The trials, which were testing the tyrosine kinase inhibitor masitinib, had previously been paused. AB Science’s decision not to resume them was a matter of prioritization, not safety, the biotech said.
AB Science is formally terminating three studies for immune-mediated diseases in what it characterizes as an effort to better focus the biotech’s resources on its priority programs.
The French company is axing a mid-stage study in mast cell activation syndrome (MCAS), a late-stage trial in mastocytosis and a Phase 3 study in progressive multiple sclerosis, according to a news release on Friday. All three trials were testing the tyrosine kinase inhibitor masitinib.
AB Science designated these three programs as “non-priority,” with CEO Stéphane Ledermann noting in a Friday statement that enrollment for the trials had previously been paused and “there is no prospect of a rapid resumption.”
The company emphasized that the decision to discontinue the three studies was not driven by safety issues with masitinib. AB Science promised to complete the trials “in accordance with applicable regulations.”
MCAS and mastocytosis are rare immunological diseases involving dysfunctional mast cells, white blood cells specifically involved in warding off infections. These cells are hyperactivated in MCAS, releasing immune factors even without a trigger, in turn manifesting as diarrhea, rashes, shortness of breath and, in severe cases, anaphylaxis.
Mastocytosis, meanwhile, occurs when mast cells accumulate in the skin, bone marrow and other organs. Symptoms of the two conditions overlap, though mastocytosis can worsen to cancer and organ damage. Multiple sclerosis is an autoimmune disease that arises when the body attacks the protective covering of nerves, leading to motor problems, numbness, vision loss and other complications.
AB Science will now dedicate much of its focus to its two main clinical programs. One will test masitinib for amyotrophic lateral sclerosis (ALS) while the other will focus on an investigational microtubule destabilizer, dubbed AB8939, for acute myeloid leukemia.
Last month, the biotech announced that AB8939, when combined with Roche and AbbVie’s Venclexta, elicited a 67% overall response rate in a Phase 1 study of patients with relapsed or refractory disease. The company is now moving the candidate to the next part of the early trial, looking at combining AB8939 with Venclexta and the chemotherapy azacitidine.
According to the biotech’s website, there remain two other masitinib programs: a Phase 3 trial in Alzheimer’s disease and a Phase 2 study for sickle cell disease. AB Science also has a preclinical candidate for sarcoma and solid tumors.
