Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net loss	$ (2,223)	$ (2,414)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	14	11
Amortization of operating lease right-of-use assets	75	69
Share-based compensation expense	52	70
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(588)	(590)
Accounts payable	159	46
Operating lease liability	(79)	(71)
Accrued expenses and other liabilities	(645)	(843)
Net cash used in operating activities	(3,235)	(3,722)
Cash flows from financing activities:
Proceeds from exercise of warrants	8,509	286
Proceeds from issuance of common stock and warrants, net of commissions and issuance costs		6,035
Net cash provided by financing activities	8,509	6,321
Increase in cash and cash equivalents and restricted cash	5,274	2,599
Cash, cash equivalents and restricted cash at beginning of period	19,603	6,716
Cash, cash equivalents and restricted cash at end of period	$ 24,877	9,315
Supplemental disclosure of cash flow information and non-cash investing and financing activities:
Fair value of warrants issued in connection with the financing activities		$ 3,683