Inclusion Criteria:

          -  Histologically confirmed diagnosis of follicular lymphoma (FL) as defined in the World
             Health Organization (WHO) classification scheme, limited to Grade 1, 2, or 3a

          -  Subjects that have had progression of disease or had no response to therapy after at
             least 2 prior systemic therapies for FL

          -  Age ≥ 18

          -  At least one bi-dimensionally measurable nodal lesion > 1.5 cm in its longest diameter
             by computed tomography (CT) scan as defined by the Lugano Classification

          -  Adequate hematologic, renal and hepatic parameters at screening unless abnormal values
             are due to FL per Investigator assessment

          -  QT-interval corrected according to Fridericia's formula (QTcF) ≤ 450 milliseconds
             (msec);

          -  Left ventricular ejection fraction (LVEF) ≥ 45%

        Exclusion Criteria:

          -  Histologically confirmed FL Grade 3b transformation from FL to an aggressive lymphoma

          -  Known lymphomatous involvement of the central nervous system

          -  Uncontrolled clinically significant illness

          -  Ongoing or history of drug-induced pneumonitis

          -  History of clinically significant cardiovascular abnormalities

          -  History of clinically significant GI conditions

          -  Known history of, or active HIV infection