FDA Approves Incyte and Syndax's Niktimvo for Chronic Graft Versus Host Disease

Incyte and Syndax Pharmaceuticals' Niktimvo (axatilimab-csfr) has recently received approval from the US Food and Drug Administration (FDA) for the treatment of chronic graft versus host disease (GVHD). This new anti-CSF-1R antibody is indicated for adult and pediatric patients weighing at least 40 kilograms who have not responded to at least two prior lines of systemic therapy.

Chronic GVHD is a significant complication that affects approximately 42% of patients undergoing allogeneic stem cell transplants. This condition arises when the transplanted cells mount an immune response against the recipient's organs. There are two primary forms of GVHD: acute and chronic. Chronic GVHD begins to manifest more than 100 days post-transplant, and nearly half of these patients will require at least three different lines of treatment to manage the disease.

Niktimvo specifically addresses key factors that drive inflammation and fibrosis associated with chronic GVHD. The FDA's approval of Niktimvo was based on data from the phase 2 AGAVE-201 study. In this study, the treatment showed durable responses across multiple organs and patient subgroups. Among the patients who received the recommended dose of 0.3mg/kg every two weeks, 75% achieved an overall response rate within the first half-year of treatment. Impressively, 60% of these patients maintained their response after one year.

The trial also reached an important exploratory endpoint, as 56% of patients experienced at least a seven-point improvement in the modified Lee Symptom Scale score. This scale is used to measure symptom severity and quality of life in patients with chronic GVHD.

Michael Metzger, CEO of Syndax, described the FDA approval as a "significant treatment advancement" for patients affected by this condition. He expressed enthusiasm about introducing this first-in-class anti-CSF-1R antibody to patients in need of new treatment options. Metzger also highlighted ongoing efforts to explore Niktimvo's potential in combination with other standard treatments for chronic GVHD and in additional medical conditions.

Future research on Niktimvo includes a phase 2 trial evaluating its efficacy alongside ruxolitinib and a late-stage trial combining it with steroids. These trials are expected to begin by the end of the year. Additionally, Niktimvo is being investigated in an ongoing phase 2 trial for patients with idiopathic pulmonary fibrosis.

Niktimvo will be co-commercialized by Incyte and Syndax in the United States. Outside the US, Incyte holds exclusive commercial rights for the drug. This collaboration aims to extend the reach of Niktimvo to benefit more patients globally who are struggling with chronic GVHD and potentially other fibrotic and inflammatory diseases.