Condensed Consolidated Statements of Operations (unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue	$ 7,596,776	$ 30,050,227	$ 19,584,085	$ 38,083,205
Operating expenses:
Research and development	30,012,918	16,588,050	75,155,694	46,779,047
General and administrative	9,331,925	7,957,364	26,072,404	20,038,772
Total operating expenses	39,344,843	24,545,414	101,228,098	66,817,819
Income (loss) from operations	(31,748,067)	5,504,813	(81,644,013)	(28,734,614)
Other income (expenses)
Other income, net	144,215	405,302	841,967	840,153
Interest income	800,236	1,112,415	3,065,220	3,394,269
Interest expense	(16,250)	(22,903)	(48,750)	(69,319)
Total other income	928,201	1,494,814	3,858,437	4,165,103
Loss from equity method investment	0	(24,675,000)	0	(24,675,000)
Net loss	$ (30,819,866)	$ (17,675,373)	$ (77,785,576)	$ (49,244,511)
Net loss per common share, basic and diluted	$ (0.79)	$ (0.54)	$ (2.01)	$ (1.54)
Weighted average common shares outstanding, basic and diluted	39,058,294	32,740,486	38,784,569	31,876,074