Stockholders' Equity (Tables)

9 Months Ended

Sep. 30, 2021

Equity [Abstract]

Summary of Unvested Shares and Unvested Stock Liability

A summary of the Company’s unvested shares and unvested stock liability is as follows (in thousands, except share amounts):

	Number of Unvested Shares			Unvested Stock Liability
Balance at December 31, 2020		36,492		$	27
Vested shares		(28,262	)		(20	)
Repurchased shares		(2,695	)		(1	)
Balance at September 30, 2021		5,535		$	6

Summary of Stock Option Activity

A summary of the Company’s stock option activity is as follows (in thousands, except share and per share amounts):

	Number of Outstanding Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (In Years)		Aggregate Intrinsic Value
Balance at December 31, 2020		3,136,076		$	5.23		7.95	$	8,963
Granted		1,000,405		$	8.81
Exercised		(489,179	)	$	2.24
Cancelled		(229,078	)	$	6.56
Balance at September 30, 2021		3,418,224		$	6.62		8.41	$	601
Vested and expected to vest at September 30, 2021		3,418,224		$	6.62		8.41	$	601
Exercisable at September 30, 2021		1,204,210		$	4.66		7.51	$	510

Summary of Fair Value of Stock Option Grants

The assumptions used in the Black-Scholes option pricing model to determine the fair value of stock option grants were as follows:

	Nine Months Ended September 30,
	2021			2020
Risk-free interest rate	0.6% - 1.1%			0.4% – 0.7%
Expected volatility	86.2% - 89.5%			82.4% – 94.8%
Expected term (in years)	5.5 – 6.07			5.8 – 10.0
Expected dividend yield		0	%		0	%

Summary of Restricted Stock Units Activity

A summary of the Company’s restricted stock units activity is as follows (in thousands, except share and per share amounts):

	Number of Outstanding Awards			Weighted Average Grant Date Fair Value		Aggregate Intrinsic Value
Balance at December 31, 2020		-		$	-
Granted		579,150		$	4.09
Cancelled		(26,500	)	$	4.09
Balance at September 30, 2021		552,650		$	4.09	$	1,896
Vested and expected to vest at September 30, 2021		552,650		$	4.09	$	1,896

Summary of Stock-Based Compensation Expense Recognized

Stock-based compensation expense recognized for all equity awards has been reported in the unaudited condensed consolidated statements of operations and comprehensive loss as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
General and administrative	$	1,528	$	1,449	$	3,864	$	2,312
Research and development		626		342		1,396		839
Total stock-based compensation	$	2,154	$	1,791	$	5,260	$	3,151

Schedule of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance consists of the following:

	September 30,		December 31,
	2021		2020
Common stock options outstanding		3,418,224		3,136,076
Restricted stock units outstanding		552,650		—
Shares available for issuance under equity incentive plans		2,600,197		2,907,742
Shares available for issuance under the ESPP		616,724		405,000
Common stock warrant		23,122		23,122
Total		7,210,917		6,471,940