Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net loss	$ (4,154)	$ (4,140)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	36	41
Non-cash lease expense	55	0
Non-cash stock-based compensation	222	78
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(304)	(240)
Accounts payable	186	31
Accrued expenses	(96)	463
Lease Liability	(53)	0
Net cash used in operating activities	(4,108)	(3,767)
Cash flows from investing activities:
Cash paid for purchase of property and equipment	(16)	0
Net cash used in investing activities	(16)	0
Cash flows from financing activities:
Net proceeds from the issuance of common stock and/or warrants	0	5,501
Proceeds from the exercise of pre-funded warrants	60	0
Proceeds from the issuance of common stock in connection with the employee stock purchase plan	1	0
Net cash provided by financing activities	61	5,501
Net (decrease) increase in cash and restricted cash	(4,063)	1,734
Cash and restricted cash at the beginning of period	14,929	3,631
Cash and restricted cash at the end of period	10,866	5,365
Supplemental disclosure of non-cash investing and financing activities:
Right of use asset	$ 620	$ 0