The Company’s Amended 2013 Plan provides for the granting of stock options, restricted stock awards, restricted stock units, stock bonus awards and performance-based awards. As of September 30, 2016, the Company had 3,075,224 of authorized unissued shares reserved and available for issuance upon exercise and conversion of outstanding awards under the Amended 2013 Plan.

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, 2016:

The following table summarizes unvested stock options as of September 30, 2016:

The Company recognized expenses of $539,976 and $1,753,804 relating to stock options and warrants issued to employees, consultants, officers, and directors during the three months ended September 30, 2016 and 2015, respectively. The Company recognized expenses of $1,357,684 and $3,477,592 relating to stock options and warrants issued to employees, consultants, officers, and directors during the nine months ended September 30, 2016 and 2015, respectively. The Company recognized expenses of $108,001 and $0 relating to common stock issued to employees, consultants, officers, and directors during the three months ended September 30, 2016 and 2015, respectively. The Company recognized expenses of $541,126 and $0 relating to common stock issued to employees, consultants, officers, and directors during the nine months ended September 30, 2016 and 2015, respectively. For the three months ended September 30, 2016 and 2015, stock-based compensation of $647,977 and $1,746,440, was expensed to selling, general and administration, respectively. For the nine months ended September 30, 2016 and 2015, stock-based compensation of $1,898,810 and $3,448,715, was expensed to selling, general and administration, respectively. For the three months ended September 30, 2016 and 2015, stock-based compensation of $0 and $7,364, was expensed to research and development, respectively. For the nine months ended September 30, 2016 and 2015, stock-based compensation of $0 and $28,877, was expensed to research and development, respectively. As of September 30, 2016, total unrecognized compensation cost related to non-vested stock-based compensation arrangements granted to employees, officers, and directors was $2,427,741, which is expected to be recognized over a weighted-average period of 1.80 years.