outstanding	'	'	'
Net loss per common share	'	'	'
Anti-dilutive securities (in shares)	'	7,229,590	5,385,353
Warrants for convertible preferred stock	'	'	'
Net loss per common share	'	'	'
Anti-dilutive securities (in shares)	'	36,074	36,074
Warrants for common stock	'	'	'
Net loss per common share	'	'	'
Anti-dilutive securities (in shares)	36,074	'	'
Exchangeable shares	'	'	'
Net loss per common share	'	'	'
Anti-dilutive securities (in shares)	'	403,841	346,147
Common stock options	'	'	'
Net loss per common share	'	'	'
Anti-dilutive securities (in shares)	1,726,991	1,432,369	305,192

Asset_Acquisition_of_Verio_The2

Asset Acquisition of Verio Therapeutics Inc. (Details) (USD $)

0 Months Ended

3 Months Ended

12 Months Ended

80 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

Oct. 04, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Apr. 07, 2010

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Maximum

Verio

Apr-10

Mar-11

May-11

Apr-12

Jul-13

Acquisition

Exchangeable Shares issued

884,605

900,000

Shares issuable on exchange of exchangeable shares

138,462

480,763

138,462

92,308

115,380

57,691

76,922

Net liabilities

$212,000

Initial fair value of exchangeable shares (in dollars)

234,000

1,009,000

234,000

156,000

195,000

78,000

346,000

Total purchase price

446,000

Common stock issued pursuant to the redemption of the exchangeable shares

480,763

Potential increase in shares issuable on exchange of Exchangeable Shares based on achievement of additional milestones

403,842

Potential increase in shares issuable on achievement of certain preclinical milestones

76,923

Potential increase in shares issuable on achievement of certain clinical milestones

211,538

Potential increase in shares issuable on achievement of certain commercialization milestones

115,381

Change in fair value of exchangeable shares

400,000

2,421,000

-90,000

5,000

2,309,000

2,400,000

100,000

-5,000

Reclassification of the exchangeable share liability to additional paid-in capital

$3,300,000

Fair value per share of underlying common stock (in dollars per share)

$1.69

$1.37

$4.49

Property_and_Equipment_Details

Property and Equipment (Details) (USD $)	12 Months Ended			80 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Property and equipment	'	'	'	'
Property and equipment, gross	$3,106	$2,910	'	$3,106
Less accumulated depreciation and amortization	-2,296	-1,749	'	-2,296
Property and equipment, net	810	1,161	'	810
Depreciation expense	571	590	672	2,508
Gains (losses) on the disposal of long-lived assets	18	'	117	135
Furniture and fixtures	'	'	'	'
Property and equipment	'	'	'	'
Property and equipment, gross	247	242	'	247
Computer and office equipment	'	'	'	'
Property and equipment	'	'	'	'
Property and equipment, gross	123	129	'	123
Software	'	'	'	'
Property and equipment	'	'	'	'
Property and equipment, gross	103	103	'	103
Leasehold improvements - building	'	'	'	'
Property and equipment	'	'	'	'
Property and equipment, gross	60	'	'	60
Scientific equipment	'	'	'	'
Property and equipment	'	'	'	'
Property and equipment, gross	$2,573	$2,436	'	$2,573

LongTerm_Debt_Commitments_and_2

Long-Term Debt, Commitments and Contingencies (Details) (USD $)

0 Months Ended

12 Months Ended

80 Months Ended

1 Months Ended

12 Months Ended

0 Months Ended

2 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

Oct. 04, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2011

Aug. 31, 2011

Dec. 31, 2013

Dec. 31, 2011

Dec. 31, 2009

Oct. 04, 2013

Jul. 31, 2013

Dec. 31, 2013

Oct. 04, 2013

Dec. 31, 2013

Aug. 31, 2013

Oct. 04, 2013

Dec. 31, 2011

Dec. 31, 2009

Oct. 04, 2013

Aug. 31, 2011

Dec. 31, 2009

31-May-12

Loan and security agreement

June and July 2013 Convertible Note Financing

August 2013 Convertible Note Financing

Warrant

Convertible Series B Preferred Stock Warrant

Convertible Series C Preferred Stock Warrant

Jan-19

Aug-21

Warrant

Long-term debt

$1,750,000

$3,750,000

$1,750,000

$1,800,000

Less debt discount, net of current portion

-18,000

Long-term debt, net of discount

1,750,000

3,732,000

1,750,000

Less current portion of long-term debt

-1,750,000

-2,000,000

-1,750,000

Long-term debt, net of current portion

1,732,000

Current portion of debt discount

-18,000

-59,000

-18,000

Current portion of long-term debt, net

1,732,000

1,941,000

1,732,000

Maximum borrowing capacity

4,000,000

3,000,000

Amount drawn under the credit facility

3,000,000

Warrants issued (in shares)

