Sanofi backs down in Paris, double setback on experimental drug

(Il Sole 24 Ore Radiocor) - Sanofi is trading at a loss on the Paris Stock Exchange after a double setback on an experimental therapy to treat two forms of multiple sclerosis. The French pharmaceutical giant's stock was also among the day's worst performers in the Stoxx Europe 600. In two separate announcements, the company announced a further delay of the US Food and Drug Administration (FDA) decision on tolebrutinib - for the treatment of secondarily progressive, non-relapsing multiple sclerosis - and disclosed the discontinuation of studies on the drug for another form of the disease, following the failure of a phase 3 study.

The company expects that 'the ongoing US regulatory review process for tolebrutinib in secondary progressive non-relapsing multiple sclerosis (nrSPMS) will extend beyond the previously communicated US target date of 28 December 2025' and expectsfurther guidance from the Fda by the end of the first quarter of 2026. In response to a request from the Fda, Sanofi submitted 'an expanded access protocol for tolebrutinib, confirming the company's commitment to providing eligible patients with access to this investigational therapy. Sanofi firmly believes in the risk-benefit profile of tolebrutinib for the treatment of nrSPMS'.

In September, Sanofi announced that the Fda had extended the review of tolebrutinib for this form of the disease by three months. Separately, the French group disclosed that 'results from the phase 3 PerseusS study showed that tolebrutinib did not meet its primary endpoint in delaying time to confirmed composite disability progression (cCDP) at 6 months in participants with primary progressive multiple sclerosis (PMS), which represents 10% of the overall multiple sclerosis patient population'.

Based on these results, Sanofi will not apply for regulatory registration for SMPP. "We are disappointed with today's results. However, we believe that these results will improve our understanding of the biology of the underlying disease of multiple sclerosis," Houman Ashrafian, executive vice president, head of research and development at Sanofi, said in the statement. Despite the setback, the stock pared losses after Barclays reiterated its 'Buy' rating on the stock, with a stable price target at EUR 105.