Share-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2023

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Summary of Stock Option Activity

The following table summarizes stock option activity under all equity plans (excluding RSUs) during the nine months ended September 30, 2023:

	Number of Shares			Weighted Average Exercise Price		Weighted Average Contractual Term		Aggregate Intrinsic Value
						(in years)		(in thousands)
Outstanding as of December 31, 2022		3,979,099		$	10.99		5.27	$	1
Granted		46,413			1.74
Exercised		—			—
Forfeited or cancelled		(1,110,322	)		10.71
Outstanding as of September 30, 2023		2,915,190		$	10.95		5.87	$	1
Outstanding as of September 30, 2023 - vested and    expected to vest		2,915,190		$	10.95		5.87	$	1
Exercisable at September 30, 2023		2,346,087		$	10.28		5.47	$	—

Summary of Activity of Options and RSUs of Performance-Based Options

The following table summarizes RSU activity under all equity plans during the nine months ended September 30, 2023:

	Number of RSU Shares			Weighted Average Grant Date Fair Value
Outstanding as of December 31, 2022		1,160,397		$	8.29
Granted		4,272,199			1.81
Vested and released		(328,645	)		7.30
Forfeited or cancelled		(341,306	)		7.19
Outstanding as of September 30, 2023		4,762,645		$	2.62

Summarizes Inducement PSU activity under all equity plans

The following table summarizes Inducement PSU activity under all equity plans during the nine months ended September 30, 2023:

	Number of Inducement PSU Shares			Weighted Average Grant Date Fair Value
Outstanding as of December 31, 2022		140,000		$	1.08
Granted		—			—
Vested and released		(70,001	)		1.08
Forfeited or cancelled		—			—
Outstanding as of September 30, 2023		69,999		$	1.08

Summary of Share-Based Compensation Expense

The Company recorded share-based compensation expense related to incentive stock options, nonqualified stock options, stock grants, and stock-based awards in the following expense categories of its consolidated statements of operations and comprehensive loss (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Research and development expenses	$	619	$	730	$	2,006	$	2,595
General and administrative expenses		1,289		1,376		3,929		4,031
Total	$	1,908	$	2,106	$	5,935	$	6,626