Equity Incentive Plans (Tables)

6 Months Ended

Jun. 30, 2022

Share-Based Payment Arrangement [Abstract]

Summary of Company's stock option activity

The Company’s stock option activity during the six months ended June 30, 2022 was as follows:

				Weighted-		Weighted-		Aggregate
				Average		Average		Intrinsic
	Options			Exercise		Remaining		Value
	Outstanding			Price		Term		(000’s)
Balance at December 31, 2021		6,553,594		$	16.07
Granted		2,527,579		$	20.40
Exercised		(429,955	)	$	8.18
Forfeited and expired		(132,460	)	$	18.90
Balance at June 30, 2022		8,518,758		$	17.71		8.3	$	23,987
Vested and expected to vest at June 30, 2022		8,518,758		$	17.71		8.3	$	23,987
Exercisable at June 30, 2022		3,407,092		$	14.85		7.0	$	18,928

Summary of Company's restricted stock unit activity

The Company’s restricted stock unit activity during the six months ended June 30, 2022 was as follows:

				Weighted-		Aggregate
	Restricted Stock			Average		Fair
	Units			Grant Date		Value
	Outstanding			Fair Value		(000’s)
Balance at December 31, 2021		—			—
Granted		306,919		$	20.02
Vested		—			—
Forfeited		(25,018	)	$	20.02
Balance at June 30, 2022		281,901		$	20.02	$	5,643
Vested and expected to vest at June 30, 2022		281,901		$	20.02	$	5,643

Weighted Average Assumptions Used to Estimate Fair Value of Stock Awards Granted to Employees

The Company utilizes the Black-Scholes option pricing model to value awards under its equity plans. The following table summarizes the weighted average assumptions used to estimate the fair value of stock options granted under the Company’s stock option plans for the six months ended June 30, 2022 and 2021:

Stock Option Awards	2022	2021
Expected option term	6.0 years	6.0 years
Expected volatility	88%	87%
Risk free interest rate	2.2%	1.0%
Expected dividend yield	—%	—%

Summary of Stock-based Compensation Expense for the Equity Awards Issued to Employees and Non-Employees

Stock-based compensation expense for the equity awards issued by the Company to employees and non-employees for the periods presented below was as follows (in thousands):

	Three months ended June 30,				Six months ended June 30,
	2022		2021		2022		2021
Included in research and development	$	3,681	$	2,357	$	6,872	$	4,170
Included in general and administrative		3,450		1,876		6,014		3,469
Total stock-based compensation expense	$	7,131	$	4,233	$	12,886	$	7,639