CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 29,639	$ 36,559
Prepaid expenses and other current assets	6,938	4,383
Total current assets	36,577	40,942
Property and equipment, net	57	64
Right-of-use lease asset	15	30
Non-current deposits	2,980	1,551
Total assets	39,629	42,587
Current liabilities:
Accounts payable	2,850	2,117
Accrued and other current liabilities	3,354	3,177
Total current liabilities	6,204	5,294
Lease liability	15	30
Total liabilities	6,219	5,324
Stockholders' equity:
Common stock, $0.001 par value; 100,000,000 shares authorized at December 31, 2021 and March 31, 2022; 9,993,135 shares issued and outstanding at December 31, 2021 and March 31, 2022.	10	10
Additional paid-in capital	423,290	422,960
Accumulated other comprehensive loss	(823)	(748)
Accumulated deficit	(389,067)	(384,959)
Total stockholders' equity	33,410	37,263
Total liabilities and stockholders' equity	39,629	42,587
6% convertible exchangeable preferred stock
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized at December 31, 2021 and March 31, 2022;
Series A Convertible Preferred Stock
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized at December 31, 2021 and March 31, 2022;
Series B Convertible Preferred Stock
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized at December 31, 2021 and March 31, 2022;

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
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- 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).