A Study to Compare the Efficacy and Safety of Golcadomide Plus R-CHOP vs Placebo Plus R-CHOP in Participants with Previously Untreated High-risk Large B-cell Lymphoma

INTERVENTION: Intervention1: Golcadomide(BMS‐986369/CC‐99282) Plus R‐CHOP: 1) Drug: Golcadomide, Route of Administration: PO, Intervention Dose: 0.4mg once daily, Dosing Day(s)(21‐day cycle): 1‐7 2)Drug: Rituximab Route of Administration: IV/SC Intervention Dose:375 mg/m2 (IV) or 1400 mg (SC) Dosing Day(s)(21‐day cycle): 1 3) Drug: Cyclophosphamide Route of Administration: IV Intervention Dose:750 750 mg/m^2 Dosing Day(s)(21‐day cycle): 1 4) Drug: Doxorubicin Route of Administration: IV Intervention Dose:50 mg/m^2 Dosing Day(s)(21‐day cycle): 1 Vincristine Route of Administration: IV Intervention Dose:1.4 mg/m2 (ma Xof 2.0 mg total) Dosing Day(s)(21‐day cycle): 1 5) Drug: Prednisone/Prednisolone (Day 1 IV administration is acceptable) a Route of Administration: PO Intervention Dose:100 mg Dosing Day(s)(21‐day cycle): 1‐5 Abbreviations: IV, intravenous; PO, by mouth; R‐CHOP, rituximab, doxorubicin, vincristine, cyclophosphamide, and prednisone; SC, subcutaneous. a: Prednisolone IV products to be sourced locally by sites. Control Intervention1: Placebo Plus R‐CHOP: 1) Drug: Placebo Route of Administration: PO Intervention Dose: Once daily Dosing Day(s)(21‐day cycle): 1‐7 2)Drug: Rituximab Route of Administration: IV/SC Intervention Dose: 375 mg/m 2 (IV) or 1400 mg (SC) Dosing Day(s)(21‐day cycle): 1 3)Drug: Cyclophosphamide Route of Administration: IV Intervention Dose: 750 mg/m 2 Dosing Day(s)(21‐day cycle): 1 4)Drug: Doxorubicin Route of Administration: IV Intervention Dose: 50 mg/m 2 Dosing Day(s)(21‐day cycle): 1 5)Drug: Vincristine Route of Administration: IV Intervention Dose: 1.4 mg/m 2 (ma Xof 2.0 mg total) Dosing Day(s)(21‐day cycle): 1 6)Drug: Prednisone/Prednisolone (Day 1 IV administration is acceptable) a Route of Administration: PO Intervention Dose: 10 CONDITION: Health Condition 1: C858‐ Other specified types of non‐Hodgkin lymphoma PRIMARY OUTCOME: To evaluate the efficacy of golcadomide plus R‐CHOP vs placebo‐R‐CHOP in participants with untreated high‐risk large B‐cell lymphoma with respect to PFS as assessed by the investigator.Timepoint: At baseline, 24 Months and until Progression free survival up to 5 years or study achieves endpoints SECONDARY OUTCOME: evaluate the efficacy of golcadomide plus ; R‐CHOP vs placebo‐R‐CHOP in participants ; with untreated high‐risk large B‐cell lymphoma ; with respect to CMR as assessed by the IRACTimepoint: 1) Complete metabolic response per IRAC defined as participant achieving CMR at EOT as assessed by IRAC based on the Lugano response criteria ; 2) Baseline cycle 4 day 1 & cycle6 day 8, End of treatment visit. To evaluate the efficacy of golcadomide plus ; R‐CHOP vs placebo‐R‐CHOP in participants ; with untreated high‐risk large B‐cell lymphoma ; with respect to EFS as assessed by the ; InvestigatorTimepoint: 1) Death, disease progression or relapse, initiation of subsequent systemic anti‐lymphoma therapy,biopsy‐proven disease after end of treatment ; 2)Baseline cycle 4 day 1 & cycle6 day 8, End of treatment visit. To evaluate the efficacy of golcadomide plus ; R‐CHOP vs placebo‐R‐CHOP in participants ; with untreated high‐risk large B‐cell lymphoma ; with respect to MRD negativity at EOT.Timepoint: 1) MRD negativity defined as participant having undetectable ctDNA levels at EOT. ; 2) Baseline cycle 4 day 1 & cycle6 day 8, End of treatment visit. To evaluate the efficacy of golcadomide plus ; R‐CHOP vs placebo‐R‐CHOPTimepoint: 1) OS defined as the time from randomization to death ; from any cause ; 2) Baseline cycle 4 day 1 & cycle6 day 8, End of treatment visit. INCLUSION CRITERIA: A) · Participant has histologically confirmed (per local evaluation) diagnosis of de novo, previously untreated LBCL according to 2022 WHO classification including: 1) DLBCL, NOS (including GCB and ABC types) 2) High‐grade B‐cell lymphoma, with MYC and BCL2 rearrangements 3) High‐grade B‐cell lymphoma, NOS 4) T‐cell/histiocyte/rich large B‐cell lymphoma (THRLBCL) 5) EBV plus DLBCL B) · Participant has: 1) IPI score 1 or 2 with LDH more than equal to 1.3 XULN and/or bulky disease defined as single lesion of more than equal to 7 cm OR IPI more than equal to 3 2) Measurable disease defined by at least 1 FDG‐avid lesion for FDG‐avid subtype and 1 bi‐ dimensionally measurable (more than 1.5 cm in longest diameter) disease by CT or MRI, as defined by the Lugano classification. 3) Participants must have Ann Arbor Stage II‐IV disease