Condensed Consolidated Balance Sheets - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 95,637,572	$ 25,031,280
Short-term investment securities	13,823,332	19,853,860
Interest receivable	22,824	83,852
Prepaid research and development	8,422,375	5,678,755
Other current assets	1,057,715	216,397
Total current assets	118,963,818	50,864,144
Restricted cash	584,213	583,208
Leasehold interest, net	2,491,211	2,042,281
Equipment, net	307,732	328,148
Goodwill	799,391	799,391
Other assets	110,067	164,375
Total assets	123,256,432	54,781,547
Current liabilities:
Accounts payable and accrued expenses	18,916,064	15,267,668
Accrued compensation	483,555	1,389,516
Current portion of deferred revenue	152,381	152,381
Notes payable	174,657	68,875
Total current liabilities	19,726,657	16,878,440
Deferred rent	1,307,063	816,257
Deferred revenue, net of current portion	1,180,953	1,219,048
Total liabilities	22,214,673	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 March 31, 2017 and December 31, 2016)	0	0
Common stock, $0.001 par value per share (150,000,000 shares authorized, 66,816,455 and 56,820,423 shares issued, 66,775,146 and 56,779,114 shares outstanding at March 31, 2017 and December 31, 2016, respectively)	66,817	56,820
Additional paid-in capital	365,323,608	272,432,139
Treasury stock, at cost, 41,309 shares at March 31, 2017 and December 31, 2016	(234,337)	(234,337)
Accumulated deficit	(264,114,329)	(236,386,820)
Total stockholders’ equity	101,041,759	35,867,802
Total liabilities and stockholders’ equity	$ 123,256,432	$ 54,781,547