Participants receiving venetoclax for chronic lymphocytic leukemia according to the approved local label, and the decision to prescribe Venetoclax is independent from the enrollment into the study.

An adverse event (AE) is defined as any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and which does not necessarily have a causal relationship with this treatment. The investigator assessed the relationship of each event to the use of study drug as either reasonable possibility or no reasonable possibility. A serious adverse event (SAE) is an event that results in death, is life-threatening, requires or prolongs hospitalization, results in a congenital anomaly, persistent or significant disability/incapacity or is an important medical event that, based on medical judgment, may jeopardize the subject and may require medical or surgical intervention to prevent any of the outcomes listed above. For more details on adverse events please see the Adverse Event section.

Overall Response will be assessed by the physician in charge of the study in accordance with the International Workshop on Chronic Lymphocytic Leukemia (iwCLL) guidelines.