Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2016

Fair Value Disclosures [Abstract]

Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table summarizes the assets measured at fair value on a recurring basis at June 30, 2016 (in thousands):

Description	Total		Active Markets (Level 1)		Observable Inputs (Level 2)		Unobservable Inputs (Level 3)
Assets:
Cash and cash equivalents	$	8,484	$	8,484	$	—	$	—
Total	$	8,484	$	8,484	$	—	$	—

Description	Total		Active Markets (Level 1)		Observable Inputs (Level 2)		Unobservable Inputs (Level 3)
Liabilities:
Warrant liability	$	13	$	—	$	—	$	13
Total	$	13	$	—	$	—	$	13

The following table summarizes the assets and liabilities measured at fair value on a recurring basis at December 31, 2015 (in thousands):

Description	Total		Active Markets (Level 1)		Observable Inputs (Level 2)		Unobservable Inputs (Level 3)
Assets:
Cash and cash equivalents	$	36,079	$	36,079	$	—	$	—
Total	$	36,079	$	36,079	$	—	$	—

Description	Total		Active Markets (Level 1)		Observable Inputs (Level 2)		Unobservable Inputs (Level 3)
Liabilities:
Warrant liability	$	115	$	—	$	—	$	115
Total	$	115	$	—	$	—	$	115

Summary of Assumptions Used in Valuing Warrants

The Company measures the fair value of the warrants classified as a liability at each reporting date using the Black-Scholes option pricing model using the following assumptions:

	June 30, 2016		December 31, 2015
Risk-free interest rate	0.52	%	1.06	%
Expected dividend yield	—	%	—	%
Expected term (in years)	1.42		1.92
Expected volatility	79.43	%	70.67	%

Summary of Changes in the Fair Value of the Company's Preferred Stock Warrant Liability

The following table sets forth a summary of changes in the fair value of the Company’s common stock warrant liability, which represented a recurring measurement classified within Level 3 of the fair value hierarchy, wherein fair value was estimated using significant unobservable inputs (in thousands):

Beginning balance, January 1, 2016	$	115
Change in fair value	(102		)
Ending balance, June 30, 2016	$	13