Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2016

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock-Based Compensation Expense

Total stock-based compensation expense related to the Company’s equity incentive plans and 2016 ESPP was as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
Research and development	$	190	$	43	$	400	$	129
General and administrative		244		121		563		219
Total stock-based compensation expense	$	434	$	164	$	963	$	348

Schedule of Estimated Fair Value of Stock Options Granted

The following table summarizes the weighted-average Black-Scholes option pricing model assumptions used to estimate the fair value of stock options granted under the 2016 Plan and 2015 Plan and the shares purchasable under the 2016 ESPP during the periods presented:

	Three Months Ended September 30,					Nine Months Ended September 30,
	2016			2015		2016			2015
2016 Plan and 2015 Plan
Expected term		6.07			—		5.99			6.29
Expected volatility		81	%		—		87	%		87	%
Risk-free interest		1.16	%		—		1.28	%		1.37	%
Dividend yield		0	%		—		0	%		0	%
2016 ESPP
Expected term		0.50			—		0.45			—
Expected volatility		81	%		—		82	%		—
Risk-free interest		0.57	%		—		0.49	%		—
Dividend yield		0	%		—		0	%		—