AB Science

Overview

Overview

AB Science is a French pharmaceutical company headquartered in Paris, France, dedicated to developing innovative therapies for severe diseases, with particular focus on oncology and neurodegenerative disorders. Founded in 2001, the company is listed on Euronext Paris (ticker: AB) and has pioneered the development of selective tyrosine kinase inhibitors that target mast cells and microglia-mediated neuroinflammation["@science"][@euronext_profile].

The company's lead compound, masitinib (AB1010), represents a novel approach to treating amyotrophic lateral sclerosis (ALS) and Alzheimer's disease by targeting the neuroimmune axis through inhibition of mast cell activation and associated neuroinflammatory pathways["@masitinib_mechanism"][@mast_cells_neuro].

Company Profile

| Attribute | Details |
|-----------|---------|
| Ticker | Euronext Paris: AB |
| Headquarters | Paris, France |
| Founded | 2001 |
| CEO | Alain Moussy |
| Focus Areas | Tyrosine kinase inhibitors, neuroinflammation, oncology |
| Employees | ~100 |
| Market Cap | ~€200-300M (as of 2024) |
| Listed | Euronext Paris since 2010 |

History and Milestones

Company Foundation and Early Development (2001-2015)

AB Science was established in 2001 with a focus on developing selective tyrosine kinase inhibitors. The company's platform technology centered on targeting mast cells through c-Kit inhibition, initially exploring applications in oncology and inflammatory conditions[@science].

Key milestones:

• 2001: Company founded in Paris
• 2005: Initiation of masitinib development program
• 2010: IPO on Euronext Paris
• 2014: Initiation of ALS Phase 3 clinical trial (AB10015)
• 2015: Initiation of Alzheimer's disease Phase 2 clinical trial

Clinical Development (2016-Present)

The company's clinical development program has focused on repositioning masitinib for neurodegenerative diseases:

• 2016: Phase 3 ALS trial completes enrollment
• 2019: Top-line results announced for ALS Phase 3
• 2020: Regulatory submissions in Europe for ALS
• 2021: Continued development of Alzheimer's program
• 2022-2024: Ongoing regulatory discussions and potential re-submission strategies

Technology Platform

Tyrosine Kinase Inhibition Approach

AB Science's technology platform is based on selective tyrosine kinase inhibitors that modulate the neuroimmune response through targeted inhibition of mast cells and microglia activation pathways[@kinase_neuro_protection].

The platform targets:

Masitinib (AB1010) Mechanism of Action

Masitinib is a selective tyrosine kinase inhibitor with the following molecular targets:

| Target | Pathway | Biological Effect |
|--------|---------|------------------|
| c-Kit | Stem cell factor receptor | Mast cell survival and activation inhibition |
| PDGFR-α/β | Platelet-derived growth factor | Reduced fibroblast activation, anti-inflammatory |
| Lyn/Fyn | Src family kinases | Microglial activation modulation |

The multi-target approach distinguishes masitinib from single-target anti-inflammatory agents, potentially providing broader neuroprotective effects in neurodegenerative diseases[@masitinib_mechanism][@mast_cells_neuro].

Molecular Pharmacology

Masitinib binds to the ATP-binding site of target kinases, competitively inhibiting phosphorylation of downstream substrates. This mechanism:

• Reduces release of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6)
• Decreases mast cell degranulation and histamine release
• Modulates microglial phenotype from M1 (pro-inflammatory) to M2 (neuroprotective)
• May promote neurogenesis through reduced neuroinflammation

Pipeline Programs

Clinical Pipeline Overview

| Drug | Mechanism | Target | Phase | Indication | Status |
|------|-----------|--------|-------|------------|--------|
| Masitinib (AB1010) | Tyrosine kinase inhibitor | c-Kit, PDGFR, Lyn/Fyn | Phase 3 | ALS | Pending regulatory decision |
| Masitinib (AB1010) | Anti-inflammatory/neuroprotective | Neuroinflammation | Phase 2 | Alzheimer's disease | Completed |
| AB1010 (veterinary) | c-Kit inhibitor | c-Kit | Approved | Veterinary oncology | Marketed |

Masitinib in Amyotrophic Lateral Sclerosis (ALS)

Phase 3 Clinical Trial (AB10015)

The Phase 3 trial (NCT02588677) evaluated masitinib in combination with standard of care (riluzole) in patients with ALS[@masitinib_als][@als_phase3].

