Modern approaches to the treatment of chronic lymphocytic leukemia: chemoimmunotherapy, targeted therapy, and minimal residual disease assessment

Chronic lymphocytic leukemia (CLL) is one of the most common B-cell lymphoproliferative disorders characterized by the progressive accumulation of monoclonal CD5+, CD19+, and CD23+ lymphocytes in the peripheral blood, bone marrow, lymph nodes, liver, and spleen. Over the past two decades, therapeutic strategies for CLL have evolved significantly, transitioning from conventional chemotherapy to chemoimmunotherapy and, subsequently, to targeted molecular therapies. The fludarabine, cyclophosphamide, and rituximab (FCR) regimen has long remained the standard first-line treatment for fit patients, demonstrating high response rates and prolonged progression-free survival. However, the development of Bruton tyrosine kinase inhibitors, BCL-2 inhibitors, and phosphoinositide 3-kinase inhibitors has substantially changed the therapeutic landscape.