Performance-Based Restricted Stock Units
On March 20, 2017, the Company granted to certain employees a total of 49,332 performance-based restricted stock units (“PSUs)”. These PSUs vest upon the achievement of certain regulatory and manufacturing milestones. If the milestones do not occur on or before the three-year anniversary of the grant date, all unvested PSUs will be cancelled. As of September 30, 2017, all 49,332 of these PSUs were outstanding, none had vested and the weighted average grant date fair value of all shares was $79.75 per share. The Company has not yet recognized any PSU-related stock-based compensation as regulatory and manufacturing milestones have not yet been met; however, in the event the performance conditions are met, $3.9 million of research and development compensation expense will be recognized by the Company. There were no PSUs issued and outstanding during the nine months ended September 30, 2016.
Restricted Stock Granted to Non-Employees
In January 2014, the Company issued 2,334,391 shares of restricted common stock to Dr. Brian Kaspar pursuant to a consulting agreement for scientific advisory services. Of these shares, 583,597 common shares were vested at the time of grant and the remaining restricted shares were scheduled to vest in the amount of 25% per year on the second, third and fourth anniversary of the grant date pursuant to a restricted stock purchase agreement, which became effective upon the effectiveness of the consulting agreement.
In January 2016, the Company entered into an employment agreement with Dr. Kaspar. Upon the effectiveness of the employment agreement, Dr. Kaspar’s 1,750,794 unvested shares granted pursuant to the restricted stock purchase agreement vested in full. As a result of the vesting of the remainder of this award the Company recorded $10.4 million of additional stock-based compensation expense during the year ended December 31, 2016.
Warrants Granted to Non-Employees
During the nine month period ended September 30, 2017, there were no warrants exercised and as a result no proceeds received by the Company. As of September 30, 2017, there were 305,775 common stock warrants vested and outstanding issued to non-employees with a weighted-average exercise price of $2.57.
7.Net Loss Per Common Share
Basic net loss per common share is computed using the weighted average number of common shares outstanding during the period. Diluted net loss per common share is computed using the sum of the weighted average number of common shares outstanding during the period and, if dilutive, the weighted average number of potential shares of common stock, including the assumed exercise of stock options, stock warrants and unvested restricted common stock.
The Company applies the two-class method to calculate its basic and diluted net loss per share attributable to common stockholders, as its preferred stock and common stock are participating securities. The two-class method is an earnings allocation formula that treats a participating security as having rights to earnings that otherwise would have been available to common stockholders. However, the two-class method does not impact the net loss per share of common stock as the Company was in a net loss position for each of the periods presented. For the three and nine month periods