CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 19,824	$ 23,910
Prepaid expenses and other current assets	2,863	2,064
Total current assets	22,687	25,974
Property and equipment, net Property and equipment, net	43	29
Total assets	22,730	26,003
Current liabilities:
Accounts payable	1,675	1,558
Accrued and other current liabilities	2,319	2,555
Total current liabilities	3,994	4,113
Other liabilities	112	124
Total liabilities	4,106	4,237
Stockholders' equity:
Preferred stock, value
Common stock, $0.001 par value; 100,000,000 shares authorized at December 31, 2017 and June 30, 2018; 11,997,447 shares issued and outstanding at December 31, 2017 and June 30, 2018.	12	12
Additional paid-in capital	365,123	365,057
Accumulated other comprehensive loss	(801)	(794)
Accumulated deficit	(345,710)	(342,509)
Total stockholders' equity	18,624	21,766
Total liabilities and stockholders' equity	22,730	26,003
Convertible Exchangeable Preferred Stock
Stockholders' equity:
Preferred stock, value
Series A convertible preferred stock
Stockholders' equity:
Preferred stock, value

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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Data Type:	xbrli:monetaryItemType
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).