Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024
Cash flows from operating activities:
Net loss	$ 34,590	$ (62,278)
Adjustments to reconcile net loss to net cash used in operating activities
Stock-based compensation expense	10,192	9,375
Depreciation	4,173	3,957
Net accretion of discounts/premiums on marketable securities	(1,766)	(1,163)
Gain on disposal of property and equipment	(59)	0
Changes in operating assets and liabilities
Accounts receivable	0	(9,000)
Other receivables	(2,196)	(337)
Prepaid expenses and other current assets	(1,713)	(2,412)
Accounts payable	(11,976)	(4,676)
Accrued expenses and other current liabilities	(5,077)	(1,842)
Defined benefit plan liability	957	(29)
Right-of-use assets and operating lease liabilities	(427)	(768)
Deferred revenue	(106,910)	3,241
Net cash used in operating activities	(80,212)	(65,932)
Cash flows from investing activities:
Purchases of property and equipment	(3,282)	(3,406)
Purchases of marketable securities	(157,047)	(130,027)
Proceeds from maturities of marketable securities	85,424	82,128
Net cash provided by (used in) investing activities	(74,905)	(51,305)
Cash flows from financing activities:
Proceeds from sale of common stock pursuant to the at-the-market sales agreement, net of underwriter's discount of $29	0	944
Proceeds from underwritten public offering , net of underwriter's discount of $3,000	0	47,001
Proceeds from the issuance of pre-funded warrants	0	50,000
Payment of common stock and pre-funded warrant issuance costs	0	(641)
Proceeds from exercise of employee stock options	14	667
Proceeds from employee stock purchase plan	365	298
Net cash provided by financing activities	379	98,269
Net decrease in cash, cash equivalents and restricted cash	(154,738)	(18,968)
Cash, cash equivalents and restricted cash—beginning of period	229,117	132,681
Cash, cash equivalents and restricted cash-end of period	74,379	113,713
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	69,429	108,847
Restricted cash	4,950	4,866
Total cash, cash equivalents and restricted cash	74,379	113,713
Supplemental disclosure of noncash items
Purchases of property and equipment in accounts payable and accrued expenses	$ 450	$ 235