Background Waldenström macroglobulinemia (WM) is a clonal B-cell lymphoproliferative disorder characterized by the presence of monoclonal IgM paraprotein. The traditional treatment approach was chemotherapy in combination with an anti-CD20 antibody. However, the treatment approach underwent a paradigm shift with the approval of Bruton tyrosine kinase inhibitors (BTKis). This retrospective analysis aims to highlight the efficacy and safety of BTKis in WM. Methodology Medical records of patients with WM who received BTKis were retrospectively reviewed. Relevant details regarding demographics, clinical and laboratory investigations, imaging reports, treatment, post-treatment response, adverse events, and infection were extracted from electronic medical records. Descriptive statistics and categorical variables were presented as frequencies and percentages. Survival outcomes were estimated by the Kaplan-Meier method. Results In total, 22 patients received BTKis. Of these, 12 patients received ibrutinib, whereas 10 patients received acalabrutinib. The median age was 64 years. MYD88 L265P positivity was seen in 19 (90.5%) cases, whereas CXCR4 mutations were seen in two (13.3%) cases. The most common indication for treatment with BTKis was anemia (n = 11, 50%). Overall response rate was seen in 18 (81.8%) cases, whereas major response rates were seen in 14 (63.7%) cases. At a median follow-up of 30 months, overall survival and progression-free survival were 91% (95% confidence interval (CI) = 0.87-0.95) and 82% (95% CI = 0.77-0.87), respectively. Neutropenia and thrombocytopenia were seen in 6 (27.3%) and 7 (31.8%) cases, respectively. Bleeding, arrhythmias, and infections were seen in 2 (9.1%), 3 (13.6%), and 18 (81.8%) cases, respectively. Conclusions BTKis are effective in WM but are associated with high rates of hematologic and non-hematologic side effects.
Singh et al. (Wed,) studied this question.