MEI Pharma Announces Expansion of Phase 1b Study Evaluating Zandelisib and Clinical Pipeline Update

SAN DIEGO, Jan. 4, 2021 /PRNewswire/ -- MEI Pharma, Inc. (NASDAQ: MEIP), a late-stage pharmaceutical company focused on advancing new therapies for cancer, today announced that the Phase 1b trial arm exploring zandelisib, an investigational selective phosphatidylinositol 3-kinase ("PI3K") delta inhibitor, in combination with zanubrutinib (marketed as BRUKINSA®), an inhibitor of Bruton's tyrosine kinase ("BTK") developed by BeiGene, Ltd. ("BeiGene"), completed the safety evaluation stage in patients with B-cell malignancies and is expanding into disease specific B-cell malignancy cohorts. The Safety Review Committee recommended moving forward with a dosing regimen found to be generally well tolerated and active following a planned safety analysis.

"Inhibition of the PI3K and BTK pathways with combination therapy is believed to present a promising opportunity for inducing a robust and durable response against various B-cell malignancies," said Richard Ghalie, M.D., senior vice president, clinical development, of MEI Pharma. "The intermittent dosing schedule and unique therapeutic profile of zandelisib makes it an attractive option for combination therapy. We are encouraged that the data to date supported the recommendation of the Safety Review Committee to move forward with the expansion cohorts, initially in follicular and mantle cell lymphomas, and we look forward to further exploring the potential of this and other combinations of zandelisib in patients with various B-cell malignancies with our global development partner, Kyowa Kirin."

A Series of Important Pipeline Updates in 2021
MEI Pharma also provided an update on pipeline programs and anticipated milestones for 2021 for zandelisib, voruciclib and ME-344.

Zandelisib - PI3K delta inhibitor for the treatment of various B-cell malignancies

    --  Completion of enrollment in the Phase 2 TIDAL study evaluating
        zandelisib as a monotherapy for patients with relapsed or refractory
        follicular lymphoma anticipated around the end of first quarter of 2021,
        subject to the continuing impact of the COVID-19 pandemic
    --  Initiation of a second arm in the Phase 2 TIDAL study enrolling patients
        with relapsed or refractory marginal zone lymphoma anticipated in the
        first quarter of 2021
    --  Initiation of the Phase 3 study of zandelisib in combination with
        rituximab evaluating follicular and marginal zone lymphoma patients who
        received one or more prior lines of treatment anticipated in mid-2021;
        this study is intended to act as the required confirmatory study for the
        potential accelerated approval of zandelisib in patients with relapsed
        or refractory follicular lymphoma
    --  Clinical updates for the Phase 1b study of zandelisib, including the
        combination with zanubrutinib, anticipated in mid-2021
    --  Top line clinical data from the Phase 2 TIDAL study anticipated in the
        fourth quarter of 2021

Voruciclib - CDK9 inhibitor for the treatment of B-cell malignancies and acute myeloid leukemia

    --  Program updates, including data from the Phase 1 program evaluating
        voruciclib in combination with venetoclax, anticipated in 2021

ME-344 - tumor selective mitochondrial inhibitor

    --  Update plans for a potential Phase 2 pilot study of ME-344 in solid
        tumors anticipated by year-end 2021

MEI Pharma also confirmed today that it has a cash runway to fund operations through calendar year 2023.

H.C. Wainwright BIOCONNECT 2021 Virtual Conference Presentation
MEI Pharma will present at the H.C. Wainwright BIOCONNECT 2021 Virtual Conference. The presentation will provide a company overview and business update and will be available for on-demand listening beginning Monday January 11, 2020 at 6:00 a.m. Eastern Time. The presentation can be accessed on the Events & Presentations page of the Investors section of MEI Pharma's website at http://www.meipharma.com.

About Zandelisib
Zandelisib (formerly called ME-401) is an investigational oral phosphatidylinositol 3-kinase ("PI3K") delta inhibitor in clinical development for the treatment of patients with B-cell malignancies. In March 2020 the U.S. FDA granted zandelisib Fast Track designation.

PI3K delta is often overexpressed in cancer cells and plays a key role in the proliferation and survival of hematologic cancers. Zandelisib displays high selectivity for the PI3K delta isoform and has distinct pharmaceutical properties from other PI3K delta inhibitors.

