CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities
Net loss	$ (23,635)	$ (21,661)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	2,046	2,130
Depreciation and amortization	27	30
Amortization of discount on investments	108	3
Non-cash lease expense	166	155
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(285)	1,186
Accounts payable and accrued expenses	892	(209)
Accrued compensation and benefits	(582)	(112)
Other assets	27	31
Other liabilities	(131)	(34)
Net cash used in operating activities	(21,367)	(18,481)
Cash flows from investing activities
Purchases of property and equipment	(6)	(22)
Purchase of investments	(12,978)	(60,828)
Proceeds from maturities of investments	39,000	0
Net cash provided by (used in) investing activities	26,016	(60,850)
Cash flows from financing activities
Payment of deferred offering costs	(227)	0
Proceeds from exercise of stock options	2	143
Proceeds from issuance of common stock related to employee stock purchase plan	38	96
Proceeds from issuance of long-term debt, net of issuance costs of $10		4,990
Repayment of term loan		(4,770)
Net cash (used in) provided by financing activities	(187)	459
Net increase (decrease) in cash, cash equivalents and restricted cash	4,462	(78,872)
Cash, cash equivalents, and restricted cash at beginning of period	42,964	157,366
Cash, cash equivalents, and restricted cash at end of period	47,426	78,494
Supplemental cash flow data:
Cash paid for interest	110	97
Supplemental disclosure of non-cash investing and financing activities:
Tax withholding payments on restricted stock units	(40)	0
Deferred offering costs included in accounts payable and accrued expenses	$ 50	$ 0