A Study to Investigate the Efficacy and Safety of Sonrotoclax Plus Zanubrutinib Compared With Placebo Plus Zanubrutinib in Adults With Relapsed/Refractory Mantle Cell Lymphoma (CELESTIAL-RRMCL)

Inclusion Criteria: * Histologically locally confirmed diagnosis of MCL based on the World Health Organization 2022 classification of Haematolymphoid Tumors (WHO-HAEM5), or based on International Consensus Classification (ICC) * Ability to provide archival or fresh tumor tissue for retrospective central confirmation of MCL diagnosis * Received 1 to 5 prior lines of systemic therapy including an anti-CD20 monoclonal antibody (mAb)-based immunotherapy or chemoimmunotherapy and requiring treatment in the opinion of the investigator * Relapsed or refractory disease after the last line of therapy * Measurable disease defined as ≥ 1 nodal lesion that is > 1.5 cm in longest diameter, or ≥ 1 extranodal lesion that is > 1 cm in longest diameter * Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 to 2Performance status * Adequate organ function Exclusion Criteria: * Prior therapy with B-cell lymphoma-2 inhibitor (BCL2i) * Prior therapy with BTK degraders * Prior therapy with covalent or non-covalent Bruton tyrosine kinase inhibitor (BTKi) unless the participant was intolerant of non-zanubrutinib covalent or non-covalent BTKi. Participants with refractory disease to BTKi therapy or relapse attributed to failure of BTKi therapy are ineligible. * Prior autologous stem cell transplantation or chimeric antigen receptor T-cell therapy within 3 months before first dose of study drug * Prior allogeneic stem cell transplant within 6 months of the first dose of the study drug * Known central nervous system involvement by lymphomaBrain metastases * Clinically significant cardiovascular diseaseCardiac * History of stroke or intracranial hemorrhage within 6 months before first dose of study drug Note: Other protocol defined Inclusion/Exclusion criteria may apply.