CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Operating activities
Net loss	$ (65,581)	$ (48,557)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	14,233	11,968
Lease Impairment Charge	0	4,925
Depreciation and amortization	2,048	1,461
Premiums and discounts on available-for-sale marketable securities	(2,525)	(3,072)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	2,776	(3,005)
Accounts receivable	0	15,000
Contract asset	(19,053)	1,732
Accounts payable	3,917	75
Accrued expenses and other current liabilities	(11,690)	(15,394)
Deferred revenue	(2,100)	(8,257)
Operating lease right-of-use assets	673	619
Operating lease liabilities	(1,154)	2,636
Other assets and liabilities	(694)	278
Net cash used in operating activities	(79,150)	(39,591)
Investing activities
Purchase of property and equipment, net	(467)	(7,402)
Purchases of investments	(83,656)	(422,704)
Maturities of investments	132,738	99,499
Net cash provided by (used in) investing activities	48,615	(330,607)
Financing activities
Issuance of common stock and accompanying pre-funded warrants from January 2024 public offering, net of issuance costs of $14.9 million	0	301,373
Proceeds from issuance of common stock through At-The Market Sales Agreement, net of issuance costs of $1.2 million	0	48,740
Proceeds from stock option exercises	535	3,933
Payments on finance leases	(277)	(290)
Net cash provided by financing activities	258	353,756
Net increase in cash, cash equivalents and restricted cash	(30,277)	(16,442)
Cash, cash equivalents and restricted cash at beginning of period	126,050	115,777
Cash, cash equivalents and restricted cash at end of period	95,773	99,335
Supplemental disclosure of cash flow activities
Cash paid for interest	77	49
Supplemental disclosure of noncash investing and financing activities
Property and equipment purchases included in accounts payable and accrued expenses	357	1,205
Cash and cash equivalents	89,966	93,510
Restricted cash	5,807	5,825
Total cash, cash equivalents, and restricted cash	$ 95,773	$ 99,335