Quarterly report pursuant to Section 13 or 15(d)

Condensed Statement of Changes in Stockholders' Equity

v3.8.0.1
Condensed Statement of Changes in Stockholders' Equity - 3 months ended Mar. 31, 2018 - USD ($)
Total
Common Stock [Member]
Additional Paid-in Capital [Member]
Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2017 $ 11,758,730 $ 225 $ 185,659,954 $ (173,901,449)
Beginning balance (in shares) at Dec. 31, 2017   22,584,588    
Stock-based compensation - restricted stock units ("RSUs") 4,251,961   4,251,961  
Stock-based compensation - employee stock purchase plan ("ESPP") 154,545   154,545  
Stock-based compensation - performance share units ("PSUs") 202,702   202,702  
Issuance of shares for RSUs   $ 3 (3)  
Issuance of shares for RSUs (in shares)   341,936    
Issuance of shares for PSUs   $ 1 (1)  
Issuance of shares for PSUs (in shares)   80,098    
Exercise of stock options 981,053 $ 2 981,051  
Exercise of stock options (in shares)   179,732    
Cashless exercise of warrants (in shares)   7,989    
Proceeds from contributions to the ESPP 200,935   200,935  
Issuance of shares in an at-the-market ("ATM") offering, net of issuance costs 38,846,815 $ 22 38,846,793  
Issuance of shares in an at-the-market ("ATM") offering, net of issuance costs (in shares)   2,221,455    
Net loss (13,443,457)     (13,443,457)
Ending balance at Mar. 31, 2018 $ 42,953,284 $ 253 $ 230,297,937 $ (187,344,906)
Ending balance (in shares) at Mar. 31, 2018   25,415,798