20th Annual Needham Virtual Healthcare Conference

NASDAQ: MEIP

April 12, 2021

Forward-Looking Statements

• This presentation contains, and our officers and representatives may from time to time make, statements that are “forward-looking

statements” within the meaning of the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995. Examples of

forward-looking statements include, among others, statements regarding our development strategy; potential advantages of our product

candidates; the initiation and completion of preclinical and clinical studies and the reporting of the results thereof; the timing of regulatory

submissions and actions; the sufficiency of our existing cash; and all other statements relating to our plans, objectives, expectations and

beliefs regarding future performance, operations, financial condition and other future events (including assumptions underlying or

relating to any of the foregoing).

• These forward-looking statements rely on a number of assumptions concerning future events and are subject to a number of risks,

uncertainties, and other factors, many of which are outside of our control. Important factors that could cause our actual results and

financial condition to differ materially from those indicated in forward-looking statements include, among others: uncertainties relating to

the initiation and completion of preclinical and clinical studies; whether preclinical and clinical study results will validate and support the

safety and efficacy of our product candidates; the outcome of regulatory reviews of our product candidates; varying interpretation of

research and development and market data; 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; risks and uncertainties relating to intellectual property and the other factors discussed under the caption “Item

1A. Risk Factors” in our most recent annual report on Form 10-K and our most recent quarterly report on Form 10-Q.

• Any forward-looking statement made by us in this presentation is based only on information currently available to us and speaks only as

of the date on which it is made. In addition, we operate in a highly competitive and rapidly changing environment, and new risks may

arise. Accordingly, you should not place any reliance on forward-looking statements as a prediction of actual results. We disclaim any

intention to, and undertake no obligation to, update or revise any forward-looking statement. You are urged to carefully review and

consider the various disclosures in our most recent annual report on Form 10-K, our most recent Form 10-Q and our other public filings

with the SEC since the filing of our most recent annual report.

2

MEI Pharma: Who We Are

• Clinical Development Company Building a Leading

Oncology Franchise with 4 Clinical-Stage Programs:

Focus On HemOnc

• Zandelisib (f/k/a ME-401) Potential Best-in-Class PI3Kδ

Inhibitor in Phase 2 Study Intended to Support Accelerated

Approval with U.S. FDA

• Well Capitalized with ~$180 Million*

* As of December 31, 2020, MEI had $180.1 million in cash, cash equivalents, and short-term investments with no outstanding debt. 3

PROGRAMS INDICATION COMBINATION PHASE 1/1B PHASE 2 PHASE 3COMMERCIAL

RIGHTS

ZandelisibOral P13K Delta

Inhibitor

Follicular & Marginal

Zone Lymphomas

Relapsed/refractoryMonotherapy

U.S. co-promote;

ex-U.S. Kyowa Kirin

exclusive rights

B-Cell Malignancies

Relapsed/refractory

• Monotherapy

• Rituxan®(rituximab)

• Zanubrutinib2

VoruciclibOral CDK Inhibitor

B-Cell Malignancies

& AML

Relapsed/refractory

• Monotherapy

• Venclexta® (venetoclax)3

ME-344Mitochondrial Inhibitor

Solid Tumors Avastin® (bevacizumab)4

PracinostatHDAC Inhibitor

Myelodysplastic

Syndrome

Treatment-naïve

Vidaza® (azacitidine)

Late-Stage Diversified Clinical Pipeline

TIDAL Study1

Clinical Collaboration

1. Phase 2 study intended to support an accelerated approval marketing applications with FDA. 2. Study arm initiated under clinical collaboration with BeiGene, Ltd. 3. Initiation of clinical studies is subject to opening of a new Investigational New Drug Application with FDA 4. Investigator-initiated trial.

