The study is designed as a multicenter, prospective, observational registry of CLL/SLL patients who are initiating approved oral kinase inhibitors, BCL-2 inhibitors or other approved anti-CLL therapies/regimens. The study will characterize treatment patterns and their association with patient characteristics, healthcare resource utilization, and clinical outcomes, as well as patient-reported outcome (PRO) measures.

This multicenter, prospective, observational registry of CLL patients is designed to characterize and describe treatment patterns for those initiating treatment with approved oral kinase inhibitors and other approved anti-CLL therapies/ regimens. The registry will provide information on regimens used to treat first-line and later lines of CLL as well as the sequencing of treatment regimens. The registry will also evaluate the association of these treatment patterns with patient characteristics, healthcare resource utilization, and functional outcomes including patient-reported HRQoL. These data will provide information to physicians that may help guide clinical practice and appropriate use of therapies, and will also provide information on HRQoL and healthcare resource utilization that will be of interest to healthcare decision makers.

Inclusion Criteria:

• Age of at least 18 years
• Clinical diagnosis of CLL/SLL that meets published diagnostic criteria (Hallek 2008)
• Initiating anti-CLL/SLL treatment regimen (excluding clinical trials) within ±45 days of enrollment
• Availability of documentation of previous CLL/SLL treatment and duration of response in the patient's medical records if patient has received prior line(s) of treatment (i.e. NOT treatment naïve)
• Willing and able to provide informed consent
• Willing and able to complete PRO instrument
• Willing and able to provide information on patient survey questionnaire
• Willing and able to provide a blood sample at time of enrollment prior to receiving treatment, as possible

Exclusion Criteria:

• Diagnosis of B-cell malignancies other than CLL/SLL
• Estimated life expectancy <6 months
• Currently receiving treatment in an interventional clinical trial at time of entry into this study * Note- Exceptions: 1) Patients may enroll in interventional clinical trials for indications other than CLL/SLL, 2) The interventional clinical trial treatment is not the treatment used for meeting Inclusion Criteria #2 (or "Index Treatment"), 3) Patients may enroll in an interventional clinical trial indicated for CLL/SLL as later line of treatment after discontinuing the Index Treatment

The registry will aim to enroll approximately 1500 patients with CLL/SLL from a total of 200 sites in the US over a 45 month enrollment period. In order to best capture real-world treatment patterns, site recruitment will aim to include approximately 85% of sites from the community hematology-oncology setting.