CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities
Net loss	$ (17,579)	$ (18,638)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	2,638	2,401
Amortization of premiums on marketable securities	0	76
Depreciation expense	266	196
Non cash interest expense	0	626
Reduction in operating lease right-of-use asset	143	125
Changes in operating assets and liabilities:
Collaboration revenue receivable, billed and unbilled	314	(218)
Prepaid expenses and other assets	2,891	1,048
Accounts payable	1,502	(131)
Accrued expenses and other current liabilities	713	(880)
Operating lease liability	(147)	(126)
Net cash used in operating activities	(9,259)	(15,521)
Cash flows from investing activities
Sales and maturities of marketable securities	0	50,000
Purchases of marketable securities	0	(4,477)
Purchases of property and equipment	(70)	(159)
Deposits	0	(146)
Net cash (used in) provided by investing activities	(70)	45,218
Cash flows from financing activities
Proceeds from exercise of stock options	7	0
Debt issuance costs	0	(17)
Equity issuance costs	(112)	0
Repayment of financing lease	0	(2)
Proceeds from issuance of common stock, net of issuance costs	30,301	0
Net cash provided by (used in) financing activities	30,196	(19)
Net increase in cash, cash equivalents and restricted cash	20,867	29,678
Cash and cash equivalents at the beginning of the period	34,273	15,752
Cash and cash equivalents at the end of the period	55,140	45,430
Supplemental disclosure of noncash investing and financing activities:
Property and equipment purchases payable or accrued at period end	0	291
Change in unrealized gain on marketable securities	0	(35)
Cash paid for interest	0	1,468
Right-of-use asset obtained in exchange for lease obligation	$ 0	$ 99