Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
CURRENT ASSETS
Cash and cash equivalents	$ 49,544	$ 29,294
Marketable securities	18,491	3,768
Restricted cash		80
Accounts receivable - grant	1,571	1,697
Deferred offering costs		2,535
Prepaid expenses and other current assets	2,073	912
Total current assets	71,679	38,286
Property and equipment, net	342	348
Other non-current assets	40	20
TOTAL ASSETS	72,061	38,654
CURRENT LIABILITIES
Accounts payable	523	176
Deferred revenue	181	0
Accrued and other current liabilities	3,133	2,347
Total current liabilities	3,837	2,523
Other non-current liabilities	26	27
TOTAL LIABILITIES	3,863	2,550
Commitments and Contingencies (Note 11 and 13)
STOCKHOLDERS’ EQUITY (DEFICIT)
Preferred stock, $0.0001 par value; 10,000,000 shares and no shares authorized as of September 30, 2016 and December 31, 2015, respectively; no shares issued and outstanding as of September 30, 2016 and December 31, 2015, respectively
Common stock, $0.0001 par value; 500,000,000 shares and 25,000,000 shares authorized as of September 30, 2016 and December 31, 2015, respectively; 13,430,833 shares and 757,336 shares issued and outstanding as of September 30, 2016 and December 31, 2015, respectively	1	0
Additional paid-in capital	107,988	1,373
Accumulated other comprehensive income (loss)	3	(1)
Accumulated deficit	(39,794)	(23,579)
TOTAL STOCKHOLDERS’ EQUITY (DEFICIT)	68,198	(22,207)
TOTAL LIABILITIES, CONVERTIBLE PREFERRED STOCK, AND STOCKHOLDERS’ EQUITY (DEFICIT)	$ 72,061	38,654
Series A Convertible Preferred Stock
CURRENT LIABILITIES
Convertible preferred stock		13,573
Series B Convertible Preferred Stock
CURRENT LIABILITIES
Convertible preferred stock		$ 44,738