Counting the CHIPs: The High-Stakes Role of Clonal Hematopoiesis in Multiple Myeloma

Clonal hematopoiesis of indeterminate potential (CHIP) is the clonal expansion of somatically mutated hematopoietic stem cells (HSCs) in the bone marrow. CHIP mutations are relatively common in multiple myeloma (MM) and have been identified as potential biomarkers for poorer survival outcomes. MM is a hematological malignancy that, despite treatment advances, remains aggressive and incurable for many patients. The potential impact of CHIP mutations on the outcomes of MM treatments has been the topic of several recent studies, yet both the magnitude and the modality by which CHIP exerts its negative effects on treatment and disease progression remain to be fully elucidated. Evidence suggests that CHIP mutations may contribute to inferior survival and treatment tolerances, as well as contribute to greater treatment toxicity and related frailty. In this review, we synthesize and discuss the available literature to provide an updated understanding of the complex role that CHIP plays in altering the MM microenvironment, and the resulting impact on standard MM treatments, autologous stem cell transplant (ASCT) and B-cell maturation antigen (BCMA)-targeted therapy/CAR-T, and the important role of immunomodulatory drug (IMiD) maintenance therapy in clinical outcomes.