Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating expenses:
Research and development	$ 62,784	$ 39,644	$ 41,737
General and administrative	25,952	21,628	23,612
Total operating expenses	88,736	61,272	65,349
Loss from operations	(88,736)	(61,272)	(65,349)
Interest income	500	2,151	2,389
Gain on extinguishment of Royalty Purchase Liability	0	0	125,000
Other income (expense), net	(6)	151	(16)
Income (loss) before income tax benefit	(88,242)	(58,970)	62,024
Income tax benefit	3,695	111	1,063
Net income (loss)	$ (84,547)	$ (58,859)	$ 63,087
Net income (loss) per common share:
Basic (in dollars per share)	$ (1.14)	$ (1.39)	$ 1.70
Dilutive (in dollars per share)	$ (1.14)	$ (1.39)	$ 1.70
Weighted average common shares outstanding:
Basic (in shares)	74,185	42,224	37,061
Dilutive (in shares)	74,185	42,224	37,088