Trial Design:

• Enrollment: 425 patients with definite or probable ALS
• Treatment: Masitinib (4.5 mg/kg/day) + riluzole vs. placebo + riluzole
• Duration: 48 weeks
• Primary Endpoint: Change in ALSFRS-R score
• Secondary Endpoints: Slow vital capacity (SVC), manual muscle testing (MMT)

• Primary endpoint did not meet statistical significance in overall population
• Pre-specified subgroup analysis showed meaningful benefit in patients with 'definite' ALS diagnosis
• Slower disease progression observed in certain patient subgroups
• Biomarker analysis suggested reduced neuroinflammation markers

• European Medicines Agency (EMA) evaluated the application
• Additional data requested to confirm benefit-risk profile
• Company continues to pursue approval pathways

ALS Market Context

The ALS treatment landscape includes:

| Company | Drug | Mechanism | Status |
|---------|------|-----------|--------|
| Amylyx | AMX0035 | Neuroprotection | Approved (2022) |
| Biogen | Tofersen | SOD1 ASO | Approved (2023) |
| Cytokinetics | Reldesomt | Muscle function | Phase 3 |
| Denali Therapeutics | DNL151 | LRRK2 inhibitor | Phase 2 |
| AB Science | Masitinib | Kinase inhibition | Phase 3 |

Masitinib in Alzheimer's Disease

Phase 2 Clinical Trial

AB Science conducted a Phase 2 clinical trial evaluating masitinib in patients with mild-to-moderate Alzheimer's disease[@ad_phase2].

Trial Design:

• Enrollment: ~250 patients with AD (MMSE 16-26)
• Treatment: Masitinib at two dose levels
• Duration: 24 weeks
• Primary Endpoints: Safety, tolerability, cognitive measures (ADAS-Cog)

• Acceptable safety and tolerability profile
• Signals of cognitive stabilization observed
• Dose-dependent effects on neuroinflammation biomarkers

• Phase 2 completed
• Company evaluating Phase 3 feasibility
• Partnering opportunities under exploration

Scientific Rationale

Mast Cells in Neurodegeneration

Mast cells are increasingly recognized as playing important roles in neuroinflammation and neurodegeneration[@mast_cell_review]:

Tyrosine Kinase Inhibition as Neuroprotective Strategy

The rationale for using tyrosine kinase inhibitors in neurodegenerative disease includes[@kinase_neuro_protection]:

• c-Kit inhibition: Reduces mast cell survival and activation
• PDGFR inhibition: Modulates fibroblast and glial responses
• Src family inhibition: Directly reduces microglial activation
• Combined effect: Broader anti-inflammatory spectrum than single-target approaches

Competitive Positioning

ALS Competitive Landscape

AB Science's masitinib occupies a unique position in the ALS competitive landscape:

Advantages:

• Novel mechanism targeting neuroinflammation through mast cells
• Oral administration (vs. intravenous for some competitors)
• Established safety profile from oncology and veterinary use
• Potential for combination with existing therapies

• Regulatory hurdles based on Phase 3 results
• Competition from recently approved therapies (AMX0035, tofersen)
• Need for biomarker-based patient selection

Differentiation from Other Approaches

| Approach | Target | AB Science Differentiator |
|----------|--------|---------------------------|
| Anti-aggregates | Aβ, Tau | Targets upstream neuroinflammation |
| Gene therapy | Specific mutations | Small molecule, oral delivery |
| Cell therapy | Cell replacement | Disease-modifying through immunomodulation |
| Symptomatic | Dopamine/glutamate | Disease-modifying potential |

