Condensed Consolidated Balance Sheets - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 77,602,363	$ 25,031,280
Short-term investment securities	8,808,930	19,853,860
Interest receivable	43,290	83,852
Prepaid research and development	9,662,237	5,678,755
Other current assets	927,657	216,397
Total current assets	97,044,477	50,864,144
Restricted cash	585,229	583,208
Leasehold interest, net	2,479,349	2,042,281
Equipment, net	289,305	328,148
Goodwill	799,391	799,391
Other assets	0	164,375
Total assets	101,197,751	54,781,547
Current liabilities:
Accounts payable and accrued expenses	19,556,942	15,267,668
Accrued compensation	896,805	1,389,516
Current portion of deferred revenue	152,381	152,381
Notes payable	152,568	68,875
Total current liabilities	20,758,696	16,878,440
Deferred rent	1,321,180	816,257
Deferred revenue, net of current portion	1,142,857	1,219,048
Total liabilities	23,222,733	18,913,745
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value per share (10,000,000 shares authorized, none issued and outstanding as of June 30, 2017 and December 31, 2016)	0	0
Common stock, $0.001 par value per share (150,000,000 shares authorized, 68,127,202 and 56,820,422 shares issued, 68,085,893 and 56,779,113 shares outstanding at June 30, 2017 and December 31, 2016, respectively)	68,127	56,820
Additional paid-in capital	370,608,641	272,432,139
Treasury stock, at cost, 41,309 shares at June 30, 2017 and December 31, 2016	(234,337)	(234,337)
Accumulated deficit	(292,467,413)	(236,386,820)
Total stockholders’ equity	77,975,018	35,867,802
Total liabilities and stockholders’ equity	$ 101,197,751	$ 54,781,547