New research presented at the American Thoracic Society virtual symposium showed the first-in-class drug reduced severe asthma exacerbation rate by 35% vs placebo.
“Masitinib, a first-in-class tyrosine kinase inhibitor targeting mast cell activity in severe asthma patients, demonstrated a positive benefit/risk ratio over a sustained period and may provide a new treatment option in severe asthma, irrespective of baseline eosinophil level,” wrote study authors, led by Pascal Chanez, MD, PhD, professor of Respiratory Diseases, Aix-Marseille University, France.
The AB07015 study was a randomized, double-blinded, placebo-controlled trial that evaluated oral masitinib (6 mg/kg/day) treatment of severe persistent asthma remaining uncontrolled by OCS (>5 mg/day) vs placebo.
The primary endpoint was reduction of annualized severe asthma exacerbation rate for overall exposure, with a severe exacerbation event defined as worsening asthma leading to an increase from stable maintenance dose of OCS for ≥3 days or hospitalization. The authors noted a key predefined subgroup analysis was the assessment of patients with initial eosinophil count of ≥150 cells/µL.
A total of 355 patients were included in the primary analysis population who were randomized 2:1 to receive either masitinib or placebo for 36 weeks, with a possible extension period until at least week 96.
The results showed masitinib significantly reduced severe asthma exacerbation rate by 35% vs placebo (rate ratio [RR], 0.64 [95% CI, 0.48-0.84; p=0.0014]). In addition, the eosinophil ≥150 cells/µL subpopulation demonstrated a significant reduction in severe asthma exacerbations by 38% (RR, 0.69 [95% CI, 0.49-0.95; p=0.0249]).
Also, the rates for serious adverse events (AE) and severe AE for the masitinib group were 17.7% and 16.5%, respectively; for placebo, the rates for serious AE and severe AE were 48% and 45.9%, respectively.