Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
CURRENT ASSETS:
Cash and cash equivalents	$ 100,348	$ 109,007
Prepaid expenses and other current assets	1,377	1,343
Total current assets	101,725	110,350
Property and equipment, net	154	400
Other assets	319	223
TOTAL ASSETS	102,198	110,973
CURRENT LIABILITIES:
Accrued liabilities	6,133	5,121
Accounts payable	1,339	2,604
Total current liabilities	7,472	7,725
TOTAL LIABILITIES	7,472	7,725
Commitments and Contingencies (Note 6)
STOCKHOLDERS' EQUITY:
Preferred stock, $0.001 par value; 10,000,000 shares authorized as of December 31, 2017 and December 31, 2016; nil shares issued and outstanding as of December 31, 2017 and December 31, 2016
Common stock, $0.001 par value; 500,000,000 shares authorized as of December 31, 2017 and 2016; 52,395,223 and 30,370,946 shares issued and outstanding as of December 31, 2017 and 2016	52	30
Additional paid-in capital	718,751	685,272
Accumulated deficit	(624,077)	(582,054)
TOTAL STOCKHOLDERS' EQUITY	94,726	103,248
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 102,198	$ 110,973

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
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).