ALS Association


AB Science Publishes the Positive Phase 2/3 Clinical Trial of Masitinib in ALS

AB Science has completed a Phase 2/3 human clinical trial of masitinib in ALS with promising results. The company published the results of its trial, conducted in Spain, in the journal Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration. A confirmatory Phase 3 study will be launched later in 2019 with all locations yet to be announced. 

Click here for the company press release. 

Preclinical studies show that masitinib inhibits the functionality of microglia and mast cells implicated in ALS progression by blocking the release of cytotoxic substances that might further damage the motor nerves. In addition to slowing microglial-related disease progression, reducing neuro-inflammation, and modulating neuron behaviors in the central and peripheral nervous systems. 

The targeted population for primary analysis in this study was “normal progressors.” This is defined as an ALS Functional Rating Score Revised (ALSFRS-R) progression rate from disease onset to baseline of less than 1.1 points per month. At the same time, a secondary assessment of the broader participant population was carried out. 

Primary analysis showed that masitinib at 4.5 mg/kg/day in combination with riluzole significantly slowed ALSFRS-R decline by 27 percent compared to riluzole only at week 48. Participants on masitinib also showed a lower deterioration in quality-of-life, as measured by ALSAQ-40 and respiratory function as measured by forced vital capacity (FVC). Time to event analysis was also statistically significant. There was no discernible difference in overall survival (OS) with median OS not being reached in either the masitinib or placebo treatment-arms. Adverse effects were comparable between masitinib and placebo. 

This trial was a multicenter, double-blind, computer-randomized, placebo-controlled, parallel-group, comparative study of oral masitinib in the treatment of people living with ALS. Eligible patients were aged 1875 years with a laboratory-supported probable, probable, or definite diagnosis of ALS. Three hundred ninety-four patients enrolled at a 1:1:1 ratio to receive riluzole plus either placebo, masitinib at 4.5 or 3.0 mg/kg/day. 

In recognition of the critical need for new treatments, masitinib received orphan drug designation for ALS from both the U.S. Food and Drug Administration (FDA) and the European Medicine Agency (EMA). 

AB Science, based in Paris, was founded in 2001 by a team of scientists to develop new drugs targeting unmet needs in the fields of oncology, chronic inflammatory diseases, and neurological degenerative disorders, including as ALS. 


Phase 3 clinical trial pages: 

Phase 2/3 trial information:

AB Science site: