Condensed Consolidated Statements of Cash Flow (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash Flows From Operating Activities
Net loss	$ (25,935)	$ (37,793)
Adjustment to reconcile net loss to net cash from operating activities:
Depreciation and amortization	191	82
Amortization on marketable securities	191	98
Stock-based compensation	6,195	7,617
Amortization of right of use asset	237	374
Lease liability	(400)	(361)
Changes in operating assets and liabilities:
Inventory	(1,367)
Accounts receivable	746
Prepaid expenses and other current assets	(2,952)	(518)
Accounts payable and accrued expenses	535	(2,498)
Employee related accrued expenses	(4,842)	(2,636)
Net cash used in operating activities	(27,401)	(35,635)
Cash Flows From Investing Activities
Purchase of marketable securities		(9,378)
Maturities of marketable securities	15,311	22,499
Purchases of property and equipment	(287)	(96)
Net cash provided by investing activities	15,024	13,025
Cash Flows From Financing Activities
Proceeds from exercise of options into ordinary shares	4	293
Issuance cost related to at-the-market issuances		(203)
Net cash provided by financing activities	4	90
Decrease in Cash and Cash Equivalents	(12,373)	(22,520)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	54,090	50,211
Cash, Cash Equivalents and Restricted Cash at End of Period	41,717	27,691
Supplemental Disclosures of Non-Cash Activities
Non-cash new lease liabilities	$ (20)	$ 72