A Study of INCB050465 in Relapsed or Refractory Follicular Lymphoma

Inclusion Criteria:

Aged 18 years or older.
Histologically confirmed, relapsed or refractory, follicular B-cell non-Hodgkin lymphoma (NHL) (follicular lymphoma) Grade 1, 2, and 3a.
Ineligible for hematopoietic stem cell transplant.
Must have been treated with at least 2 prior systemic therapies.
Radiographically measurable lymphadenopathy or extranodal lymphoid malignancy (defined as the presence of ≥ 1 lesion that measures > 1.5 cm in the longest dimension and ≥ 1.0 cm in the longest perpendicular dimension as assessed by computed tomography or magnetic resonance imaging.
Must be willing to undergo an incisional, excisional, or core needle lymph node or tissue biopsy or provide a lymph node or tissue biopsy from the most recent available archival tissue.
Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2.

Exclusion Criteria:

Known histological transformation from indolent NHL to diffuse large B-cell lymphoma.
History of central nervous system lymphoma (either primary or metastatic).
Prior treatment with idelalisib, other selective phosphatidylinositol 3-kinase delta (PI3Kδ) inhibitors, or a pan-PI3K inhibitor.
Prior treatment with a Bruton's tyrosine kinase inhibitor (eg, ibrutinib).
Allogeneic stem cell transplant within the last 6 months, or autologous stem cell transplant within the last 3 months before the date of study treatment administration.
Active graft-versus-host disease.
Participants positive for hepatitis B surface antigen or hepatitis B core antibody will be eligible if they are negative for hepatitis B virus-deoxyribonucleic acid (HBV-DNA). Participants positive for anti-hepatitis C virus (HCV) antibody will be eligible if they are negative for HCV-ribonucleic acid (RNA).