Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net loss	$ (33,577)	$ (26,202)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	4,950	2,000
Depreciation and amortization	944	686
Change in fair value of warrant liability	0	5,381
Changes in operating assets and liabilities:
Accounts receivable	(2,685)	5,064
Research and development incentives receivable	937	(4,813)
Prepaid expenses and other current assets	(773)	(1,638)
Operating lease right-of-use assets	570	528
Other assets	(719)	(216)
Accounts payable	193	516
Accrued expenses and other current liabilities	1,030	(611)
Lease liabilities	(193)	(526)
Deferred revenue	27,782	(4,502)
Other long-term liabilities	369	639
Net cash used in operating activities	(1,172)	(23,694)
Cash used in investing activities:
Purchases of property and equipment	(716)	(1,164)
Net cash used in investing activities	(716)	(1,164)
Cash flows from financing activities:
Proceeds from the issuance of ADSs, net of issuance costs	46,373	56,957
Proceeds from the exercise of share options and sale of ordinary shares	98	21
Proceeds from the exercise of warrants	1	6
Proceeds from issuance of debt	15,000
Payments of debt issuance costs	(373)
Net cash provided by financing activities	61,099	58,318
Effect of exchange rate changes on cash	(1,486)	(886)
Net increase in cash	57,725	32,574
Cash at beginning of period	92,117	63,380
Cash at end of period	149,842	95,954
Supplemental disclosure of cash flow information
Cash paid for income taxes	124	73
Public offering costs accrued but not paid	50
Cash paid for amounts included in the measurement of operating lease liabilities	823	447
Purchases of property and equipment included in accounts payable and accrued expenses	40
Debt issuance costs accrued but not paid	$ 200
Conversion of convertible preferred shares to ordinary shares upon closing of the initial public offering		123,780
Reclassification of warrant liability to additional paid-in capital		10,021
Series B2 Convertible Preferred Shares
Cash flows from financing activities:
Proceeds from issuance of convertible preferred shares, net of issuance costs		$ 1,334