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 2
* 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 lymphoma
* Clinically significant cardiovascular disease
* History of stroke or intracranial hemorrhage within 6 months before first dose of study drug

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