Stockholders' Equity - Additional Information 2 (Detail)							12 Months Ended
	Aug. 04, 2015 shares	May 08, 2015 USD ($) $ / shares shares	May 01, 2015 USD ($) $ / shares shares	Mar. 23, 2015 USD ($) $ / shares shares	Feb. 28, 2014 USD ($) $ / shares shares	Jul. 10, 2006 Right $ / shares $ / Right shares	Dec. 31, 2015 USD ($) shares	Dec. 31, 2014 USD ($)
Stockholders Equity [Line Items]
Stock-based compensation | $							$ 985,114	$ 508,628
Unvested stock-based compensation at fair value of remaining shares | $							30,444
Stock option compensation expense, recognized | $							985,114	508,628
Intrinsic value of options outstanding | $							1,400	0
Exchange and Redemption Agreement with Sabby Healthcare Volatility Master Fund, Ltd. [Member]
Stockholders Equity [Line Items]
Stock option compensation expense, recognized | $							$ 693,801
2005 Equity Incentive Plan [Member]
Stockholders Equity [Line Items]
Common stock reserved for issuance							283,058
Plan expiration date							Oct. 20, 2015
Options expiration term							10 years
2005 Equity Incentive Plan [Member] | Directors, Officers and Chief Medical Advisor [Member]
Stockholders Equity [Line Items]
Common stock warrants, issued				1,125,000	1,457,100
Common stock warrants, term				10 years	10 years
Common stock warrants, exercise price | $ / shares				$ 0.60	$ 0.80
Common stock warrants, premium percentage				216.00%	57.00%
Common stock warrants, fair value per share | $ / shares				$ 0.10	$ 0.34
Stock-based compensation | $				$ 117,375	$ 505,057
2005 Equity Incentive Plan [Member] | Directors, Officers and Chief Medical Advisor [Member] | Exchange and Redemption Agreement with Sabby Healthcare Volatility Master Fund, Ltd. [Member]
Stockholders Equity [Line Items]
Stock-based compensation | $				$ 215,893			$ 371,770	$ 505,057
Common stock issued upon common stock warrants exercisable				2,250,000	3,885,598
2005 Equity Incentive Plan [Member] | Directors and Employees [Member]
Stockholders Equity [Line Items]
Common stock warrants, issued			550,000
Common stock warrants, term			10 years
Common stock warrants, exercise price | $ / shares			$ 0.60
Common stock warrants, premium percentage			20.00%
Common stock warrants, fair value per share | $ / shares			$ 0.37
Stock-based compensation | $			$ 166,627
Common stock warrants, vested			300,000
Vesting period			1 year
2005 Equity Incentive Plan [Member] | Directors and Employees [Member] | 1 Year Cliff Vesting [Member]
Stockholders Equity [Line Items]
Common stock warrants, vested			250,000
2005 Equity Incentive Plan [Member] | Directors and Employees [Member] | Exchange and Redemption Agreement with Sabby Healthcare Volatility Master Fund, Ltd. [Member]
Stockholders Equity [Line Items]
Stock-based compensation | $			$ 106,138
Common stock issued upon common stock warrants exercisable			1,100,000
2005 Equity Incentive Plan [Member] | Consultant [Member]
Stockholders Equity [Line Items]
Common stock warrants, issued		100,000
Common stock warrants, term		10 years
Common stock warrants, exercise price | $ / shares		$ 0.60
Common stock warrants, premium percentage		33.00%
Common stock warrants, fair value per share | $ / shares		$ 0.41
Stock-based compensation | $		$ 6,868
Common stock warrants, vested		40,000
Agreement termination date							Aug. 04, 2015
Common stock warrants cancelled	60,000
2005 Equity Incentive Plan [Member] | Consultant [Member] | Warrants Vested Over Three Quarters [Member]
Stockholders Equity [Line Items]
Common stock warrants, vested		60,000
Stockholder Rights Plan [Member]
Stockholders Equity [Line Items]
No of right for each share | Right						1
Description of event for occurrence of right							Acquisition of, 15% or more of our common stock
Portion of newly created Series A Preferred Stock for each Right						0.001
Series A Junior Participating Preferred Stock , Exercise Price | $ / shares						$ 40.00
Expiration of plan							Jul. 10, 2016
Non-qualified Stock Options [Member] | Directors [Member]
Stockholders Equity [Line Items]
Options expiration term				7 years
Stock-based compensation | $				$ 262
Non-qualified stock options issued to directors				10,000
Options exercise price per share | $ / shares				$ 0.19
Stock options fair value per share | $ / shares				$ 0.14
Series A Preferred Stock [Member] | Stockholder Rights Plan [Member]
Stockholders Equity [Line Items]
Redemption of right | $ / Right						0.001