Selected Balance Sheet Information (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Other Current Assets [Line Items]
Clinical consulting services refund receivable	$ 612	$ 0
Prepaid conferences, travel and other expenses	382	295
Grant receivable	315	185
Prepaid insurance	185	358
Prepaid clinical research organizations	46	1,677
Total	$ 1,540	$ 2,515

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Sum of the amount paid in advance for clinical research organization.

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Carrying amount as of the balance sheet date of amounts due under the terms of governmental, corporate, or foundation grants. For classified balance sheets, represents the current amount receivable, that is amounts expected to be collected within one year or the normal operating cycle, if longer.

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Amount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer.

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