CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue	$ 1,528,000		$ 3,740,000
Operating expenses:
Research and development	12,912,000	$ 8,582,000	34,581,000	$ 24,720,000
General and administrative	3,197,000	1,733,000	9,288,000	6,094,000
Total operating expenses	16,109,000	10,315,000	43,869,000	30,814,000
Loss from operations	(14,581,000)	(10,315,000)	(40,129,000)	(30,814,000)
Other income, net	237,000	344,000	763,000	1,033,000
Net loss before taxes	(14,344,000)	(9,971,000)	(39,366,000)	(29,781,000)
Provision for income taxes	287,000	0	791,000	0
Net loss	(14,631,000)	(9,971,000)	(40,157,000)	(29,781,000)
Other comprehensive income (loss):
Foreign currency translation adjustment	(70,000)	15,000	(65,000)	17,000
Unrealized gain (loss) on marketable securities	(33,000)		119,000
Total comprehensive loss	$ (14,734,000)	$ (9,956,000)	$ (40,103,000)	$ (29,764,000)
Net loss per share, basic and diluted	$ (0.60)	$ (12.41)	$ (1.67)	$ (40.15)
Weighted average number of shares used in computing net loss per share, basic and diluted	24,449,115	803,229	23,989,926	741,711