CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 11,435	$ 18,345
Prepaid expenses and other current assets	7,539	6,066
Total current assets	18,974	24,411
Property and equipment, net	31	32
Right-of-use lease asset	139	142
Non-current deposits	2,916	2,916
Total assets	22,060	27,501
Current liabilities:
Accounts payable	2,509	2,561
Accrued and other current liabilities	4,829	4,831
Total current liabilities	7,338	7,392
Lease liability	80	106
Total liabilities	7,418	7,498
Redeemable common stock, $0.001 par value, 3,117,100 shares issued and outstanding at March 31, 2023 and December 31, 2022 (Note 10)	4,494	4,494
Stockholders' equity:
Common stock, $0.001 par value; 100,000,000 shares authorized at March 31, 2023 and December 31, 2022; 12,539,189 shares issued and outstanding at March 31, 2023 and December 31, 2022	9	9
Additional paid-in capital	423,324	422,973
Accumulated other comprehensive loss	(1,224)	(1,316)
Accumulated deficit	(411,961)	(406,157)
Total stockholders' equity	10,148	15,509
Total liabilities and stockholders' equity	22,060	27,501
6% convertible exchangeable preferred stock
Stockholders' equity:
Preferred stock, value
Series A Convertible Preferred Stock
Stockholders' equity:
Preferred stock, value
Series B 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).