230,000

100,000

30,000

200,000

Exercise price (in dollars per share)

$7.21

Additional payment upon maturity as a percentage of maximum loan amount

5.00%

Repayment of remaining outstanding principal amount

2,000,000

250,000

800,000

4,650,000

600,000

Warrants issued

200,000

Term Advances

2,000,000

Period of interest only payments

'12 months

Period for monthly principal and interest payments

'24 months

Interest rate (as a percent)

7.00%

2.00%

Term of debt

'36 months

'1 year

Loss on extinguishment of debt

323,000

9,000

332,000

Fair values of warrants issued

184,000

200,000

100,000

Warrants to purchase shares of common stock issued on conversion

36,074

5,305

30,769

Warrant liability reclassified to additional paid-in capital

200,000

Debt issued

3,700,000

20,000,000

Warrants to purchase shares of convertible preferred stock which are converted

230,000

625,828

3,053,573

Debt discount related to beneficial conversion feature

300,000

Debt discount amortization

394,000

84,000

23,000

535,000

300,000

Outstanding debt

20,000,000

Repayment of outstanding principal and unpaid accrued interest in cash

1,700,000

1,679,000

1,700,000

Aggregate interest expense

$100,000

LongTerm_Debt_Commitments_and_3

Long-Term Debt, Commitments and Contingencies (Details 2) (USD $)	1 Months Ended	12 Months Ended						72 Months Ended	80 Months Ended
	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2013	Dec. 31, 2013	Oct. 04, 2013
Long-Term Debt, Commitments and Contingencies	'	'	'	'	'	'	'	'	'	'
Lease period extended	'2 years	'	'	'	'	'	'	'	'	'
Cash-collateralized irrevocable standby letter of credit	'	$100,000	'	'	'	'	'	$100,000	$100,000	'
Rent expense	'	900,000	700,000	700,000	'	'	'	'	3,800,000	'
License Agreements	'	'	'	'	'	'	'	'	'	'
Minimum annual payments to maintain cancelable licenses	'	300,000	'	'	'	'	'	'	'	'
Shares of Common Stock (in shares)	'	7,692	15,385	'	3,077	46,923	18,462	91,539	'	'
Fair Value of Common Shares (in dollars per share)	'	$13	$21	'	$5	$17	$1	$13	$13	$6
Long-Term Debt	'	'	'	'	'	'	'	'	'	'
Years Ending December 31, 2014	'	2,011,000	'	'	'	'	'	2,011,000	2,011,000	'
Long-term debt, net of discount	'	1,750,000	3,732,000	'	'	'	'	1,750,000	1,750,000	'
Less interest	'	-61,000	'	'	'	'	'	-61,000	-61,000	'
Less additional payments due upon maturity	'	-200,000	'	'	'	'	'	'	'	'
Less current portion of long-term debt	'	1,732,000	1,941,000	'	'	'	'	1,732,000	1,732,000	'
Long-term debt, net of current portion	'	'	1,732,000	'	'	'	'	'	'	'
Operating Lease	'	'	'	'	'	'	'	'	'	'
Years Ending December 31, 2014	'	911,000	'	'	'	'	'	911,000	911,000	'
Years Ending December 31, 2015	'	943,000	'	'	'	'	'	943,000	943,000	'
Years Ending December 31, 2016	'	480,000	'	'	'	'	'	480,000	480,000	'
Total	'	2,334,000	'	'	'	'	'	2,334,000	2,334,000	'
Total	'	'	'	'	'	'	'	'	'	'
Years Ending December 31, 2014	'	2,922,000	'	'	'	'	'	2,922,000	2,922,000	'
Years Ending December 31, 2015	'	943,000	'	'	'	'	'	943,000	943,000	'
Years Ending December 31, 2016	'	480,000	'	'	'	'	'	480,000	480,000	'
Total	'	$4,345,000	'	'	'	'	'	$4,345,000	$4,345,000	'

