Consolidated Statements of Cash Flows $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)
Cash flows from operating activities:
Net loss	$ (2,414)	$ (2,635)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	11	16
Amortization of operating lease right-of-use assets	69	65
Share-based compensation expense	70	67
Non-cash investment (income) expense, net		1
Changes in operating assets and liabilities:
Prepaid expenses	(590)	(674)
Accounts payable	46	173
Operating lease liability	(71)	26
Accrued expenses and other liabilities	(843)	(397)
Net cash used in operating activities	(3,722)	(3,358)
Cash flows from financing activities:
Proceeds from issuance of stock under ESPP		1
Proceeds from exercise of warrants	286
Repayment of loan payable		(100)
Proceeds from issuance of common stock and warrants, net of commissions and issuance costs	6,035
Net cash (used in) provided by financing activities	6,321	(99)
Decrease in cash and cash equivalents and restricted cash	2,599	(3,457)
Cash, cash equivalents and restricted cash at beginning of period	6,716	16,774
Cash, cash equivalents and restricted cash at end of period	9,315	13,317
Supplemental disclosure of cash flow information and non-cash investing and financing activities:
Cash paid for interest		1
Fair value of warrants issued in connection with the 2020 Offering	$ 3,683
Right-of-use assets and lease liability recorded upon adoption of ASC 842		$ 1,475