4

Zandelisib: Data Driven Advancement in B-cell

Malignancies

The GapNavigating T-reg mediated toxicity to

achieve clinical potential

Zandelisib: Potential to Bridge the Gap and Realize the Promise of PI3Kδ Inhibition

The Challenge The Promise

6

Zandelisib: Potential to Bridge the Gap and Realize the Promise of PI3Kδ Inhibition

* MEI Pharma clinical and preclinical data on file.

**Zandelisib data reported from ongoing Phase 1b study of 57 patients, including ORR and DOR in r/r FL (36) and other B-cell malignancies (21). Data cutoff presented: April 13, 2020.

The Challenge: The Promise:

7

Zandelisib:

Bridging The Gap

• Binding kinetics• Selective inhibition

• Trough Plasma >EC90

• Tumor penetration

• High volume of distribution

• Tumor Accumulation

Properties Supporting Potential Clinical Profile Optimization*

Realize utility of PI3Kδ

in B-cells but limit

toxicity associated with

target in T-regs

Emerging Zandelisib

Profile*

• High Response Rates

• Durable to Date

• Well-tolerated

Daily

x1 week

(60mg)

No therapy

x3 weeks

Daily dosing x2 cycles

(60mg)

Cycles 1 and 2 IS on Cycles ≥3

• Phase 1b single arm, dose escalation/expansion study with safety and tolerability endpoints*

• Main Eligibility Criteria: ECOG 0‒2, failure of ≥1 prior therapy for B-cell malignancies,

measurable disease, no prior PI3K or BTK therapy

• 57 patients treated on Intermittent Schedule (IS) beginning in Cycle 3

• Treatment groups: 60 mg daily as monotherapy / 60 mg in combination with rituximab

Zandelisib Phase 1b Study: Evaluation of an Intermittent Schedule (IS) to Mitigate Immune-Related Toxicities

8* 120 patients treated to date in this multi-arm study evaluating zandelisib as a monotherapy, or in combination with rituximab or zanubrutinib (NCT02914938)

Zandelisib Phase 1b Study: Key Findings

• Intermittent Schedule yields a high ORR in R/R FL and CLL/SLL

• FL: 76% as monotherapy (n =17) and 89% with rituximab (n=19)

• CLL/SLL: 89% (n=9)

• Median DOR in FL is not reached with a median follow-up 13.2 months

• Durable responses regardless of prior lines of therapy, treatment group

(± rituximab) or tumor bulk

• Treatment dose and schedule appear to be well tolerated

• Low incidence of Grade ≥3 AESI

• No Grade ≥3 AESI reported after Cycle 3

• Discontinuation rate due to adverse events = 7%

9Zelenetz et al, ASCO 2020. Data cutoff: April 13, 2020.

Low Incidence of AESI: No Increased Toxicity Over Time

Gr3 Adverse Events of

Special Interest (AESI)

Diarrhea

Diarrhea

Colitis

2 (3.5%)

2 (3.5%)

Rash, all Types 1 (1.8%)

ALT/AST elevation 1 (1.8%)

Stomatitis 0

Pneumonia / Infectious

pneumonitis0*

Non-infectious pneumonitis 1 (1.8%)

10

• All Grade 3 AESI occurred in Cycles 1-3

• No Grade 4 AESI

Time to First Grade ≥ 3 AESI (N=57)

No. of

Subjects

with Events

Incidence

Rate

Follow-up Time

Median

(min-max)

7 12.2% 12.5 m ( 0.6 – 28.6)

*1 patient with Grade 5 Covid-19 pneumonia in Cycle 15 not included

• Discontinuations due to AEs in 4 patients (7%)

0 2 4 6 8 10 12 14 16 18

Discontinuation Rate: TEAEs (Any Grade)

Zandelisib

BCL2i3

BTKi2

Zandelisib Emerging Profile: Potential for Broad Acceptance Across B-Cell Malignancies & Supports Combinations with Other Modalities

