Can Monoclonal Antibodies Change the Course of Multiple System Atrophy?

Patients with multiple system atrophy (MSA) survive only about 6 to 10 years from symptom onset; we lack disease-modifying therapies. In this phase 2, randomized, double-blind, placebo-controlled, industry-sponsored trial, investigators tested whether amlenetug, an investigational (not FDA-approved) anti–α-synuclein monoclonal antibody, could slow MSA disease progression. The 61 participants in the U.S. and Japan, with either cerebellar or parkinsonian MSA, received intravenous amlenetug or placebo every 4 weeks for up to 72 weeks. The primary end point was disease progression at the end of treatment according to the Unified Multiple System Atrophy Rating Scale (UMSARS).