Forward Looking Statements These slides and the accompanying oral presentation contain forward looking statements. Actual events or results may differ materially from those projected in any of such statements. Additional

Expect to unblind study and report topline data in March 2015 29 Phase II Front Line MDS Study (MEI 003) Patient Demographics Study MEI 003 (N=102) Pub (N=99) Pub (N=179) Age Median 65 65 70 yrs 29% 71% 69 yrs NR NR 69 yrs 32% 68% Gender Male Female 69% 31% 72% 27% 74% 26% PS 0 1 2 34% 57% 9% NR NR NR 44% 48% 7% IPSS INT 2 High 65% 35% 11% 9% 43% 46% 1 Based on unclean data; study closed to enrollment on August 29, 2014 2 Vidaza package insert, table 1 (Silverman, JCO 2002 study) 3 Vidaza package insert, table 2 (Fenaux, Lancet Oncology 2009 study) 1 2 3 30 2015 Clinical Milestones Pracinostat Top line data from Phase II study in front line MDS (March) Full data set from Phase II study in front line MDS (June) Initiation of Phase III study in front line elderly AML (June) ME 344 Data from Phase Ib trial in small cell lung ovarian cancers PWT143 Initiation of first in human study [ NASDAQ: MEIP ] Analyst Investor Event December 8, 2014 Q A

Mass, MD Chief Medical Officer 27 Elderly (Age 60 years) Patients with Newly Diagnosed AML Unsuitable for Intensive Therapy Pracinostat + Azacitidine Placebo + Azacitidine Proposed Phase III AML Study Designs Primary endpoint: CR Secondary endpoints: OS, ORR, transfusion independency rate, duration of response, PFS, tolerability and AE rate, PK ~450 patients, one to one randomization Estimated initiation: June 2015 28 Intermediate Risk 2 or High Risk MDS Patients Previously Untreated w/ HMA Pracinostat + Azacitidine Placebo + Azacitidine Phase II Front Line MDS Study (MEI 003) Primary Endpoint: CR Secondary endpoints: overall response rate, hematologic improvement, clinical benefit rate, duration of response, progression free survival, rate of leukemic transformation, overall survival, safety tolerability 102 evaluable patients enrolled, one to one randomization 24 sites in the U.S.

