Balance Sheets - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 24,840,000	$ 54,116,000
Marketable securities	64,714,000	60,025,000
Accounts receivable	1,032,000	2,136,000
Prepaid expenses	1,775,000	1,020,000
Other current assets	1,010,000	851,000
Total current assets	93,371,000	118,148,000
Marketable securities	69,412,000	102,226,000
Property and equipment, net	9,324,000	538,000
Cost method investments	0	300,000
Restricted cash	225,000
Other assets	400,000	168,000
Total assets	172,732,000	221,380,000
Current liabilities
Accounts payable	1,543,000	1,014,000
Accrued expenses and other current liabilities	8,126,000	3,198,000
Advance payments		127,000
Total current liabilities	9,669,000	4,339,000
Deferred rent, net of current portion	1,326,000	233,000
Total liabilities	10,995,000	4,572,000
Commitments and contingencies (Note 6)
Stockholders’ equity
Preferred stock; $0.0001 par value; 10,000 shares authorized, and no shares issued and outstanding at December 31, 2016 and December 31, 2015
Common stock; $0.0001 par value; 100,000 shares authorized at December 31, 2016 and December 31, 2015; 26,477 and 26,313 shares issued and outstanding at December 31, 2016 and December 31, 2015, respectively	3,000	3,000
Additional paid-in capital	276,354,000	269,144,000
Accumulated other comprehensive loss	(33,000)	(719,000)
Accumulated deficit	(114,587,000)	(51,620,000)
Total stockholders’ equity	161,737,000	216,808,000
Total liabilities and stockholders’ equity	$ 172,732,000	$ 221,380,000