Stockholders equity (Tables)

12 Months Ended

Dec. 31, 2023

Equity [Abstract]

Schedule of Stock-Based Compensation Expense

Stock-based compensation expense recognized for all equity awards under the 2020 Plan has been reported in the statements of operations and comprehensive loss as follows (in thousands):

	Years ended December 31,
	2023		2022
Research and development	$	5,462	$	5,419
General and administrative		8,082		9,144
Total	$	13,544	$	14,563

Summary of Restricted Stock Units

The following table summarizes RSU activity under the 2020 Plan for the years ended December 31, 2023 and 2022:

	Number of Shares			Weighted - average grant date fair value
Outstanding at December 31, 2021		975,046		$	—
Granted		—		$	—
Vested		(446,260	)	$	18.00
Forfeited		(18,747	)
Outstanding at December 31, 2022		510,039		$	18.00
Granted		45,290		$	2.35
Vested		(433,948	)	$	16.37
Forfeited		(22,277	)	$	18.00
Outstanding at December 31, 2023		99,104		$	18.00

Summary of Stock Option Activity

The following table summarizes stock option activity under the 2020 Plan for the year ended December 31, 2023 and 2022 (in thousands, except share and per option data and years):

	Number of options			Weighted - average exercise price per option		Weighted - average remaining contractual term (in years)		Aggregate intrinsic value
Balance at December 31, 2021		1,086,902		$	26.76		9.22	$	991,495
Granted		1,718,200		$	6.35
Exercised		—		$	—
Forfeited		(50,387	)	$	21.64
Expired		(17,797	)	$	40.00
Balance at December 31, 2022		2,736,918		$	13.82	8.82		$	3,636,148
Granted		4,020,395		$	3.74
Exercised		—		$	—
Forfeited		(371,439	)	$	7.20
Expired		(112,367	)	$	20.96
Balance at December 31, 2023		6,273,507		$	7.62		8.64	$	74,680
Vested and expected to vest at December 31, 2023		6,273,507		$	7.62		8.64	$	74,680
Exercisable at December 31, 2023		1,429,449		$	14.98		7.75	$	2,007

Summary of Assumptions Used in Black-Scholes Model

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,
	2023			2022
Expected volatility		77.9	%		74.9	%
Risk-free interest rate		3.89	%		2.14	%
Expected dividend yield		0.0	%		0.0	%
Expected term	6.05 years			6.04 years

Schedule of Common Stock Reserved for Future Issuance

Common stock reserved for future issuance are as follows in common equivalent shares:

	December 31,
	2023		2022
Common stock options and restricted stock units issued and outstanding		6,372,611		3,246,957
Awards available for future issuance under the 2020 Plan		991,413		3,012,554
Awards available for future issuance under the ESPP		1,412,802		1,070,402
Total common stock reserved for future issuance		8,776,826		7,329,913