CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (63,053)	$ (73,201)
Adjustments to reconcile net loss to net cash used in operating activities:
Change in fair value of contingent consideration liability	86	1,560
Impairment loss on construction-in-progress		8,070
Stock-based compensation expense	6,209	4,200
Depreciation and amortization	31	434
Unrealized (gains) losses on foreign currency exchange	(183)	297
Changes in operating assets and liabilities:
Accounts receivable	(204)	3,036
Prepaid expenses and other assets	3,204	(5,263)
Accounts payable	(615)	(606)
Accrued expenses and other liabilities	7,555	6,916
Income tax and R&D incentive receivables	1,690	(1,714)
Net cash used in operating activities	(45,280)	(56,271)
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sales and maturities of short-term investments		82,406
Purchases of short-term investments	(74,292)	(7,592)
Purchases of property and equipment, net	(88)	(11,970)
Cash paid for internally developed patents		(190)
Net cash (used in) provided by investing activities	(74,380)	62,654
CASH FLOWS FROM FINANCING ACTIVITIES:
Payments of deferred offering costs		(118)
Proceeds from issuance of common stock in at-the-market offerings, net	56,166	52,356
Proceeds from issuance of common stock from Employee Stock Purchase Plan	181	225
Proceeds from exercises of stock options, net	477	100
Net cash provided by financing activities	56,824	52,563
Net (decrease) increase in cash and cash equivalents and restricted cash	(62,836)	58,946
Cash, cash equivalents and restricted cash at beginning of period	190,335	115,952
Cash, cash equivalents and restricted cash at end of period	127,499	174,898
SUPPLEMENTAL NON-CASH ACTIVITIES:
Common stock issued related to contingent consideration liability	$ 6,176
Operating lease liability and right of use asset addition		$ 72