Share-Based Payment Awards (Tables)

3 Months Ended

Mar. 31, 2025

Share-Based Payment Arrangement [Abstract]

Stock Option Activity Under Plan

The following table provides a reconciliation of stock option activity under the Company’s equity incentive plan and for inducement awards for the three months ended March 31, 2025:

	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life		Aggregate Intrinsic Value
						(in years)		(in thousands)
Outstanding at January 1, 2025		7,670,647		$	12.47		7.43		7,478
Granted		2,142,935			8.21
Exercised		(68,779	)		3.26
Forfeited		(187,786	)		10.64
Expired		(162,331	)		21.13
Outstanding at March 31, 2025		9,394,686		$	11.46		7.80	$	3,473
Exercisable at March 31, 2025		4,262,537		$	12.51		6.36	$	2,032

Schedule of Key Assumptions Used

In determining the grant date fair value of option awards during the three months ended March 31, 2025, the Company applied the Black-Scholes option pricing model based on the following key assumptions:

	Three Months Ended
	March 31,
	2025
Option life (in years)	5.5 - 6.08
Stock volatility	99% - 102%
Risk-free interest rate	3.99% - 4.45%
Expected dividends	0.0%

Summary of Information about Stock Options

The following table summarizes information about employee, non-executive director and external consultant stock options for the three months ended March 31, 2025 (in thousands except per share amount):

	Three Months
	Ended
	March 31, 2025
Weighted average grant date fair value per share	$	6.62
Total cash received from exercise of stock options		224
Total intrinsic value of stock options exercised		209

Summary of Restricted Stock Unit Activity

The following table provides a reconciliation of RSU activity under the 2016 Plan and the 2023 Plan for the three months ended March 31, 2025:

	Number of Restricted Stock Units			Weighted Average Grant Date Fair Value
Nonvested at January 1, 2025		1,315,629		$	11.74
Granted		818,708			8.26
Vested		(561,706	)		10.57
Forfeited		(21,097	)		15.69
Nonvested at March 31, 2025		1,551,534		$	10.27

Compensation Expense from Stock-Based Payment Awards

The Company’s condensed consolidated statements of comprehensive loss included total compensation expense from stock-based payment awards as follows (in thousands):

	Three Months Ended March 31,
	2025		2024
Compensation expense included in:
Research and development	$	3,464	$	7,827
General and administrative		4,356		4,872
	$	7,820	$	12,699