CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 12,967	$ 17,504
Prepaid expenses and other current assets	2,869	2,283
Total current assets	15,836	19,787
Property and equipment, net	28	36
Right-of-use lease asset	1,213
Total assets	17,077	19,823
Current liabilities:
Accounts payable	887	2,719
Accrued and other current liabilities	1,184	1,732
Total current liabilities	2,071	4,451
Lease liability	1,154
Other liabilities		100
Total liabilities	3,225	4,551
Stockholders' equity:
Common stock, $0.001 par value; 100,000,000 shares authorized at December 31, 2018 and September 30, 2019; 12,497,447 and 17,199,974 shares issued and outstanding at December 31, 2018 and September 30, 2019.	17	12
Additional paid-in capital	370,071	365,817
Accumulated other comprehensive loss	(913)	(760)
Accumulated deficit	(355,323)	(349,797)
Total stockholders' equity	13,852	15,272
Total liabilities and stockholders' equity	17,077	19,823
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).