Study of Pembrolizumab (MK-3475) Plus Chemotherapy Versus Placebo Plus Chemotherapy in Participants With Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma (MK-3475-585/KEYNOTE-585)

Official Title

A Phase III, Randomized, Double-Blind, Clinical Trial of Pembrolizumab (MK-3475) Plus Chemotherapy (XP or FP) Versus Placebo Plus Chemotherapy (XP or FP) as Neoadjuvant/Adjuvant Treatment for Subjects With Gastric and Gastroesophageal Junction (GEJ) Adenocarcinoma (KEYNOTE-585)

Summary:

The purpose of this study is to evaluate the efficacy of pembrolizumab (MK-3745) in the neoadjuvant (prior to surgery) or adjuvant (after surgery) treatment of previously untreated adults with gastric and gastroesophageal junction (GEJ) adenocarcinoma. The primary study hypotheses are that: - Neoadjuvant and adjuvant pembrolizumab plus chemotherapy, followed by adjuvant pembrolizumab is superior to neoadjuvant and adjuvant placebo plus chemotherapy, followed by adjuvant placebo in terms of Event-free Survival (EFS) based on Response Evaluation Criteria in Solid Tumours Version 1.1 (RECIST 1.1), and - Neoadjuvant pembrolizumab plus chemotherapy is superior to neoadjuvant placebo plus chemotherapy in terms of rate of Pathological Complete Response (pathCR) at the time of surgery.

Trial Description

Primary Outcome:

• Event-free Survival (EFS) Per Response Criteria in Solid Tumours Version 1.1 (RECIST 1.1) - Pembrolizumab+Chemotherapy and Placebo+Chemotherapy Treatment Arms
• Pathological Complete Response (pathCR) Rate - Pembrolizumab+Chemotherapy and Placebo+Chemotherapy Treatment Arms
• Overall Survival (OS) - Pembrolizumab+Chemotherapy and Placebo+Chemotherapy Treatment Arms
• Percentage of Participants Who Experience One or More Adverse Events (AEs) - Pembrolizumab+FLOT and Placebo+FLOT Cohorts
• Percentage of Participants Who Discontinue Study Treatment Due to an Adverse Event (AE) - Pembrolizumab+FLOT and Placebo+FLOT Cohorts

• Percentage of Participants Who Experience One or More Adverse Events (AEs) - Pembrolizumab+Chemotherapy and Placebo+Chemotherapy Treatment Arms Separately and in Combination with the Pembrolizumab+FLOT and Placebo+FLOT Cohorts
• Percentage of Participants Who Discontinue Study Treatment Due to an Adverse Event (AE) - Pembrolizumab+Chemotherapy and Placebo+Chemotherapy Treatment Arms Separately and in Combination with the Pembrolizumab+FLOT and Placebo+FLOT Cohorts
• Disease-free Survival (DFS) Per Response Criteria in Solid Tumours Version 1.1 (RECIST 1.1) - Pembrolizumab+Chemotherapy and Placebo+Chemotherapy Treatment Arms
• Overall Survival (OS) - Pembrolizumab+Chemotherapy and Placebo+Chemotherapy Treatment Arms and Pembrolizumab+FLOT and Placebo+FLOT Cohorts
• Event-free Survival (EFS) Per Response Criteria in Solid Tumours Version 1.1 (RECIST 1.1) - Pembrolizumab+Chemotherapy and Placebo+Chemotherapy Treatment Arms and Pembrolizumab+FLOT and Placebo+FLOT Cohorts

View this trial on ClinicalTrials.gov