Condensed Consolidated Balance Sheets (unaudited) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
CURRENT ASSETS
Cash and cash equivalents	$ 10,760,000	$ 12,817,000
Marketable securities	32,715,000	37,482,000
Accounts receivable - grant	3,373,000	3,078,000
Prepaid expenses and other current assets	1,995,000	1,614,000
Total current assets	48,843,000	54,991,000
Property and equipment, net	810,000	854,000
Other non-current assets	133,000	232,000
TOTAL ASSETS	49,786,000	56,077,000
CURRENT LIABILITIES
Accounts payable	763,000	389,000
Deferred revenue	0	20,000
Accrued and other current liabilities	5,002,000	5,220,000
Total current liabilities	5,765,000	5,629,000
Other non-current liabilities	101,000	111,000
TOTAL LIABILITIES	5,866,000	5,740,000
Commitments and Contingencies (Note 9)
STOCKHOLDERS’ EQUITY
Preferred stock, $0.0001 par value; 10,000,000 shares authorized as of March 31, 2018 and December 31, 2017; no shares issued and outstanding as of March 31, 2018 and December 31, 2017
Common stock, $0.0001 par value; 500,000,000 shares authorized as of March 31, 2018 and December 31, 2017; 16,809,669 shares and 16,670,188 shares issued and outstanding as of March 31, 2018 and December 31, 2017, respectively	2,000	2,000
Additional paid-in capital	124,648,000	122,950,000
Accumulated other comprehensive loss	(98,000)	(102,000)
Accumulated deficit	(80,632,000)	(72,513,000)
TOTAL STOCKHOLDERS’ EQUITY	43,920,000	50,337,000
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 49,786,000	$ 56,077,000