Study to Evaluate the Safety and Efficacy of a Combination of Favezelimab (MK-4280) and Pembrolizumab (MK-3475) in Participants With Hematologic Malignancies (MK-4280-003)

Inclusion Criteria:

Has measurable disease, defined as ≥1 lesion that can be accurately measured in 2 dimensions with diagnostic quality cross sectional anatomic imaging (computed tomography or magnetic resonance imaging). Minimum measurement must be >15 mm in the longest diameter or >10 mm in the short axis
Is able to provide a core or excisional tumor biopsy for biomarker analysis from an archival (within 3 months) or newly obtained biopsy at screening
Has a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG)

Exclusion Criteria:

Has known clinically active central nervous system (CNS) involvement
Has received prior therapy with an anti-lymphocyte activation gene-3 (LAG-3) antibody
Has received chimeric antigen receptors (CAR)-T-cell therapy for cHL and DLBCL Cohorts
Has received prior anticancer therapy or thoracic radiation therapy within 14 days before the first dose of study treatment
Has ≥Grade 2 non-hematological residual toxicities from prior therapy
Has had a prior anticancer monoclonal antibody within 4 weeks prior to study Day 1 or who has not recovered (i.e., ≤Grade 1 or at baseline) from AEs due to agents administered ≥4 weeks earlier
Has received a live vaccine within 30 days prior to first dose of study treatment. Administration of killed vaccines are allowed
Has received an investigational agent or used an investigational device within 4 weeks prior to intervention administration
Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior the first dose of study drug
Has a known additional malignancy that is progressing or requires active treatment with the exception of basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or in situ cervical cancer that has undergone potentially curative therapy
Has active autoimmune disease that has required systemic treatment in past 2 years (i.e., with use of disease modifying agents, corticosteroids or immunosuppressive drugs)
Has a history of (non-infectious) pneumonitis that required steroids or current pneumonitis
Has an active infection requiring intravenous systemic therapy
Has a known history of human immunodeficiency virus (HIV) infection
Has known, active hepatitis B or hepatitis C infection
Is pregnant or breastfeeding, or expecting to conceive or father children within the projected duration of the study, starting with the screening visit through 120 days after the last dose of study treatment
Has had an allogeneic hematopoetic stem cell/solid organ transplantation within the last 5 years