Consolidated Balance Sheets - USD ($)	Dec. 31, 2018	Dec. 31, 2017
CURRENT ASSETS
Cash and cash equivalents	$ 22,461,000	$ 12,817,000
Marketable securities	52,052,000	37,482,000
Accounts receivable - grant		3,078,000
Prepaid expenses and other current assets	2,158,000	1,614,000
Total current assets	76,671,000	54,991,000
Property and equipment, net	1,018,000	854,000
Other non-current assets	50,000	232,000
TOTAL ASSETS	77,739,000	56,077,000
CURRENT LIABILITIES
Accounts payable	663,000	389,000
Deferred revenue		20,000
Accrued and other current liabilities	9,576,000	5,220,000
Total current liabilities	10,239,000	5,629,000
Other non-current liabilities	72,000	111,000
TOTAL LIABILITIES	10,311,000	5,740,000
Commitments and Contingencies (Note 13 and 15)
STOCKHOLDERS’ EQUITY
Preferred stock, $0.0001 par value; 10,000,000 shares authorized as of December 31, 2018 and 2017; no shares issued and outstanding as of December 31, 2018 and 2017
Common stock, $0.0001 par value; 500,000,000 shares authorized as of December 31, 2018 and 2017, 24,140,097 shares and 16,670,188 shares issued and outstanding as of December 31, 2018 and 2017, respectively	2,000	2,000
Additional paid-in capital	184,314,000	122,950,000
Accumulated other comprehensive loss	(27,000)	(102,000)
Accumulated deficit	(116,861,000)	(72,513,000)
TOTAL STOCKHOLDERS’ EQUITY	67,428,000	50,337,000
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 77,739,000	$ 56,077,000