Condensed Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities
Net loss	$ (160,572)	$ (120,227)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	1,667	1,377
Stock-based compensation expense	29,209	35,331
Non-cash operating lease expense	2,640	1,833
Net amortization (accretion) on short-term investments and debt	1,945	(10,215)
Changes in operating assets and liabilities:
Accounts receivable	0	1,983
Prepaid expenses and other current assets	5,739	(3,583)
Other non-current assets	(35)	367
Accounts payable	2,358	1,797
Accrued liabilities	9,935	2,082
Operating lease liabilities	(727)	(2,004)
Net cash used in operating activities	(107,841)	(91,259)
Cash flows from investing activities
Purchase of short-term investments	(177,930)	(525,572)
Maturity of short-term investments	282,777	367,499
Purchase of property and equipment	(3,639)	(860)
Net cash provided by (used in) investing activities	101,208	(158,933)
Cash flows from financing activities
Proceeds from issuances of common stock under benefit plans	3,106	4,769
Proceeds from term loan, net of issuance costs	19,909	0
Payment of offering costs	0	(834)
Proceeds from sale of common stock in a public offering	0	270,251
Net cash provided by financing activities	23,015	274,186
Net increase in cash and cash equivalents	16,382	23,994
Cash and cash equivalents and restricted cash at beginning of period	64,716	33,685
Cash, cash equivalents and restricted cash at end of period	81,098	57,679
Supplemental disclosures of cash flow information:
Cash paid for interest	1,850	864
Reconciliation of cash, cash equivalents, and restricted cash reported in the balance sheets
Cash and cash equivalents	79,616	57,679
Restricted cash	1,482	0
Total cash, cash equivalents, and restricted cash	81,098	57,679
Supplemental disclosures of noncash investing and financing activities:
Net unrealized gain on short-term investments	503	51
Purchase of property and equipment in accounts payable and accrued liabilities	132	0
Supplemental disclosures of cash flow information related to leases:
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 29,779	$ 0