A Phase 2, Multicenter, Open-Label Study of IBI376, a PI3Kδ Inhibitor, in Patients with Relapsed or Refractory Follicular Lymphoma/Marginal Zone Lymphoma

Patients will be recruited for 2 cohorts. Cohort A will recruit 58 RRFL subjects, and Cohort B will recruit 62 RRMZL subjects.

Inclusion Criteria:

1. Aged 18 years or older.
2. Histologically confirmed, relapsed or refractory, follicular B-cell non-Hodgkin lymphoma (NHL) (FL) Grade 1, 2, and 3a or MZL.
3. Ineligible for hematopoietic stem cell transplant.
4. Definition of RRFL or RRMZL: Subjects should have received 2 or more prior therapies for FL/MZL included at least one regimen containing Rituximab. Subjects should be refractory to Rituximab or experienced disease progression after achieved remission or disease progression within 6 months since last therapy.
5. 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 (CT) or magnetic resonance imaging (MRI).
6. Subjects 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.
7. ECOG performance status 0 to 2.
8. Life expectancy ≥ 12 weeks.
9. Adequate hematologic, hepatic, and renal function.
10. Willingness to avoid pregnancy or fathering children.

Exclusion Criteria:

1 . Known histological transformation from indolent NHL to diffuse large B-cell lymphoma.

2. History of central nervous system lymphoma (either primary or metastatic).

3. Prior treatment with idelalisib, other selective PI3Kδ inhibitors, or a pan-PI3K inhibitor.

4. Prior treatment with a Bruton's tyrosine kinase inhibitor (eg, ibrutinib).

5. 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.

6. Active graft-versus-host disease. 7. Subjects positive for hepatitis B surface antigen or hepatitis B core antibody will be eligible if they are negative for HBV-DNA. Subjects positive for anti-HCV antibody will be eligible if they are negative for HCV-RNA.