Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Revenues	$ 15,345,000	$ 21,675,000	$ 26,467,000	$ 30,440,000
Costs and expenses:
Manufacture and supply	4,466,000	3,539,000	7,223,000	7,198,000
Research and development	4,262,000	3,847,000	7,921,000	8,201,000
Selling, general and administrative	13,134,000	13,894,000	26,365,000	28,507,000
Total costs and expenses	21,862,000	21,280,000	41,509,000	43,906,000
(Loss) income from operations	(6,517,000)	395,000	(15,042,000)	(13,466,000)
Other income/(expenses):
Interest expense	(2,757,000)	(2,747,000)	(5,518,000)	(5,518,000)
Interest expense related to the sale of future revenue, net	(3,466,000)	0	(6,800,000)	0
Interest income and other income, net	373,000	18,000	321,000	120,000
Net loss before income taxes	(12,367,000)	(2,334,000)	(27,039,000)	(18,864,000)
Income taxes	0	0	0	0
Net loss	(12,367,000)	(2,334,000)	(27,039,000)	(18,864,000)
Comprehensive loss	$ (12,367,000)	$ (2,334,000)	$ (27,039,000)	$ (18,864,000)
Net loss per share - basic (in dollars per share)	$ (0.33)	$ (0.07)	$ (0.74)	$ (0.56)
Net loss per share - diluted (in dollars per share)	$ (0.33)	$ (0.07)	$ (0.74)	$ (0.56)
Weighted-average number of common shares outstanding - basic and diluted (in shares)	37,065,300	33,589,174	36,318,437	33,579,434