The focus of multiple sclerosis (MS) treatment is shifting toward preventing long-term disability, even as existing therapies effectively reduce relapse rates, according to a recent discussion among neurology pharmacists. The change in emphasis reflects a growing understanding that chronic neurodegeneration and “smoldering” disease activity—neurological worsening occurring without acute relapses—contribute significantly to long-term disability and are not adequately addressed by traditional anti-inflammatory treatments.
Aimee Banks, PharmD, BCPS, MSCS and Millad Sobhanian, PharmD, BCPS, highlighted the evolving treatment landscape in a series of discussions examining the need to move beyond simply controlling acute inflammation. Experts are now seeking therapies that target the underlying disease mechanisms driving progressive disability, according to a report published February 13, 2026, by Pharmacy Times.
Bruton’s tyrosine kinase inhibitors (BTK inhibitors) are emerging as a promising new class of therapies in this effort. Unlike many currently approved MS treatments that primarily target circulating immune cells and relapse-driven inflammation, BTK inhibitors modulate both B-cell and myeloid cell activity within the central nervous system. This dual action addresses both peripheral immune activity and compartmentalized neuroinflammation, a key factor in progressive MS.
BTK is an intracellular signaling molecule involved in the regulation of maturation, survival, migration, and activation of B-cells and microglia, according to a review published in Therapeutic Advances in Neurological Disorders in April 2024. The review, authored by Laura Airas and colleagues, notes that B cells and microglia are considered central to the immunopathogenesis of progressive MS.
The mechanism of action of BTK inhibitors is distinct from other FDA-approved therapies, offering a potential advantage in slowing or halting long-term disease progression. Current therapies, while effective at reducing relapse frequency, have shown limited efficacy in preventing the accumulation of disability, particularly in patients with progressive forms of MS. BTK inhibitors aim to address this unmet need by targeting immune cells on both sides of the blood-brain barrier.
Five BTK inhibitors are currently under investigation in clinical trials for MS, differing in selectivity, strength of inhibition, binding mechanisms, and their ability to modulate immune cells within the CNS, according to a recent review in Nature. The potential of these inhibitors lies in their ability to concurrently target both adaptive and innate immune mechanisms in the periphery and within the central nervous system.
Further exploration of BTK inhibitors, including key learnings from evobrutinib trials and safety data from the HERCULES trial, is planned in a forthcoming episode focusing on clinical trial insights and early safety data.
