Inclusion Criteria:

1. Patient has a histologically confirmed diagnosis of mantle cell lymphoma, follicular
lymphoma, or diffuse large B cell lymphoma.

2. Patient has relapsed or refractory disease and received at least one prior therapy.

3. Patient with diffuse large B cell lymphoma has received or is ineligible for
autologous or allogeneic stem cell transplant.

4. Patient has at least one measurable nodal lesion (≥2 cm) according to Cheson criteria
(Cheson 2007). In case where the patient has no measurable nodal lesions ≥ 2 cm in
the long axis at baseline, then the patient must have at least one measurable
extra-nodal lesion.

5. Patient has an Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2.

6. Patient has adequate bone marrow and organ function.

Exclusion Criteria:

1. Patient has received previous treatment with PI3K inhibitors

2. Patient has evidence of graft versus host disease (GVHD).

3. Patient has active or history of central nervous system (CNS) disease.

4. Patient has a concurrent malignancy or has a malignancy within 3 years of study
enrollment (with the exception of adequately treated basal or squamous cell carcinoma
or non-melanomatous skin cancer).

5. Patient has a score ≥ 12 on the PHQ-9 questionnaire.

6. Patient has a GAD-7 mood scale score ≥ 15.

7. Pregnant or nursing women

8. Patient who does not use highly effective contraception methods to avoid becoming
pregnant or conceiving offspring.

Other protocol-defined inclusion/exclusion criteria may apply.