Nasal anti-CD3 monoclonal antibody (Foralumab) reduces PET microglial activation and blood inflammatory biomarkers in two patients with non-active secondary progressive MS

ABSTRACT

Introduction: There are no effective treatments for non-active secondary progressive MS (SPMS), which is mediated by compartmentalized CNS inflammation, including activated microglia. We found that fully human anti-CD3 intranasal monoclonal antibody (Foralumab) suppressed disease in a chronic EAE model by dampening microglia and astrocyte inflammation. Nasal Foralumab does not enter the bloodstream or brain. A dose-finding study of nasal Foralumab in controls dosed at 10ug, 50ug and 250ug for 5 days found the drug to be safe with immune effects seen at 50ug. COVID patients dosed with 100ug of nasal Foralumab for 10 days was well-tolerated and exhibited positive effects on blood markers and lung inflammation. Objective(s) To determine if nasal Foralumab has a therapeutic effect on patients with non-active SPMS. Method(s) Two patients were identified with non-active SPMS and sustained clinical progression, despite use of approved DMT. EA1 is a 61-year-old male diagnosed for over 20 years and EA2 is a 42-year-old male diagnosed for 8 years, both last treated with ocrelizumab for 3 years. Treatment occurs in 3-week cycles with intranasal Foralumab 50ug/day administered 3x/week for 2 weeks with 1 week rest. Each cycle, clinical and neurological assessments are repeated, and imaging is repeated every 3 months. Result(s) EA1 has completed 6 months and EA2 has completed 3 months of treatment. To date, there have been no adverse reactions, local irritation, or laboratory abnormalities, and symptom progression has subsided. EA1 is feeling more stable, subjectively, and has noted improvement in lower extremity strength. EDSS, pyramidal motor score and T25FW have stabilized or improved. SDMT and 9HPT were stable during treatment. Microglial activation as measured by [F-18]PBR06 PET scan was significantly reduced 3 months after the start of nasal Foralumab, and this reduction was sustained after 7-week washout and at 6 months. Serum protein measurements of cytokines showed reduction of IFN-gamma, IL-18, IL-1s and IL-6 levels (Olink assay). Cellular immune studies showed increase in CD8 naive cells and decrease in CD8 effector cells, and alteration in gene expression as measured by single cell RNA sequencing. EA2 3-month laboratory and imaging results are pending and will be presented. Conclusion(s) Nasal Foralumab in non-active SPMS patients treated for at least 3 months reduced microglial activation, decreased levels of proinflammatory cytokines, and had positive clinical effects.