CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities
Net loss	$ (27,999)	$ (27,772)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,733	1,569
Share-based compensation expense	4,355	4,294
Change in fair value of derivative financial instruments	(2,015)	2,027
Unrealized foreign exchange gains	(4,824)	(1,820)
Changes in operating assets and liabilities:
Accounts receivable and accrued income, prepaid expenses and other current assets	(1,282)	(2,763)
Accounts payable	(546)	(246)
Accrued expenses, other liabilities and operating leases	(2,645)	(1,190)
Deferred revenue	270	(537)
Net cash used in operating activities	(32,953)	(26,438)
Cash flows from investing activities
Purchases of intangible assets	(2,213)	(996)
Purchases of property, plant and equipment	(677)	(234)
Net cash used in investing activities	(2,890)	(1,230)
Cash flows from financing activities
Proceeds from issuance of shares related to employee stock option and purchase plans	1,010	2,178
Proceeds from exercise of warrants		500
Net cash generated from financing activities	1,010	2,678
Currency effect on cash, cash equivalents and restricted cash	(943)	(635)
Net increase in cash, cash equivalents and restricted cash	(35,776)	(25,625)
Cash, cash equivalents and restricted cash at beginning of period	380,726	237,342
Cash, cash equivalents and restricted cash at the end of period	344,950	211,717
Total cash, cash equivalents and restricted cash	344,950	211,717
Supplemental cash flow disclosures:
Cash paid for interest	$ 780	$ 751