Unaudited Condensed Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue	$ 1,925	$ 11,463	$ 10,922	$ 11,463
Operating expenses:
Royalty and direct contract acquisition costs		1,000	1,305	1,000
Research and development	1,709	3,616	5,789	16,950
General and administrative	1,429	3,613	5,393	9,440
Severance expense			830
Total operating expenses	3,138	8,229	13,317	27,390
(Loss) income from operations	(1,213)	3,234	(2,395)	(15,927)
Other (expense) income:
Interest expense related to amortization of debt issuance costs and discount	(578)	(371)	(1,723)	(981)
Interest expense on principal	(1,163)	(1,208)	(3,620)	(3,669)
Fair value adjustment related to derivative and warrant liability	(137)	1,351	(65)	1,783
Interest and other income (expense), net	48	60	(135)	295
Total other expenses	(1,830)	(168)	(5,543)	(2,572)
(Loss) income before income taxes	(3,043)	3,066	(7,938)	(18,499)
Income tax benefit (expense)	34	(3)	34	14
Net (loss) income	$ (3,009)	$ 3,063	$ (7,904)	$ (18,485)
Net (loss) income per share of common stock:
Basic (in dollars per share)	$ (0.04)	$ 0.09	$ (0.13)	$ (0.65)
Diluted (in dollars per share)	$ (0.04)	$ 0.06	$ (0.13)	$ (0.65)
Weighted average number of shares of common stock outstanding:
Basic (in shares)	70,809,221	30,126,704	60,718,998	28,417,450
Diluted (in shares)	70,809,221	31,672,149	60,718,998	28,417,450