Consolidated Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Product revenue, net	$ 12,142,000
Costs and operating expenses:
Cost of sales	745,000
Research and development	64,436,000	$ 41,590,000	$ 51,791,000
Selling, general and administrative	23,900,000	20,559,000	17,113,000
Total costs and operating expenses	89,081,000	62,149,000	68,904,000
Loss from operations	(76,939,000)	(62,149,000)	(68,904,000)
Interest expense	(3,559,000)	(3,594,000)	(3,406,000)
Interest income	158,000	704,000	2,073,000
Other income (expense), net	46,487,000	(12,000)	(15,000)
Loss before provision for income taxes	(33,853,000)	(65,051,000)	(70,252,000)
Provision for income taxes	64,000	0	0
Net loss	$ (33,917,000)	$ (65,051,000)	$ (70,252,000)
Net loss per common share, basic and diluted	$ (1.00)	$ (2.31)	$ (3.08)
Weighted-average common shares outstanding, basic and diluted	33,944,342	28,143,391	22,785,611