Efficacy and Safety of Ibrutinib for Chronic Graft-Versus-Host Disease: A Systematic Review.

Introduction: Allogeneic hematopoietic cell transplantation (allo-HCT) serves as a potentially curative intervention for various hematologic disorders. However, its utility can be limited by the emergence of chronic graft-versus-host disease (cGVHD). The clinical manifestations of cGVHD result from a complex immune response characterized by the involvement of both B and T cells. Ibrutinib, a pharmacological agent, acts as an inhibitor of Bruton's tyrosine kinase (BTK) pathway, which becomes activated through the B-cell receptor and regulates B-cell survival. By exerting inhibitory effects on both BTK and inhibitor of interleukin-2 inducible T-cell kinase (ITK), ibrutinib exhibits promise as a therapeutic approach for managing cGVHD. Ibrutinib may be considered as a viable treatment option for active cGVHD in cases where patients exhibit an inadequate response to corticosteroid-based therapies. This systematic review seeks to assess the efficacy and safety of ibrutinib in the context of cGVHD patient management.

Method: We incorporated search engines from PubMed, Embase, Cochrane Library, Scopus, Web of Science, and ClinicalTrials.gov. The study was performed following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 and Assessing The Methodological Quality of Systematic Review (AMSTAR). We used Risk of Bias- 2 (RoB-2) tool for assess the risk of bias in randomized controlled studies (RCTs) and Newcastle Ottawa Scale (NOS) for observational and open-label studies.

Results: A total of 7 studies were included in this study consisted of four open-label studies, two retrospective cohort studies, and one RCT study. These studies compared Ibrutinitib with standard therapies. Two studies investigated the pediatric population, and five studies investigated the adult population. Overall, these studies reported the overall response rate (ORR) of ibrutinib for cGVHD were 54%-78%. The results showed that in pediatric patients, the ORR were 54-78%. The results also showed that in adult patients, the ORR were 67%-76%. The most common adverse effects observed across the seven studies included pyrexia, diarrhea, abdominal pain, cough, nausea, stomatitis, vomiting, headache, bleeding and bruising, infection, muscle aches, fatigue, oral bleeding, elevated transaminases, lower gastrointestinal bleeding, persistent dizziness, sepsis, pneumonia, reduced platelet count, exhaustion, sleeplessness, peripheral edema, and fatigue.

Conclusion: The majority of studies have indicated that ibrutinib exhibits a high ORR and provides long-lasting responses, while also having manageable side effects.