SAN DIEGO – Early results of the novel human endogenous retrovirus-W antagonist GNbAC1 in a phase 2 trial of patients with relapsing-remitting multiple sclerosis demonstrated evidence of remyelination at week 24 among high-dose users, but it did not meet its primary endpoint of active lesions seen on MRI.
In an interview at ACTRIMS Forum 2018, held by the Americas Committee for Treatment and Research in Multiple Sclerosis, study author Robert Glanzman, MD, said that GNbAC1 is a monoclonal antibody that targets and blocks the envelope protein pHER-W ENV, a potent agonist of Toll-like receptor 4. It thereby inhibits TLR4-mediated pathogenicity, which includes activation of macrophages and microglia into proinflammatory phenotypes and direct inhibition of remyelination via TLR4.
“Because we’re not directly suppressing the immune system, what we think we’re doing is taking away a driver of autoimmunity,” explained Dr. Glanzman, chief medical officer for Switzerland-based GeNeuro, which is developing GNbAC1.In a study known as CHANGE-MS, 270 patients with relapsing-remitting MS were randomized to one of three doses of the GNbAC1 (6, 12, or 18 mg/kg), or placebo via monthly IV infusion over 6 months. The study was conducted at 70 centers in 13 European countries over the past 3 years. It had a 24-week, double-blind, placebo-controlled period, followed by a 24-week, dose-blind, active-only treatment period, with placebo patients randomized to the three different doses of GNbA1C. Brain MRI scans were performed at weeks 12, 16, 20, 24, and 48, to look for evidence of remyelination.