MEI Pharma and Kyowa Kirin Announce Discontinuation of Zandelisib
Development Outside of Japan Following Recent FDA Meeting
SAN DIEGO and TOKYO, December 5 and 6, 2022 — MEI Pharma, Inc. (Nasdaq: MEIP), apharmaceutical company focused on advancing new therapies for cancer, and Kyowa Kirin Co.,
Ltd. (Kyowa Kirin, TSE: 4151), a Japan‐based global specialty pharmaceutical company creating
innovative medical solutions utilizing the latest biotechnology, today announced that after
receiving the most recent guidance from a late November meeting with the U.S. Food and DrugAdministration (FDA), the companies are discontinuing global development of zandelisib
outside of Japan for B‐cell malignancies. Kyowa Kirin is continuing the ongoing clinical trials
including Phase 2 MIRAGE study evaluating Japanese patients with relapsed or refractoryindolent B‐cell non‐Hodgkin lymphomas and will explore the potential for a submission toJapanese health authorities based on data from the MIRAGE and TIDAL clinical trials.
“Based on the most recent guidance received from the FDA at a late November meeting, wehave jointly decided with Kyowa Kirin to discontinue development of zandelisib outside ofJapan. We are very disappointed to share this decision in light of our belief in the potential ofzandelisib to benefit patients and meet the ongoing need for new options to treat relapsed or
refractory indolent non‐Hodgkin lymphomas,” said Daniel P. Gold, Ph.D., president and chief
executive officer of MEI Pharma. “However, in light of FDA’s guidance, we no longer believe
clinical development can be completed within a time period that would support furtherinvestment, or with sufficient certainty of the regulatory requirements to justify continued
global development efforts.”“We share MEI’s disappointment in making this decision,” said Yoshifumi Torii, Ph.D., executive
officer, vice president, head of R&D division of Kyowa Kirin. “However, given the Phase 2 data
we previously announced on zandelisib, we still see potential to continue the program in Japanto address unmet patient needs. We are continuing the Japanese clinical trials including Phase 2MIRAGE trial and will consult the PMDA to understand the potential it offers for a regulatory
submission.”
In March 2022, MEI Pharma and Kyowa Kirin reported the outcome of an end of Phase 2
meeting with the FDA wherein the agency discouraged a filing based on the single‐arm Phase 2TIDAL trial evaluating zandelisib in patients with relapsed or refractory follicular lymphoma. At
this meeting, the FDA stated that a randomized trial should be used to support an initial
zandelisib registration in patients with indolent non‐Hodgkin lymphoma and, accordingly, data
generated from single arm studies such as the Phase 2 TIDAL trial are insufficient to adequately
assess the risk/benefit of PI3K inhibitors evaluating indolent non‐Hodgkin lymphoma. At thattime the FDA emphasized that the companies continue efforts with the ongoing randomized
Phase 3 COASTAL trial evaluating patients with relapsed or refractory follicular or marginal zonelymphomas. Subsequently, at an April 2022 meeting of the FDA Oncology Drugs Advisory
Committee, the committee voted that future approvals of PI3K inhibitors for hematologic
malignancies should be supported by randomized data.

In late November 2022, MEI Pharma and Kyowa Kirin met with the FDA in a follow‐up meeting
to the March 2022 end of Phase 2 meeting. At this meeting, FDA provided further guidance
regarding the design and statistical analysis for the COASTAL trial. Following the November
meeting, the companies concluded that a clinical trial consistent with the recent FDA guidance,
including modification of the COASTAL trial, would likely not be feasible to complete within atime period that would support further investment. As a result, global development ofzandelisib for indolent forms of non‐Hodgkin lymphoma, except for Japan, is being
discontinued.
The discontinuation of zandelisib development outside of Japan is a business decision based on
the most recent regulatory guidance from the FDA and is not related to the zandelisib clinicaldata generated to date. Kyowa Kirin is continuing the ongoing clinical trials including Phase 2MIRAGE trial evaluating Japanese patients with relapsed or refractory indolent B‐cell non‐
Hodgkin lymphomas and will explore submitting the MIRAGE and TIDAL trials for marketing
authorization in Japan. MIRAGE is a Phase 2 trial, similar in design to the global Phase 2, single‐arm, TIDAL trial. In November 2022 Kyowa Kirin and MEI announced positive topline data fromthe Phase 2 MIRAGE trial. MEI and Kyowa Kirin plan to immediately start winding‐down
ongoing clinical studies outside of Japan, including the Phase 3 COASTAL trial and the Phase 2
CORAL trial evaluating patients with relapsed or refractory chronic lymphocytic leukemia.
Depending on the achievement of certain regulatory and commercial milestones in Japan, MEI
may be eligible for additional payments from Kyowa Kirin under the current agreement. MEI
may also be entitled to royalties on any sales of zandelisib in Japan.

About zandelisib
Zandelisib, a selective PI3Kδ inhibitor, is an investigational cancer treatment being developed as
an oral, once‐daily, treatment for patients with B‐cell malignancies.
In April 2020, MEI and Kyowa Kirin entered a global license, development, andcommercialization agreement to further develop and commercialize zandelisib. MEI and Kyowa
Kirin were to co‐develop and co‐promote 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.
About MEI Pharma
MEI Pharma, Inc. (Nasdaq: MEIP) is a pharmaceutical company focused on developing potential
new therapies for cancer. MEI Pharma's portfolio of drug candidates includes clinical stage
candidates with differentiated mechanisms of action intended to address unmet medical needs
and 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.
About Kyowa Kirin

Kyowa Kirin strives to create and deliver novel medicines with life‐changing value. As a Japan‐
based global specialty pharmaceutical company with a heritage of more than 70 years, thecompany applies cutting‐edge science, including expertise in antibody research andengineering, to address the needs of patients across multiple therapeutic areas such as
nephrology, oncology, immunology/allergy and neurology. Across its four regions – Japan, Asia
Pacific, North America and EMEA/International – Kyowa Kirin focuses on its purpose, to makepeople smile, and is united by its shared values of commitment to life, teamwork, innovationand integrity. Learn more about the Company at www.kyowakirin.com.
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 includedin 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 of1995 including, without limitation, statements regarding: MEI’s plans to discontinue
development of zandelisib, wind down the currently ongoing clinical studies of zandelisib being
conducted by MEI, , the potential, safety, efficacy, and regulatory and clinical progress of our
product candidates, including the anticipated timing for initiation of clinical trials and release ofclinical 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 ouractual 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 ability to successfully wind down thecurrently ongoing clinical studies of zandelisib; our ability to negotiate a termination of theexisting zandelisib global development and commercialization agreement between MEI andKyowa Kirin and negotiate a license agreement for Japan; our failure to successfullycommercialize our product candidates; final data from our pre‐clinical studies and completedclinical 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 suchapproval, of our product candidates; uncertainties or differences in interpretation in clinical trialresults; adverse effects on the Company's business as a result of the restatement of ourpreviously 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; ourinability 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 businesswithout infringing the patents and proprietary rights of others; general economic conditions; thefailure 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.