ACHN 2018 Proxy Statement

(10) Represents $348 of life insurance premiums paid by Achillion and $7,950 in matching company contributions pursuant to Achillion’s 401(k) defined contribution plan. (11) Represents $457 of life insurance premiums paid by Achillion, $8,100 in matching company contributions pursuant to Achillion’s 401(k) defined contribution plan, $20,000 for travel and living expense reimbursement incurred as a result of Ms. Manning’s commuting from Pennsylvania to our offices in Connecticut and $17,328 for a tax gross-up payment to reimburse her for the federal and state income taxes associated with receipt of the reimbursement. (12) In connection with his promotion to Executive Vice President and Chief Operating Officer in September 2017, Mr. Truitt’s annual base salary was increased from $382,130 to $408,200. (13) Represents $348 of life insurance premiums paid by Achillion, $7,950 in matching company contributions pursuant to Achillion’s 401(k) defined contribution plan, $11,175 for travel and living expense reimbursement incurred as a result of Mr. Truitt’s commuting from Pennsylvania to our offices in Connecticut and $8,746 for a tax gross-up payment to reimburse him for the federal and state income taxes associated with receipt of the reimbursement. (14) Dr. Apelian ceased to be an employee on December 28, 2017. Dr. Apelian’s annual base salary for 2017 was $500,065. (15) Because Dr. Apelian ceased to be an employee of the company on December 28, 2017, he did not receive a discretionary cash performance-based bonus awards for 2017 performance. (16) Represents $457 of life insurance premiums paid by Achillion, $17,400 for travel and living expense reimbursement incurred as a result of Dr. Apelian’s commuting from New Jersey to our offices in Connecticut and $14,925 for a tax gross-up payment to reimburse him for the federal and state income taxes associated with receipt of the reimbursement. (17) Represents $360 of life insurance premiums paid by Achillion, $17,400 for travel and living expense reimbursement incurred as a result of Dr. Apelian’s commuting from New Jersey to our offices in Connecticut and $14,892 for a tax gross-up payment to reimburse him for the federal and state income taxes associated with receipt of the reimbursement. (18) Represents $348 of life insurance premiums paid by Achillion, $17,400 for travel and living expense reimbursement incurred as a result of Dr. Apelian’s commuting from New Jersey to our offices in Connecticut and $14,592 for a tax gross-up payment to reimburse him for the federal and state income taxes associated with receipt of the reimbursement. (19) Dr. Barrish ceased to be an employee on July 14, 2017. Dr. Barrish’s annual base salary for 2017 was $453,200. (20) Because Dr. Barrish ceased to be an employee of the company on July 14, 2017, in accordance with the terms of Dr. Barrish’s employment agreement, upon his termination, Dr. Barrish repaid $100,000 of the sign on bonus originally paid to him upon commencement of his employment in January 2016. (21) Represents $267 of life insurance premiums paid by Achillion, $8,100 in matching company contributions pursuant to Achillion’s 401(k) defined contribution plan, $10,000 for travel and living expense reimbursement incurred as a result of Dr. Barrish’s commuting from Pennsylvania to our offices in Connecticut and $8,769 for a tax gross-up payment to reimburse him for the federal and state income taxes associated with receipt of the reimbursement. (22) Dr. Barrish’s employment with the Company commenced in January 2016. Dr. Barrish’s annual base salary was $440,000. (23) Represents stock option awards made in connection with Dr. Barrish’s commencement of employment in January 2016 and his transitioning into his new role. (24) Comprised of a $200,000 sign on bonus in connection with Dr. Barrish’s commencement of employment in January 2016 and the discretionary cash performance-based bonus award approved by the Compensation Committee in January 2017 in connection with our annual performance review process for 2016 performance. Dr. Barrish’s non-equity incentive plan compensation was calculated based on his non pro-rated salary. (25) Represents $360 of life insurance premiums paid by Achillion, $7,950 in matching company contributions pursuant to Achillion’s 401(k) defined contribution plan, $20,000 for travel and living expense reimbursement incurred as a result of Dr. Barrish’s commuting from Pennsylvania to our offices in Connecticut and $17,328 for a tax gross-up payment to reimburse him for the federal and state income taxes associated with receipt of the reimbursement. CEO Pay Ratio As required by Section 953(b) of the Dodd-Frank Wall Street Reform and Consumer Protection Act and Item 402(u) of Regulation S-K, we are required to disclose the ratio of our principal executive officer’s annual total compensation to the annual total compensation of our median employee. During fiscal 2017, the principal executive officer of Achillion was our President and Chief Executive Officer, Milind Deshpande, Ph.D. For 2017, the annual total compensation for Dr. Deshpande, as reported in the Summary Compensation Table, was $2,212,218 , and the annual total compensation for our median employee was $205,705, resulting in a pay ratio of approximately 11:1. 46