Sonrotoclax, Rituximab, and Zanubrutinib in Treating Participants With Chronic Lymphocytic Leukemia, Small Lymphocytic Lymphoma, and Mantle Cell Lymphoma

This phase II trial studies the side effects of an escalated ramp-up of sonrotoclax following initial debulking with zanubrutinib or rituximab in treating patients with chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL), and mantle cell lymphoma (MCL) that is newly diagnosed, has come back after a period of improvement (relapsed) or does not respond to treatment (refractory). Rituximab is a monoclonal antibody that binds to a protein called CD20, which is found on B-cells, and may kill tumor cells. Zanubrutinib may stop the growth of tumor cells by blocking a protein called Bruton's tyrosine kinase (BTK), which is needed for tumor cell growth. Sonrotoclax works by blocking a protein called B-cell lymphoma-2 (BCL-2). This protein helps certain types of blood tumor cells to survive and grow. When sonrotoclax blocks Bcl-2 it slows down or stops the growth of tumor cells and helps them die. Giving an increased dose of sonrotoclax over a shorter period of time in combination with zanubrutinib or rituximab may be safe and tolerable in treating patients with newly diagnosed, relapsed or refractory CLL, SLL, and MCL.

OUTLINE: This is a dose escalation study of sonrotoclax in combination with zanubrutinib or rituximab. Patients are assigned to 1 of 2 arms. ARM I: Patients not refractory to a Bruton's tyrosine kinase inhibitor (BTKi) undergo debulking and receive zanubrutinib orally (PO) once daily (QD) on day 1 of cycles 1-15. Beginning on day 1 of cycle 4, patients receive a ramp up of sonrotoclax PO QD until target dose is reached. Then patients will continue sonrotoclax PO QD and zanubrutinib PO QD through Cycle 15. Cycles repeat every 28 days for up to 15 cycles in the absence of disease progression or unacceptable toxicity. Patients also undergo computed tomography (CT) during screening and on study and blood sample collection throughout the study. Additionally, patients may undergo bone marrow biopsy and endoscopy on study. ARM II: Patients who are refractory to a BTKi undergo debulking and receive rituximab PO QD on days 1, 8, 15, and 22 of 1 cycle. Beginning on day 1 of cycle 2, patients receive a ramp up of sonrotoclax PO QD until target dose is reached. Patients will continue sonrotoclax PO QD through cycle 13. Patients also continue to receive ritiximab PO QD on day 1 of cycles 3-6. Cycles repeat every 28 in the absence of disease progression or unacceptable toxicity. Patients also undergo CT during screening and on study and blood sample collection throughout the study. Additionally, patients may undergo bone marrow biopsy and endoscopy on study. After completion of study treatment, patients are followed up at 14 days and up to 5 years.