Sanofi's MS Drug Misses Key Trial Goals, Raises Safety Concerns

Sanofi's advanced multiple sclerosis drug candidate, tolebrutinib, failed to meet the main objectives in two late-stage trials for relapsing MS forms. However, it succeeded in a third trial for a progressive form of the disease. Investors remain cautious due to safety concerns, particularly liver damage risks, and regulatory decisions are expected by the end of 2024.

Sanofi's leading multiple sclerosis (MS) drug candidate has failed to achieve the primary goals in two key late-stage trials, disappointing prospects for a highly anticipated drug class aimed at relapsing forms of MS.

The French pharmaceutical company announced on Monday that two Phase III trials demonstrated its experimental daily pill tolebrutinib did not outperform its established MS drug Aubagio in reducing relapse rates in prevalent forms of MS marked by isolated outbreaks followed by temporary improvements. However, a third late-stage trial showed tolebrutinib was effective in treating a less common, steadily worsening form of MS, which currently lacks treatments.

In this successful trial, tolebrutinib slowed the progression of disability compared to a placebo, or ineffective dummy drug. Houman Ashrafian, head of research & development, hailed tolebrutinib as a potential groundbreaking treatment offering significant clinical benefits in managing disability accumulation. Sanofi plans to discuss these results with regulators and aims to file for approval by the end of 2024. CEO Paul Hudson's efforts to regain investor confidence in the company's drug pipeline continue amidst ongoing challenges and opportunities.

(With inputs from agencies.)