Treatment with Vaccinex’s experimental antibody VX15 was seen to stop loss of brain volume and activity in patients with late prodromal (pre-manifest) and early manifest Huntington’s disease, according to preliminary results of the SIGNAL clinical trial.
VX15 is an antibody that inhibits a protein called semaphorin 4D (SEMA4D), which participates in inflammatory processes in the brain. The chronic activation of these processes seems to be implicated in the development of Huntington’s and other diseases, such as progressive multiple sclerosis (MS).
SIGNAL (NCT02481674) is an ongoing Phase 2 multi-center, randomized, double-blind, placebo-controlled clinical trial in patients with late prodromal (pre-manifest) and early manifest Huntington’s disease.
The aim of the study is to investigate the safety and effectiveness of monthly intravenous administration of a single dose of VX15, compared to placebo. It also aims to assess the drug’s properties and behavior once within the body (pharmacokinetics).
Researchers also are assessing other parameters, such as brain volumes and clinical features of Huntington’s disease, including cognition, motor function, behavior, functional abilities and global function, after the treatment.
Patients were divided into two groups: cohort A and B. The results refer to cohort A. Patients in cohort A received either VX15 or placebo for six months, after which all patients received VX15 for another five months, followed by three months of follow-up. This group included 36 patients, whose assessment is now completed.
Those in cohort B received VX15 or placebo for 18 months, followed by three months of safety follow-up. Research in this group of patients is still ongoing.
Patients in cohort A underwent brain imaging at the study’s start and after six and 11 months of treatment. Results showed that VX15 treatment controlled or prevented a decrease in brain volume and activity in many brain regions, which decreased around 2% to 3% percent per year in the placebo group.
Despite the small number of enrolled patients in cohort A and the short duration of treatment, Vaccinex believes these results are encouraging and help project the number of patients to be included in cohort B to further study the effects of VX15 in Huntington’s disease.
“We believe that preliminary imaging measures in Cohort A of our SIGNAL clinical trial have provided an early indication of potential benefit of VX15 in [Huntington’s disease],” Maurice Zauderer, Vaccinex’s president and CEO, said in a press release. “These data have provided important direction to the design and prospective designation of clinical endpoints for the continuing Cohort B.”