Summary of Significant Accounting Policies Equity Incentive Awards (Tables)

3 Months Ended

Mar. 31, 2023

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Abstract]

Schedule of Accrued Liabilities

Accrued liabilities: Accrued liabilities consisted of the following:

	As of March 31,		As of December 31,
	2023		2022
	(in thousands)
Accrued research and development services	$	3,937	$	3,252
Accrued compensation and benefits	4,348		7,830
Short term lease liability	1,291		1,291
Other	484		404
Total accrued liabilities	$	10,060	$	12,777

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Expected Volatility		Risk-free Interest Rate		Expected Term	Dividend Rate
March 31, 2023:
Employees	112	%	4.1	%	4	—	%
Officers and non-employee directors	98	%	3.9	%	6	—	%
March 31, 2022:
Employees	104	%	1.8	%	4	—	%
Officers and non-employee directors	91	%	1.9	%	7	—	%

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Options	Weighted Average Exercise Price
	(in thousands)
Outstanding at December 31, 2022	12,349	$	5.10
Granted	5,077	2.43
Expired	(129)	14.83
Forfeited	(170)	3.65
Outstanding at March 31, 2023	17,127	4.25
Exercisable at March 31, 2023	6,877	$	6.20

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]

	Shares	Weighted Average Grant Date Fair Value
	(in thousands)
Outstanding at December 31, 2022	2,748	$	3.78
Granted	4,070	2.43
Vested	(1,216)	3.92
Forfeited	(112)	2.94
Outstanding at March 31, 2023	5,490	$	2.77