Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Schedule of Short-term Investment

Short-term investments at December 31, 2016 consist of the following:

	Cost Basis		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
Current:
Certificates of deposit	$	22,046	$	—	$	—		$	22,046
Agency bonds		5,917		—		(4	)		5,913
United States Treasury securities		68,766		1		(51	)		68,716
	$	96,729	$	1	$	(55	)	$	96,675

Short-term investments at December 31, 2015 consist of the following:

	Cost Basis		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
Current:
Certificates of deposit	$	16,160	$	—	$	—		$	16,160
Agency bonds		10,036		—		(5	)		10,031
United States Treasury securities		5,053		—		(6	)		5,047
	$	31,249	$	—	$	(11	)	$	31,238

Schedule of Estimated Useful Life of Asset Classification

Depreciation and amortization is provided using the straight-line method over the estimated useful lives of the assets, which are as follows:

Asset Classification	Estimated Useful Life
Computer hardware and software	3 - 5 years
Laboratory equipment	5 years
Office equipment	5 years
Leasehold improvements	Shorter of useful life or remaining life of lease

Schedule of Computation of Basic and Diluted EPS

The following table sets forth the computation of basic and diluted EPS attributable to the Company’s common stockholders:

	For the Years Ended December 31,
	2016			2015
	(in thousands, except share and per share amounts)
Numerator:
Net loss	$	(42,854	)	$	(67,982	)
Accretion and dividends on convertible preferred stock		-			(131	)
Net loss applicable to common stockholders	$	(42,854	)	$	(68,113	)
Denominator:
Weighted average common shares outstanding—basic    and diluted		26,735,175			18,311,333
Net loss per share applicable to common    stockholders—basic and diluted	$	(1.60	)	$	(3.72	)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The following common stock equivalents were excluded from the calculation of diluted net loss per share for the periods indicated as including them would have an anti-dilutive effect:

	For the Years Ended December 31,
	2016		2015
Shares issuable upon conversion of the 2021    Convertible Notes		6,483,791		—
Warrants for common stock		56,408		56,408
Stock options		2,675,458		1,631,677
Restricted Stock Units		470,000		—
Total		9,685,657		1,688,085