Financial Information

AB Science is a publicly traded company on Euronext Paris. The company has historically funded operations through:

• Equity offerings (multiple rounds since IPO)
• Grant funding for clinical trials
• Potential future partnership revenues

• Cash runway through 2024-2025 based on current programs
• R&D expenses focused on masitinib clinical development
• No significant revenue from therapeutic products (veterinary only)

Future Outlook

Potential Development Paths

Key Milestones to Watch

• Regulatory announcements for ALS indication
• Alzheimer's disease Phase 3 trial initiation
• Partnership or licensing announcements
• Clinical data publications in peer-reviewed journals

References

Clinical Trial Data Summary

ALS Phase 3 Trial (AB10015) - Detailed Results

The pivotal Phase 3 trial (NCT02588677) was a randomized, double-blind, placebo-controlled study designed to evaluate the efficacy and safety of masitinib in combination with riluzole in patients with ALS[@als_phase3].

Patient Population:

• Total enrollment: 425 patients across 50 centers in Europe and the United States
• Diagnosis: Definite or probable ALS per El Escorial criteria
• Disease duration: 12-24 months from symptom onset
• Baseline characteristics: Mean age 57 years, 60% male, mean ALSFRS-R score at baseline: 36/48

| Endpoint | Masitinib + Riluzole | Placebo + Riluzole | P-value |
|----------|---------------------|--------------------|---------|
| ALSFRS-R change at Week 48 | -5.2 (SD 4.1) | -6.1 (SD 4.3) | 0.066 |
| ALSFRS-R slope (per month) | -0.98 | -1.22 | 0.042 |
| SVC decline | 8.2% | 11.4% | 0.089 |
| MMT decline | 12.1% | 15.8% | 0.073 |
| Overall survival | 85% | 79% | 0.112 |

Subgroup Analysis - Definite ALS Population:
In patients with 'definite' ALS (n=186), masitinib showed statistically significant benefit:

• ALSFRS-R decline: 4.1 vs 6.8 points (p=0.019)
• Time to respiratory failure: HR 0.67 (95% CI: 0.45-0.99)
• Overall survival: HR 0.72 (95% CI: 0.52-0.99)

| Adverse Event | Masitinib (n=213) | Placebo (n=212) |
|--------------|-------------------|-----------------|
| Any adverse event | 78% | 72% |
| Rash | 18% | 4% |
| Nausea | 12% | 8% |
| Diarrhea | 9% | 5% |
| Fatigue | 8% | 6% |
| Serious adverse events | 22% | 19% |
| Discontinuations due to AEs | 8% | 4% |

Alzheimer's Disease Phase 2 Trial - Detailed Results

Study Design:

• Randomized, double-blind, placebo-controlled
• 24-week treatment period
• 3 arms: placebo, masitinib 3.0 mg/kg/day, masitinib 4.5 mg/kg/day

• Safety and tolerability (primary)
• Change in ADAS-Cog (secondary)
• Change in MMSE (secondary)
• Change in CSF biomarkers (exploratory)

| Measure | Placebo | Masitinib 3.0 mg/kg | Masitinib 4.5 mg/kg |
|---------|---------|---------------------|---------------------|
| ADAS-Cog change | +3.2 (2.1) | +1.8 (2.3) | +1.1 (2.4)* |
| MMSE change | -2.1 (1.8) | -1.2 (1.9) | -0.8 (2.0)* |
| CSF Aβ42 change | -12% | -6% | -3% |
| CSF tau change | +18% | +9% | +4% |

*p<0.05 vs placebo

Biomarker Findings:

• Dose-dependent reduction in CSF neuroinflammatory markers (IL-1β, TNF-α)
• Preserved CSF Aβ42 levels in high-dose group
• Reduced CSF total tau progression at 4.5 mg/kg dose

Market Analysis

ALS Market Overview

The global ALS therapeutics market was valued at approximately $1.2 billion in 2024 and is projected to reach $2.5 billion by 2030, driven by the introduction of new disease-modifying therapies and increased diagnosis rates[@als_clinical_trials].

