Update on the US regulatory review of tolebrutinib in non-relapsing, secondary progressive multiple sclerosis Paris, September 22, 2025. The US Food and Drug Administration (FDA) has extended by three months the target action date of its review of the new drug application (NDA) of tolebrutinib, an oral and brain-penetrant investigational Bruton's tyrosine kinase (BTK) inhibitor to treat non-relapsing, secondary progressive multiple sclerosis (nrSPMS) and to slow disability accumulation independent of relaps ...