Recruiting

Phase 2

Phase 3

PF-08634404 with ChemotherapySymbiotic-GI-16: A Study to Learn About the Study Medicine Called PF-08634404 in Combination With Chemotherapy in Gastroesophageal Cancer

Sponsor:

Pfizer

Code:

NCT07392892

Conditions

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

Metastatic Gastric Cancer

Gastroesophageal Junction Cancer

Esophageal Adenocarcinoma

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

PF-08634404

Chemotherapy

Nivolumab

Study Details

Brief summary:

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.

Conditions

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

Metastatic Gastric Cancer

Gastroesophageal Junction Cancer

Esophageal Adenocarcinoma

Study ID

NCT07392892

Start date

May 14, 2026

Status verified date

Aug, 2026

Completion date

Jul 21, 2032

Anticipated

Primary completion date

Jul 22, 2031

Anticipated

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

Histological or cytological confirmed gastric, gastroesophageal junction or esophageal adenocarcinoma.
Evidence of locally advanced or metastatic disease.
Eastern Cooperative Oncology Group performance status (ECOG) 0-1
No prior systemic therapy for advanced or metastatic disease.
Adequate hepatic, liver, and renal function
HER-2 negative status based on local testing
PD-L1 positive status based on local testing

Exclusion Criteria:

Participants with known active CNS metastases, including leptomeningeal, brainstem, meningeal, or spinal cord metastases or compression
Clinically significant risk of hemorrhage or fistula
Major surgery or severe trauma within 4 weeks prior to the first dose, or planned major surgery during the study
History of allogeneic organ transplantation and allogeneic hematopoietic stem cell transplantation.
Any Grade ≥3 bleeding/hemorrhage events within 28 days of Cycle 1 Day 1, or prior history of clinically significant bleeding events
Clinically significant cardiovascular disease, or other comorbidities, within 6 months prior to first dose
Participants with active autoimmune diseases requiring systemic treatment within the past 2 years
Evidence of non-infectious or drug-induced interstitial lung disease (ILD) pneumonitis

Study Design

Enrollment

840 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Phase 2 Portion

PF-08634404 + Chemotherapy

experimental: Phase 3: Arm A

PF-08634404 + Chemotherapy

active comparator: Phase 3: Arm B

Nivolumab + Chemotherapy

Interventions

PF-08634404

Participants will receive PF-08634404 intravenously.

Chemotherapy

Participants will receive PF-08634404 intravenously in combination with Chemotherapy.

Nivolumab

Participants will receive Nivolumab intravenously.

Primary outcome measure

Phase 2: Confirmed Objective response rate (ORR) using RECIST 1.1 as assessed by investigator [ Time Frame: Approximately 4 years ]
Phase 2: Number of participants with treatment-emergent adverse events [ Time Frame: Through 90 days after the last study intervention; Approximately 4 years ]
Phase 3: Progression Free Survival (PFS) using RECIST 1.1 as assessed by BICR [ Time Frame: Approximately 4 years ]
Phase 3: Overall Survival (OS) [ Time Frame: Approximately 4 years ]

Central Contacts and Locations

Central contacts

Pfizer CT.gov Call Center

1-800-718-1021 ClinicalTrials.gov_Inquiries@pfizer.com

Locations