Overview

Researchers are looking for new ways to treat follicular lymphoma (FL). A standard (usual) treatment for FL includes a targeted therapy called rituximab and chemotherapy. In this study, researchers want to learn if giving a study medicine called MK-1045 and rituximab can treat FL. MK-1045 is a type of treatment called immunotherapy.

The goals of this study are to learn:

• About the safety of MK-1045 and rituximab, and if people tolerate them when given together
• If people who receive MK-1045 and rituximab have the cancer go away
• If people who receive MK-1045 and rituximab live longer without their cancer getting worse compared to those who receive standard treatment (rituximab and chemotherapy)

Eligibility

Inclusion Criteria:

• Has biopsy-proven, previously untreated, histologically confirmed cluster of differentiation (CD)19-positive and CD20-positive classical follicular lymphoma (FL), with Ann Arbor Stage II-IV disease and a Follicular Lymphoma International Prognostic Index (FLIPI) score of 2-5.
• Has radiographically measurable disease per the Lugano Response Criteria.
• Has provided a newly obtained core or excisional biopsy or archival tissue of a tumor lesion not previously irradiated.
• If human immunodeficiency virus (HIV)-positive, has well-controlled HIV on antiretroviral therapy (ART).
• If hepatitis B surface antigen (HBsAg)-positive, has undetectable hepatitis B virus (HBV) viral load and has received HBV antiviral therapy for at least 4 weeks and will continue it.
• If history of hepatitis C virus (HCV) infection, has undetectable HCV viral load.

Exclusion Criteria:

• Has received prior systemic anticancer therapy or radiotherapy for FL.
• Has follicular large B-cell lymphoma or any other subtype of FL other than classical FL.
• Has FL that has transformed into a more aggressive type of lymphoma.
• History or presence of clinically relevant central nervous system (CNS) diseases.
• Has history of serious cardiovascular and cerebrovascular diseases.
• Is HIV-infected with a history of Kaposi's sarcoma and/or Multicentric Castleman's Disease.
• Has received a live or live-attenuated vaccine within 30 days before the first dose of study intervention.
• Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy.
• Has a known additional malignancy that is progressing or has required active treatment within the past 3 years.
• Has known active CNS lymphoma or involvement.
• Has an active autoimmune disease that has required systemic treatment in the past 2 years.
• Has active infection requiring systemic therapy.
• Has chronic liver disease, including liver cirrhosis of Child-Pugh class B or C.
• Has not adequately recovered from major surgery or has ongoing surgical complications.