ACHN 2018 Proxy Supplement

INFORMATION ABOUT EXECUTIVE AND DIRECTOR COMPENSATION Following Dr. Deshpande’s cessation of service as Chief Executive Officer, it is anticipated that Dr. Deshpande will provide certain scientific advisory and other consulting services to the Company for a one year period following the end of his employment. Dr. Deshpande will not receive cash compensation for and during such services, but all of Dr. Deshpande’s stock options granted to him during his employment with the Company will continue to vest and be exercisable in accordance with the terms of the option agreements governing such stock options. In connection with Mr. Truitt’s appointment as Chief Executive Officer, the Company entered into a second amended and restated employment agreement with Mr. Truitt, which became effective on May 1, 2018, superseding his previous employment agreement dated August 4, 2017. The term of Mr. Truitt’s employment under his second amended and restated employment agreement ends on December 31, 2018 and is automatically renewable after such initial term for successive one-year periods unless either the Company or Mr. Truitt provide written notice to the other at least six months prior to the expiration of the applicable term. Under the agreement, Mr. Truitt receives an annualized base salary of $560,000, subject to adjustment at the discretion of our Board of Directors. In addition, Mr. Truitt is eligible to receive an annual performance bonus at a target rate of 55% of his annualized base salary, based on the Company’s achievement of performance goals for the applicable fiscal year and Mr. Truitt’s achievement of his performance goals for such year, both as determined by our Board of Directors. Mr. Truitt is also entitled to reimbursement for expenses he incurs commuting between his residence and the Company’s headquarters (on a grossed up basis), as well as participation in all benefit programs that the Company establishes and makes available to its executives, to the extent that he is eligible under the plan documents governing those programs. In the event the Company terminates Mr. Truitt’s employment for reasons other than cause, death or disability, or if he terminates his employment for good reason (as defined in his second amended and restated employment agreement), in each case other than during the period 60 days prior to or within twelve months following a change in control of the Company and subject to Mr. Truitt entering into a severance and release of claims agreement, Mr. Truitt is entitled to receive (i) his salary in effect on the date of termination until the date that is eighteen months following the termination date; (ii) if he is eligible for and elects to receive COBRA continuation, payment of the premiums for his medical or dental insurance benefits for eighteen months or, if earlier, the expiration of his COBRA continuation coverage; (iii) a payment equal to a pro-rated portion of his target bonus for the fiscal year in which termination occurred; and (iv) immediate vesting and exercisability of 25% of the original number of shares subject to unvested option grants and unvested grants of restricted stock and restricted stock units (if any are outstanding). In the event such termination occurs during the period 60 days prior to or within twelve months following a change in control of the Company, and subject to Mr. Truitt entering into a severance and release of claims agreement, then Mr. Truitt will receive (i) his salary in effect on the date of termination until the date that is eighteen months following the termination date, (ii) if he is eligible for and elects to receive COBRA continuation, payment of the premiums for his medical or dental insurance benefits for eighteen months or, if earlier, the expiration of his COBRA continuation coverage; and (iii) a payment equal to 150% his target bonus for the fiscal year in which termination occurred, and his equity will vest as described in the next paragraph. In addition to the benefits described above, upon a change in control, Mr. Truitt is entitled to immediate vesting and exercisability of 50% of the original number of shares subject to unvested option grants and unvested grants of restricted stock and restricted stock units (if any are outstanding). In the event the Company terminates Mr. Truitt’s employment for reasons other than cause, death or disability, or if Mr. Truitt terminates his employment for good reason, during the period 60 days prior to or within twelve months following a change in control of the Company, then Mr. Truitt is entitled to immediate vesting and exercisability of all outstanding unvested option grants and unvested grants of restricted stock and restricted stock units. If Mr. Truitt’s employment were to terminate due to his death, Mr. Truitt’s estate would be entitled to 12 months of his salary in effect on the date of his death. In addition, Mr. Truitt’s amended and restated employment agreement provides that, subject to approval by our Compensation Committee, Mr. Truitt will be granted an option to purchase 632,000 shares of the Company’s common stock, such option to (i) have an exercise price per share equal to the closing price per share of the Company’s common stock on the Nasdaq Global Select Market on the date of grant and (ii) vest and become exercisable, subject to Mr. Truitt’s continued service on each applicable vesting date, at a rate of 25% of the total shares underlying the option on the first anniversary of the date of grant and as to an additional 6.25% of the total shares underlying the grant at the end of each full calendar quarter thereafter. Mr. Truitt receives no compensation for serving as a member of the Board of Directors.