Axatilimab, a novel treatment strategy, was found to be effective with a favorable safety profile for chronic graft-versus-host disease (cGVHD), according to study results published in the Journal of Clinical Oncology.

The most common late complication of allogenic hematopoietic cell transplant is cGVHD, affecting up to 70% of patients and associating with morbidity and mortality. In early-phase clinical trials, axatilimab, a high-affinity, humanized immunoglobulin (Ig)G4 monoclonal antibody, was found to eliminate nonclassical monocytes from peripheral blood.

In this phase 1/2 open-label trial, optimal dosing, safety, and efficacy of axatilimab was evaluated in 40 patients ages 6 years and older who had refractory cGVHD.


Continue Reading

The study population was median age 59 years (range, 16 to 73), 37.5% were female, 85.0% had severe cGVHD, 65% had 4 or more involved organs, and 57.5% had received at least 4 prior lines of therapy.

In the phase I portion of the trial, patients received axatilimab 0.15, 0.5, 1, or 3.0 mg/kg once every 2 weeks or 3.0 mg/kg once every 4 weeks. The optimal dosing, used in phase 2 (23 patients), was determined to be 1.0 mg/kg every 2 weeks.

Among all axatilimab recipients, the treatment-related adverse event rate was 75.0% and related serious adverse event rate was 10.0%. Adverse events led to dose modification in 32.5% and discontinuation in 17.5%. One death occurred.

The overall response rate at cycle 7 was 50% and the best response rate was 69%. Responses were similar in patients with moderate (83%) and severe (67%) cGVHD and in patients who were pretreated with ruxolitinib (65%), ibrutinib (58%), and belumosudil (50%).

The median time to response was 4 to 5 weeks and the median duration of axatilimab exposure among responders was 38 weeks.

This study found evidence supporting the development of axatilimab for the treatment of cGVHD and is currently being investigated in the ongoing trial AGAVE-201.

Disclosure: Some authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Reference

Kitko CL, Arora M, DeFilipp Z, et al. Axatilimab for chronic graft-versus-host disease after failure of at least two prior systemic therapies: results of a phase I/II study. J Clin Oncol. Published online December 2, 2022. doi:10.1200/JCO.22.00958