MNKD 2018 Proxy Statement

MANNKIND CORPORATION 30930 Russell Ranch Road, Suite 301 Westlake Village, California 91362 (818) 661-5000 PROXY STATEMENT FOR THE 2018 ANNUAL MEETING OF STOCKHOLDERS To be held on May 16, 2018 QUESTIONS AND ANSWERS ABOUT THESE PROXY MATERIALS AND VOTING Why did I receive a notice regarding the availability of proxy materials on the internet? Pursuant to rules adopted by the Securities and Exchange Commission (the “SEC”), we have elected to provide access to our proxy materials over the internet. Accordingly, we have sent you a Notice of Internet Availability of Proxy Materials (the “Notice”) because the Board of Directors (sometimes referred to as the “Board”) of MannKind Corporation (sometimes referred to as, “we,” “us,” the “Company” or “MannKind”) is soliciting your proxy to vote at the 2018 Annual Meeting of Stockholders (the “Annual Meeting”), including any adjournments or postponements of the Annual Meeting. You are invited to attend the annual meeting to vote on the proposals described in this proxy statement. However, you do not need to attend the meeting to vote your shares. All stockholders will have the ability to access the proxy materials on the website referred to in the Notice or request to receive a printed set of the proxy materials. Instructions on how to access the proxy materials over the internet or to request a printed copy may be found in the Notice. The Notice is expected to be first mailed to our stockholders of record entitled to vote at the Annual Meeting on or about April 4, 2018. Will I receive any other proxy materials by mail? We may send you a proxy card, along with a second Notice, on or after April 14, 2018. Who can vote at the Annual Meeting? Only stockholders of record at the close of business on March 19, 2018 (the “record date”) will be entitled to vote at the Annual Meeting. On this record date, there were 123,011,353 shares of common stock outstanding and entitled to vote. Stockholder of Record: Shares Registered in Your Name If on the record date your shares were registered directly in your name with MannKind’s transfer agent, Computershare, then you are a stockholder of record. As a stockholder of record, you may vote in person at the meeting or vote by proxy. Whether or not you plan to attend the Annual Meeting, we urge you to vote by proxy pursuant to the instructions set forth below to ensure your vote is counted. Beneficial Owner: Shares Registered in the Name of a Broker or Bank If on the record date your shares were held, not in your name, but rather in an account at a brokerage firm, bank, dealer, or other similar organization, then you are the beneficial owner of shares held in “street name” and Notice is being forwarded to you by that organization. The organization holding your account is considered to be the stockholder of record for purposes of voting at the Annual Meeting. As a beneficial owner, you have the right to direct your broker or other agent on how to vote the shares in your account. You are also invited to attend the Annual Meeting. However, because you are not the stockholder of record, you may not vote your shares in person at the Annual Meeting unless you request and obtain a valid proxy from your broker or other agent. 1