Convertible_Preferred_Stock_an2

Convertible Preferred Stock and Stockholders' Equity (Deficit) (Details) (USD $)

0 Months Ended

80 Months Ended

0 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

0 Months Ended

Oct. 04, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2010

Dec. 31, 2009

Dec. 31, 2008

4-May-13

Jul. 31, 2012

31-May-12

Dec. 31, 2009

Jul. 31, 2012

Mar. 31, 2011

Oct. 04, 2013

Dec. 31, 2008

Dec. 31, 2007

Dec. 31, 2009

Oct. 04, 2013

Dec. 31, 2012

Jul. 31, 2012

Mar. 31, 2011

Oct. 04, 2013

Jul. 31, 2012

Oct. 04, 2013

Dec. 31, 2012

Oct. 31, 2012

Jul. 31, 2012

4-May-12

Oct. 04, 2013

Series C stock purchase agreement

Convertible notes payable

Takeda

Series A

Series B

Series B-1

Series C

Series C-1

Series A and Series C convertible preferred stock

Series B and Series B-1 convertible preferred stock

item

Series C stock purchase agreement

Convertible notes payable

Series C stock purchase agreement

Takeda

Series C stock purchase agreement

item

Series C stock purchase agreement

Convertible preferred stock

Reverse stock split ratio

0.154

Shares Authorized

68,360,186

62,200,000

14,609,186

12,080,000

1,500,000

29,000,000

11,171,000

Shares Outstanding (in shares)

44,967,690

14,609,186

12,050,000

1,500,000

16,808,504

Shares issued on conversion of convertible preferred stock

7,229,590

150,000

64,527

4,833,490

2,396,100

Conversion ratio (per share of common stock)

0.1538

0.1768

Convertible preferred stock, share sold

44,967,690

12,953,751

1,655,435

12,050,000

1,500,000

7,563,825

3,124,310

6,120,369

Share price of convertible preferred stock (in dollars per share)

$13

$21

$17

$6.90

$0.92

$2.33

$6.90

$0.99

Convertible preferred stock, proceeds from shares issued

$24,100,000

$3,500,000

Convertible preferred stock converted into shares of common stock

3,679,401

4,194,180

Convertible notes payable issued upon conversion of convertible preferred stock

8,388,000

7,500,000

Accrued interest

900,000

Interest rate (as a percent)

7.50%

2.00%

Number of notes issued

Principal amount of subordinated note

1,000,000

Number of shares of common stock exchanged

23,077

Convertible preferred stock issued in exchange of common stock

1,500,000

Debt amount issued in exchange of common stock

1,000,000

Accrued interest issued in exchange of common stock

25,000

Fair value of shares of common stock exchanged

32,000

Fair value of forfeiture of convertible preferred stock

1,400,000

Loss on exchange of common stocks

$300,000

Number of investors

Convertible_Preferred_Stock_an3

Convertible Preferred Stock and Stockholders' Equity (Deficit) (Details 2) (USD $)

12 Months Ended

80 Months Ended

12 Months Ended

80 Months Ended

12 Months Ended

80 Months Ended

0 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Sep. 13, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Aug. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Aug. 28, 2013

Research and development

General and administrative

Conversion of convertible preferred stock

Stock warrants

ESPP

Stock option

Employee stock option

Restricted stock awards

Awards available under the 2013 Plan

Exchangeable shares

Non-employee stock option

Combined plans

2007 Plan

2013 Plan

Performance-based milestones and market conditions

Stock option

Restricted stock awards

Restricted stock awards inside the plans

Restricted stock awards outside the plans

Performance-based

Performance-based milestones and market conditions

Maximum

Cliff vest

Convertible Preferred Stock and Stockholders' Equity (Deficit)

Shares authorized

2,423,072

Stock options generally vested on first anniversary (as a percent)

