Consolidated Statements of Operations (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Revenue $ 1,974,019 $ 4,421,689 $ 7,039,010
Operating expenses      
Research and development 45,498,916 23,991,151 17,616,892
General and administrative 8,599,359 4,662,317 6,135,581
Total operating expenses 54,098,275 28,653,468 23,752,473
Operating loss (52,124,256) (24,231,779) (16,713,463)
Other income (expense)      
Interest income 66,580 7,184 4,604
Interest expense (1,123,579) (4,705) (292,496)
Change in fair value of warrant liability   355,352 4,916,785
Derivative (expense) income     1,036,403
Investment tax credits 140,556   694,331
Other expense (265,239) (47,615) (117,494)
Other income (expense), net (1,181,682) 310,216 6,242,133
Net loss (53,305,938) (23,921,563) (10,471,330)
Accretion of redeemable convertible preferred stock (See Note 19) (863,226) 4,772,991 (351,371)
Less: Preferred stock dividend due to exchanges of preferred shares (See Note 19)   (14,726,088)  
Net loss attributable to common stockholders $ (54,169,164) $ (33,874,660) $ (10,822,701)
Net loss attributable to common stockholders per share, basic and diluted (in Dollars per share) $ (3.12) $ (147.37) $ (54.58)
Weighted average shares outstanding, basic and diluted (in Shares) 17,367,665 229,865 198,306