Senolytics for Secondary Progressive MS

Multiple sclerosis (MS) is a chronic immune-mediated inflammatory and neurodegenerative disorder of the central nervous system (CNS), which afflicts approximately one million people in the United States. Age is the strongest driver of disease course in MS. With increasing age, most older adults with MS develop a progressive disease phenotype characterized by gradual accrual of irreversible neurological disability, for which there are no effective treatments that reliably slow disease progression. Cellular senescence is a hallmark of aging, whereby senescent cells accumulate with age and produce mediators of inflammation through the senescence-associated secretory phenotype (SASP). In MS, senescent cells have been identified in both the central nervous system and peripheral immune compartments contributing to SASP expression, promoting chronic inflammation, axonal damage, and failure of myelin repair, and ultimately leading to functional decline. Senescent cells can be selectively removed by senolytic drugs, which delay age-related dysfunction in animal models and show potential for improving functional outcomes in human clinical trials. The senolytic drug combination of dasatinib and quercetin (D+Q) selectively induces apoptosis of senescent cells in human tissue. Our pilot data shows D+Q treatment improves function and survival in experimental autoimmune encephalomyelitis, the widely used animal model of MS. Emerging evidence from early phase clinical trials of D+Q in age-related diseases shows improvement of gait speed in idiopathic pulmonary fibrosis and CNS penetrance of dasatinib in Alzheimer's disease. However, studies of senolytic therapy for people with MS have yet to be conducted. The investigators hypothesize that treatment with D+Q will be well tolerated, improve physical and cognitive function, reduce circulating biomarkers of senescence and neurodegeneration, and attenuate T-cell immune exhaustion. The investigators will test this hypothesis through a single arm, open label, study to 1) determine the feasibility of 3 months of intermittent D+Q treatment in 30 older adults age 50-85 with secondary progressive MS and 2) to obtain preliminary data of D+Q treatment on physical and cognitive function and 3) serum biomarkers of senescence, neurodegeneration, and the circulatory T cell repertoire. Targeting cellular senescence represents a novel strategy for treating progressive MS, and results from the study will lay the foundation for a future randomized controlled trial of senolytics to treat progressive MS.