25.00%

General vesting period after first year

'3 years

'4 years

Term of stock awards

'10 years

Shares reserved for issuance

3,899,433

9,737,086

3,899,433

7,229,590

36,074

729,000

1,726,991

1,432,369

1,003,526

154,448

403,842

884,605

1,020,000

Additional shares authorized (as a percent)

2.00%

4.00%

Monthly vesting period

'4 years

Additional shares authorized

450,000

Stock purchases under the plan (in shares)

Options

Outstanding at the beginning of the period (in shares)

163,573

1,432,369

272,001

Granted (in shares)

355,780

Exercised (in shares)

-35,853

Canceled (in shares)

-25,305

Outstanding at the end of the period (in shares)

163,573

1,726,991

1,432,369

174,730

272,001

Vested and expected to vest at the end of the period (in shares)

1,555,091

Exercisable at the end of the period (in shares)

668,667

Weighted Average Exercise Price Per Share

Balance at the beginning of the period (in dollars per share)

$1.43

Granted (in dollars per share)

$5.60

Exercised (in dollars per share)

$0.65

Canceled (in dollars per share)

$2.24

Balance at the end of the period (in dollars per share)

$2.30

$1.43

Vested and expected to vest at the end of the period (in dollars per share)

$1.92

Exercisable at the end of the period (in dollars per share)

$1.52

Weighted Average Remaining Contractual Term

Outstanding at the end of the period

'8 years 5 months 19 days

'9 years 1 month 20 days

Vested and expected to vest at the end of the period

'8 years 4 months 13 days

Exercisable at the end of the period

'7 years 10 months 20 days

Aggregate Intrinsic Value

Outstanding at the end of the period (in dollars)

$7,203,000

$51,000

Vested and expected to vest at the end of the period (in dollars)

6,935,000

Exercisable at the end of the period (in dollars)

3,190,000

Aggregate grant date fair value

800,000

200,000

Unrecognized compensation cost related to outstanding options

1,900,000

800,000

Expected recognition period of unrecognized compensation cost

'2 years 10 months 24 days

'3 years 4 months 24 days

Weighted-average grant date fair value per share of employee options granted (in dollars per share)

$4.40

$1.11

$1.24

Cash received upon exercise of options (in dollars per share)

23,000

15,000

14,000

Proceeds received from issuance of common stock

23,000

207,000

14,000

294,000

200,000

Number of Shares

Balance at the beginning of the period (in shares)

434,884

564,904

Balance at the end of the period (in shares)

434,884

564,904

Weighted-Average Price

Balance at the beginning of the period (in dollars per share)

$0.47

$0.01

Balance at the end of the period (in dollars per share)

$0.47

$0.01

Unvested shares issued (in shares)

91,740

121,332

Number of shares vested

56,713

35,027

Weighted-average assumptions to determine fair value of stock options

Risk-free interest rate (as a percent)

1.60%

1.00%

1.10%

2.10%

1.20%

1.10%

Expected volatility (as a percent)

90.00%

94.00%

90.00%

91.00%

94.00%

90.00%

Expected term

'5 years 10 months 24 days

'6 years 1 month 6 days

'7 years 3 months 18 days

'7 years 6 months

'6 years 1 month 6 days

Expected dividend yield (as a percent)