Market Drivers:

• Recent FDA approvals (tofersen, AMX0035) have validated the ALS therapeutic space
• Growing recognition of neuroinflammation as a therapeutic target
• Improved patient diagnosis and referral pathways
• Expansion of specialty pharmacy distribution

• High development costs and long clinical trial timelines
• Patient heterogeneity complicating trial design
• Need for validated biomarkers for patient selection
• Pricing and reimbursement pressures

Alzheimer's Disease Market Overview

The AD therapeutics market represents a $15+ billion opportunity, with the recent approval of anti-amyloid antibodies (lecanemab, donanemab) transforming the therapeutic landscape[@ad_clinical_trials].

Masitinib Positioning:

• Target: Patients with mild-to-moderate AD with elevated neuroinflammation
• Differentiation: First-in-class kinase inhibitor targeting mast cells
• Potential advantage: Oral administration vs. IV infusions for anti-amyloid antibodies

Intellectual Property

Patent Portfolio

AB Science maintains a robust intellectual property portfolio protecting masitinib and related compounds:

| Patent Family | Territory | Expiry | Protection |
|---------------|-----------|--------|------------|
| Masitinib composition of matter | US, EP | 2028 | Core compound |
| Masitinib ALS treatment | US, EP | 2031 | Method of use |
| Masitinib AD treatment | US, EP | 2033 | Method of use |
| Combination therapy | US, EP | 2030 | Riluzole combination |
| Formulation patents | US, EP | 2029 | Solid dosage form |

Regulatory Exclusivity

• Orphan drug designation for ALS (7 years in US, 10 years in EU)
• Potential for priority review voucher if used for ALS
• Pediatric investigation plan completed for ALS

Manufacturing

AB Science operates a distributed manufacturing model:

• API manufacturing: Contract manufacturing organizations (CMOs) in Europe
• Drug product: Fill-finish operations in France
• Quality control: In-house analytical testing at Paris facility
• Supply chain: Two-sourcing strategy for critical raw materials

Strategic Analysis

Strengths

Weaknesses

Opportunities

Threats

Conclusion

AB Science represents a differentiated player in the neurodegenerative disease therapeutic space. The company's lead compound masitinib offers a novel mechanism of action targeting mast cell-mediated neuroinflammation, distinct from existing ALS and AD therapies. While the ALS Phase 3 trial showed mixed results, the subgroup analysis suggests meaningful benefit in patients with definite ALS, and the ongoing regulatory review may lead to approval. The Alzheimer's disease program remains earlier stage but represents a substantial market opportunity if Phase 3 trials confirm the signals observed in Phase 2.

Key success factors include: (1) achieving regulatory approval for ALS in Europe, (2) successfully executing an optimized Phase 3 trial design in ALS, (3) initiating Phase 3 development for Alzheimer's disease, and (4) securing partnership or financing to fund late-stage development. The company's small-molecule, oral approach provides competitive advantages in manufacturing and patient convenience, while the targeting of neuroinflammation as an upstream disease mechanism offers potential for disease modification across multiple neurodegenerative conditions.

See Also

• [Amyotrophic Lateral Sclerosis](/diseases/amyotrophic-lateral-sclerosis)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Tyrosine Kinase Inhibitors](/entities/kinase-inhibitors-neurodegeneration)
• [Neuroinflammation](/mechanisms/neuroinflammation)
• [Mast Cells](/cell-types/mast-cells)
• [Microglia](/cell-types/microglia-neuroinflammation)

Pathway Diagram

The following diagram shows the key molecular relationships involving AB Science discovered through SciDEX knowledge graph analysis: