Consolidated Statements of Comprehensive Loss-Unaudited - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenues:
Royalties and other revenue	$ 39	$ 23	$ 111	$ 284
Stock-based compensation expense associated with research and development expense	939	1,138	3,069	3,608
Operating expenses:
Research and development, including stock-based compensation of $939, $1,138, $3,069 and $3,608 respectively	10,557	15,682	38,839	38,548
Selling, general and administrative, including stock-based compensation of $1,709, $1,574, $5,183 and $4,741 respectively	12,577	7,303	31,754	23,496
Total operating expenses	(23,134)	22,985	70,593	62,044
Loss from operations	(23,095)	(22,962)	(70,482)	(61,760)
Interest expense	(864)	(171)	(1,677)	(507)
Interest and other income, net	572	11	709	120
Net loss	$ (23,387)	$ (23,122)	$ (71,450)	$ (62,147)
Net income (loss) per common share, Basic	$ (0.13)	$ (0.16)	$ (0.45)	$ (0.43)
Shares used in computing net loss per common share, Basic	174,904	145,820	157,984	144,558
Unrealized gain on investments		$ 0
Unrealized gain on investments	$ (341)	(1)	$ (481)	$ 1
Comprehensive loss	$ (23,728)	$ (23,122)	$ (71,931)	$ (62,146)