Commitments and Contingencies - Additional Information (Details)			3 Months Ended	6 Months Ended
	Jun. 30, 2015 patient	May 06, 2014 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2016 USD ($) $ / shares shares	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Aug. 21, 2014 USD ($)	Jul. 17, 2014 USD ($)	Sep. 17, 2013 USD ($)
Commitments And Contingencies [Line Items]
Deposits for clinical trial services			$ 3,449,006	$ 3,449,006		$ 4,176,280
Discretionary cash bonus				$ 0	$ 0
Options, Granted (in shares) | shares				1,937,750
Exercise option price (in USD per share) | $ / shares				$ 0.29
Lease monthly rent			8,063	$ 8,063
Percentage of annual increase of monthly base rent				3.00%
Operating lease rent expense				$ 54,000	$ 50,000
Rent expense, monthly amount			8,554
Novella Clinical
Commitments And Contingencies [Line Items]
Number of patients | patient	414
Deposits for clinical trial services			3,255,772	$ 3,255,772
Termination notice period				60 days
ICON
Commitments And Contingencies [Line Items]
Deposits for clinical trial services			$ 308,224	$ 308,224
Termination notice period				60 days
Estimated payments for services							$ 3,500,000	$ 2,300,000	$ 2,700,000
Service fee, amendments and aggregate		$ 170,004
JHU
Commitments And Contingencies [Line Items]
Period within effective date of License Agreement				30 days
PharmaCell B.V Agreement
Commitments And Contingencies [Line Items]
Written notice period for termination				90 days
Written notice period for early termination				30 days
Employment Agreement With Management
Commitments And Contingencies [Line Items]
Base salary				$ 1,300,000
Discretionary cash bonus				$ 450,000
Options, Granted (in shares) | shares				825,000
Exercise option price (in USD per share) | $ / shares				$ 0.33
Stock options, vesting period				4 years
Restricted shares issued by the company (in shares) | shares				285,000