There’s been another detour in tolebrutinib’s path to market, with developer Sanofi revealing that the US Food and Drug Administration (FDA) has delayed an approval decision date by three months.
Sanofi was due to find out whether tolebrutinib would be approved for a type of multiple sclerosis (MS) by 28 September.
However, the FDA now needs additional time to review additional data submitted by Sanofi during the review period, which the agency said constituted a major amendment to the original new drug application (NDA).
A new target action date for the Bruton's tyrosine kinase (BTK) inhibitor has been set for 28 December 2025.
Sanofi stated it is “confident in the potential positive impact tolebrutinib can provide and will continue to collaborate closely with the FDA during the review period”.
The NDA is seeking tolebrutinib’s approval to treat non-relapsing secondary progressive MS (nrSPMS) and to slow disability accumulation independent of relapse activity in adult patients.
Nearly one million individuals are living with MS in the US, as per the latest data available from 2019. nrSPMS is a form of the neurological disease where disability steadily worsens without relapses.
Analysis by GlobalData forecasts that tolebrutinib sales could reach global sales of $1.4bn by 2031, entering blockbuster territory the year prior.
GlobalData is the parent company of Pharmaceutical Technology.
The French drugmaker incorporated tolebrutinib into its pipeline as part of a $3.7bn acquisition of Principia Biopharma in 2021. Despite optimism at the time, the drug has struggled to find a smooth development pathway. In June 2022, the FDA placed a partial hold on further enrolment to a trial evaluating tolebrutinib in myasthenia gravis (MG). Sanofi discontinued the trial (NCT05132569) later in the same year.
Tolebrutinib then failed two of three Phase III trials across different subtypes of MS in September 2024. The successful trial, namely the Hercules study (NCT04411641), evaluated tolebrutinib in patients with nrSPMS. The trial hit its primary endpoint of delaying progression of disability compared to placebo. These results ultimately provided the indication for which tolebrutinib is currently under review.
Despite tolebrutinib’s route to market being delayed, Sanofi had recent success with another candidate acquired in the Principia acquisition. Wayrilz (rilzabrutinib), also a BTK inhibitor, was FDA-approved for adults with persistent or chronic immune thrombocytopenia (ITP) last year.
Away from its own pipeline, Sanofi announced it would add $625m to its corporate venture arm, Sanofi Ventures, on 24 September. The cash will help support investments in young biotechs and digital health-focused companies, the drugmaker said.
