A Trial to Learn if Odronextamab is Safe and Well-Tolerated and How Well it Works Compared to Rituximab Combined With Different Types of Chemotherapy for Adult Participants With Previously Untreated Follicular Lymphoma

Key Inclusion Criteria: 1. Diagnosis of Cluster of Differentiation 20^+ (CD20^+) FL Grade 1-3a, stage II bulky or stage III / IV 2. Need for treatment as described in the protocol 3. Have measurable disease on cross-sectional imaging documented by diagnostic imaging Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) 4. Eastern Cooperative Oncology Group (ECOG) performance status of 0-2Performance status 5. Adequate bone marrow function and hepatic function, as described in the protocol Key Exclusion Criteria: 1. Central Nervous System (CNS) lymphoma or leptomeningeal lymphomaBrain metastases 2. Histological evidence of transformation to a high-grade or diffuse large B-cell lymphoma 3. Waldenström Macroglobulinemia (WM, lymphoplasmacytic lymphoma), Grade 3b follicular lymphoma, chronic lymphocytic leukemia, or small lymphocytic lymphoma 4. Treatment with any systemic anti-lymphoma therapy 5. Infections and allergy/hypersensitivity to study drug or excipient, as described in the protocol NOTE: Other protocol defined inclusion/exclusion criteria apply