Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (14,864,000)	$ (9,818,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	353,000	43,000
Stock-based compensation expense	941,000	1,023,000
Amortization of premium (discount) on marketable securities	312,000	(196,000)
Non-cash loss on termination of lease	137,000	0
Gain on sale of equipment	(9,000)	0
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(2,262,000)	(1,633,000)
Accounts payable	(3,084,000)	(404,000)
Other liabilities	1,974,000	(1,575,000)
Net cash used in operating activities	(16,502,000)	(12,560,000)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(7,000)	(64,000)
Purchases of available-for-sale marketable securities	(1,027,000)	(81,379,000)
Proceeds from sales and maturities of marketable securities	20,540,000	9,395,000
Net cash provided by (used in) investing activities	19,506,000	(72,048,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from initial public offering, net of issuance costs	0	90,506,000
Proceeds from exercise of stock options	0	258,000
Net cash provided by financing activities	0	90,764,000
Net change in cash and cash equivalents	3,004,000	6,156,000
Cash and cash equivalents at beginning of period	8,305,000	2,416,000
Effect of exchange rates on cash	(21,000)	0
Cash and cash equivalents at end of period	11,288,000	8,572,000
Supplemental non-cash disclosure: NONCASH INVESTING AND FINANCING ACTIVITY:
Conversion of Series A and B convertible preferred stock to common stock	0	73,037,000
Operating right-of-use asset obtained in exchange for operating lease liability	824,000	0
Derecognition of operating right-of-use asset and operating lease liability upon termination of lease	714,000	0
Unrealized loss on available-for-sale marketable securities	$ 242,000	$ 112,000