Waldenström Macroglobulinemia: Targeted Agents Taking Center Stage

With the worldwide approval of the oral covalent Bruton tyrosine kinase (BTK) inhibitors ibrutinib and zanubrutinib for treating patients with Waldenström macroglobulinemia (WM), targeted agents have certainly taken center stage in the therapeutic landscape of WM. This review discusses the biological and clinical data supporting current and up-and-coming targeted agents in WM. Bruton tyrosine kinase inhibitors induce fast, deep, and durable responses in patients with WM, comparable to chemoimmunotherapy; however, there is a glaring absence of comparative studies between these regimens. The high response and progression-free survival rate and the ease of administration of BTK inhibitors must be balanced against their specific adverse-event profile with unique toxicity (e.g., bleeding and cardiac arrhythmia) and the indefinite duration of the therapy. Novel targeted agents of interest include BCL2 antagonists (e.g., venetoclax and sonrotoclax) and non-covalent BTK inhibitors (e.g., pirtobrutinib and nemtabrutinib), among others. The therapeutic landscape of patients with WM will benefit from the robust participation of patients in clinical trials.