Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Operating activities
Net loss	$ (8,866,000)	$ (1,805,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	974,000	58,000
Depreciation expense	112,000	0
Change in fair value of derivative liability		445,000
Change in fair value of grant liability		(97,000)
Accretion of discounts on convertible notes		172,000
Non-cash interest expense		46,000
Amortization of premiums and accretion of discounts on available-for-sale securities, net	131,000
Changes in operating assets and liabilities:
Unbilled grant receivables, prepaid expenses and other current assets	308,000	(57,000)
Accounts payable and accrued expenses	(374,000)	63,000
Operating lease liability	410,000
Net cash (used in) operating activities	(7,305,000)	(1,175,000)
Investing activities
Purchases of available-for-sale securities	(93,143,000)
Maturities of available-for-sale securities	70,739,000
Purchases of property and equipment	(304,000)
Principal payments received on stockholder note receivable		1,000
Net cash (used in) provided by investing activities	(22,708,000)	1,000
Financing activities
Proceeds from exercise of common stock options	39,000	176,000
Proceeds from follow-on public offering, net of issuance costs	97,172,000
Proceeds from issuance of convertible notes, including derivative, net of issuance costs		1,664,000
Net cash provided by financing activities	97,211,000	1,840,000
Net increase (decrease) in cash and cash equivalents	67,198,000	666,000
Cash and cash equivalents, beginning of period	60,625,000	2,056,000	$ 2,056,000
Cash and cash equivalents, end of period	127,823,000	$ 2,722,000	$ 60,625,000
Supplemental disclosures of cash flow information:
Purchases of property and equipment included in accounts payable and accrued liabilities	57,000
Right-of-use asset obtained in exchange for new operating lease liability	$ 518,000