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): November 19, 2012

MEI Pharma, Inc.

(Exact name of registrant as specified in its charter)

11975 El Camino Real, Suite 101, San Diego, California 92130

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: (858) 792-6300

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

On November 19, 2012, Novogen Limited (“Novogen”) provided MEI Pharma, Inc. (the “Company”) written notice of conversion with respect to all of the 1,000 shares (the “Preferred Shares”) of the Company’s outstanding Series A Convertible Preferred Stock held by Novogen. In accordance with the terms of the Preferred Shares, on November 20, 2012, the Company issued to Novogen 4,827,000 shares of the Company’s common stock, par value $0.00000002 per share. As previously disclosed, the Preferred Shares were issued to Novogen by the Company in May 2011 pursuant to the Asset Purchase Agreement, dated December 21, 2010, between the Company and Novogen.

The information set forth in Item 5.07 below is incorporated by reference into this Item 5.03.

On November 16, 2012, the board of directors of the Company approved, subject to stockholder approval, a modification to the terms of the previously announced reverse stock split that the Company intends to effect by the filing of an amendment (the “Amendment”) to the Company’s Restated Certificate of Incorporation. The modifications will permit the Company to effect the reverse stock split at a ratio between 1-for-2 and 1-for-10, with the exact ratio to be determined by the board of directors in its discretion subsequent to the effectiveness of the approval of the reverse stock split by the Company’s stockholders. On November 19, 2012, Novogen, as holder of a majority of the Company’s outstanding common stock, executed a written consent approving the modifications to the terms of the reverse stock split, which approval will become effective 20 days after the Company has mailed a definitive information statement to its stockholders.

The Company expects that the Reverse Stock Split will become effective in December 2012; however, there can be no assurance that the Reverse Stock Split will be consummated or that it will achieve its intended effects. The Company reserves the right, in its discretion, to abandon the Reverse Stock Split at any time prior to filing the Amendment with the Delaware Secretary of State.

The Company will file the definitive information statement with the SEC which will provide additional important information concerning the Reverse Stock Split, including the text of the certificate of amendment to the Company’s certificate of incorporation. The Company will mail the definitive information statement to stockholders when completed. The Company’s stockholders will be able to obtain, without charge, a copy of the definitive information statement and other relevant documents filed with the SEC from the SEC’s website at http://www.sec.gov. The Company’s stockholders will also be able to obtain, without charge, a copy of the definitive information statement and other relevant documents (when available) by directing a request by mail or telephone to MEI Pharma, Inc., 11975 El Camino Real, Suite 101, San Diego, California 92130, Attn: Investor Relations, telephone: (858) 792-6300, or from the Company’s website, www.meipharma.com.

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: November 21, 2012