Chronic graft-versus-host disease (cGVHD) is a severe complication following allogeneic stem cell transplantation, with limited treatment options available after corticosteroid failure. A recent multicenter, open-label study evaluated the safety and efficacy of Ibrutinib, a first-in-class inhibitor of Bruton tyrosine kinase (BTK) and interleukin-2–inducible T-cell kinase (ITK), in patients with active cGVHD who had an inadequate response to corticosteroid-containing therapies.
Key Findings:
- High Response Rate: The study found that Ibrutinib induced a high rate of sustained responses, with 67% of patients achieving a best overall response. Among responders, 71% showed a sustained response for ≥20 weeks.
- Reduction in Corticosteroid Use: Responders experienced a significant decrease in corticosteroid dose, from a median of 0.29 mg/kg per day at baseline to 0.12 mg/kg per day at week 49, with five responders discontinuing corticosteroids entirely.
- Safety Profile: The most common adverse events were fatigue, diarrhea, muscle spasms, nausea, and bruising, with most being grade 1 or 2. Serious adverse events included pneumonia and infections.
Study Design: The study enrolled 42 patients who had failed 1 to 3 prior treatments for cGVHD. Patients received a daily dose of 420 mg Ibrutinib until cGVHD progression. The primary efficacy endpoint was cGVHD response based on 2005 National Institutes of Health criteria.
Conclusion: Ibrutinib demonstrated clinically meaningful responses with an acceptable safety profile in patients with cGVHD who had failed prior systemic therapy. These results supported the approval of Ibrutinib in the United States for the treatment of adult patients with cGVHD after failure of one or more lines of systemic therapy. This study highlights the potential of Ibrutinib as a promising treatment option for cGVHD, offering hope for patients with limited therapeutic options.