Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net loss	$ (69,484)	$ (82,764)	$ (114,780)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash other income/expense, net	50	(40)	362
Non-cash interest income		22	45
Non-cash interest expense	636	519	(104)
Loss on extinguishment of debt	2,757
Depreciation and amortization expense	417	396	510
Amortization of right-of-use assets	403	374
Stock-based compensation	5,219	9,748	5,154
In-process research and development in connection with acquisition			32,048
Other, net	62	48	14
Changes in operating assets and liabilities:
Increase/(decrease) in long-term receivables	8	50	(3)
Increase/(decrease) in accounts receivable, net and other receivables and prepaid expenses	(5,887)	2,582	1,139
Increase in inventory	(5,141)	(682)
Increase/(decrease) in accounts payable	(1,813)	1,310	(2,969)
Increase/(decrease) in accrued expenses and other liabilities	714	(3,209)	5,742
Increase in deferred revenue	750
Increase/(decrease) in other non-current liabilities	(2)	(172)	61
Increase/(decrease) in income tax liabilities	(20)	(74)	58
Net cash used in operating activities	(71,331)	(71,892)	(72,723)
Cash flows from investing activities
Purchases of plant and equipment and intangible assets	(113)	(61)	(229)
Purchases of term deposits			(115)
Changes in restricted cash	(161)	392
Transaction costs related to Zavante acquisition, net of cash acquired			(4,260)
Net cash used in investing activities	(274)	331	(4,604)
Cash flows from financing activities
Proceeds from exercise of warrants	665
Proceeds from issuance of ordinary shares and warrants	53,460	20,138	50,000
Proceeds from at-the-market facility	7,520	27,945	24,219
Proceeds from long-term debt, net of issuance costs		9,980	23,545
Proceeds from employee stock purchase plan	43	372
Repayments of long-term borrowings	(30,000)
Equity transaction costs	(4,764)	(2,360)	(4,841)
Net cash provided by financing activities	26,924	56,075	92,923
Effects of exchange rate changes on the balance of cash and cash equivalents held in foreign currencies	(140)	(106)	(362)
Net increase/(decrease) in cash, cash equivalents and restricted cash	(44,821)	(15,592)	15,234
Cash, cash equivalents, and restricted cash at beginning of year	86,411	102,003	86,769
Cash, cash equivalents and restricted cash at end of year	41,590	86,411	102,003
Supplemental disclosure of cash flow information:
Interest paid	1,396	2,560	7
Taxes paid	(4)	(11)	(4)
Equity transaction costs incurred in prior periods and paid in current period	$ 765	$ 552	$ 120