Phase 1 Study of Axatilimab (SNDX-6352), a CSF-1R Humanized Antibody, for Chronic Graft-Versus-Host Disease after 2 or More Lines of Systemic Treatment

Background:Chronic graft versus host disease (cGVHD) is a major cause of morbidity and late non-relapse mortality after allogeneic hematopoietic cell transplantation and is commonly associated with prolonged immune suppression. Patients (pts) with inadequate response to steroids have few effective therapeutic options and represent an unmet medical need. Available therapies are associated with significant toxicity, immunosuppression, and increased risk of infections. Preclinical studies demonstrate that CSF-1/CSF-1R is a key regulatory pathway involved in the expansion and infiltration of donor-derived macrophages that mediate cGVHD. Axatilimab (SNDX-6352, axa) is a humanized, full-length IgG4 antibody with high affinity to CSF-1R. Axa affects the migration, proliferation, differentiation, and survival of monocytes and macrophages by binding to CSF-1R and blocking its activation by its two known ligands, CSF-1 and IL-34. It offers a novel therapeutic option for treatment of these pts