French biotech AB Science is celebrating after a pivotal trial of its lead drug masitinib for motor neurone disease hit its objectives.
The phase II/III study showed that masitinib was able to slow down the progression of symptoms in patients with amyotrophic lateral sclerosis (ALS), a form of MND which leads to muscle-weakness and wasting and shortened lifespan and affects around 50,000 people in Europe. Almost 80% of
ALS patients die within 5 years and 90% die within 10 years.
Two doses of masitinib (3 or 4.5mg/kg) or placebo were given on top of the only approved therapy for ALS – riluzole – and the effects of the regimens were measured against a standard rating scale of ALS symptom progression.
Not only was AB Science’s drug more effective than placebo in reducing progression over a 48-week follow-up period, but patients on masitinib also lived longer without their disease progressing. Riluzole has been shown to confer a modest survival benefit, but does not have much impact on muscle strength or neurological function.
“This is very good news for the patients,” said AB Science’s chief executive Alain Moussy. “These final data confirm findings from the study’s interim analysis and proves that masitinib is capable of slowing down motoneuron degenerative disease such as ALS, which is a devastating condition with an urgent unmet medical need.”
AB Science said in a statement that this was the first time that a tyrosine kinase inhibitor such as masitinib has been shown to be effective in ALS in an advanced-stage controlled trial. The drug has a novel mechanism of action, targeting mast cells and microglia and reducing inflammation and the release of cytotoxic substances thought to contribute to the neurodegenerative process in ALS.
It is already sold as a veterinary medicine to treat mast cell tumours in dogs, but AB Science has been trying without success so far to get approval for its use in humans.
The company filed it for approval in Europe for another indication called severe indolent systemic mastocytosis last September, but was rejected by the EMA for advanced inoperable pancreatic cancer in 2014 and also turned it down for gastrointestinal stromal tumours (GIST) a year earlier. The EMA took issue with aspects of the trial design, as well as the safety of the drug and its manufacturing process.
Masitinib is also in phase III testing for Alzheimer’s disease, multiple sclerosis, asthma, rheumatoid arthritis, and for various cancers. It has been granted orphan status for ALS from both the EMA and FDA.