Note: These data are based on cross-trial comparisons and not based on any head-to-head preclinical studies or clinical trials. As a result, the values shown may not be directly comparable and do not report robust comparative analyses. Zandelisib data is from an ongoing Phase 1b study evaluating patients on the intermittent schedule as a monotherapy or in combination with Rituxan® (rituximab). Data cutoff is April 13, 2020

R24

1. Rate of discontinuation due to an adverse reaction from the FDA label for Tazmetostat as indicated for the treatment of follicular lymphoma (n=99). 2 Includes the FDA approved BTK inhibitors: IMBRUVICA (ibrutinib), CALQUENCE® (acalabrutinib) and BRUKINSA® (zanubrutinib). Rates of discontinuation due to an adverse reaction are from the FDA labels for IMBRUVICA (n=1,124), CALQUENCE (n=1,029) and BRUKINSA (n=629), across clinical trials evaluating patients with CLL/SLL, MCL, WM, and MZL. 3. Rates of discontinuation due to an adverse reaction are from the FDA label for VENCLEXTA (Venetoclax®) as indicated for the treatment CLL/SLL (n=758). 4. Rate of discontinuation due to an adverse reaction is from the FDA label for Revlimid® (lenalidomide) as indicated for the treatment of follicular lymphoma and marginal zone (AUGMENT trial: n=176).

8.3% (avg.)(Range: 6.5% - 10.0%)

14.6%

12.5% (avg.)(Range: 9% - 16%)

7.0%

11

8.0%Tazemetostat1

12

Zandelisib at 60 mg

daily x2 cycles (28

Days)

N = 120

Zandelisib at 60 mg for 1

wk on / 3wks off

starting at Cycle 3 until

toxicity or PD If toxicity: Re-challenge

at resolution with IS

• Histologically confirmed diagnosis of FL, Grade 1, 2, or 3a

• FL, relapsed or refractory to 2 prior systemic therapies including an anti-CD20 antibody and chemotherapy

• No prior therapy with PI3Kδ inhibitors

• No histological transformation to an aggressive lymphoma

12

If PD: Change to CS

Phase 2 TIDAL Trial Intended to Support Accelerated Approval Marketing Application – The Initial Opportunity in r/r FL

(NCT03768505)

Expanding Zandelisib Development Activities to Explore Full Potential

• TIDAL study arm evaluating zandelisib monotherapy as ≥3rd line therapy in

marginal zone lymphoma (MZL)

• COASTAL Phase 3 study evaluating zandelisib + rituximab as ≥2nd line therapy in R/R FL and MZL

• Expanding evaluation of combination with zanubrutinib into disease specific B-cell malignancy cohorts

• Japan PMDA registrational Phase 2 study evaluating zandelisib monotherapy in

R/R indolent B-cell lymphoma

• Selective IIT’s (e.g., zandelisib + R-CHOP as 1st line therapy in DLBCL at the Cleveland Clinic)

13

$582Min potential development, regulatory and

commercial milestones

KKC exclusive ex-U.S. rights, MEI to receive escalating tiered royalties starting in teens

U.S. COST SHARING, KKC responsible for incremental ex-U.S. costs

AGREED ON BROAD DEVELOPMENT PLAN for B-cell malignancies

Global License, Development and Commercialization Agreement Optimizes Zandelisib Value (April 2020)

$100M upfront to MEI

50/50U.S. co-promote,

MEI books U.S. sales

14

Market Opportunity

Zandelisib has the Potential to Set the Clinical and Commercial Opportunity Bar for the PI3Kd Class

