Ibrutinib Plus Venetoclax Long-Term Outcomes in CLL

This study is focused on tracking the long-term health of patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) treated with a combination of two drugs, ibrutinib and venetoclax, as part of the original CAPTIVATE clinical trial. Purpose and Goals While new treatments have significantly improved survival for patients with CLL, the disease remains incurable and often requires multiple rounds of treatment over a person's life. The primary goal of this study is to understand what happens to patients after they have completed their initial (frontline) treatment with a combination of two drugs, ibrutinib and venetoclax, as part of the original CAPTIVATE clinical trial. Researchers specifically want to: * Identify the types and frequency of "second-line" treatments patients receive if their disease returns. * Assess the long-term safety and effectiveness of the initial ibrutinib and venetoclax treatment. * Study how the disease might become resistant to these treatments over time. Who Can Participate? The study is specifically for individuals who were previously enrolled in the original CAPTIVATE study. Only patients at participating medical centers who provide their informed consent can join. Study Methods and Procedures This is an observational study, meaning researchers will monitor patients' health during their routine medical care rather than testing a new, experimental treatment. Key aspects of the study include: * Long-Term Monitoring: Patients will be followed for up to 10 years. * Data Collection: Researchers will collect information on disease status, treatment history, new health issues (comorbidities), and survival. * Optional Testing: With additional consent, patients may provide blood samples every six months to check for "measurable residual disease" (MRD)-very small amounts of cancer cells that remain after treatment. * Genetic Analysis: If a patient's CLL progresses, researchers may analyze blood samples to look for specific genetic mutations that might explain why the treatment stopped working. Participation is entirely voluntary, and patients can choose to withdraw from the study or opt out of specific tests (like blood sampling) at any time without affecting their standard medical care.