Pembrolizumab Phase 3 Trial for Esophageal Carcinoma Completes Primary Study

A Phase 3 study evaluating pembrolizumab (Keytruda) for esophageal carcinoma reached its primary completion on January 21, 2026. The trial, known as KEYNOTE-975, enrolled 703 participants to assess the efficacy and safety of pembrolizumab in combination with definitive chemoradiotherapy.

Background

The study investigated pembrolizumab in participants with Esophageal Squamous Cell Carcinoma (ESCC), Gastroesophageal Junction Carcinoma (GEJC), and Esophageal Adenocarcinoma (EAC). These participants were receiving chemotherapy and radiation therapy. The trial aimed to determine if adding pembrolizumab to definitive chemoradiotherapy (dCRT) could improve outcomes compared to dCRT alone.

Trial design

The Phase 3 study (NCT04210115), titled "Study of Pembrolizumab (MK-3475) Versus Placebo in Participants With Esophageal Carcinoma Who Are Receiving Chemotherapy and Radiation Therapy (MK-3475-975/KEYNOTE-975)", enrolled 703 participants. The trial compared treatment with definitive chemoradiotherapy (dCRT) plus pembrolizumab against dCRT plus placebo. Interventions included pembrolizumab, placebo, cisplatin, 5-fu, and leucovorin. The primary study hypotheses focused on Event-free Survival (EFS) and Overall Survival (OS) in participants whose tumors expressed Programmed Death-Ligand 1 (PD-L1) Combined Positive Score (CPS) ≥10, those with PD-L1 CPS ≥1, and all participants.

What this means

The primary completion of this Phase 3 trial indicates that the main data collection phase for its primary endpoints has concluded. While this marks a significant milestone in the study of pembrolizumab for esophageal carcinoma, specific efficacy or safety results are not yet available. Clinicians and researchers will need to await the release of detailed data to understand the potential impact of pembrolizumab in combination with chemoradiotherapy for this patient population.

Source

The information regarding the primary completion of this trial was obtained from ClinicalTrials.gov, a public database of clinical studies. The update for the study NCT04210115 was posted on January 21, 2026 on clinicaltrials.gov.