ACHN 2018 Proxy Statement

OPTION EXERCISES AND STOCK VESTED IN 2017 Option Awards Name Number of Shares Acquired on Exercise (#) Value Realized on Exercise ($)(1) Milind Deshpande, Ph.D. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . — — Director and Chief Executive Officer Mary Kay Fenton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Executive Vice President, Chief Financial Officer and Treasurer Martha Manning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . — — Executive Vice President, General Counsel and Corporate Secretary Joseph Truitt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . — — President and Chief Operating Officer David Apelian, M.D., Ph.D. (2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . — — Former Executive Vice President and Chief Medical Officer Joel Barrish, Ph.D. (3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . — — Former Executive Vice President and Chief Scientific Officer (1) Calculated by multiplying the number of shares times the difference of the market price of the stock on the date of exercise less the exercise price. (2) Dr. Apelian ceased to be an employee on December 28, 2017. (3) Dr. Barrish ceased to be an employee on July 14, 2017. Employment Agreements and Potential Payments Upon Termination or Change in Control We have entered into employment agreements with each of Drs. Deshpande, Apelian and Barrish, Mr. Truitt, Ms. Fenton and Ms. Manning. These employment agreements generally provide base salary in an amount annually reviewable for increase, but not decrease, at the discretion of our Board of Directors or a committee of the Board of Directors. The employment agreements also entitle each officer to receive an annual cash performance bonus in an amount that is expressed as a percentage of base salary if the Board of Directors in its discretion determines that such officer has achieved or surpassed performance goals established by the Board of Directors or Compensation Committee in consultation with our management. For 2017, the target bonus percentage was 60% for Dr. Deshpande, 40% for Ms. Fenton, 40% for Mr. Truitt, 40% for Dr. Apelian, 40% for Dr. Barrish, and 35% for Ms. Manning. Dr. Apelian ceased to be an employee on December 28, 2017. Dr. Barrish ceased to be an employee on July 14, 2017. Each officer is also eligible to participate in any of our equity incentive programs. In addition, each officer’s employment agreement provides for severance benefits in the event Achillion terminates such officer’s employment for reasons other than cause (as defined in their respective employment agreements), death or disability, or they terminate their employment for good reason (as defined in their respective employment agreements). In addition, if, within one year following a change in control of Achillion, such officer’s employment is terminated without cause or if such officer terminates his or her employment for good reason, the officer is entitled to additional change-in-control benefits. The obligation of the Company to make the payments following a termination of employment as described above, is conditioned upon the Executive signing and delivering to the Company a severance and release of claims agreement (which will include, at a minimum, a release of all releasable claims and non-disparagement and cooperation obligations). For additional information about our executive compensation program generally and the terms of our employment agreements with our named executive officers, including officer base salaries, target bonus amounts, target option awards, option awards actually granted and severance and change in control benefits, please see the section of this proxy statement entitled “Compensation Discussion and Analysis.” 50