Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net loss	$ (2,418)	$ (4,613)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash stock-based compensation	673	1,501
Depreciation and amortization	30	34
Changes in operating assets and liabilities:
Other current assets	184	154
Accounts payable	300	538
Accrued development expense	23	(399)
Accrued compensation and benefits	(1)	4
Other current liabilities	14	12
Net cash used in operating activities	(1,195)	(2,769)
Cash flows from investing activities:
Purchases of property and equipment	(18)
Net cash used in investing activities	(18)
Cash flows from financing activities:
Issuance costs from 2018 sale of common stock and warrants	(60)
Proceeds from issuance of common stock and warrants, net of issuance costs		1,898
Net cash (used in) / provided by financing activities	(60)	1,898
Net decrease in cash and cash equivalents	(1,273)	(871)
Cash and cash equivalents at beginning of period	19,807	10,479
Cash and cash equivalents at end of period	$ 18,534	$ 9,608