Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 17,030	$ 16,369
Prepaid expenses and other current assets	889	1,094
Total current assets	17,919	17,463
Property and equipment, net	258	321
Restricted cash	113	113
Total assets	18,290	17,897
Current liabilities:
Accounts payable	1,115	773
Accrued expenses	2,164	2,432
Current portion of notes payable, net of discount	1,657	2,479
Other liability	341	332
Total current liabilities	5,277	6,016
Deferred rent, net of current portion	82	89
Total liabilities	5,359	6,105
Commitments (Note 7)
Stockholders' equity:
Preferred stock, $0.001 par value per share, 5,000,000 shares authorized and no shares issued and outstanding
Common stock, $0.001 par value per share, 150,000,000 shares authorized; 29,035,502 and 23,645,247 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively	29	24
Additional paid-in capital	191,988	183,202
Accumulated deficit	(179,086)	(171,434)
Total stockholders' equity	12,931	11,792
Total liabilities and stockholders' equity	$ 18,290	$ 17,897

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).