Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities
Net loss	$ (25,735)	$ (38,700)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash other income/expense, net	73	(15)
Non-cash interest income		3
Non-cash interest expense	249	218
Loss on extinguishment of debt		2,757
Depreciation and amortization expense	188	209
Amortization of right-of-use assets	281	171
Stock-based compensation	1,738	3,103
Other, net	16	39
Changes in operating assets and liabilities:
Increase/(decrease) in other non-current assets	(10)	10
Increase in accounts receivable, net and other receivables and prepaid expenses	(13,382)	(3,247)
Increase in inventory	(4,290)	(4,514)
Decrease in accounts payable	(1,249)	(1,950)
Increase/(decrease) in accrued expenses and other liabilities	1,630	(3,427)
Decrease in deferred revenue	(187)
Increase/(decrease) in other non-current liabilities	(192)	4
Decrease in income tax liabilities	670	(33)
Net cash used in operating activities	(40,200)	(45,372)
Cash flows from investing activities
Purchases of plant and equipment and intangible assets	(18)	(85)
Changes in restricted cash	(51)	(163)
Net cash used in investing activities	(69)	(248)
Cash flows from financing activities
Proceeds from issuance of ordinary shares and warrants	25,462	38,414
Proceeds from at-the-market facility	37,970	3,688
Proceeds from employee stock purchase plan		43
Repayments of long-term borrowings		(30,000)
Equity transaction costs	(3,276)	(2,977)
Net cash provided by financing activities	60,156	9,168
Effects of exchange rate changes on the balance of cash held in foreign currencies	(157)	(70)
Net increase/(decrease) in cash, cash equivalents and restricted cash	19,730	(36,522)
Cash, cash equivalents, and restricted cash at beginning of period	41,590	86,411
Cash, cash equivalents and restricted cash at end of period	61,320	49,889
Supplemental disclosure of cash flow information:
Interest paid	248	1,147
Equity transaction costs included in accounts payable and accrued expenses	$ 806	$ 319