Debulking Therapy with Obinutuzumab Is Helpful and Safe in Chronic Lymphocytic Leukemia with Extreme Hyperleukocytosis: A Case Report

Introduction: Chronic lymphocytic leukemia (CLL) represents the most frequent leukemia in the Western world, with an incidence of 4.2/100,000/year, and is often challenging to manage, especially in patients with extremely high WBC count due to the high risk of TLS. The adequate and best treatment is an open question that should be addressed beyond the biological features of the disease in order to guarantee the best outcome. Case presentation: We present the case of an elderly patient with a high tumor burden due to an extremely high white blood cell count (above 800,000/mmc), who received fixed-duration treatment with venetoclax–obinutuzumab (BCL2 inhibitor and anti-CD20) as first-line therapy. Despite the high risk for tumor lysis syndrome, we demonstrated that with cautious management it is possible to drastically reduce the WBC count, leading to a better quality of life and also even reaching a complete response in this grouping of patients. Obinutuzumab was first administered in the inpatient setting as the initial first-line debulking therapy, using personalized low-velocity treatment which led to a sustained and prolonged white blood cell count decrease, followed by venetoclax association. Conclusions: With proper support therapy, debulking obinutuzumab followed by venetoclax represented a life-saving treatment, able to normalize the blood count and achieve a complete response in a CLL patient with an extremely high risk of TLS, avoiding losing this therapeutic option.