Axatilimab (Niktimvo®) in chronic graft-versus-host disease: a profile of its use

Axatilimab (axatilimab-csfr; Niktimvo®), an anti-colony stimulating factor 1 receptor (CSF1R) monoclonal antibody, is a useful addition to treatment options in the USA for chronic graft-versus-host disease (cGVHD) in patients weighing ≥ 40 kg who have failed ≥ two prior lines of systemic therapy. It acts through a novel mechanism, inhibiting macrophage activation and differentiation via CSF1R blockade. In the AGAVE-201 clinical trial, axatilimab 0.3 mg/kg once every 2 weeks improves patient condition and reduces patient-reported symptom severity. While no patients achieved overall complete responses, responses were observed in all affected organs, including organs with difficult-to-treat fibrotic manifestations. The tolerability profile of axatilimab at the approved dosage was generally manageable. Infections were the most common adverse events, and laboratory abnormalities caused by CSF1R blockade were transient and not associated with end-organ damage. Current evidence is limited by the small patient population and open-label phase 2 trial design; results from ongoing clinical trials of axatilimab in cGVHD are awaited with interest. Chronic graft-versus-host disease (cGVHD) is a major cause of morbidity and non-relapse mortality for patients who have undergone allogeneic hematopoietic stem-cell transplantation. Over half of cGVHD patients do not achieve durable responses with first-line corticosteroids, and response rates with new agents vary, with many patients experiencing disease progression and end-organ damage. Axatilimab (axatilimab-csfr; Niktimvo®), an anti-colony stimulating factor 1 receptor monoclonal antibody, was recently approved in the USA for the treatment of cGVHD in patients weighing ≥ 40 kg who have failed ≥ two prior lines of systemic therapy. In a phase 2 clinical trial, axatilimab 0.3 mg/kg once every 2 weeks improved patient condition and reduced patient-reported symptom severity. Improvements were observed across all affected organs, including those with difficult-to-treat fibrotic manifestations. The tolerability profile of axatilimab at the approved dosage was generally manageable; infections were the most common adverse events, and changes in laboratory results were temporary and not associated with end-organ damage. Axatilimab is a useful addition to treatment options in the USA for patients with recurrent or refractory cGVHD who have failed ≥ two prior lines of systemic therapy.