Slide 1: AB Science Highlights
AB Science Highlights January 2026
Slide 2: Forward-looking statements and disclaimer 1/2
Forward-looking statements and disclaimer 1/2 This corporate presentation (the “Presentation”) has been prepared by AB Science S.A (the “Company” and, together with its subsidiary, the “Group”) and is provided for information purposes only. It is not for promotional use. References herein to the Pre
Slide 3: Forward-looking statements and disclaimer 2/2
Forward-looking statements and disclaimer 2/2 Forward-looking statements cannot, under any circumstance, be construed as a guarantee of the Group's future performance as to strategic, regulatory, financial or other matters and the Group’s actual performance, including its financial position, results
Slide 4: AB Science management is experienced, stable, and committed to deliver these milestones
AB Science management is experienced, stable, and committed to deliver these milestones CHRISTIAN FASSOTTE, MD, Chief ALAIN MOUSSY, Co-founder and CEO Medical Officer Former Head of Carrefour Corporate Medical Doctor. 30 years of experience, Development including executive position at Sanofi for Pre
Slide 5: AB Science is a European clinical development stage company with ALS and AML as key indications
AB Science is a European clinical development stage company with ALS and AML as key indications Proprietary Drug Portfolio Key Considerations Drug / Therapeutic ❖ AML Phase 1 and expansion phase are fully Platform Indication Development Stage Target area financed Tyrosine Masitinib Registered in the
Slide 6: Masitinib in Amyotrophic Lateral Sclerosis
MASITINIB IN AMYOTROPHIC LATERAL SCLEROSIS
Slide 7: Masitinib is an orally-administered kinase inhibitor targeting mast cells and macrophages
Masitinib is an orally-administered kinase inhibitor selectively targeting mast cells and macrophages, uniquely positioned to realize its therapeutic potential in neurodegenerative diseases (NDDs) Masitinib targets mast cells Microglia and mast cells are at the cutting edge of research • Masitinib i
Slide 8: Masitinib has a proven mechanism of action in animal models of ALS
Masitinib has a proven mechanism of action in animal models of ALS, published in several peer-reviewed journals Masitinib treatment initiated 7 Masitinib restored days after paralysis onset motor function in a prolonged survival by 40 % in zebrafish model of SOD1 model mutant TDP-43 overexpression R
Slide 9: Phase 2B enrolled 394 patients with broad inclusion criteria
Phase 2B enrolled 394 patients with broad inclusion criteria and evaluated Masitinib after 48 weeks of treatment. The primary analysis was preplanned in the population defined as “Normal” progressors, following an early protocol amendment Design Statistical analysis Design: Two distinct populations
Slide 10: Study AB10015 generated consistent results on primary and secondary endpoints
Study AB10015 generated consistent results on primary and secondary endpoints ALSFRS-R (Normal Progressors ; M4.5 vs P) Analysis (M4.5 vs placebo) Difference p-value ▪ Primary analysis : 27% difference in slope of deterioration mLOCF Method (PRIMARY) 3.39 0.0157 ▪ Copy Increment in Reference (CIR) a
Slide 11: A large proportion of patients treated with masitinib survived more than 5 years
A large proportion of patients in phase 2B/3 treated with masitinib 4.5 mg/kg/day had a survival duration of more than 5 years from onset Masitinib Masitinib Survival Duration Survival Duration 4.5 mg/kg/day (N=128) 4.5 mg/kg/day (N=55) Alive > 5yrs 55 (43.0%) Observed overall survival (average in m
Slide 12: EMA considered the safety of Masitinib acceptable for further trials in ALS
In its benefit-risk assessment, EMA considered the safety of Masitinib acceptable for further trials in ALS Masitinib Safety Profile based on a Large Database Masitinib Safety is Deemed Acceptable in ALS Number of Patients Randomized in Masitinib Treatment Arms CHMP Latest Assessment Report Safety P
Slide 13: There was an imbalance in 14% of the study population
There was an imbalance in 14% of the study population (defined as patients with a complete loss of function in at least one individual component of the ALSFRS-R) Distribution of patients with complete loss of function in at least one individual component of the ALSFRS-R in the primary analysis popul
Slide 14: A strong hypothesis was generated for confirmatory phase 3
A strong hypothesis was generated from this phase 2B/3 for confirmatory phase 3 with the identification of an optimal population AB10015 - Primary Analysis Population AB10015 – Subgroup (Normal Progressors) Analysis ∆ALSFRS-R (primary endpoint) Diff. of mean 3.39 4.04 (mLOCF – pirmary analysis) Subg
Slide 15: All key parameters are aligned to maximize chances of success of the phase 3 study
All key parameters are aligned to maximize risks of success of the phase 3 study ❖ Having validated masitinib MoA, modulating microglia and inhibiting mast cells ❖ Reducing heterogeneity of the study population through identification of an optimal population : patients prior to loss of function ❖ Ha
Slide 16: The objections raised by EMA have been mitigated in the confirmatory phase 3
The objections raised by EMA in the context of a conditional marketing authorization procedure have been mitigated and solutions integrated into the next confirmatory phase 3 study authorized now both by EMA and FDA EMA Assessment Mitigation ▪ Exclusion of Fast progressors and the definition of fast
Slide 17: The confirmatory phase has been authorized by FDA and EMA
The confirmatory phase 3 has been authorized by FDA and EMA and is endorsed by prominent opinion leaders in ALS Authorized Phase 3 design Steering Committee Support from prominent opinion leaders in ALS 204 Institution Expert Masitinib 4.5mg/kg/day + Optional Extension Riluzole University of Ulm – G