Very high rates of clinical and cytogenetic response with the combination of the histone deacetylase inhibitor Pracinostat (sb939) and 5 azacitidine in high risk myelodysplastic syndrome. 2012 ASH Annual Meeting, Abstract 3821 1 2 G. Garcia Manero, et al. Phase 1 Study of the Oral Deacetylase Inhibitor, SB939, in Patients with Advanced Hematologic Malignancies. 2010 ASH Annual Meeting, Abstract 3292 9 MDS Pilot Study Patient Characteristics Patient 1 2 3 4 5 6 7 8 9 10 Median (range) Age (years) 71 71 63 57 22 70 18 71 52 66 64.5 (18 71) Sex F M F F F M M F F F % BM blasts 18 8 2 9 3 3 6 1 12 9 7 (1 18) Hemoglobin g/dL 11 9.3 10.9 9.5 10.2 9.2 8.2 10.7 11.1 9.9 10.05 (8.2 11.1) WBC K/uL 3.2 1.5 2.3 2.5 0.7 2.6 9.3 4.5 1.2 1.5 2.4 (0.7 9.3) ANC K/uL 1.44 0.2 1.3 1.55 0.9 1.7 4.7 2.8 0.4 0.25 1.37 (0.2 4.7) Platelets k/uL 29 56 130 14 27 32 269 13 92 52 42 (13 269) Creatinine mg/dL 1.03 0.99 0.72 0.7 0.5 1 0.8 0.67 0.78 0.6 0.75 (0.5 1.03) Bilirubin mg/dL 1.1 0.7 0.6 1.3 0.4 1 1.1 0.6 0.8 0.5 0.75 (0.4 1.3) Cytogenetics C C C 7 7 C t(6;9) 7 C C t MDS Y Y Y Y N Y Y Y Y N Response CR CRp CR CRp CR NR CRp CR CR CR MDS Pilot Study Three Years Later 10 11 Stage 2 (n = 13) Pracinostat plus Azacitidine Three or more patients required to achieve CR/CRi/MLFS to advance to Stage 2 Stage 1 (n = 27) Pracinostat plus Azacitidine Elderly (Age 65 years) Patients with Newly Diagnosed AML AML, acute myeloid leukemia; CR, complete response; CRi, complete response with incomplete blood count recovery; MLFS, morphologic leukemia free state Phase II Study in Front Line AML (MEI 004) 12 Pracinostat 60 mg is administered orally 3 days a week (days 1,3 and 5 of each week) for 21 days of each 28 day cycle Azacitidine is administered subcutaneously or intravenously on days 1 7 or days 1 5 8 9 (per site preference) of each 28 day cycle Dose Modifications: Reductions Treatment Regimen Indicated for treatment related Grade 3 non hematologic toxicity following maximal medical treatment Indicated for treatment related Grade 3 hematologic toxicity in the absence of disease Delays (between or within cycles) Subsequent reduction to 45 mg of Pracinostat is allowed Begin with Azacitidine which may be reduced to 75% of the starting dose 13 Key Inclusion: Age 65 years Newly diagnosed de novo, secondary, or treatment related AML with intermediate or unfavorable risk cytogenetics based on the Southwest Oncology Group (SWOG) classifications (Slovak et al, 2000). 20% bone marrow blasts Adequate renal, cardiac and liver function QTcF 450 ms for males or 470 ms for females Key Exclusion: Acute promyelocytic leukemia (FAB M3); t(15;17), t(8;21), t(16;16), del(16q), or inv(16) karyotype Candidate for intensive chemotherapy (induction chemotherapy, bone marrow, or stem cell transplant) within the next 4 months Active central nervous system (CNS) disease Eligibility Criteria 14 Study Evaluations Primary Endpoint: Complete Response (CR) + Complete Response with Incomplete Blood Count Recovery (CRi) + Marrow CR (Morphologic Leukemia Free State, MLFS) Secondary Endpoints: Overall response rate (CR + CRi + partial response [PR] + PR with incomplete blood count recovery [PRi] + MLFS) Complete cytogenetic response (CRc) + molecular complete remission (CRm) Duration of response Event free survival (EFS) Overall survival (OS) Assess the tolerability and adverse event profile Response assessments end of cycle 1 or 2, and then every other cycle until CR is achieved or as clinically indicated 15 N = 41 Number of Patients Active 25 Number of Patients Discontinued Reasons for discontinuation: Progressive Disease Adverse Event Other 16 6 6 4 50 patients enrolled between December 2013 December 2014 at 15 sites 41 patients enrolled at data cutoff Other includes patient or physician decision Patient Disposition 16 Number of Patients at Baseline n = 41 (%) Age (years) Median 76 Range 69 84 Gender Male 24 (59) Female 17 (41) Newly diagnosed de novo 29 (71) Secondary (AHD treatment related) 12 (29) 0 1 33 (80) 2 8 (20) Median 38 20 29% Range 13 (32) 30 50% Range 15 (36) 50% Range 13 (32) Intermediate 23 (56) High 17 (41) Not Evaluable 1 (3) AHD, antecedent hematologic disorder; AML, acute myeloid leukemia; ECOG, Eastern Cooperative Oncology Group AML Disease Status ECOG Status Bone Marrow Blasts at Baseline Cytogenetic Risk Category Baseline Characteristics 17 Treatment Emergent Adverse Events in 10% of Patients (all causality) All Grades (%), n=41 Grades 3 4 (%), n=41 Hematologic Febrile Neutropenia 12 (29) 10 (24) Thrombocytopenia 11 (27) 10 (24) Anemia 9 (22) 4 (10) Neutropenia 4 (10) 4 (10) Leukopenia 4 (10) 1 (2) Non Hematologic Nausea 18 (44) 2 (5) Constipation 17 (41) 0 Fatigue 17 (41) 4 (10) Peripheral Edema 6 (15) 0 Vomiting 6 (15) 0 Diarrhea 5 (12) 1 (2) Dizziness 5 (12) 0 Headache 5 (12) 1 (2) Hypokalemia 5 (12) 0 Pyrexia 4 (10) 0 Cellulitis 4 (10) 4 (10) Rash 4 (10) 0 Hypotension 4 (10) 0 Cough 4 (10) 0 Dyspnea 4 (10) 0 QTc Prolongation* 2 (5) 1 (2) QTC events were seen in 10% of patients, however are noted here 18 Treatment Emergent Adverse Events Leading to Drug Discontinuation AE Term Grade Discontinuation (Cycle/Day) Outcome Peripheral Motor Neuropathy 3 3/1 Resolved Parainfluenza 3 3/22 Resolved Prolonged QTc/AF 3 2/15 Resolved Subdural Hematoma 5 3/22 Fatal Sepsis 5 2/3 Fatal Sepsis 5 2/14 Fatal AE, adverse event; AF, atrial fibrillation. 19 Response Interim Response Assessment n=33 (%) CR/CRi/MLFS (Primary endpoint) 15 (45) CR 9 (27) CRi 4 (12) MLFS 2 (6) PR/PRi 3 (10) Stable Disease 4 (12) Progressive Disease 6 (18) Clinical Benefit** 1 (3) No Clinical Benefit 4 (12) *All patients who have had at least 1 on study disease assessment OR discontinued study therapy prior to an on study disease assessment due to adverse event or other reasons ** Patients did not meet strict International Working Group (IWG) response criteria, but were determined to have clinical benefit by Investigator 20 Evolution of Clinical Responses: Interim Efficacy and Duration on Study 21 Event Free Survival 22 Overall Survival 23 Bone Marrow Response in MDS and AML n = 27; 6 patients had no on study BM performed MDS Pilot Study n = 9 Phase II AML Study 200 180 160 140 120 100 80 60 40 20 0 20 40 60 80 100 120 50 40 30 20 10 0 10 20 30 40 50 60 70 80 90 100 110 24 Conclusions Pracinostat in combination with azacitidine demonstrates significant clinical activity in elderly patients with newly diagnosed AML To date, 15 of 33 patients (45%) achieved the primary endpoint of CR+CRi+MLFS No patient who achieved a clinical response has progressed Most clinical responses occur within the first 2 cycles and continue to improve with ongoing therapy The observed Response Rate may increase with longer follow up of patients achieving PR or SD The 60 day mortality rate is approximately 10% (3/33) 25 Conclusions (cont d) Pracinostat in combination with azacitidine was well tolerated in this population of elderly AML patients The most common treatment emergent AEs included neutropenia, febrile neutropenia, thrombocytopenia, nausea, fatigue and anemia Adverse events resulting in dose reductions were uncommon, and frequently due to disease under study Six patients to date have received study drug beyond 230 days reflecting long term tolerability These data support definitive development of Pracinostat in combination with azacitidine in elderly AML patients Pracinostat: Looking Ahead Robert D.

