**Sanofi’s tolebrutinib has been accepted for priority review by the US Food and Drug Administration (FDA) to treat certain cases of multiple sclerosis (MS).**
The investigational drug has been granted priority review as a treatment for non-relapsing secondary progressive MS (nrSPMS) and to slow disability accumulation independent of relapse activity in adults.
Approximately 2.9 million people worldwide are living with MS, a neurodegenerative disease that disrupts communication between the brain and the rest of the body.
Relapsing MS, characterised by attacks of worsening neurologic function followed by partial or complete recovery periods, accounts for about 85% of initial diagnoses, while nrSPMS, which refers to patients who have stopped experiencing relapses but continue to accumulate disability, is much less common.
Taken orally, Sanofi’s tolebrutinib is a Bruton’s tyrosine kinase inhibitor that is thought to address the underlying pathology of progressive MS by targeting the inflammatory processes that contribute to neurodegeneration and disability accumulation.
The FDA’s decision comes just three months after it granted breakthrough therapy designation for tolebrutinib and was based on positive results from the late-stage HERCULES study, in which the drug delayed the time to onset of six-month confirmed disability progression by 31% compared to placebo in nrSPMS patients.
Results from the phase 3 GEMINI 1 and 2 studies in relapsing MS, as well as additional clinical and preclinical studies, also supported the decision.
Erik Wallström, global head of neurology development, said: “People living with nrSPMS or who experience disability independent of relapse activity suffer from disability that worsens over time due to persistent inflammation in the brain, known as smouldering neuroinflammation, which is the primary driver of disability.
“The demonstrated ability of tolebrutinib to delay disability by targeting underlying drivers of the disease represents a potential paradigm shift in treating these patients.”
The FDA grants priority review to regulatory applications seeking approval for therapies that have the potential to provide significant improvements in the treatment, diagnosis or prevention of serious conditions.
A priority review designation means the regulator will aim to take action on the application within six months, compared to ten months under its standard review pathway.