Swiss pharmaceutical company Roche announced Wednesday that it has filed regulatory submissions for its investigational multiple sclerosis treatment fenebrutinib with health authorities around the world, despite clinical trial data showing patient fatalities during testing.
The drugmaker achieved its primary objectives in advanced-stage clinical trials, but newly released information revealed that seven participants died while taking the experimental medication during research studies.
Roche had previously disclosed results from trials involving patients with primary progressive multiple sclerosis (PPMS), but Wednesday’s announcement included additional details about the drug’s performance in treating relapsing multiple sclerosis (RMS).
According to Chief Medical Officer Levi Garraway, fenebrutinib demonstrated superior efficacy compared to teriflunomide, an existing oral medication manufactured by French company Sanofi. The experimental treatment more than doubled the duration patients remained free from disease relapses, Garraway stated.
However, the safety profiles between the two drugs showed significant differences. Sanofi’s established medication, which has been commercially available for 13 years, recorded one patient death representing 0.1% of study participants. In contrast, fenebrutinib was associated with seven deaths during trials (0.9%) plus an additional fatality afterward.
“There are a couple of cases where the investigators did think the deaths were related to the study drug and both of those were infections,” Garraway explained during an interview, noting that the connection between the medication and other deaths remained uncertain.
Garraway emphasized that none of the fatalities were connected to liver-related complications, and he indicated that serious liver toxicity rates were comparable to those seen with the competing treatment.
Investment analysts at Jefferies expressed doubt in February about fenebrutinib’s prospects for regulatory clearance, citing concerns about liver side effects. They also suggested that analyst projections of peak sales reaching approximately three billion Swiss francs ($3.85 billion) might be overly optimistic.
Despite these concerns, Garraway maintained that the company views the drug’s overall risk-benefit assessment as positive and anticipates regulatory approval if authorities reach the same conclusion. While declining to discuss sales forecasts, he noted that the company does not anticipate fenebrutinib will supersede Roche’s current multiple sclerosis medication Ocrevus.
