CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues:
Royalties	$ 42,633	$ 36,852	$ 110,337	$ 98,873
Services	0	1,496	0	1,496
Total revenues	42,633	38,348	110,337	100,369
Costs and expenses:
Research and development	2,475,722	2,830,340	5,181,413	5,478,939
Selling, general and administrative	1,669,227	1,427,967	3,155,246	2,803,152
Total operating expenses	4,144,949	4,258,307	8,336,659	8,282,091
Loss from operations	(4,102,316)	(4,219,959)	(8,226,322)	(8,181,722)
Interest income	15,671	69,761	51,494	134,504
Gain (loss) from change in fair value of derivative financial instruments—warrants	(44,144)	23,789	(42,037)	14,028
Other income (expense), net	6,257	1,106	3,771	3,116
Net loss	(4,124,532)	(4,125,303)	(8,213,094)	(8,030,074)
Preferred stock dividend payable on Series A Convertible Preferred Stock	(6,060)	(6,060)	(12,120)	(12,120)
Net loss attributable to common stockholders	$ (7,397,076)	$ (4,131,363)	$ (11,491,698)	$ (8,310,463)
Net loss per common share - basic and diluted (in dollars per share)	$ (0.51)	$ (0.76)	$ (0.94)	$ (1.75)
Weighted-average shares outstanding - basic and diluted (in shares)	14,492,159	5,408,124	12,201,232	4,750,993
Series C Convertible Preferred Stock
Costs and expenses:
Deemed dividend recognized for beneficial conversion features of Convertible Preferred Stock issuance	$ 0	$ 0	$ 0	$ (268,269)
Series D Convertible Preferred Stock
Costs and expenses:
Deemed dividend recognized for beneficial conversion features of Convertible Preferred Stock issuance	(601,767)	0	(601,767)	0
Series E Convertible Preferred Stock
Costs and expenses:
Deemed dividend recognized for beneficial conversion features of Convertible Preferred Stock issuance	$ (2,664,717)	$ 0	$ (2,664,717)	$ 0