['chronic lymphocytic leukemia']
['idelalisib', 'chlorambucil', 'obinutuzumab']

        Key Inclusion Criteria:

          -  Not a candidate for fludarabine therapy based on either:

               1. creatinine clearance < 70 mL/min, or

               2. Cumulative Illness Rating Scale score > 6, by assessment of the investigator

          -  Diagnosis of B-cell CLL, with diagnosis established according to International
             Workshop on Chronic Lymphocytic Leukemia (IWCLL)

          -  No prior therapy for CLL other than corticosteroids for disease complications.

          -  CLL that warrants treatment

          -  Presence of measurable lymphadenopathy

          -  Eastern Cooperative Oncology Group (ECOG) performance status of ≤ 2

        Key Exclusion Criteria:

          -  Known histological transformation from CLL to an aggressive lymphoma (ie, Richter
             transformation)

          -  Known presence of myelodysplastic syndrome

          -  Evidence of ongoing systemic bacterial, fungal, or viral infection at the time of
             randomization

          -  Ongoing liver injury

          -  Ongoing drug-induced pneumonitis

          -  Ongoing inflammatory bowel disease

          -  History of prior allogeneic bone marrow progenitor cell or solid organ transplantation

          -  Ongoing immunosuppressive therapy other than corticosteroids

          -  Concurrent participation in another therapeutic clinical trial

          -  Undergone major surgery within 30 days prior to randomization

          -  Known hypersensitivity or intolerance to any of the active substances or excipients in
             the formulations for idelalisib, obinutuzumab, or chlorambucil

          -  History of non-infectious pneumonitis

          -  Received last dose of study drug on another therapeutic clinical trial within 30 days
             prior to randomization

        Note: Other protocol defined Inclusion/Exclusion criteria may apply.
      