Phase 2 Study of Frexalimab in Relapsing Multiple Sclerosis

Frexalimab is an investigational monoclonal antibody targeting CD40L, exhibiting anti-inflammatory effects mediated through T cells. This double-blind, industry-sponsored, phase 2 study randomized 129 patients to receive 1200 mg of intravenous frexalimab, 300 mg of subcutaneous frexalimab, or placebo weekly for 12 weeks.

From week 8 to week 12, gadolinium enhancing lesions were reduced by 89% with intravenous frexalimab and by 79% with subcutaneous administration compared with placebo. MRI T2-weighted lesions were likewise reduced, as were plasma levels of serum neurofilament light chain (a marker of neuroaxonal damage) and CXCL13 (a marker of inflammation). Adverse events occurring more than 5% in any group included COVID-19, headaches, and…