A Study to Evaluate Investigational Agents With or Without Pembrolizumab (MK-3475) in Participants With Advanced Esophageal Cancer Previously Exposed to Programmed Cell Death 1 Protein (PD-1)/ Programmed Cell Death Ligand 1 (PD-L1) Treatment (MK-3475-06B)

A Phase 1/2 Open-Label, Umbrella Platform Design Study of Investigational Agents With or Without Pembrolizumab (MK-3475) and/or Chemotherapy in Participants With Advanced Esophageal Cancer Previously Exposed to PD-1/PD-L1 Treatment (KEYMAKER-U06): Substudy 06B

This is a Phase 1/2, multicenter, randomized, open-label umbrella platform study to evaluate the safety and efficacy of investigational agents with or without pembrolizumab and/or chemotherapy, for the treatment of participants with second line (2L) esophageal squamous cell carcinoma (ESCC) who have previously been exposed to PD-1/PD-L1 based treatment.

The master protocol is MK-3475-U06.

As of Protocol Amendment 5, the Pembrolizumab Plus MK-4830 Plus Paclitaxel/Irinotecan arm and the Pembrolizumab Plus MK-4830 Plus Lenvatinib arm are no longer actively enrolling participants.

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

Inclusion Criteria:

• Histologically or cytologically confirmed diagnosis of metastatic or locally advanced unresectable esophageal squamous cell carcinoma (ESCC)
• Has experienced investigator documented radiographic or clinical disease progression on one prior line of standard therapy, that includes a platinum agent and previous exposure to an anti-programmed cell death 1 (PD1)/programmed cell death ligand 1 (PD-L1) based immune oncology (IO) therapy
• Has provided an archival or most recent tumor tissue sample obtained as part of clinical practice
• Participants who have adverse events (AEs) due to previous anticancer therapies must have recovered to ≤Grade 1 or baseline. Participants with endocrine-related AEs who are adequately treated with hormone replacement or participants who have ≤Grade 2 neuropathy are eligible

Exclusion Criteria:

• Direct invasion into adjacent organs such as the aorta or trachea
• Has experienced weight loss >10% over approximately 2 months prior to first dose of study therapy
• Has history of documented severe dry eye syndrome, severe Meibomian gland disease and/or blepharitis, or severe corneal disease that prevents/delays corneal healing
• Has active inflammatory bowel disease requiring immunosuppressive medication or previous history of inflammatory bowel disease
• Has received an investigational agent or has used an investigational device within 4 weeks prior to study intervention administration
• Known additional malignancy that is progressing or has required active treatment within the past 3 years, except basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or carcinoma in situ that has undergone potentially curative therapy
• Known active central nervous system (CNS) metastases and/or carcinomatous meningitis
• Participants with human immunodeficiency virus (HIV) with a history of Kaposi's sarcoma and/or Multicentric Castleman's Disease
• History of allogenic tissue/solid organ transplant
• Clinically significant cardiovascular disease within 12 months from first dose of study intervention
• Has risk for significant gastrointestinal (GI) bleeding such as a serious nonhealing wound, peptic ulcer, or bone fracture within 28 days prior to allocation/randomization, significant bleeding disorders, vasculitis, or has had a significant bleeding episode from the GI tract within 12 weeks prior to allocation/randomization