Summary of Significant Accounting Policies Equity Incentive Awards (Tables)

6 Months Ended

Jun. 30, 2022

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 June 30,		As of December 31,
	2022		2021
	(in thousands)
Accrued research and development services	$	3,920	$	3,669
Accrued compensation and benefits	4,329		5,711
Short term lease liability	789		1,089
Other	477		2,503
Total accrued liabilities	$	9,515	$	12,972

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

	Expected Volatility		Risk-free Interest Rate		Expected Term	Dividend Rate
June 30, 2022:
Employees	106	%	2.1	%	4	—	%
Officers and non-employee directors	91	%	1.9	%	7	—	%
June 30, 2021:
Employees	101	%	0.6	%	4	—	%
Officers and non-employee directors	90	%	1.1	%	7	—	%

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

	Options	Weighted Average Exercise Price
	(in thousands)
Outstanding at December 31, 2021	8,367	$	6.80
Granted	4,257	3.06
Expired	(163)	12.50
Forfeited	(353)	9.20
Outstanding at June 30, 2022	12,108	5.34
Exercisable at June 30, 2022	5,423	$	7.35

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

	Shares	Weighted Average Grant Date Fair Value
	(in thousands)
Outstanding at December 31, 2021	1,854	$	5.16
Granted	2,185	2.25
Vested	(1,012)	4.86
Forfeited	(108)	3.40
Outstanding at June 30, 2022	2,919	$	3.17