Ibudilast (MN-166) has shown enough promise as a treatment for progressive multiple sclerosis (MS) that its U.S. Phase 2b trial (NCT01982942) should continue, the U.S. National Institute of Health’s Data and Safety Monitoring Board has recommended.
A key goal of the 96-week trial is to determine whether ibudilast can slow the progress of brain tissue loss in both secondary and primary progressive MS patients. Another goal is to determine whether it is safe for MS treatment.
Ibudilast has been approved in Japan and Korea since 1989 to treat post-stroke complications and bronchial asthma.
Half of the 255 patients enrolled in the MS-treatment trial have finished it, with 127 remaining.
Besides effectiveness and safety, the trial will look at cognitive impairment, neuropathic pain, measures of disability, patients’ quality of life, and imaging to determine how brain and eye tissue are holding up.
Researchers are also looking at how the body processes ibudilast and investigating biomarkers of the treatment.
The trial participants were randomized to receive either ibudilast or a placebo. Patients on ibudilast get two 50-milligram doses twice a day.
Participants have been allowed to continue background treatment with glatiramer acetate and interferon beta if they want them. For better comparisons, patients in the treated and control groups were matched according to type of MS and whether they were getting other treatments.
The study is a collaboration among MediciNova, the National Institute of Neurological Diseases and Stroke, the Cleveland Clinic, and the National MS Society. It is part of the institute’s NINDS’s Network for Excellence in Neuroscience Clinical Trials (NeuroNEXT).
The fact that “this important study will continue” is “an encouraging sign,” Dr. Robert Fox of the Cleveland Clinic, the study’s principal investigator, said in a press release. “The unmet medical need for progressive MS patients is extremely high as there is no treatment approved for long-term use for these patients.”
In contrast with the many therapies targeting a single molecule, ibudilast acts on several brain factors. It blocks the enzymes PDE-4 and PDE-10 and also the macrophage migration inhibitory factor; earlier studies have shown that together, these effects of the drug can suppress cytokines promoting inflammation and neural growth.
Ibudilast also prevents the activation of glia, the main immune cells in the brain. They are increasingly recognized as key contributors to neurological conditions such as MS.
“We look forward to providing further updates as we receive results of final data analysis from the study, which are expected in the second half of 2017,” said Yuichi Iwaki, MD, PhD, MediciNova’s president and CEO.