UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 17, 2012

MannKind Corporation

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (661) 775-5300

N/A

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

(e) At our 2012 Annual Meeting of Stockholders held on May 17, 2012 (the “Annual Meeting”), our stockholders approved an amendment to our 2004 Equity Incentive Plan (the “Plan”) to increase the maximum number of shares of common stock authorized for issuance under the Plan from 25,000,000 shares to 35,000,000 shares and re-approved the Plan for purposes of Section 162(m) of the U.S. Internal Revenue Code.

A more detailed summary of the material features of the Plan is set forth in our definitive proxy statement for the Annual Meeting, filed with the Securities and Exchange Commission on April 6, 2012 (the “Proxy Statement”). The foregoing summary does not purport to be complete and is qualified in its entirety by reference to the Proxy Statement and the full text of the Plan, which is attached hereto as Exhibit 99.1 and incorporated herein by reference.

Equity Awards to Executives

On May 17, 2012, the Compensation Committee of the Board of Directors granted to the Company’s named executive officers options to purchase the Company’s common stock (“Options”) under the Company’s Amended and Restated 2004 Equity Incentive Plan (as amended, the “Plan”), which are subject to vesting as indicated below. The Options are evidenced by a form of Stock Option Agreement which, together with the Plan, set forth the terms and conditions of the Options. The Options have an exercise price of $1.69 per share, which is equal to the fair market value of the Company’s common stock on the date of grant.

The following table sets forth the Options granted to each of our named executive officers:

The foregoing is only a brief description of the material terms of the Options granted to the named executive officers on May 17, 2012, does not purport to be complete and is qualified in its entirety by reference to the Plan and the form of Stock Option Agreement under the Plan, which we have previously filed with the Securities and Exchange Commission.

The following is a brief description of each matter voted upon at the Annual Meeting, as well as the number of votes with respect to each matter.

(d) Exhibits. The following exhibit is filed herewith:

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Dated: May 22, 2012