The purpose of this study is to investigate the efficacy and safety of BGB-16673 compared with investigator's choice (idelalisib plus rituximab [for CLL only] or bendamustine plus rituximab or venetoclax plus rituximab retreatment) in participants with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) previously exposed to both BTK inhibitors (BTKi) and BCL2 inhibitors (BCL2i).

Chronic lymphocytic leukemia is a type of blood cancer that affects people around the world. People with CLL suffer from enlarged lymph nodes, spleen, or liver, or have symptoms like night sweats, weight loss and fever. They have shorter life expectancy compared to healthy people. There is an urgent need for new treatment to prolong life and control disease-related symptoms.

In this study, participants with relapsed/refractory (R/R) CLL who were previously exposed to a BTKi and a BCL2i will receive BGB-16673 or the investigator's choice of idelalisib plus rituximab (for CLL only) or bendamustine plus rituximab or venetoclax plus rituximab retreatment. The main purpose of this study is to compare the length of time that participants live without their CLL or SLL worsening between those participants who receive BGB-16673 versus the investigator's choice of treatment (idelalisib plus rituximab or bendamustine plus rituximab, or venetoclax plus rituximab).

Approximately 250 participants will be included in this study around the world. Participants will be randomly allocated to receive either BGB-16673 or the investigator's choice of treatment.

"Our company, previously known as BeiGene, is now officially BeOne Medicines. Because some of our older studies were sponsored under the name BeiGene, you may see both names used for this study on this website."

Inclusion Criteria:

1. Confirmed diagnosis of CLL or SLL, requiring treatment, based on 2018 international workshop on chronic lymphocytic leukemia (iwCLL) criteria.
2. Previously received treatment for CLL/SLL with both a BTKi and a BCL2i.
3. Participants with SLL must have measurable disease by computer tomography (CT)/magnetic resonance imaging (MRI)
4. Eastern Cooperative Oncology Group (ECOG) score 0, 1, or 2
5. Adequate liver function
6. Adequate blood clotting function

Exclusion Criteria:

1. Known prolymphocytic leukemia or history of, or currently suspected, Richter's transformation
2. Prior autologous stem cell transplant or chimeric antigen receptor-T cell therapy in the last 3 months
3. Known central nervous system involvement
4. Prior exposure to any BTK protein degraders
5. Active fungal, bacterial and/or viral infection requiring parenteral systemic therapy
6. Clinically significant cardiovascular disease

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.

BeOne shares data on completed studies responsibly and provides qualified scientific and medical researchers access to data and supporting documentation for clinical trials in dossiers for medicines and indications after submission and approval in the United States, China, and Europe. Clinical trials supporting subsequent local approvals, new indications, or combination products are eligible for sharing once corresponding regulatory approvals are achieved.

BeOne shares data only when permitted by applicable data privacy and security laws and regulations, when it is feasible to do so without compromising the privacy of study participants, and other considerations.

Qualified researchers with appropriate competencies who are engaged in novel scientific research may submit a request for participant-level data with a research proposal for BeOne review. Research teams must include a biostatistician and sign a Data Sharing Agreement prior to receiving access to clinical trial data.

See plan description

See plan description