Study of Subcutaneous Epcoritamab in Combination With Intravenous Rituximab and Oral Lenalidomide (R2) to Assess Adverse Events and Change in Disease Activity in Adult Participants With Previously Untreated Follicular Lymphoma

Inclusion Criteria

• •Diagnosis of follicular lymphoma (FL).
• •Have CD20+, histologically confirmed classic FL (previously Grade 1 to 3a FL) at most recent representative tumor biopsy based on the local pathology report, according to the 5th edition of World Health Organization (WHO) Classification of Haematolymphoid Tumours.
• •Are willing and able to comply with procedures required in the protocol.
• •Must have stage, III, IV or II with bulky disease \>= 7cm).
• •Must be in need of systemic treatment per investigator, as evidenced by meeting at least one of the Groupe d'Etude des Lymphomes Folliculaire (GELF) criteria.
• •Has one or more target lesions:
• •* A positron emission tomography (PET)/computerized tomography (CT) scan demonstrating PET-positive lesion(s), and
• •* \>=1 measurable nodal lesion (long axis \>1.5cm) or \>=1 measurable extra-nodal lesion (long axis \>1.0 cm) on CT scan or MRI
• •Eastern Cooperative Oncology Group (ECOG) performance status 0-2.
• •Able to receive at least one of the standard of care chemoimmunotherapy (CIT) treatment regimens: \[Arm B\] at the discretion of the Investigator, and rituximab and lenalidomide (R2) \[Arm C\].
• •Have laboratory values meeting the criteria in the protocol.