Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (124,084)	$ (123,665)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	8,687	6,467
Amortization (accretion) of premium (discount) on marketable securities	315	(307)
Stock-based compensation	15,309	11,467
Non-cash operating lease expense	3,132	2,246
Other	217	217
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	101	(2,934)
Other noncurrent assets	(601)	(815)
Accounts payable	(3,282)	1,660
Accrued and other current liabilities	2,256	4,348
Operating lease liabilities	(4,123)	(3,107)
Other noncurrent liabilities	1	(1)
Net cash used in operating activities	(102,072)	(104,424)
Cash flows from investing activities:
Purchases of property and equipment	(1,239)	(20,630)
Purchases of marketable securities	(56,644)	(140,476)
Proceeds from maturities of marketable securities	106,623	244,750
Other	(25)	8
Net cash provided by investing activities	48,715	83,652
Cash flows from financing activities:
Proceeds from issuance of common stock and pre-funded warrants in follow-on offering, net of issuance costs		77,387
Proceeds from at-the-market sales, net of issuance costs	3,868
Payment of accrued offering costs	(501)
Proceeds from exercise of stock options and employee stock purchase plan	682	380
Net cash provided by financing activities	4,049	77,767
Net change in cash, cash equivalents and restricted cash	(49,308)	56,995
Cash and cash equivalents and restricted cash at beginning of period	95,671	38,676
Cash and cash equivalents and restricted cash at end of period	46,363	95,671
Components of cash, cash equivalents and restricted cash:
Cash and cash equivalents	45,681	95,272
Restricted cash included in other noncurrent assets	682	399
Cash, cash equivalents and restricted cash	46,363	95,671
Supplemental disclosure of non-cash investing and financing activities:
Offering costs related to November 2022 public offering included in accounts payable and accrued and other current liabilities		501
Property and equipment included in accounts payable and accrued and other current liabilities	$ 249	$ 549