Investigational Primary Progressive MS Drug Shows Safety, But No Efficacy Benefits

Idebenone was not found to delay disease progression in multiple sclerosis compared with placebo.

Santhera Pharmaceuticals recently announced results from a phase 1/2 clinical trial of idebenone in patients with primary progressive multiple sclerosis (PPMS), according to a press release. The investigator-initiated trial was sponsored by the National Institutes of Health.

Santhera reported that the trial confirmed the safety of idebenone 2250-mg per day over a 2-year period.

However, there were not positive findings regarding the efficacy of the drug. The researchers found no difference in disease progression between cohorts treated with idebenone versus placebo, according to the release.

The double-blind, placebo-controlled trial investigated the safety and efficacy of idebenone among 77 patients with PPMS. The trial combines a 1-year observational pre-treatment phase followed by a 2-year therapeutic intervention.

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The researchers discovered no differences in rate and severity of adverse events among patients taking idebenone or placebo, which indicates that the drug was well-tolerated in patients with PPMS, according to the release.

The primary outcome of the trial was change in CombiWISE, which is a rating scale. When CombiWISE data, clinical assessments, and biomarkers were analyzed, the researchers failed to discover a difference between cohorts in terms of PPMS disease progression, according to the release.

Currently, idebenone (Raxone) is indicated in the European Union, Norway, Iceland, Liechtenstein, and Israel for the treatment of Leber's hereditary optic neuropathy. The drug is commercialized in 20 countries, according to Santhera.

“The long-term study in patients with PPMS confirms the favorable safety profile of idebenone given at higher dose than the currently approved dose for Raxone in Leber’s hereditary optic neuropathy,” said Thomas Meier, PhD, CEO, Santhera. “We thank the NIH team for conducting this long-term pilot study which will add to the knowledge of disease progression and data collection instruments. Clearly, the small sample size is a limitation when studying a therapeutic intervention in such a complex, relentlessly progressing neurological disease.”