A Study of MK-6837 as a Monotherapy and Combination Therapy in Participants With Advanced/Metastatic Solid Tumors (MK-6837-001)

A Phase 1 Open-label, Multicenter Study of MK-6837 as Monotherapy and Combination Therapy in Participants With Advanced/Metastatic Solid Tumors

The purpose of this study is to evaluate the safety, tolerability, and preliminary efficacy of MK-6837, administered as a monotherapy and in combination with pembrolizumab (MK-3475), in participants with histologically or cytologically confirmed advanced/metastatic solid tumors that have not responded to conventional therapy. There will not be any hypothesis testing in the study.

As of Amendment 04 (effective date: 18-Dec-2025), there are no pharmacokinetic (PK) secondary outcome measures in this study.

Inclusion Criteria:

The main inclusion criteria include but are not limited to the following:

• Histologically or cytologically confirmed solid tumor by pathology report that is advanced or metastatic
• Human Immunodeficiency Virus (HIV)-infected participants must have well controlled HIV on Antiretroviral Therapy (ART)
• Participants who are Hepatitis B Surface Antigen (HBsAg) positive are eligible if they have received Hepatitis B Virus (HBV) antiviral therapy for at least 4 weeks, and have undetectable HBV viral load before allocation
• Participants with history of Hepatitis C Virus (HCV) infection are eligible if HCV viral load is undetectable at screening

Exclusion Criteria:

The main exclusion criteria include but are not limited to the following:

• Has not recovered to Common Terminology Criteria for Adverse Events (CTCAE) Grade 1 or better from any Adverse Events (AEs) that were due to cancer therapeutics administered more than 4 weeks earlier
• History of a second malignancy, unless potentially curative treatment has been completed with no evidence of malignancy for 2 years
• Has clinically significant cardiovascular disease
• HIV-infected participants with a history of Kaposi's sarcoma and/or Multicentric Castleman's Disease
• Received prior systemic anticancer therapy including investigational agents within 4 weeks before the first dose of study intervention
• Has received any prior immunotherapy and was discontinued from that treatment due to a Grade 3 or higher immune-related AE (except endocrine disorders that can be treated with replacement therapy) or was discontinued from that treatment due to Grade 2 myocarditis or recurrent Grade 2 pneumonitis
• Received prior radiotherapy within 2 weeks of start of study intervention, or has radiation-related toxicities, requiring corticosteroids
• Received a live or live-attenuated vaccine within 30 days before the first dose of study intervention. Administration of killed vaccines is allowed
• Diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy or any other form of immunosuppressive therapy within 7 days before the first dose of study intervention
• Known additional malignancy that is progressing or has required active treatment within the past 2 years
• Known active Central Nervous System (CNS) metastases and/or carcinomatous meningitis
• Active autoimmune disease that has required systemic treatment in the past 2 years except replacement therapy
• History of (noninfectious) pneumonitis/interstitial lung disease that required steroids or has current pneumonitis/interstitial lung disease
• Active infection requiring systemic therapy
• History of allogeneic tissue/solid organ transplant
• Participants who have not adequately recovered from major surgery or have ongoing surgical complications