Stockholders' Equity (Tables)

6 Months Ended

Jun. 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		(21,336	)		(15	)
Repurchased shares		(2,695	)		(1	)
Balance at June 30, 2021		12,461		$	11

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		984,055		$	8.91
Exercised		(466,811	)	$	2.27
Cancelled		(206,146	)	$	6.53
Balance at June 30, 2021		3,447,174		$	6.60		8.57	$	947
Vested and expected to vest at June 30, 2021		3,447,174		$	6.60		8.57	$	947
Exercisable at June 30, 2021		1,020,384		$	4.09		7.43	$	758

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:

	Six Months Ended June 30,
	2021			2020
Risk-free interest rate	0.6% - 1.1%			0.4% – 0.7%
Expected volatility	87.9% - 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
Released		-		$	-
Cancelled		(11,800	)	$	4.09
Balance at June 30, 2021		567,350		$	4.09	$	2,156
Vested and expected to vest at June 30, 2021		567,350		$	4.09	$	2,156

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 June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
General and administrative	$	1,310	$	212	$	2,336	$	497
Research and development		276		645		770		863
Total stock-based compensation	$	1,586	$	857	$	3,106	$	1,360

Schedule of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance consists of the following:

	June 30,		December 31,
	2021		2020
Common stock options outstanding		3,447,174		3,136,076
Restricted stock units outstanding		567,350		—
Shares available for issuance under equity incentive plans		2,593,615		2,907,742
Shares available for issuance under the ESPP		616,724		405,000
Common stock warrant		23,122		23,122
Total		7,247,985		6,471,940