ACHN 2018 Proxy Statement

Types of Awards; Shares Available for Issuance The Amended and Restated 2015 Plan allows for the issuance of incentive stock options intended to qualify under Section 422 of the Code, nonstatutory stock options, SARs, restricted stock awards, RSUs and other stock- based awards. We refer to these securities as “Awards.” The Amended and Restated 2015 Plan would allow for the issuance of 18,011,357 shares of common stock, plus up to 7,095,612 shares subject to awards granted under the 2006 Plan to the extent that such awards expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right. All of the foregoing share numbers are subject, in the case of incentive stock options, to any limitations under the Code, and are also subject to adjustment upon stock splits, stock dividends, and other specified events. Certain sub-limitations apply to the shares available for issuance under the Amended and Restated 2015 Plan. The maximum number of shares with respect to which Awards may be granted to any participant under the Amended and Restated 2015 Plan may not exceed 1,500,000 shares per fiscal year (subject to adjustment upon stock splits, stock dividends, and other specified events). The maximum value (calculated based on grant date fair value for financial reporting purposes) of shares of common stock subject to Awards granted in any fiscal year to any individual non-employee director, together with the amount of any cash payments made to such non-employee director during such fiscal year, may not exceed $625,000. Subject to adjustment in the event of stock splits, stock dividends or other specified events, any Award that is not a full-value award will be counted against the share limits specified in the Amended and Restated 2015 Plan and the sub-limitations described above related to grants to non-employee directors as 1.2 shares for each one share of common stock subject to such full-value award. A “full-value award” is any Award of restricted stock, RSUs or other stock-based award with a per share price or per unit purchase price lower than 100% of fair market value on the date of grant. To the extent a share that was subject to an Award that counted as one share is returned to the Amended and Restated 2015 Plan, each applicable share reserve will be credited with one share. To the extent that a share that was subject to an Award that counts as 1.2 shares is returned to the Amended and Restated 2015 Plan, each applicable share reserve will be credited with 1.2 shares. For purposes of counting the number of shares available for grant under the Amended and Restated 2015 Plan and the sub-limitations described above: • All shares of common stock covered by SARs will be counted against the number of shares available for grant under the Amended and Restated 2015 Plan and the sub-limitations described above. However, if a SAR is granted in tandem with an option for the same number of shares of common stock and the grant provides that only one such Award may be exercised, only the shares covered by the option will be counted, and the expiration of one in connection with the other’s exercise will not restore shares to the Amended and Restated 2015 Plan. • If any Award (i) expires or is terminated, surrendered or cancelled without having been fully exercised or is forfeited in whole or in part (including as the result of shares of common stock subject to such Award being repurchased by us at the original issuance price pursuant to a contractual repurchase right) or (ii) results in any common stock not being issued (including as a result of a SAR that was settleable either in cash or in stock actually being settled in cash), the unused common stock covered by such Award will be added back to the number of shares available for the future grant of Awards. • Shares of common stock delivered to us by a participant to (i) purchase shares of common stock upon the exercise of an Award or (ii) satisfy tax withholding obligations with respect to any Award (including shares retained from the Award creating the tax obligation) will not be added back to the number of shares available for the future grant of Awards. • Shares of common stock repurchased by us on the open market using the proceeds from the exercise of an Award will not increase the number of shares available for future grant of Awards. 17