A Study to Learn About the Study Medicine Called PF-08634404 in Combination With Chemotherapy in Gastroesophageal Cancer

Conditions

• Esophageal Adenocarcinoma
• Gastroesophageal Junction Cancer
• Metastatic Gastric Cancer
• Untreated Advanced or Metastatic Gastric, Gastroesophageal Junction , or Esophageal Adenocarcinoma

Eligibility Criteria

Sex

ALL

Age

18 Years - N/A

Healthy Volunteers

Not accepted

Interventions

• PF-08634404 — BIOLOGICAL
  Participants will receive PF-08634404 intravenously.
• Chemotherapy — DRUG
  Participants will receive PF-08634404 intravenously in combination with Chemotherapy.
• Nivolumab — BIOLOGICAL
  Participants will receive Nivolumab intravenously.

Study Details

This study is being done to learn more about a new medicine called PF-08634404 and how well it works when given with chemotherapy to people with gastroesophageal cancer that is locally advanced (spread to nearby tissues) or has spread to other parts of the body. To join the study, participants must meet the following conditions: Be 18 years or older. Have locally advanced or metastatic gastric, gastroesophageal junction or esophageal adenocarcinoma Be treatment naïve for advanced or metastatic disease Be in good physical condition and have healthy organs based on medical tests. The study has two parts: * In the first part, researchers will check how safe the study medicine in combination with chemotherapy is and how well people respond to it. * In the second part, they will compare study medicine plus chemotherapy to another approved treatment (nivolumab plus chemotherapy) to see which works better. The treatment will be given in repeated time periods called cycles.

Key Dates

Start date

Apr 28, 2026

Status verified

Apr 2026

Primary completion

Jul 22, 2031

Completion

Jul 21, 2032

Study Design

Enrollment

840 participants (estimated)

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Arms

• Experimental: Phase 2 Portion
  PF-08634404 + Chemotherapy
• Experimental: Phase 3: Arm A
  PF-08634404 + Chemotherapy
• Active Comparator: Phase 3: Arm B
  Nivolumab + Chemotherapy

Primary Outcome Measure

Phase 2: Confirmed Objective response rate (ORR) using RECIST 1.1 as assessed by investigator [ Time Frame: Approximately 4 years ]

Central Contacts

• Pfizer CT.gov Call Center
  1-800-718-1021
  [email protected]

Locations (57)

Find similar trials in Aurora, CO

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