Exhibit 99.1

MEI Pharma Reports Third Quarter Fiscal Year 2022 Results and Operational Highlights

—MEI Begins Fourth Fiscal Quarter with $169.0 Million in Cash—

SAN DIEGO – May 23, 2022 – MEI Pharma, Inc. (Nasdaq: MEIP), a late-stage pharmaceutical company focused on advancing new therapies for cancer, today reported results for the quarter ended March 31, 2022, and highlighted recent corporate events.

“The third fiscal quarter of 2022 was underscored by a meeting with the FDA in which we were informed that data from randomized studies are now needed to adequately assess the benefit-risk of PI3K inhibitor drug candidates, including zandelisib, and where it was emphasized that we should continue efforts with the ongoing randomized COASTAL study. Accordingly, we no longer plan to submit an FDA marketing application under the accelerated approval pathway using the single arm TIDAL study. However, we continue to have confidence in zandelisib’s differentiated therapeutic profile as observed in our data generated to date, and remain committed to advancing the program to a marketing authorization submission with our partner, Kyowa Kirin,” said Daniel P. Gold, Ph.D., president and chief executive officer of MEI Pharma.

Dr. Gold continued: “While progression free survival is the primary endpoint for COASTAL, we are actively working with our partner, Kyowa Kirin, to determine if a more expeditious approach exists to bring zandelisib to the market sooner which we will then discuss with the FDA and we will plan to provide an update as appropriate. We remain well capitalized with $169 million to advance our pipeline and continue operations for over two years.”

Third Quarter Fiscal Year 2022 Recent Developments and Financial Highlights

Expected Drug Candidate Pipeline Developments

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

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

ME-344 – Tumor selective mitochondrial inhibitor

Third Quarter Fiscal Year 2022 Financial Results

Restatement of the Company’s 2021 Quarterly Periods

As disclosed in the Current Report on Form 8-K filed with the Securities and Exchange Commission (the “SEC”) on May 13, 2022, the Company determined that it made certain errors in the manner in which it recognized revenue from its License, Development, and Commercialization Agreement with Kyowa Kirin Co., Ltd. (the “KKC Commercialization Agreement”), with the result that revenue was overstated in some quarters and understated in other quarters in the Company’s financial statements during 2020 and 2021. The errors relate to the appropriate timing and amounts of revenue recognized over time under the cost-to-cost method associated with the KKC Commercialization Agreement. These errors and the required restatement had no effect on the Company’s previously reported operating expenses, cash flows or cash and short-term investments. The cumulative effect of these errors was a misstatement of deferred revenue and accumulated deficit of $3.9 million. As a result, the Company restated its previously filed annual and quarterly financial statements for periods from June 30, 2020 forward, which were

included in the Annual Report on Form 10-K/A for the fiscal year ended June 30, 2021 and Quarterly Reports of Form 10-Q/A for the quarters ended September 30, 2021 and December 31, 2021, filed with the SEC today. For more information concerning the restatement, please see those filings.

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 multiple clinical-stage assets, including zandelisib, currently in ongoing clinical trials which may support marketing approvals with the U.S. Food and Drug Administration and other regulatory authorities globally. 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. Follow us on Twitter @MEI Pharma and on 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 including, without limitation, statements regarding: the potential, safety, efficacy, and regulatory and clinical progress of zandelisib and our other product candidates, including the anticipated timing for initiation of clinical trials and release of clinical trial data and our expectations surrounding potential regulatory submissions, approvals and timing thereof, our business strategy and plans; and the sufficiency of our cash, cash equivalents and short-term investments to fund our operations. 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; the availability or appropriateness of utilizing the FDA’s accelerated approval pathway for our product candidates; final data from our pre-clinical studies and completed clinical trials may differ materially from reported interim data from ongoing studies and trials; 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; adverse effects on the Company’s business as a result of the restatement of our previously issued financial statements; 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.

Non-GAAP Financial Measures

To supplement our consolidated financial statements, which are prepared and presented in accordance with generally accepted accounting principles in the United States (“GAAP”), we provide investors with a non-GAAP financial measure, adjusted net loss, which we believe is helpful to our investors. We use adjusted net loss for financial and operational decision-making purposes and as a means to evaluate period-to-period comparisons. We believe this non-GAAP financial measure provides useful information about our operating results, enhances the overall understanding of past financial performance and future prospects and allows for greater transparency with respect to metrics used by our management in its financial and operational decision-making.

The presentation of adjusted net loss is not meant to be considered in isolation or as a substitute for net loss, the directly comparable financial measure prepared in accordance with GAAP. While we believe adjusted net loss is an important tool for financial and operational decision-making and for evaluating our own operating results over different periods of time, we urge investors to review the reconciliation of this financial measures to the comparable GAAP financial measures included below, and not to rely on any single financial measure to evaluate our business.

We define adjusted net loss, adjusted to exclude non-cash expenses related to changes in the fair value of the warrants. We have presented adjusted net loss because we believe excluding the non-cash expenses related to changes in the fair value of warrants can produce a useful measure for period-to-period comparisons of our business.

Contacts:

David A. Walsey

MEI Pharma

Tel: 858-369-7104

investor@meipharma.com

Jason I. Spark

Canale Communications for MEI

Tel: 619-849-6005

jason.spark@canalecomm.com

MEI PHARMA, INC.

CONDENSED BALANCE SHEETS

(In thousands, except per share amounts)

MEI PHARMA, INC.

CONDENSED STATEMENTS OF OPERATIONS

(In thousands, except per share amounts)

(Unaudited)

MEI PHARMA, INC.

Reconciliation of GAAP Net Loss to Adjusted Net Loss

(In thousands)

(Unaudited)