CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (6,685)	$ (94,616)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	2,841	1,895
Stock‑based compensation expense	13,111	9,895
Net amortization of premium (accretion of discount) on marketable securities	(5,779)	151
Changes in operating assets and liabilities:
Collaboration receivable	(5,878)	0
Prepaid expenses and other current assets	8,622	(14,022)
Right-of-use assets, operating leases	11,989	7,651
Other non-current assets	(11,563)	(4,338)
Accounts payable	(2,805)	5,287
Accrued expenses and other current liabilities	3,812	1,762
Income taxes payable	4,024	0
Deferred revenue	139,976	0
Operating lease liabilities	(11,862)	(7,451)
Net cash provided by (used in) operating activities	139,803	(93,786)
Cash flows from investing activities:
Purchases of property and equipment	(5,614)	(2,887)
Purchases of marketable securities	(407,207)	(221,977)
Maturities of marketable securities	274,426	76,214
Net cash used in investing activities	(138,395)	(148,650)
Cash flows from financing activities:
Proceeds from issuance of common stock in connection with the Vertex Agreement	19,407	0
Proceeds from exercise of stock options	1,187	195
Proceeds from issuance of common stock under the employee stock purchase plan	443	284
Net cash provided by financing activities	21,037	479
Net increase (decrease) in cash, cash equivalents and restricted cash	22,445	(241,957)
Cash, cash equivalents and restricted cash at beginning of year	49,107	291,064
Cash, cash equivalents and restricted cash at end of year	71,552	49,107
Supplemental cash flow disclosures:
Purchases of property and equipment included in accounts payable and accrued expenses	208	88
Right-of-use assets obtained in exchange for operating lease liabilities	77,584	0
Right-of-use assets surrendered as part of lease modification	9,445	0
Recognition of right-of-use assets upon adoption of ASC 842	0	32,991
Transfer of deposits for equipment from operating to investing cash flows	617	495
Vesting of options early exercised subject to repurchase	91	135
Cash paid for income taxes	$ 14,717	$ 0