Study on Treatment Outcome Patterns for Patients With CLL After Discontinuation of BTK Inhibitors

This Phase II hybrid decentralized multicenter study examines the outcomes of stopping Bruton tyrosine kinase inhibitor (BTKi) therapy in patients with chronic lymphocytic leukemia (CLL) who have remained in remission for at least two years. The primary objective is to determine how long patients remain free from disease progression or death after discontinuing treatment, measured as event free survival. The study also evaluates whether stopping BTKi therapy leads to improvements in quality of life and reductions in treatment related side effects. Researchers will follow patients over time to assess if the cancer returns, whether resistance to therapy develops, and how patients feel during the treatment free period. In addition, the trial will investigate how discontinuing BTKi therapy affects immune function, including whether immune recovery occurs and infection risk decreases. Preliminary data indicate that patients may experience a treatment free interval exceeding two years after stopping therapy, with associated improvements in quality of life. By prospectively evaluating a time limited treatment strategy, this trial aims to determine whether durable disease control can be maintained off therapy while also assessing the resolution of BTKi related adverse events and changes in patient reported outcomes. Overall, the study seeks to determine whether patients can safely discontinue BTKi therapy and potentially restart treatment later if needed, thereby maintaining disease control while reducing the burden of continuous therapy.

Inclusion Criteria: In order to participate in this study a subject must meet all of the eligibility criteria outlined below. * Written informed consent obtained to participate in the study and HIPAA authorization for release of personal health information. * Subjects is willing and able to comply with study procedures based on the judgement of the investigator. * Age ≥ 18 years at the time of consent. * Eastern Cooperative Oncology Group Performance Status of 0-3 or Karnofsky Performance Status of ≥40 * Confirmed of a diagnosis of CLL (Chronic Lymphocytic Leukemia) or SLL (Small Lymphocytic Lymphoma) according to International Workshop on Chronic Lymphocytic Leukemia 2018 Guidelines at any point prior to study enrollment. * At the time of enrollment, patients must be receiving treatment with a covalent Bruton tyrosine kinase inhibitor in the first or second line setting and have been receiving this treatment for at a minimum 2 years. Patients may have previously received anti-CD20 monoclonal antibodies (such as rituximab or obinutuzumab) in combination with the cBTKi. Exclusion Criteria: * Patients must not have evidence of progressive CLL as defined by IWCLL 2018 criteria. * Participants with history of malignancy other than CLL/SLL are allowed