Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

Summary of Fair Value Measurement Financial Asset and Liabilities

Financial assets measured at fair value on a recurring basis were as follows (in thousands):

	Fair Value Measurements at December 31, 2015
				Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs			Significant Unobservable Inputs
	Total			Level 1			Level 2			Level 3
Assets:
Money market funds		$	62,353		$	62,353		$	-		$	-
U.S Treasury securities			9,348			-			9,348			-
Government-sponsored enterprises			41,202			-			41,202			-
Corporate debt securities			137,928			-			137,928			-
Total assets measured at fair value (a)		$	250,831		$	62,353		$	188,478		$	-

	Fair Value Measurements at December 31, 2014
				Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs			Significant Unobservable Inputs
	Total			Level 1			Level 2			Level 3
Assets:
Money market funds			26,046			26,046			—			—
Restricted cash			300			300			—			—
Total assets measured at fair value		$	26,346		$	26,346		$	—		$	—

(a) Total assets measured at fair value at December 31, 2015 includes approximately $108.0 million reported in cash and cash equivalents on the balance sheet.

Estimated Useful Lives

Property and equipment are stated at cost. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is credited or charged to operations. Repairs and maintenance costs are expensed as incurred. Depreciation is computed using the straight-line method over the following estimated useful lives:

Computer equipment	3 years
Software	3 years
Furniture	10 years
Laboratory and office equipment	5 years
Leasehold improvements	Shorter of lease term or useful life

Computation of Basic and Diluted Income (Loss) Per Common Share

Basic and diluted loss per common share is computed as follows (in thousands except share and per share data):

	Year Ended December 31,
	2015			2014			2013
Numerator:
Net loss used for calculation of basic and diluted EPS	$	(20,140	)	$	(38,313	)	$	(261	)

Denominator:
Weighted average shares outstanding, basic		31,801,645			27,384,990			6,847,697
Effect of dilutive securities:
Stock options and restricted stock units		-			-			-
Weighted average shares outstanding, diluted		31,801,645			27,384,990			6,847,697

Net loss per share, basic and diluted	$	(0.63	)	$	(1.40	)	$	(0.04	)

Schedule of Antidilutive Securities Excluded from the Calculation of Diluted Income (Loss) Per Share

The following common stock equivalents were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive:

	Year Ended December 31,
	2015		2014		2013
Effect of converted preferred stock		—		—		13,189,920
Stock options		1,955,398		2,094,904		2,313,970

Summary of Significant Revenue [Member]

Summary of Percentage of Customer Concentration

The following table includes those collaborators that represent more than 10% of total revenue earned in the periods indicated:

	Year Ended December 31,
	2015		2014		2013
Janssen		71.7%		*		*
Servier		*		36.4%		51.6%
Boehringer		12.4%		28.6%		24.8%
Takeda		*		16.8%		*
Gilead		*		11.4%		13.8%

Summary of Significant Accounts Receivable[Member]

Summary of Percentage of Customer Concentration

The following table includes those collaborators that represent more than 10% of accounts receivable at the date indicated:

	December 31,
	2015		2014
Janssen		39.0%		*
U.S. government		20.0 %		*
Servier		14.0 %		33.3%
Takeda		14.0%		*
Eli Lilly		13.0%		*
Boehringer		*		21.2 %
Green Cross		*		17.9 %

* Balance is less than 10%