Chronic graft-versus-host disease (cGVHD) poses significant challenges in the management of patients who have undergone transplant procedures. Current treatment options often provide limited efficacy or unacceptable toxicity, highlighting the need for novel therapeutic strategies. The phase II AGAVE-201 trial investigated the potential of axatilimab, a high-affinity anti-CSF-1R monoclonal antibody, in patients with recurrent/refractory cGVHD. The study results demonstrated promising outcomes and opened new avenues for improving the quality of life for these vulnerable patients.
Dr. Daniel Wolff and his team at the University Hospital of Regensburg in Germany led the AGAVE-201 trial. The study revealed that axatilimab achieved rapid and durable responses in patients with cGVHD. The overall response rate (ORR) was particularly noteworthy, with the lowest dose of axatilimab at 0.3 mg/kg every 2 weeks demonstrating the highest ORR of 74% within the first 6 months. This finding highlights the importance of optimizing dosing strategies to maximize efficacy while minimizing toxicity. Additionally, the response to therapy was rapid, with a median time of 1.7 months, and this response was maintained for 12 months or longer in 60% of patients.
Chronic GVHD is a complex, multi-organ, inflammatory disease that requires multiple lines of treatment. Its impacts can significantly reduce the quality of life for patients, making it essential to develop new therapies that provide durable responses. Axatilimab targets colony-stimulating factor-1 receptor (CSF-1R)-dependent monocytes and macrophages, key players in cGVHD inflammation and fibrosis. By specifically targeting these cells, axatilimab offers a unique mechanism of action that shows promise in addressing the underlying pathology of cGVHD.
AGAVE-201 demonstrated organ-specific responses across various involved organs. Fibrosis-dominated organs, such as the esophagus, joints and fascia, lung, and skin, showed notable improvements in response to axatilimab treatment. This encouraging outcome indicates that axatilimab might be particularly effective in alleviating fibrotic complications associated with cGVHD. In addition, more than half of the patients in the low-dose cohort reported a significant improvement in symptom burden, further emphasizing the potential impact of axatilimab on patients’ quality of life.
The AGAVE-201 trial revealed important dose-response associations. The lowest dose of axatilimab exhibited the highest overall response rate and the least toxicity. This finding underscores the importance of conducting sufficiently powered studies to determine the optimal dosing strategies in this patient population. Adverse events leading to treatment discontinuation were significantly lower in the low-dose cohort compared to the higher dose cohorts, indicating a favorable safety profile. However, higher doses of axatilimab were associated with periorbital edema, pointing to the importance of careful monitoring and dose adjustments to mitigate potential side effects.
Axatilimab’s promising results in the AGAVE-201 trial have led to its recognition as a potential new therapeutic strategy in cGVHD. The study findings indicate a need for further investigation and the development of well-tolerated and rapidly working agents that provide durable responses. Developers Syndax Pharmaceuticals and Incyte have announced plans to submit a biologics license application to the FDA based on the AGAVE-201 results, demonstrating their commitment to advancing this potential treatment option. If approved, axatilimab could significantly improve the management of cGVHD and enhance the quality of life for patients.
Axatilimab shows great promise as a treatment option for patients with recurrent/refractory cGVHD. The AGAVE-201 trial demonstrated both rapid and durable responses, with the lowest dose of axatilimab achieving the highest overall response rate. By targeting CSF-1R-dependent monocytes and macrophages, axatilimab addresses the underlying inflammation and fibrosis in cGVHD. The study results highlight the importance of optimizing dosing strategies and sufficiently powered studies to maximize efficacy and minimize treatment toxicity. With further research and regulatory approval, axatilimab may represent a significant advancement in the management of cGVHD, offering renewed hope to patients and their families.