Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating activities
Net loss	$ (3,324)	$ (4,730)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	187	159
Non-cash lease expense	5	5
Depreciation	12	11
Change in assets and liabilities, net of the effects of the asset acquisitions:
Prepaid expenses and other assets	(265)	(1,202)
Accounts payable	(2,106)	637
Accrued and other liabilities	(650)	982
Net cash used in operating activities	(6,141)	(4,138)
Investing activities
Purchases of property and equipment		(2)
Net cash provided by (used in) investing activities		(2)
Financing activities
Proceeds from equity offering	10,000
Issuance costs	(908)
Exercise of stock options		53
Net cash provided by financing activities	9,092	53
Net (decrease) increase in cash and restricted cash	2,951	(4,087)
Net foreign exchange difference	(5)	(22)
Cash and restricted cash at beginning of period	10,089	13,923
Cash and restricted cash at end of period	$ 13,035	$ 9,814