Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Option Award Activity

The following is a summary of the stock option award activity during the years ended December 31, 2021 and 2020:

	Number of Stock Options			Weighted- Average Exercise Price			Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2019		77,604		$	114.11			8.12	$	—
Granted		1,899,507		$	2.02
Exercised		(16,666	)	$	(1.23	)
Forfeited		(13,322	)	$	(119.38	)
Expired		—		$	—
Outstanding at December 31, 2020		1,947,123		$	5.70			9.56	$	10,284
Granted		1,741,159		$	15.93
Exercised		(8,834	)	$	(1.23	)
Forfeited		(652,984	)	$	(9.18	)
Expired		—		$	—
Outstanding at December 31, 2021		3,026,464		$	10.84			8.51	$	6,403
Exercisable at December 31, 2021		872,570		$	9.82			7.44	$	3,352
Options expected to vest at December 31, 2021		2,153,894		$	11.25			9.04	$	3,051

Summary of Common Stock Warrant Activity

The following is a summary of the common stock warrant activity during the years ended December 31, 2021 and 2020:

	Number of Common Stock Warrants			Weighted- Average Exercise Price			Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2019		57,420		$	7.95			4.83	$	—
Granted		—		$	—
Exercised		—		$	—
Expired		(208	)	$	(96.00	)
Outstanding and exercisable at December 31, 2020		57,212		$	7.62			3.64	$	98
Granted		—		$	—
Exercised		—		$	—
Expired		(208	)	$	(192.00	)
Outstanding and exercisable at December 31, 2021		57,004		$	6.94			2.91	$	2.26

Summary of Fair Value Assumptions and Methodology

The following table presents the assumptions and the Company’s methodology for developing each of the assumptions used:

	Years Ended December 31,
	2021	2020
Volatility	89%-98%	90%-100%
Expected life (years)	5.5–6.1	0.5–6.1
Risk-free interest rate	0.4%–1.4%	0.1%–0.7%
Dividend rate	—%	—%

Summary of Stock-Based Compensation Expense

Stock-based compensation expense was recorded in the following line items in the consolidated statements of operations for the years ended December 31, 2021 and 2020 (in thousands):

	Years Ended December 31,
	2021		2020
Research and development	$	2,238	$	555
General and administrative		3,419		937
Total stock-based compensation expense	$	5,657	$	1,492