15

• R/R FL has several treatment

options but no standard of care

Zandelisib Opportunity

15

• PI3Kd inhibitors deliver potent efficacy, but utility limited by the

extensive T-reg mediated toxicity

• PI3Kd inhibitors limited to modest

≥ 3rd Line FL use due to

risk/benefit of current therapies

• Product attributes and novel

treatment schedule could reset

expectations of PI3Kd inhibitors

• Compelling emerging profile

supports best-in-class

opportunity in 3L FL

• Unique zandelisib properties and

combinability could expand utility

to earlier lines of FL and into other

BCMs

Relapsed/Refractory FL: A Significant and Expanding Addressable Market

Company estimates

~15,000: U.S. incidence of

follicular lymphoma

>50% relapse after each

remission

100K: U.S. follicular

lymphoma prevalence

>7,500 U.S. Patients

With Relapsed/Refractory

Follicular Lymphoma

$1B

Addressable

Market

16

ZandelisibConclusion

Multiple

Combination

Regimen

Opportunities

Differentiated

Profile Results in

Best-in-class

Potential

Potential to Meet

Need Across

Multiple B-cell

Malignancies

Zandelisib: Potential to Realize PI3Kδ Promise

17

Voruciclib: Oral CDK Inhibitor with

Potent CDK9 Activity

Voruciclib: Orally Administered CDK Inhibitor with Potent CDK9 Inhibition

Potential Combination Opportunities in Multiple Hematologic and Solid Tumor

Indications

Increased MCL1 is an established

venetoclax resistance mechanism

• Venetoclax inhibits BCL2 but can lead to

stabilization of MCL1

• Voruciclib inhibits MCL1 via CDK9 inhibition

19

CDK9 Regulates MCL1 and MYC

• MCL1 is a pro-survival protein in the BCL-2 family

• MYC is an oncoprotein that drives growth and proliferation in many tumor types

MYC is over expressed in many cancers,

including those with KRAS mutations

• Inhibition of CDK9 leads to reduced transcription

and stability of MYC

• Voruciclib downregulates MYC via CDK9

inhibition

Leveraging CDK9 Regulation of MCL1: Phase 1 Study in R/R B-Cell Malignancies and AML

• Study population• Relapsed/Refractory B-cell Malignancies

• AML After Treatment with Standard Therapy

• Dose escalation with standard 3+3 design

• Endpoints• Safety and tolerability

• Pharmacokinetics

• Biologic correlative studies• BH3 profiling, MCL-1 expression (Dana Farber)

• Molecular mutations analysis (City of Hope)

• Objective response rates

• CR/CRi rate

Voruciclib single agent

dose escalation

Venetoclax + Voruciclib dose

escalation

100

mg

150

mg

200

mg

50

mg

100

mg

150

mg

200

mgV2

20

Leveraging CDK9 Regulation of MYC Transcription and Protein Stability

A. Transcription of MYC B. MYC protein stability

DSIF

HEXIM

NELF

Pol II DSIF Pol II

Inhibitory Complex Cell Stimulatory Signals

Productive elongation of RNA Pol II transcription of target genes

(e.g., MYC, MCL1)

Promoter proximal pausing relieved by PTEFb &

CDK9 activity

KRAS

PI3K

GSK3β

CDK9

P P

PTEFbCDK9

PTEFb

RAF

MEK

MYC

MYC

MYC proteindegradation

by proteasome

SCF-Fbw7Ubiquitin

sotorasibadagrasib

pT58

Pin1

Pin1PP2A

pS62 pS62 pT58

(unstable)

voruciclib

voruciclib

Transcriptionof MYC

(stable)

Transcriptionalactivation of

MYC target genes

MYC MYC

ERK1

CDK9

MePCELARP7

21

Voruciclib Inhibits KRAS Mutant Cell Lines In Vitro and In Vivo in Xenograft Mice

Cell Line Indication KRAS Mut IC50 (µM)

