CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 11,885	$ 17,504
Prepaid expenses and other current assets	2,132	2,283
Total current assets	14,017	19,787
Property and equipment, net	27	36
Right-of-use lease asset	1,264
Total assets	15,308	19,823
Current liabilities:
Accounts payable	890	2,719
Accrued and other current liabilities	1,530	1,732
Total current liabilities	2,420	4,451
Lease liability	1,191
Other liabilities		100
Total liabilities	3,611	4,551
Stockholders' equity:
Preferred stock, value
Common stock, $0.001 par value; 100,000,000 shares authorized at December 31, 2018 and December 31, 2019; 12,497,447 and 17,199,974 shares issued and outstanding at December 31, 2018 and December 31, 2019.	17	12
Additional paid-in capital	370,126	365,817
Accumulated other comprehensive loss	(819)	(760)
Accumulated deficit	(357,627)	(349,797)
Total stockholders' equity	11,697	15,272
Total liabilities and stockholders' equity	15,308	19,823
6% Convertible Exchangeable Preferred Stock [Member]
Stockholders' equity:
Preferred stock, value
Series A Convertible Preferred Stock [Member]
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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Namespace Prefix:	us-gaap_
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).