Statements of cash flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (24,711)	$ (17,837)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	755	755
Share-based compensation	3,448	621
Change in fair value of warrant liability		5,538
Deferred rent	4	(2)
Forgiveness of PPP Loan	(500)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(4,281)	(2,411)
Accounts payable	1,780	504
Accrued expenses and other current liabilities	5,279	698
Net cash used in operating activities	(18,226)	(12,134)
Cash flows from investing activities:
Purchases of property and equipment	(79)	(586)
Net cash used in investing activities	(79)	(586)
Cash flows from financing activities:
Proceeds from exercise of stock options	99	20
Proceeds from exercise of common stock warrants	1,338
Proceeds from long-term debt		500
Proceeds from sale of common stock and common stock warrants	27,225	44,850
Payment of issuance costs related to the sale of common stock and common stock warrants	(559)	(5,973)
Proceeds from the sale of Series A convertible preferred stock		11,046
Payment of Series A convertible preferred stock issuance costs		(49)
Payment of equipment loan payable	(113)	(212)
Payment of capital lease obligations		(239)
Payment of offering costs	(222)
Net cash provided by financing activities	27,768	49,943
Net increase in cash and cash equivalents and restricted cash	9,463	37,223
Cash and cash equivalents and restricted cash at beginning of year	39,866	2,643
Cash and cash equivalents and restricted cash at end of year	49,329	39,866
Supplemental disclosures of cash flow information:
Cash paid for interest	14	29
Supplemental disclosures of non-cash investing and financing activities:
Conversion of Series A convertible preferred stock upon IPO		48,369
Offering costs included in accounts payable	$ 110	135
Fair value of liability-classified warrants issued in connection with Series A convertible preferred stock		1,522
Conversion of liability-classified warrants upon IPO		$ 7,060