Commitments and Contingencies (Details)			12 Months Ended
	Jun. 30, 2015 patient	Jun. 15, 2013 USD ($)	Dec. 31, 2016 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares
Loss Contingencies [Line Items]
Discretionary cash bonus			$ 0	$ 0
Options, granted (in shares) | shares			48,444	46,075	13,678
Exercise option price (in usd per share) | $ / shares			$ 11.61	$ 21.60	$ 51.20
Accrued compensation and benefits			$ 1,109,864	$ 790,487
Lease monthly rent		$ 8,063	8,554
Operating lease rent expense			$ 108,000	$ 102,000	$ 99,000
Employee Stock Option
Loss Contingencies [Line Items]
Stock options, vesting period			4 years
Restricted Stock Units (RSUs)
Loss Contingencies [Line Items]
Stock options, vesting period			2 years
JHU
Loss Contingencies [Line Items]
Period within effective date of License Agreement			30 days
Employment Agreement With Management
Loss Contingencies [Line Items]
Base salary			$ 830,000
Discretionary cash bonus			231,000
Severance costs			$ 420,000
Employment Agreement With Management | Employee Stock Option
Loss Contingencies [Line Items]
Options, granted (in shares) | shares			825,000	1,125,000	317,500
Exercise option price (in usd per share) | $ / shares			$ 13.20	$ 23.20	$ 53.60
Stock options, vesting period			4 years
Employment Agreement With Management | Restricted Stock Units (RSUs)
Loss Contingencies [Line Items]
Stock options, vesting period			2 years
Restricted shares issued by the company (in shares) | shares			3,375	6,500
Novella Clinical
Loss Contingencies [Line Items]
Number of patients | patient	542
Deposits for clinical trial services			$ 2,068,241	$ 3,725,772
Termination notice period			60 days
Noncurrent assets | Novella Clinical
Loss Contingencies [Line Items]
Deposits for clinical trial services			$ 1,725,772
Current assets | Novella Clinical
Loss Contingencies [Line Items]
Deposits for clinical trial services			342,469
Former CEO
Loss Contingencies [Line Items]
Accrued compensation and benefits			$ 700,000