CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating expenses:
General and administrative	$ 44,483,938	$ 9,325,017
Research and development	33,620,223	22,359,712
Total operating expenses	78,104,161	31,684,729
Loss from operations	(78,104,161)	(31,684,729)
Other non-operating income (expense):
Other income	83,075
Foreign currency (loss) gain	(3,824,383)	1,676,117
Convertible note inducement expense		(553,500)
Change in fair value of warrant liability	(1,514,775)	(465,633)
Interest income	53,408	26,073
Interest expense	(33,429)	(42,863)
Loss before income taxes	(83,340,265)	(31,044,535)
Benefit for income taxes	474,391	0
Net loss	(82,865,874)	(31,044,535)
Other comprehensive income (loss):
Foreign currency translation, net of tax of $474,391 and $0 in 2018 and 2017, respectively	2,316,143	(1,361,365)
Total comprehensive loss	(80,549,731)	(32,405,900)
Net loss	(82,865,874)	(31,044,535)
Accretion on convertible preferred C shares and warrants	(1,806,512)	(806,963)
Adjusted net loss	$ (84,672,386)	$ (31,851,498)
Basic and diluted net loss per ordinary share	$ (4.47)	$ (3.72)
Weighted-average number of ordinary shares outstanding	18,948,520	8,572,315