5. Stock-Based Compensation

3 Months Ended

Mar. 31, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation

Stock Options

Opexa accounts for stock-based compensation, including options and nonvested shares, according to the provisions of FASB ASC 718, "Share Based Payment.” During the three months ended March 31, 2016, Opexa recognized stock-based compensation expense of $153,853. Unamortized stock-based compensation expense as of March 31, 2015 amounted to $1,471,941.

Stock Option Activity

 A summary of stock option activity for the three months ended March 31, 2016 is presented below:

	Number of Shares			Weighted Avg. Exercise Price		Weighted Average Remaining Contract Term (# years)		Intrinsic Value
Outstanding at December 31, 2015		417,404		$	18.04
Granted		—			—
Exercised		—			—
Forfeited and canceled		(22,063	)		7.79
Outstanding at March 31, 2016		395,341		$	18.61		7.4	$	—
Exercisable at March 31, 2016		261,469		$	21.81		6.9	$	—

Employee Options, Non-Employee Options and Restricted Stock Awards:

Option awards are granted with an exercise price equal to the market price of Opexa’s stock at the date of issuance, generally have a ten-year life, and have various vesting dates that range from no vesting or partial vesting upon date of grant to full vesting on a specified date. Opexa estimates the fair value of stock options using the Black-Scholes option-pricing model and records the compensation expense ratably over the service period.

No option or restricted stock awards were granted during the three months ended March 31, 2016.  During the three months ended March 31, 2016, options to purchase 22,063 shares of common stock were forfeited and cancelled.

Opexa recognized stock based compensation expense of $153,853 and $266,954 during the three months ended March 31, 2016 and March 31, 2015, respectively, for grants made to employees in prior periods.

Warrant Activity

A summary of warrant activity for the three months ended March 31, 2016 is presented below:

	Number of Shares			Weighted Avg. Exercise Price		Weighted Average Remaining Contract Term (# years)		Intrinsic Value
Outstanding at December 31, 2015		3,662,954		$	6.30
Granted		—			—
Exercised		—			—
Forfeited and canceled		(51,823	)		83.52
Outstanding at March 31, 2016		3,611,131		$	5.19		1.96	$	—
Exercisable at March 31, 2016		3,611,131		$	5.19		1.96	$	—

In connection with the amended stock purchase agreement entered in on March 14, 2016 (See Note 4), the Company also amended and restated the Series N Warrants to purchase shares of the Company’s common stock previously issued to the Purchasers, and extend the expiration date of the Series N Warrants by six months (i.e., from April 9, 2018 to October 9, 2018).  The Company determined that there is no accounting impact to the modification of the Series N warrants since these are investor warrants.