Equity Incentive Plans (Tables)

9 Months Ended

Sep. 30, 2020

Equity Incentive Plans

Summary of stock option activity under the Equity Plans

		Weighted
		Average		Weighted		Aggregate
		Exercise Price		Average Remaining		Intrinsic
	Options	Per Share		Life in Years		Value
Outstanding at December 31, 2019	4,024,566	$	7.48	7.98	$	2
Granted	2,547,500	$	2.12
Exercised	(32,778)	$	1.53
Forfeited	(260,435)	$	6.95
Outstanding at September 30, 2020	6,278,853	$	5.35	8.18	$	1,082
Options exercisable at September 30, 2020	3,113,663	$	8.45	7.12	$	359
Options vested and expected to vest at September 30, 2020	6,278,853	$	5.35	8.18	$	1,082

Schedule of assumptions used to determine grant-date fair value of stock options

	Nine Months		Year Ended
	Ended September 30,		December 31,
	2020		2019
Expected volatility	66.94	%		66.94	%
Weighted average risk-free interest rate	0.66	%		2.07	%
Expected dividend yield	0.00	%		0.00	%
Expected term (in years)	6.85			6.77

Schedule of stock-based compensation expense related to issuance of stock option awards recognized in condensed consolidated statements of operations

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
Research and development	$	282	$	181	$	720	$	536
General and administrative		309		769		967		2,260
Total	$	591	$	950	$	1,687	$	2,796

Summary of outstanding RSU under the 2016 Plan

		Weighted
		Average
	Number of	Grant Date
	Shares	Fair Value
Outstanding at December 31, 2019	90,500	$	1.74
Awarded	753,106	$	1.49
Settled in cash	(90,500)	$	1.74
Outstanding at June 30, 2020	753,106	$	1.49