Barbara Eichhorst, MD from University of Cologne, Cologne, Germany outlines tumor lysis syndrome as a side-effect of venetoclax in treatment of patients with chronic lymphocytic leukemia (CLL). Tumor lysis syndrome can be avoided if the initial dosage begins at 20mg and is doubled every week till a dosage of 400mg is reached. Certain patients have a particularly high risk of developing tumor lysis, especially those with a high lymphoma burden, high lymphocyte count or large lymph nodes (above 10cm). These patients may have to come more frequently or stay for extended periods of time in the clinic. Recorded at the European Hematology Association (EHA) 2016 Annual Congress in Copenhagen, Denmark.