0.00%

Total stock-based compensation expense

$1,554,000

$155,000

$172,000

$2,323,000

$912,000

$97,000

$156,000

$1,569,000

$642,000

$58,000

$16,000

$754,000

Common stock reserved for future issuance

Shares reserved for issuance

3,899,433

9,737,086

3,899,433

7,229,590

36,074

729,000

1,726,991

1,432,369

1,003,526

154,448

403,842

884,605

1,020,000

Collaboration_Agreement_Detail

Collaboration Agreement (Details) (USD $)	0 Months Ended	12 Months Ended			80 Months Ended
Collaboration Agreement (Details) (USD $)	Sep. 30, 2010	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013
Collaboration agreement	'	'	'	'	'
Collaboration revenue	'	$626,000	$1,268,000	$833,000	$2,927,000
Collaboration and license agreement \| BD	'	'	'	'	'
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	'	'	'
Collaboration revenue	'	600,000	1,300,000	800,000	2,900,000
Collaboration and license agreement \| BD \| iPSC \| Achievement of commercialization goals	'	'	'	'	'
Collaboration agreement	'	'	'	'	'
Milestone payments received	'	'	500,000	'	'
Collaboration and license agreement \| BD \| iPSC \| Maximum	'	'	'	'	'
Collaboration agreement	'	'	'	'	'
Number of products developed	3	'	'	'	'
Collaboration and license agreement \| BD \| iPSC \| Maximum \| Achievement of annual sale goals	'	'	'	'	'
Collaboration agreement	'	'	'	'	'
Milestone payments received	4,000,000	'	'	'	'
Collaboration and license agreement \| BD \| iPSC one \| Achievement of commercial sale goals	'	'	'	'	'
Collaboration agreement	'	'	'	'	'
Milestone payments received	500,000	'	'	'	'
Collaboration and license agreement \| BD \| iPSC two \| Achievement of commercial sale goals	'	'	'	'	'
Collaboration agreement	'	'	'	'	'
Milestone payments received	700,000	'	'	'	'
Collaboration and license agreement \| BD \| iPSC three \| Achievement of commercial sale goals	'	'	'	'	'
Collaboration agreement	'	'	'	'	'
Milestone payments received	$800,000	'	'	'	'

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of the Company's expected federal income tax provision (benefit) to the actual income tax provision	'	'	'
Tax computed at federal statutory rate	($7,104)	($4,842)	($4,540)
State tax, net of federal tax benefit	-1,011	-777	-742
Permanent differences	755	113	135
Stock compensation	161	36	'
R&D tax credits	-621	-243	-515
Other	-8	207	5
Valuation allowance	7,828	5,506	5,657
Deferred tax assets:	'	'	'
Section 59e amortization	12,070	9,766	'
Foreign net operating losses	72	101	'
Depreciation and amortization	880	787	'
Other	845	495	'
Deferred tax assets	13,867	11,149	'
Valuation allowance	($13,867)	($11,149)	'

Income_Taxes_Details_2

Income Taxes (Details 2) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2013
U.S. Federal	'
Operating loss carryforwards	'
Net operating loss carryforwards	$45.20
California	'
Operating loss carryforwards	'
Net operating loss carryforwards	42.7
Canadian	'
Operating loss carryforwards	'
Net operating loss carryforwards	$0.30

Income_Taxes_Details_3

Income Taxes (Details 3) (Research and development, USD $)	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2013
U.S. Federal	'
Tax credit carryforwards	'
Tax credit carryforwards	$1.70
California	'
Tax credit carryforwards	'
Tax credit carryforwards	$1.60

Income_Taxes_Details_4

Income Taxes (Details 4) (USD $)	12 Months Ended
Income Taxes (Details 4) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Income Taxes	'	'
Unrecognized tax benefit	$0	'
Change in the Company's unrecognized tax benefits	'	'
Balance at the beginning of the period	11,000	'
Increase related to prior year positions	5,000	11,000
Balance at the end of the period	$16,000	$11,000

Employee_Benefits_Details

Employee Benefits (Details) (USD $)	0 Months Ended	12 Months Ended
Employee Benefits (Details) (USD $)	Jan. 02, 2009	Dec. 31, 2013
Employee Benefits	'	'
Minimum age of employees	'21 years	'
Matching contributions under 401(k) plan	'	$0

Selected_Quarterly_Financial_D2

Selected Quarterly Financial Data (Details) (USD $)	3 Months Ended								8 Months Ended	12 Months Ended						80 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2007	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2013
Selected Quarterly Financial Data	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'
Revenues	'	$209	$290	$472	$643	$528	$1,081	$418	'	$971	$2,670	$1,170	'	'	'	$5,011
Total operating expenses	4,902	5,357	4,559	3,828	4,687	4,178	3,824	3,538	'	18,646	16,227	14,463	'	'	'	87,696
Net loss	($5,739)	($6,073)	($5,534)	($3,548)	($4,155)	($4,113)	($2,737)	($3,234)	($1,224)	($20,894)	($14,239)	($13,427)	($16,222)	($13,334)	($7,169)	($86,509)
Basic and diluted net loss per common share (in dollars per share)	($0.29)	($4.81)	($4.46)	($2.92)	($3.51)	($3.51)	($2.58)	($3.43)	'	($3.54)	($13.06)	($16.16)	'	'	'	'