Inclusion Criteria - Participant has histologically confirmed Grade 1, 2 or 3a follicular lymphoma (FL) or classic FL. Formalin-fixed paraffin embedded (FFPE) archival tissue from 1 year prior to screening is allowed. If more than 1 year has passed, then a fresh biopsy must be obtained to confirm the diagnosis. - Have no prior systemic treatment for follicular lymphoma. Prior radiation therapy or surgery for previously diagnosed stage I disease is acceptable. - Stage II to IV disease. - Deemed to need treatment by treating investigator. Reasons for treatment can include, but are not limited to, the following:. i) Bulky disease defined as:. A. A nodal or extra nodal (except spleen) mass > 7cm in its greater diameter or, involvement of at least 3 nodal or extra nodal sites (each with a diameter greater than >3 cm). ii) Presence of at least one of the following B symptoms:. A. Fever (>38°C) of unclear etiology. B. Night sweats. C. Weight loss greater than 10% within the prior 6 months. iii) Splenomegaly with inferior margin below the umbilical line. iv) Any one of the following cytopenia due to lymphoma:. A. Platelets <100,000 cells/mm3 (100 x 109/L). B. Absolute neutrophil count (ANC) < 1,500 cells/mm3 (1.5 x 109/L). C. Hemoglobin < 10g/dL (6.25 mmol/L). v) Pleural or peritoneal serous effusion (irrespective of cell content). vi) Any compressive syndrome (for example, but not restricted to ureteral, orbital, gastrointestinal). Exclusion Criteria - Clinical evidence of transformed lymphoma by investigator assessment. - Follicular Large Cell as per WHO 5th classification or Grade 3b follicular lymphoma as per WHO 4th classification. - Participant has any significant medical condition, active infection, laboratory abnormality, or psychiatric illness that would prevent the participation in the study. - Other protocol-defined Inclusion/Exclusion criteria apply.