Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net loss	$ (794)	$ (3,958)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	2	3
Stock-based compensation	184	240
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(149)	233
Accounts payable and accrued expenses	(125)	(221)
Net cash used in operating activities	(882)	(3,703)
Investing activities:
Sale of short-term investments		6,209
Increase (decrease) in cash and cash equivalents	(882)	2,506
Cash and cash equivalents at beginning of period	1,115	3,535
Cash and cash equivalents at end of period	$ 233	$ 6,041

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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