CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (33,407)	$ (13,548)
Adjustments to reconcile net loss to net cash used in operating activities:
Issuance of common stock under license agreement	1,971	0
Stock-based compensation	1,667	1,409
Gain on loan extinguishment	(437)	0
Depreciation	15	9
Reduction of discount on marketable securities	0	25
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	748	112
Accounts payable	756	(1,119)
Accrued liabilities	(2,663)	(376)
Deferred revenue	0	(1,795)
Net cash used in operating activities	(31,350)	(15,283)
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures, net	(36)	0
Maturities of marketable securities	0	4,500
Net cash provided by (used in) investing activities	(36)	4,500
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from the issuance of common stock and warrants, net of issuance costs	13,685	23,265
Proceeds from the exercise of warrants	8,969	23
Proceeds from the issuance of note payable	0	437
Net cash provided by financing activities	22,654	23,725
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(8,732)	12,942
CASH AND CASH EQUIVALENTS—BEGINNING	30,115	7,232
CASH AND CASH EQUIVALENTS—ENDING	21,383	20,174
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Forgiveness of Paycheck Protection Program loan	$ 437	$ 0