Consolidated Statements of Operations (USD $)
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Revenue    
Contract research $ 2,076,580 $ 2,983,830
License 10,000,000  
Supply 1,886,786 99,119
Total revenue 13,963,366 3,082,949
Operating expenses    
Research and development 26,117,336 16,383,658
General and administrative 4,650,180 3,189,697
Total operating expenses 30,767,516 19,573,355
Loss from operations (16,804,150) (16,490,406)
Other income (expense)    
Interest income 1,754 45,124
Interest expense (614,084) (575,728)
Other income (expense), net (612,330) (530,604)
Net loss and comprehensive loss $ (17,416,480) $ (17,021,010)
Basic and diluted net loss attributable to common shareholders per share $ (0.41) $ (0.51)
Basic and diluted weighted average shares outstanding 42,670,632 33,200,950