Biogen has reported positive interim results from the ongoing, pivotal Phase III EVOLVE-MS-1 clinical trial of diroximel fumarate in patients with relapsing multiple sclerosis (MS).

According to the data, the drug was generally well-tolerated and significantly reduced disease activity.

Diroximel fumarate is an oral candidate being developed in alliance with Alkermes.

The single-arm, open-label, two-year EVOLVE-MS-1 trial is designed to assess the safety and efficacy of the therapeutic in around 1,000 patients with relapsing-remitting MS.

Interim data were obtained from 696 subjects treated with diroximel fumarate for a median of around one year. Sub-group analysis was carried out in patients naive to prior disease-modifying therapy or those who previously received interferon (IFN) or glatiramer acetate (GA).

Participants treated with IFN/GAs demonstrated significant improvements in radiological and clinical endpoints over one year with diroximel fumarate, compared to baseline.

Biogen said that adjusted annualised relapse rate decreased by 72% between baseline and week 48 when treated with the study drug.

Around 30.9% of patients discontinued the diroximel fumarate group within one year of treatment due to gastrointestinal (GI) adverse events. These events were observed to be generally mild or moderate in severity and typically occurred within the first month of therapy.

Biogen research and development (R&D) executive vice-president Michael Ehlers said: “We are excited about these data for diroximel fumarate and believe this distinct oral fumarate has the potential to be a meaningful treatment option for people living with MS.”

The drug is being evaluated by Alkermes in the five-week, head-to-head EVOLVE-MS-2 study in patients with relapsing-remitting MS, compared to dimethyl fumarate.