Gp2D CRC G12D 0.8

HCT-116 CRC G13D 1.8

LS-513 CRC G12D 0.6

SW-480 CRC G12V 3.9

SW837 CRC G12C 2.1

KYSE-410 Esoph G12C 1.9

RPMI-8226 MM G12A 2.4

A-549 NSCLC G12S 1.5

Calu-1 NSCLC G12C 2.0

HCC1171 NSCLC G12C 3.0

HCC44 NSCLC G12C 0.8

NCI-H460 NSCLC Q61H 3.1

NCI-H1373 NSCLC G12C 1.2

NCI-H1792 NSCLC G12C 1.4

NCI-H2030 NSCLC G12C 1.1

NCI-H23 NSCLC G12C 1.2

NCI-H358 NSCLC G12C 0.6

TOV-21G Ovarian G13C 1.7

AsPC-1 PDAC G12D 2.3

HPAF-II PDAC G12D 1.9

MIA PaCa-2 PDAC G12C 1.1

Panc 04.03 PDAC G12D 1.4

A. B.

Time (days)

Ave

tum

or

weig

ht

(mg) 600

500

400

100

200

300

0

0 2 4 6 8 10 12 14

1800

1600

1400

1200

1000

800

600

400

200

0

0 2 4 6

Time (days)

Ave

tum

or

weig

ht

(mg)

8 10 12

Control

VOR 100 mg/kg

VOR 50 mg/kg

VOR 200 mg/kg

6000

5000

4000

3000

2000

1000

00 2 4 6

Time (days)

Ave

tum

or

weig

ht

(mg)

8 10 12

Control

VOR 100 mg/kg

VOR 50 mg/kg

VOR 200 mg/kg

Control

VOR 100 mg/kg

VOR 200 mg/kg

HCT-116

(CRC, KRAS G13D)

SW-480

(CRC, KRAS G12V)

H460

(NSCLC, KRAS Q61H)

22

Leveraging CDK9 Regulation of MYC: Exploring Synergy with Direct KRAS Inhibitors

23

Synergy Scores

Cell LineKRASmut

Sensitivity to G12C Inhibitors

Voruciclib + Sotorasib

Voruciclib +Adagrasib

NCI-H23 G12C High

HCC1171 G12C High

MIA Paca-2 G12C High

SW837 G12C Moderate - High

NCI-H2030 G12C High

Calu-1 G12C Moderate - High

HCC-44 G12C Moderate - High

NCI-H1373 G12C Moderate - High

NCI-H358 G12C High

NCI-H1792 G12C Moderate - High

KYSE-410 G12C Low - High

Panc 04.03 G12D Low

Gp2D G12D Low

LS-513 G12D Low - Moderate

AsPC-1 G12D Low

HPAF-II G12D Low

TOV-21G G13C Low Low HighModerate

Esophageal cancer cell lineColorectal cancer cell lines

Non-small cell lung cancer cell linesPancreatic adenocarcinoma cell lines

Ovarian cell line

VORUCICLIB SYNERGIZES WITH KRAS G12C INHIBITORS IN VITRO

Leveraging CDK9 Regulation of MYC: Exploring Synergy with Direct KRAS Inhibitors

24

VORUCICLIB SYNERGIZES

WITH SOTORASIB

IN AN IN VIVO

MIA PaCa-2 TUMOR MODELCon VOR

SOTO Combo

40X

Representative IHC images of DAPI and H&E staining in a Murine Xenograph Model

Key Upcoming 12 Month Milestones Across Portfolio• Zandelisib

• TIDAL: announce top-line data in Q4 2021

• New clinical studies to expand development, including:• COASTAL, intended confirmatory Phase 3 study + Rituxan® in 2L FL/MZL

• 3L MZL (TIDAL Study arm)

• 1L DLBCL + RCHOP (IIT)

• Initial data of phase 1b evaluating zandelisib with zanubrutinib under

clinical collaboration with BeiGene

• Voruciclib

• Initial data, Phase 1 monotherapy and +BCL2i data updates

• ME-344

• Institute plan to leverage clinically demonstrated anti-tumor activity in

combination with anti-VEGF

• Pracinostat

• Program / Phase 2 MDS Helsinn Update

Timing subject to developments related to the COVID-19 pandemic 25

20th Annual Needham Virtual Healthcare Conference

NASDAQ: MEIP

April 12, 2021