AB Science Reports Positive Interim Results in Phase 3 Trial of Masitinib as an ALS Therapy

AB Science announced that its Phase 2/3 clinical trial evaluating masitinib, the company’s lead compound to treat amyotrophic lateral sclerosis (ALS) patients, has met its primary objective. The ongoing study is currently recruiting participants and expects to finish in June 2017.

“The positive outcome of this study in ALS is a significant milestone for the development of masitinib in neurology. We plan to share the data with EMA [European Medicines Agency] and FDA [U.S. Food and Drug Administration] to discuss the possibility of filing an application for marketing authorization for masitinib in ALS,” Alain Moussy, CEO and co-founder of AB Science, said in a press release.

Tyrosine kinase inhibitors (TKIs) such as masitinib are compounds that target a class of enzymes — tyrosine kinases — responsible for the activation of several proteins in a number of cell signaling pathways. Blocking the selected activation of these proteins has been shown to have therapeutic benefits in numerous diseases, from cancer and inflammatory diseases, to central nervous system (CNS) disorders. Masitinib, an orally administered TKI, targets mast cells and macrophages, immune cells involved in important, and sometimes harmful, immune responses. Mast cells and microglia are also the main cells of the CNS immune system, so the drug has the potential to treat symptoms associated with primary progressive MS, which, unlike relapsing-remitting MS, has no approved disease-modifying therapies.

The Phase 2/3 clinical trial (NCT02588677) is comparing the efficacy and safety of masitinib combined with riluzole, versus placebo with riluzole, in the treatment of ALS patients. The reported results refer to the interim analysis that was planned after the 191 of patients (50 percent of the study’s population) had reached the 48-week treatment time point.

The trial’s primary outcome is the change from baseline to week 48 in the Amyotrophic Lateral Sclerosis functional rating scale (ALSFRS), a validated rating tool for monitoring disability progression in ALS patients, and one that correlates significantly with quality of life and survival. Change in the ALSFRS score is a recommended guideline by both U.S. and EU regulatory agencies as an ALS endpoint for trial registration. Secondary outcome measures included change from baseline to week 48 in forced vital capacity (FVC) and combined assessment of function (CAFS).

Results revealed the primary outcome measure was successfully achieved, and the study was also successful on its secondary endpoints. The frequency of adverse events (AEs), serious AEs, and AEs leading to discontinuation were similar among the two treatment arms.

“Amyotrophic lateral sclerosis is a fatal neurodegenerative disease with a high unmet medical need. The challenge in treating ALS patients is underscored by the fact that there have been no drug advances for improving patient survival since the approval of riluzole over 20 years ago,” said Dr. Jesús Mora, the study’s international coordinator. “The interim results from this masitinib phase 3, randomized trial are therefore very impressive and provide encouragement that we may soon have a new and more effective treatment option available, pending approval from regulatory agencies.”

More information on this clinical trial, including enrollment information, is available through its clinical trials.gov site.