Accrued Expenses (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Accrued Expenses
Accrued manufacturing development costs	$ 2,321,708	$ 513,606
Accrued payroll, bonus and deferred compensation	2,545,909	761,556
Accrued construction in process	2,877,251
Accrued professional fees	909,343	348,165
Accrued issuance costs for planned initial public offering		371,043
Accrued employee expenses	45,380
Accrued clinical trial costs	111,938	93,621
Accrued license maintenance fees	46,187	68,311
Accrued severance	128,020	153,846
Accrued franchise tax	129,168
Deferred rent	113,661
Other	388,059	126,869
Accrued expenses	$ 9,616,624	$ 2,437,017