Condensed Consolidated Statements of Cash Flow (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash Flows From Operating Activities
Net loss	$ (52,157)	$ (69,142)
Adjustment to reconcile net loss to net cash from operating activities:
Depreciation and amortization	401	178
Accrued financing on prepaid forward obligation	2,330
Amortization on marketable securities	181	234
Stock-based compensation	12,241	14,736
Amortization of right of use asset	469	753
Lease liability	(652)	(748)
Changes in operating assets and liabilities:
Inventory	(1,457)	(1,125)
Accounts receivable	(2,465)	(402)
Prepaid expense and other current assets	(1,944)	(1,035)
Other non-current assets	(1,026)
Accounts payable and accrued expense	319	(2,046)
Employee related accrued expense	(2,781)	(967)
Other current liabilities	195
Net cash used in operating activities	(46,346)	(59,564)
Cash Flows From Investing Activities
Purchases of marketable securities	(41,655)	(29,688)
Maturities of marketable securities	26,295	60,610
Purchases of property and equipment	(356)	(383)
Net cash (used in) provided by investing activities	(15,716)	30,539
Cash Flows From Financing Activities
Proceeds from prepaid forward arrangement	72,472	503
Proceeds from exercise of options into ordinary shares	58
Issuances of ordinary shares, net of issuance expense		15,885
Issuance cost related to at-the-market issuances	(11)
Net cash provided by financing activities	72,519	16,388
Increase (Decrease) in Cash and Cash Equivalents	10,457	(12,637)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	54,090	50,211
Cash, Cash Equivalents and Restricted Cash at End of Period	64,547	37,574
Supplemental Disclosures of Non-Cash Activities
Non-cash purchases of property and equipment		219
Non-cash new lease liabilities	$ (36)	29
Non-cash issuance cost		$ 32