Condensed Balance Sheets (Unaudited) - USD ($)
Jun. 30, 2015
Dec. 31, 2014
Current assets:    
Cash and cash equivalents $ 62,954,955 $ 75,947,516
Prepaid expenses and other current assets 815,520 925,773
Total current assets 63,770,475 76,873,289
Restricted cash 200,000  
Property and equipment, net 221,923 24,809
Total assets 64,192,398 76,898,098
Current liabilities:    
Accounts payable 2,991,697 997,269
Accrued expenses 1,761,528 912,320
Deferred rent 9,166  
Long-term debt, current portion 1,228,599  
Total current liabilities 5,990,990 1,909,589
Long-term debt, net of current portion $ 8,616,905 $ 9,741,080
Stockholders’ equity (deficit):    
Preferred stock, $0.0001 par value; 5,000,000 shares authorized; no shares issued and outstanding    
Common stock, $0.0001 par value; 300,000,000 shares authorized; 13,690,902 and 13,671,311 shares issued and outstanding at June 30, 2015 and December 31, 2014, respectively; $ 1,369 $ 1,366
Additional paid-in capital 135,637,656 134,920,775
Accumulated deficit (86,054,522) (69,674,712)
Total stockholders’ equity 49,584,503 65,247,429
Total liabilities and stockholders’ equity $ 64,192,398 $ 76,898,098