FDA Approves Axatilimab for Chronic GVHD

The US Food and Drug Administration (FDA) has approved axatilimab (Niktimvo, Incyte Corporation) for the treatment of adult and pediatric patients with chronic graft versus host disease (GVHD) who have not responded to at least two prior lines of systemic therapy and who weigh ≥ 40 kg.

Chronic GVHD is a potentially life-threatening complication of allogeneic hematopoietic stem cell transplantation that develops in about 50% of transplant recipients.

The first-in-class treatment for chronic GVHD is a monoclonal antibody that targets the colony-stimulating factor 1 (CSF-1) receptor. Approval for axatilimab followed priority review of Incyte’s Biologic License Application and was based on findings from the open-label phase 2 AGAVE-201 trial. 

Study participants had chronic GVHD after allogeneic hematopoietic stem cell transplantation and had failed to respond to at least two prior lines of systemic therapy (median, four lines of therapy). Prior therapies included ruxolitinib, belumosudil, and ibrutinib in 74%, 23%, and 31% of patients, respectively. Overall, 239 patients were enrolled at 121 study sites and were randomly assigned 1:1:1 to three doses.

The FDA recommended dose of axatilimab is 0.3 mg/kg (to a maximum of 35 mg) as an intravenous infusion over 30 minutes every 2 weeks until disease progression or unacceptable toxicity. Other doses tested in the AGAVE-201 trial were 1 mg/kg every 2 weeks and 3 mg/kg every 4 weeks. 

The trial measured overall response rate over the first six cycles (24 weeks). In the 79 patients who received the recommended 0.3-mg/kg dose, the overall response rate was 75%, and the median time to first response was 1.5 months (range, 0.9-5.1). The median duration of response — measured from first response to progression, death, or switch to a new systemic therapy for chronic GVHD — was 1.9 months. 

In those who responded to the therapy, there were no deaths or new therapies required in 60% of patients.

The most common adverse reactions, occurring in 15% or more patients, included increased aspartate aminotransferase, infection (pathogen unspecified), increased alanine aminotransferase, decreased phosphate, decreased hemoglobin, musculoskeletal pain, increased lipase, fatigue, increased amylase, increased calcium, increased creatine phosphokinase, nausea, headache, diarrhea, cough, pyrexia, and dyspnea. 

In the AGAVE-201 trial results, researchers noted that drug discontinuation from treatment-emergent adverse events occurred in 6% of patients in the 0.3-mg/kg cohort, in 22% in the 1-mg/kg cohort, and in 18% in the 3-mg/kg cohort. Fatal treatment-emergent adverse events occurred in 1.3% of patients in the 0.3-mg/kg cohort. 

Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape, MDedge and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at sworcester@mdedge.com or on Twitter: @SW_MedReporter.