Convertible Preferred Stock and Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2020

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 data):

	Number of Unvested Shares			Unvested Stock Liability
Balance at December 31, 2019		197,549			109
Repurchased shares		(4,269	)		(2	)
Vested shares		(156,788	)		(80	)
Balance at December 31, 2020		36,492		$	27

Summary of Stock Option Activity

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

	Number of Outstanding Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (In Years)		Aggregate Intrinsic Value
Balance at December 31, 2019		1,684,630		$	2.47		8.73	$	911
Granted		1,872,266		$	7.23
Exercised		(102,792	)	$	1.56
Cancelled		(318,028	)	$	3.56
Balance at December 31, 2020		3,136,076		$	5.23		7.95	$	8,963
Vested and expected to vest at December 31, 2020		3,136,076		$	5.23		7.95	$	8,963
Exercisable at December 31, 2020		1,018,775		$	2.58		5.35	$	5,384

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:

	Years Ended December 31,
	2020	2019
Risk-free interest rate	0.4% – 0.7%	1.8% –1.9%
Expected volatility	82.4% – 94.8%	72.6% – 81.0%
Expected term (in years)	5.8 – 10.0	5.1 – 6.1
Expected dividend yield	0.0%	0.0%

Summary of Stock-Based Compensation Expense Recognized

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

	Years Ended December 31,
	2020		2019
Research and development	$	1,233	$	836
General and administrative		3,788		1,096
Total stock-based compensation	$	5,021	$	1,932

Schedule of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance consists of the following:

	Years Ended December 31,
	2020		2019
Conversion of preferred stock		—		16,685,014
Common stock options outstanding		3,136,076		1,684,630
Shares available for issuance under equity incentive plans		2,907,742		616,423
Shares available for issuance under the ESPP		405,000		—
Common stock warrant		23,122		—
Preferred stock warrant		—		23,122
Total common stock reserved for future issuance		6,471,940		19,009,189