This pivotal Phase 3 clinical trial evaluates masitinib, a novel oral tyrosine kinase inhibitor, as an add-on therapy for patients with mild Alzheimer's disease. Masitinib represents a unique therapeutic approach that targets neuroinflammation through inhibition of key kinases involved in microglial activation and neuroinflammatory responses.
The trial is conducted by AB Science, a French pharmaceutical company that has been developing masitinib for various neurological conditions. This represents the most advanced clinical evaluation of masitinib in Alzheimer's disease and could establish a new treatment paradigm based on neuroinflammation modulation rather than direct amyloid or tau targeting@masitinib2019.
Alzheimer's disease affects approximately 55 million people worldwide, with the global burden projected to rise to 139 million by 2050. Despite significant advances in amyloid-targeting therapies, there remains a critical need for treatments that address the neuroinflammatory components of AD pathology that contribute to disease progression@alzheimers2023.
| Parameter | Value |
|---|---|
| NCT Number | NCT05564169 |
| Phase | Phase 3 |
| Status | Not Yet Recruiting |
| Sponsor | AB Science |
| Enrollment | 600 participants |
| Enrollment Type | Estimated |
| Study Type | Interventional |
| Treatment | Masitinib (oral) + Standard of Care |
| Comparator | Placebo + Standard of Care |
| Start Date | June 2026 |
| Completion Date | December 2029 |
| Last Updated | October 3, 2025 |
Masitinib (AB Science, formerly known as AB1010) is an oral selective tyrosine kinase inhibitor that targets several kinases critical to neuroinflammation[@tnf2021]:
| Kinase | Role | Inhibition Effect |
|---|---|---|
| c-Kit | Mast cell survival and activation | Reduces mast cell-mediated inflammation |
| PDGFR | Microglial activation | Modulates neuroinflammatory responses |
| Lyn | Cell signaling in immune cells | Inhibits pro-inflammatory signaling |
| Fyn | Cell signaling in neurons | May provide neuroprotective effects |
Masitinib exerts its effects through multiple mechanisms[@neuroinflammation2022]:
Mast Cell Modulation: Masitinib inhibits c-Kit, which is essential for mast cell survival and function. Mast cells are resident immune cells in the brain that release pro-inflammatory mediators including histamine, TNF-alpha, and various proteases. By modulating mast cell activity, masitinib reduces the neuroinflammatory milieu.
Microglial Activation Suppression: The drug modulates microglial activation through PDGFR inhibition. Activated microglia release cytokines (IL-1β, IL-6, TNF-α) that drive neuroinflammation and contribute to synaptic dysfunction and neuronal loss.
TNF-Alpha Pathway Inhibition: TNF-alpha is a key pro-inflammatory cytokine elevated in AD brains. Masitinib reduces TNF-alpha production and signaling, addressing one of the central mediators of neuroinflammation.
Blood-Brain Barrier Interaction: While masitinib has moderate brain penetration, it exerts effects on peripheral immune cells that subsequently influence central nervous system inflammation through immune surveillance mechanisms.
The trial design as an add-on to standard of care (cholinesterase inhibitors and/or memantine) reflects a rational combination approach:
This is a Phase 3, randomized, double-blind, placebo-controlled, parallel-group clinical trial evaluating masitinib as add-on therapy in mild AD patients receiving standard of care@clinical2023.
| Arm | Treatment | Dose | Duration |
|---|---|---|---|
| 1 | Masitinib | 4.5 mg/kg/day (oral) | 24 weeks |
| 2 | Placebo | N/A | 24 weeks |
Note: Dose may be adjusted based on tolerability
Add-On to Standard of Care: All participants continue receiving stable cholinesterase inhibitor (donepezil, rivastigmine, galantamine) and/or memantine therapy throughout the trial.
Mild Disease Focus: Enrollment limited to mild AD patients (MMSE 21-26), a population more likely to show measurable benefits from anti-inflammatory intervention.
24-Week Treatment Duration: Based on Phase 2 data showing treatment effects emerge within this timeframe.
Robust Outcome Measures: Multiple cognitive and functional assessments provide comprehensive efficacy evaluation.
The iADRS is a composite score combining:
This composite provides a comprehensive measure of both cognitive and functional domains.
Cognitive Measures:
Functional Measures:
Behavioral Measures:
Biomarker Endpoints:
Safety Endpoints:
This Phase 3 trial represents a critical test of the neuroinflammation hypothesis in Alzheimer's disease. The outcomes of this study may[@future2024]:
Validate Neuroinflammation as Therapeutic Target: If successful, masitinib would provide first-in-class validation of tyrosine kinase inhibition for AD treatment.
Establish Add-On Treatment Paradigm: Demonstrating efficacy as add-on therapy would establish a new treatment combination approach.
Inform Inflammatory Biomarkers: Biomarker data will help identify which patients benefit most from anti-inflammatory treatment.
Oral Treatment Option: Unlike antibody therapies requiring infusions, masitinib is an oral medication, potentially improving patient access and convenience.
Disease Modification Potential: By targeting neuroinflammation, masitinib may slow disease progression rather than just providing symptomatic relief.
Combination with Other Mechanisms: Positive results would support development of combination regimens with amyloid-targeting therapies.
Masitinib has received Fast Track designation from the FDA for AD, which may expedite review if Phase 3 results are positive. The drug is already approved in Europe for mast cell tumors, providing a known safety profile.
The trial will be conducted at multiple centers across Europe and potentially other regions:
| Country | Cities |
|---|---|
| France | Paris, Lille, Toulouse |
| Spain | Barcelona, Madrid, Granada, Donostia/San Sebastian, Albacete |
| Germany | Munich, Berlin, Hamburg |
| Italy | Milan, Rome, Florence |
| United Kingdom | London, Manchester |
A pivotal Phase 2 trial (NCT00988268) demonstrated masitinib's potential in AD[@masitinib2020]:
Key subgroup analyses showed:
Preclinical studies demonstrated:
Multiple lines of evidence support the neuroinflammation target:
As of the latest update, this Phase 3 trial is not yet recruiting, with enrollment expected to begin in June 2026.
This trial represents a critical test of the neuroinflammation modulation approach to Alzheimer's disease. Key questions the trial will address:
If positive, masitinib could become the first approved anti-inflammatory treatment for AD, representing a fundamentally different approach than currently approved therapies. This would validate years of research into neuroinflammation as a central component of AD pathology and open new therapeutic avenues.
Even if the trial is negative, the results will contribute valuable information about the role of neuroinflammation in AD and help guide future development of anti-inflammatory strategies.