Consolidated Statements of Operations and Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating expenses:
Research and development	$ 20,950,672	$ 14,194,732	$ 13,392,631
General and administrative	8,593,626	2,294,671	2,459,744
Total operating expenses	29,544,298	16,489,403	15,852,375
Other income (expense):
Interest expense	156,351	(182)	(15)
Foreign currency gain	1,328,140	961,316	662,140
Total other income (expense)	1,484,491	961,134	662,125
Net loss	(28,059,807)	(15,528,269)	(15,190,250)
Other comprehensive income (loss):
Foreign currency translation	(2,772,453)	(473,919)	495,160
Total comprehensive loss	$ (30,832,260)	$ (16,002,188)	$ (14,695,090)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (4.67)	$ (13.45)	$ (13.17)
Weighted-average common shares outstanding, basic and diluted (in shares)	6,002,486	1,154,368	1,153,069