On July 23, 2014, Company shareholders approved the Amended 2013 Plan, which provides for the granting of stock options, restricted stock awards, restricted stock units, stock bonus awards and performance-based awards. The Amended 2013 Plan serves as the successor to the 2013 Equity Incentive Plan. There were no option awards under the 2013 Equity Incentive Plan. Under the Amended 2013 Plan, the Company may grant up to 10,000,000 shares of new stock. On September 4, 2015, the Board approved an amendment to the Amended 2013 Plan to increase the number of shares available for issuance under the plan to 15,000,000 shares of common stock. Such amendment will be effective upon the approval of the Company’s stockholders. As of September 30, 2015, the Company had approximately 741,112 of authorized unissued shares reserved and available for issuance.

The stock options are exercisable at no less than the fair market value of the underlying shares on the date of grant, and restricted stock and restricted stock units are issued at a value not less than the fair market value of the common stock on the date of the grant. Generally, stock options awarded are vested in equal increments ranging from two to four years on the annual anniversary date on which such equity grants were awarded. The stock options generally have a maximum term of 10 years. The following table summarizes stock option activity for the Amended 2013 Plan during the nine months ended September 30, 2015:

The following table summarizes unvested stock options as of September 30, 2015:

The Company recognized expenses of $1,753,804 and $3,477,592 relating to stock options issued to employees, non-employees, officers, and directors during the three and nine months ended September 30, 2015, respectively. The Company recognized expenses of $0 and $898,900 relating to common stock issued to employees, non-employees, officers, and directors during the three and nine months ended September 30, 2015. For the three and nine months ended September 30, 2015, stock-based compensation of $1,746,440 and $3,448,715, was expensed to selling, general and administration, respectively. For the three and nine months ended September 30, 2015, stock-based compensation of $7,364 and $28,877, was expensed to research and development, respectively. As of September 30, 2015, total unrecognized compensation cost related to non-vested stock-based compensation arrangements granted to employees, officers, and directors was $4,491,433, which is expected to be recognized over a weighted-average period of 2.16 years. There was no stock-based compensation expense for the three and nine months ended September 30, 2014.