Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]

0001626199 (http://www.sec.gov/CIK)

Balance Sheets	Period [Axis]
	2016-12-31	2015-12-31
Balance Sheets
Assets
Current assets:
Cash and cash equivalents	24,203,000	24,991,000
Marketable securities	36,832,000	62,263,000
Prepaid expenses and other current assets	628,000	432,000
Total current assets	61,663,000	87,686,000
Property and equipment and other assets, net	272,000	223,000
Total assets	61,935,000	87,909,000
Liabilities and stockholders' equity (deficit)
Current liabilities:
Accounts payable	1,921,000	994,000
Accrued direct program expenses	2,646,000	1,555,000
Accrued employee benefits	1,879,000	1,675,000
Accrued other liabilities	53,000	195,000
Total current liabilities	6,499,000	4,419,000
Commitments and contingencies	xsi:nil	xsi:nil
Convertible preferred stock with liquidation preference; $0.001 par value; zero and 23,228,986 shares authorized, respectively; zero and 19,978,986 shares issued and outstanding, respectively
Stockholders' equity (deficit):
Preferred stock, $0.001 par value; 10,000,000 shares authorized for both periods presented; no shares issued and outstanding	xsi:nil	xsi:nil
Common stock, $0.001 par value; 200,000,000 shares authorized for both periods presented; 15,565,973 and 15,462,030 shares issued and outstanding, respectively	16,000	15,000
Additional paid-in capital	235,737,000	232,309,000
Accumulated other comprehensive income (loss)	(17,000)	3,000
Accumulated deficit	(180,300,000)	(148,837,000)
Total stockholders' equity (deficit)	55,436,000	83,490,000
Total liabilities and stockholders' equity (deficit)	61,935,000	87,909,000