A Study of BGB-21447, a Bcl-2 Inhibitor, in Mature B-Cell Malignancies

This study is testing the safety and tolerability of BGB-21447 monotherapy in participants with relapsed or refractory (R/R) non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). The study aims to determine the maximum tolerated dose (MTD), maximum administered dose (MAD), recommended Phase 2 dose (RP2D), and pharmacokinetic profile of the drug. Additionally, preliminary antitumor activity will be characterized. The study is divided into 2 main parts: Part 1 "Monotherapy Dose Finding" and Part 2 "Monotherapy Dose Optimization."

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 (per World Health Organization \[WHO\] guidelines, unless otherwise noted) of one of the following: Cohort A1 and Cohort A2: 1. R/R DLBCL (for Cohort A1 and Cohort A2.1) * High-grade B-cell lymphomas with translocations of MYC and Bcl-2 and/or Bcl-6 are not allowed in Cohort A1 but may be allowed in Cohort A2.1 2. R/R FL (for Cohort A1 and Cohort A2.2) 3. R/R MZL (for Cohort A1 and Cohort A2.2) 4. Transformed B-cell NHL (for Cohort A1 only) 5. Richter's transformation to DLBCL (for Cohort A1 only) 2. Measurable disease by computed tomography/magnetic resonance imaging. Exclusion Criteria: 1. Prior malignancy (other than the disease under study) within the past 2 years, except for curatively treated basal or squamous skin cancer, superficial bladder cancer, carcinoma in situ of the cervix or breast, or localized Gleason score ≤ 6 prostate cancer or lentigo maligna melanoma that has been curatively resected 2. Known central nervous system involvement by lymphoma/leukemia 3. Prior autologous stem cell transplant \< 3 months before the first dose of study drug. Or prior chimeric antigen receptor T-cell (CAR-T) therapy \< 3 months before the first dose of study drug 4. Prior allogeneic stem cell transplant. 5. Major surgery \< 4 weeks before the first dose of study treatment NOTE: Other protocol-defined Inclusion/Exclusion criteria may apply.