Slide 18: A clear plan is laid out to read-out phase 3 by Q4 2028
A clear plan is laid out to read-out phase 3 study by Q4 2028, initiate early access program in Q2 2029 and launch end 2029, assuming study initiating in Q1 2026 Phase 3 Early Access Market Launh Read-out Program 2026 2027 2028 2029 2030 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Appro
Slide 19: Masitinib has blockbuster potential in ALS, with projected peak sales of 2B€
Masitinib has a blockbuster potential in ALS, with projected peak sales of 2B€, if approved, based on strategic consulting survey EUROPE US 6 per 100.000 6 per 100.000 Global disease Prevalence Number of ALS patients 30,000 20,000 % of patients targeted in the 75% 75% disease* Expected market share
Slide 20: AB8939 in Acute Myeloid Leukemia
AB8939 IN ACUTE MYELOID LEUKEMIA
Slide 21: AB8939 targets proliferating leukemia blasts and leukemia stem cells
AB8939 targets proliferating leukemia blasts and leukemia stem cells Problem in AML is recurrence This problem may be solved by the dual Moa of AB8939 of tumor ▪ Destabilizes microtubules a well known MoA in cancer BLOCKING but that suffers for known drugs (taxol, taxotere, PROLIFERATING vincristine
Slide 22: Phase 1 in monotherapy completed and phase 1 in combination has begun
Phase 1 in monotherapy has been completed and phase 1 in combination has begun Step 1 Step 2 Step 3 MTD* 3 DAYS MTD 14 DAYS MTD 14 DAYS AB8939 alone AB8939 alone AB8939 Combination 28 patients randomized 13 patients randomized (some patients received several cycles at increased ▪ AB8939 + Venetoclax
Slide 23: AB8939 + Venetoclax generated responses in patients in Line 3 or 4
In combination, AB8939 + Venetoclax remarkably generated responses in patients in Line 3 or 4 with high risk adverse profile, complex karyotypes, TP53, Mecom and NRAS mutation. There was no toxicity, no DLT Outcome of the first four patients receiving AB8939 + Venetoclax in Step 3 of phase 2 study P
Slide 24: Objective is to position AB8939 combination as standard of care in high-risk AML
The objective is to position AB8939 combination treatment to be the standard of care in AML with a high risk profile adverse genetic, which represents a market size potential above EUR 2 billions per annum ▪ Adverse genetics regroup TP53 mutant, NRAS/KRAS mutant, complex karyotype, monosomy 5 and 7,
Slide 25: Masitinib in Progressive Forms of Multiple Sclerosis and in Mild Alzheimer's Disease
MASITINIB IN PROGRESSIVE FORMS OF MULTIPLE SCLEROSIS AND IN MILD ALZHEIMER’S DISEASE
Slide 26: Tremendous unmet need in progressive MS with few approved drugs
There is a tremendous unmet need in progressive MS, with no approved drugs for non-active secondary progressive MS and one for primary progressive MS ▪ Vast majority of drugs are effective only in active MS patients because these drugs stop immune attacks (active inflammation) but cannot repair myel
Slide 27: Phase 2B/3 MS study showed significant benefit on disability progression
Phase 2B/3 enrolled 656 MS patients tested 2 doses in two sub-studies and demonstrated a significant benefit on disability progression with masitinib 4.5 mg/kg/day in patients with advanced stage of the disease Primary endpoint Sub-study I Sub-study II Significant reduction in progression on EDSS (P
Slide 28: Masitinib results are promising in light of tolebrutinib results
Although head-to-head comparison is not possible, results with masitinib are promising in light of tolebrutinib results Masitinib Tolebrutinib 37% risk reduction of time to 3-months confirmed 24% risk reduction of time to 3 months confirmed disability disability progression progression 3-month confi
Slide 29: Confirmatory phase MS study is authorized by FDA and key European countries
Confirmatory phase 3 MS study is authorized by FDA and key European countries Confirmatory phase 3 study design has been discussed Authorized Phase 3 design with FDA and EMA Approved countries Randomizatioion 400 Masitinib 4.5mg/kg/day ▪ Bulgaria, France, Germany, Greece, Italy, Netherlands, End of
Slide 30: Masitinib is being developed for more advanced stages of Alzheimer's disease
Masitinib is being developed for more advanced stages of Alzheimer’s disease as compared with biologics recently approved AD severity based on MMSE score 30 26 20 10 Prodromal Mild Moderate Severe Lecanemab (Eisai/Biogen): MMSE [22 – 30] Approved Donanemag (Eli Lilly): MMSE [20 – 28] Phase 3 * Masit
Slide 31: Phase 2B/3 study enrolled 718 AD patients and showed reduced cognitive impairment
Phase 2B/3 study enrolled 718 AD patients in two sub-studies and demonstrated a significant reduction in cognitive impairment based on ADAS-COG (p=0.0003) and improvement on daily activity based on ADCS-ADL (p=0.0381) with masitinib 4.5 mg/kg/day Significant effect on cognitive function after 24 wee
Slide 32: Clinical benefit on ADAS-Cog was greater in patients with mild impairment
The clinical benefit on ADAS-Cog was greater in patients with mild impairment than in patients with moderate impairment Significant effect on Composite ADAS-COG Mean (+/SEM) Plot of ADAS-COG - Masitinib 4.5 versus Pooled Placebo (FAS)) Mastinib 4.5 mg (N=78) Placebo 3/4.5 mg (N=78) 2 LS Mean LS Mean
Slide 33: Confirmatory phase AD study is authorized by FDA and key European countries
Confirmatory phase 3 AD study is authorized by FDA and key European countries Confirmatory phase 3 study design has been discussed Authorized Phase 3 design with FDA and EMA 300 Approved countries Extension period Randomizatioion Masitinib 4.5mg/kg/day ▪ Belgium, Bulgaria, Czech Republic, France, Ge