Sanofi has announced a three-month extension to the review period with US health authorities for BTK inhibitor tolebrutinib in non-relapsing secondary progressive multiple sclerosis (nrSPMS) with new target action date of 28 December 2025. The delay follows submission of additional analyses deemed a major amendment to the new drug application (NDA). Tolebrutinib holds breakthrough therapy designation (BTD) as first brain-penetrant BTK inhibitor for nrSPMS, targeting central nervous system (CNS) resident immune cells driving disability progression independent of relapses.

The application is supported by Phase III HERCULES trial in nrSPMS and GEMINI trials in relapsing MS showing reduction in disability progression. Sanofi's PERSEUS trial in primary progressive MS (PPMS) remains ongoing with results expected for H2 2025. Tolebrutinib uses a novel mechanism addressing unmet needs in progressive MS, where current therapies primarily target peripheral immune cells with limited impact on neurodegeneration and disability accumulation.

PharmCube's NextBiopharm® database shows that tolebrutinib is also being developed in myasthenia gravis (MG) and neurology. Click here to request a free trial for NextBiopharm®.