AB Science SA (Euronext: AB) announced publication of a study on medRxiv showing survival benefits for amyotrophic lateral sclerosis patients treated with masitinib. The analysis examined long-term survivors from the phase 2b/3 AB10015 study who received masitinib at 4.5 mg/kg/day.

The study reported a 5-year survival rate from disease onset of 42.3% among 130 patients receiving masitinib, compared to historical benchmarks ranging from 7% to 27.8%. In patients without complete loss of functionality at baseline, the 5-year survival rate reached 52.9%.

Among long-term survivors who reached the 5-year milestone, 49% maintained quality of life without requiring mechanical assistance such as ventilation, gastrostomy, tracheostomy, or wheelchair dependence. The median overall survival for long-term masitinib-treated survivors was 121 months compared to 42 months predicted by the ENCALS model.

"This analysis of long-term survivors in study AB10015 appears to reveal a substantial and clinically meaningful survival advantage for ALS patients treated with masitinib as compared to historical benchmarks," stated Albert Ludolph, lead author and Senior Professor of Neurology at the University of Ulm.

The study suggested that long-term survivors were largely independent of traditional ALS prognostic factors, indicating a potential patient subpopulation whose disease progression may be driven by microglial and mast cell activity. Masitinib is a tyrosine kinase inhibitor that targets these cellular mechanisms.

AB Science is conducting study AB23005, a phase 3 trial designed to confirm masitinib's efficacy in 408 ALS patients with normal disease progression. The study compares masitinib combined with riluzole against riluzole with placebo over 48 weeks of treatment.

The research was published as a preprint on medRxiv, which provides early access to studies prior to peer review. AB Science noted that further confirmatory evidence would be needed for clinical practice implementation.