Ongoing clinical studies of zandelisib include TIDAL (Trials of PI3K DeltA in Non-Hodgkin's Lymphoma), a global Phase 2 clinical trial evaluating the candidate as a monotherapy for the treatment of adults with relapsed or refractory follicular lymphoma after failure of at least two prior systemic therapies including chemotherapy and an anti-CD20 antibody. Subject to the results, upon completion of the Phase 2 clinical trial, MEI is planning a submission with the FDA to support an accelerated approval of a marketing application under 21 CFR Part 314.500, Subpart H.

Also ongoing is the multicenter, open-label, single-arm pivotal Phase 2 study of zandelisib in patients with indolent B-cell non-Hodgkin's lymphoma (iNHL) without Small lymphocytic lymphoma, lymphoplasmacytic lymphoma (LPL), and Waldenström's macroglobulinemia (WM) in Japan to evaluate zandelisib as a monotherapy for the treatment of Japanese patients with relapsed or refractory iNHL with at least two prior systemic therapies.

In October 2018, MEI entered a clinical collaboration with BeiGene to evaluate the safety and efficacy of zandelisib in combination with BeiGene's zanubrutinib for the treatment of patients with various relapsed or refractory B-cell malignancies. Clinical study costs in the Phase 1b study evaluating the combination are equally shared, and each company is supplying its own investigational agent. MEI retains all commercial rights to zandelisib and BeiGene retains all commercial rights to zanubrutinib.

In April 2020, MEI and Kyowa Kirin Co., Ltd. (Kyowa Kirin) entered a global license, development, and commercialization agreement to further develop and commercialize zandelisib. MEI and Kyowa Kirin are co-developing and co-promoting zandelisib in the U.S., with MEI booking all revenue from the U.S. sales. Kyowa Kirin has exclusive commercialization rights outside of the U.S.

In May 2020, updated data from the Phase 1b study of zandelisib was presented at the American Society of Clinical Oncology (ASCO) 2020 Virtual Scientific Program. These data evaluating patients on an intermittent dosing schedule showed that treatment was generally well tolerated and demonstrated an 83% overall response rate in patients with relapsed or refractory follicular lymphoma. Responses appeared durable: median duration of response was not yet reached after median follow-up of 13.2 months (range: 3.0-27.6).

About MEI Pharma
MEI Pharma, Inc. (Nasdaq: MEIP) is a late-stage pharmaceutical company focused on developing potential new therapies for cancer. MEI Pharma's portfolio of drug candidates contains four clinical-stage assets, including zandelisib, currently in an ongoing Phase 2 clinical trial which may support an accelerated approval marketing application with the U.S. Food and Drug Administration. Each of MEI Pharma's pipeline candidates leverages a different mechanism of action with the objective of developing therapeutic options that are: (1) differentiated, (2) address unmet medical needs and (3) deliver improved benefit to patients either as standalone treatments or in combination with other therapeutic options. For more information, please visit www.meipharma.com and follow us on Twitter and LinkedIn.

Forward-Looking Statements
Under U.S. law, a new drug cannot be marketed until it has been investigated in clinical studies and approved by the FDA as being safe and effective for the intended use. Statements included in this press release that are not historical in nature are "forward-looking statements" within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. You should be aware that our actual results could differ materially from those contained in the forward-looking statements, which are based on management's current expectations and are subject to a number of risks and uncertainties, including, but not limited to, our failure to successfully commercialize our product candidates; costs and delays in the development and or FDA approval, or the failure to obtain such approval, of our product candidates; uncertainties or differences in interpretation in clinical trial results; the impact of the COVID-19 pandemic on our industry and individual companies, including on our counterparties, the supply chain, the execution of our clinical development programs, our access to financing and the allocation of government resources; our inability to maintain or enter into, and the risks resulting from our dependence upon, collaboration or contractual arrangements necessary for the development, manufacture, commercialization, marketing, sales and distribution of any products; competitive factors; our inability to protect our patents or proprietary rights and obtain necessary rights to third party patents and intellectual property to operate our business; our inability to operate our business without infringing the patents and proprietary rights of others; general economic conditions; the failure of any products to gain market acceptance; our inability to obtain any additional required financing; technological changes; government regulation; changes in industry practice; and one-time events. We do not intend to update any of these factors or to publicly announce the results of any revisions to these forward-looking statements.

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SOURCE MEI Pharma, Inc.