Mass, MD Professor, Department of Leukemia, MD Anderson Cancer Center Chief, Section of Myelodysplastic Syndromes, MD Anderson Cancer Center Deputy Chair, Translational Research, MD Anderson Cancer Center Co Chair, MDS Clinical Research Consortium Principal Investigator of Pracinostat studies Chief Medical Officer, MEI Pharma Former Head of Medical Affairs, BioOncology, Genentech Clinical Development Pipeline 5 Pracinostat HDAC Inhibitor Myelodysplastic Syndrome Front Line, Int 2 High Risk Azacitidine (Vidaza ) Acute Myeloid Leukemia Front Line, Elderly Azacitidine (Vidaza ) Myelodysplastic Syndrome Refractory to HMA Azacitidine (Vidaza ) or Decitabine (Dacogen ) Myelofibrosis Front Line Relapsed/Refractory Ruxolitinib (Jakafi ) ME 344 Mitochondrial Inhibitor Small Cell Lung Cancer Advanced or Metastatic Topotecan (Hycamtin ) Ovarian Cancer Advanced or Metastatic Topotecan (Hycamtin ) PWT143 PI3K Delta Inhibitor Hematologic Cancers DRUG CANDIDATE INDICATION / COMBINATION PHASE I PRE CLINICAL PHASE II PHASE III Pracinostat: A Clinical Perspective Guillermo Garcia Manero, MD MD Anderson Cancer Center 7 Pracinostat: A Differentiated HDAC Inhibitor Potent inhibitor of Class I, II and IV HDAC isoenzymes Tested in 300+ patients in multiple Phase I and Phase II clinic trials Hematologic and solid tumor indications, adult and pediatric patients Well tolerated Manageable side effects consistent with drugs of this class Best in class pharmacokinetic profile, broadly active SB991, the major in vivo metabolite of Pracinostat, demonstrates higher activity than Pracinostat Combined on target IC 50 activity for HDAC1 predicted to be 24 hours 8 Evidence of Clinical Activity in MDS and AML Evidence of single agent activity in elderly AML 1 14% (2/14) CR rate in Phase I dose escalation study Evidence of activity in combination with azacitidine in MDS 2 80% (8/10) CR/CRi rate in pilot Phase II study Rapid complete bone marrow responses observed 50% (5/10) achieved complete cytogenetic bone marrow response 50% (5/10) went on to bone marrow transplantation Quint s Cardama et al.

Gold, PhD 6:05 pm Pracinostat: A Differentiated HDAC Inhibitor Guillermo Garcia Manero, MD Update on MDS Pilot Study Guillermo Garcia Manero, MD Review of Front Line AML Data Guillermo Garcia Manero, MD 6:25 pm Next Steps for Pracinostat in AML Robert D. Mass, MD Preview of Front Line MDS Data Robert D. Mass, MD 6:30 pm Q A All 7:00 pm Conclusion 4 Introductions Guillermo Garcia Manero, MD Professor, Department of Leukemia, MD Anderson Cancer Center Chief, Section of Myelodysplastic Syndromes, MD Anderson Cancer Center Robert D.

[ NASDAQ: MEIP ] Analyst Investor Event December 8, 2014 Exhibit 99.1 2 Forward Looking Statements These slides and the accompanying oral presentation contain forward looking statements. Actual events or results may differ materially from those projected in any of such statements. Additional information concerning factors that may cause actual events or results to differ from those projected is contained in MEI Pharma s most recent annual report on Form 10 K and quarterly reports on Form 10 Q, as well as other subsequent filings with the SEC. 3 Agenda Time Presentation Speaker 6:00 pm Welcome Introduction Daniel P.