Authorised Phase II and Phase III (Integrated) LOCALLY ADVANCED OR METASTATIC GASTRIC, GASTROESOPHAGEAL JUNCTION, OR ESOPHAGEAL ADENOCARCINOMA

SYMBIOTIC-GI-16: A Study to Learn About the Study Medicine Called PF-08634404 in Combination With Chemotherapy in Previously Untreated Participants With LA/m Gastroesophageal Cancers

EU CTIS ID: 2025-524717-86-00

What this study is testing

Phase 2 - To evaluate antitumor activity of PF-08634404 in combination with chemotherapy. - To evaluate safety and tolerability of PF-08634404 in combination with chemotherapy. Phase 3 - To demonstrate that PF-08634404 in combination with chemotherapy (experimental arm) is superior to nivolumab in combination with chemotherapy (control arm) in prolonging PFS by Blinded Independent Central Review (BICR). - To demonstrate that PF-08634404 in combination with chemotherapy (experimental arm) is superior to nivolumab in combination with chemotherapy (control arm) in prolonging OS.

Phase II and Phase III (Integrated)

A plain-language read of the study's public EU CTIS listing. The study team confirms the details.

Who can take part

You may be able to join if

1. 18 years of age or older (or the minimum age of consent in accordance with local regulations) at screening.
2. Histologically or cytologically confirmed diagnosis of gastric, gastroesophageal junction, or esophageal adenocarcinoma, with evidence of locally advanced unresectable or metastatic disease.
3. For Phase 2: At least one measurable lesion according to RECIST 1.1 per investigator assessment. Participants with prior definitive radiotherapy must have measurable disease per RECIST 1.1 that is outside the radiation field or have unequivocal progression of previously irradiated lesions. For Phase 3: At least one evaluable lesion according to RECIST 1.1 per investigator.
4. No prior systemic therapy for advanced or metastatic disease.
5. ECOG PS score of 0 or 1.
6. Sufficient tumor tissue available to submit for correlative studies, either as an FFPE tumor tissue block, or slides containing unstained FFPE tumor tissue sections, from a core or excisional biopsy (cytology samples, including cell blocks generated from FNA biopsies, and biopsies containing bone are not adequate).

You likely can't join if

1. Participants have squamous cell or undifferentiated gastroesophageal cancer.
7. Any Grade ≥3 bleeding/hemorrhage events within 28 days of Cycle 1 Day 1, or prior history of clinically significant bleeding events, including unhealed wounds following surgical procedure.
8. Participants with acute, chronic, or symptomatic infections.
12. Unresolved toxicities from prior antitumor therapy that did not recover to NCI CTCAE version 5.0 Grade 0 or 1 or to levels specified in the inclusion/exclusion criteria, with the exception of alopecia. Participants who experience irreversible toxicity that is not expected to worsen with continued administration of the study intervention (eg, hearing loss) may be enrolled in the study after consultation with the medical monitor. Participants with long-term toxicity from radiotherapy that is deemed irreversible by the investigator may be enrolled in the study after consultation with the medical monitor.
13. Grade >1 baseline peripheral neuropathy.
14. History of esophageal varices, severe ulcers, unhealed wounds, gastrointestinal perforation, abdominal fistula, gastrointestinal obstruction, intra-abdominal abscess, or acute gastrointestinal bleeding within 6 months prior to the first dose.

See the full eligibility criteria

Who can join

1. 18 years of age or older (or the minimum age of consent in accordance with local regulations) at screening.
2. Histologically or cytologically confirmed diagnosis of gastric, gastroesophageal junction, or esophageal adenocarcinoma, with evidence of locally advanced unresectable or metastatic disease.
3. For Phase 2: At least one measurable lesion according to RECIST 1.1 per investigator assessment. Participants with prior definitive radiotherapy must have measurable disease per RECIST 1.1 that is outside the radiation field or have unequivocal progression of previously irradiated lesions. For Phase 3: At least one evaluable lesion according to RECIST 1.1 per investigator.
4. No prior systemic therapy for advanced or metastatic disease.
5. ECOG PS score of 0 or 1.
6. Sufficient tumor tissue available to submit for correlative studies, either as an FFPE tumor tissue block, or slides containing unstained FFPE tumor tissue sections, from a core or excisional biopsy (cytology samples, including cell blocks generated from FNA biopsies, and biopsies containing bone are not adequate).
7. Participants whose tumors express PD-L1 (TAP ≥1% or CPS ≥1) based on local testing results.
8. HER2-negative status based on local testing results.
9. Adequate hematologic, hepatic, and renal function.

What rules you out

1. Participants have squamous cell or undifferentiated gastroesophageal cancer.
7. Any Grade ≥3 bleeding/hemorrhage events within 28 days of Cycle 1 Day 1, or prior history of clinically significant bleeding events, including unhealed wounds following surgical procedure.
8. Participants with acute, chronic, or symptomatic infections.
12. Unresolved toxicities from prior antitumor therapy that did not recover to NCI CTCAE version 5.0 Grade 0 or 1 or to levels specified in the inclusion/exclusion criteria, with the exception of alopecia. Participants who experience irreversible toxicity that is not expected to worsen with continued administration of the study intervention (eg, hearing loss) may be enrolled in the study after consultation with the medical monitor. Participants with long-term toxicity from radiotherapy that is deemed irreversible by the investigator may be enrolled in the study after consultation with the medical monitor.
13. Grade >1 baseline peripheral neuropathy.
14. History of esophageal varices, severe ulcers, unhealed wounds, gastrointestinal perforation, abdominal fistula, gastrointestinal obstruction, intra-abdominal abscess, or acute gastrointestinal bleeding within 6 months prior to the first dose.
15. Participants with any history of another malignancy within 3 years before the first dose of study intervention, or any evidence of residual disease from a previously diagnosed malignancy. Exceptions are malignancies with a negligible risk of metastasis or death (eg, 5-year OS ≥ 90%), such as adequately treated carcinoma in situ of the cervix, nonmelanoma skin carcinoma, localized prostate cancer, ductal carcinoma in situ, or Stage I uterine cancer. Participants with a history of other curatively treated malignancies with low risk of recurrence not listed may also be considered eligible after consultation with sponsor or designee.
16. Known or suspected hypersensitivity to any component of study intervention or their excipients at the planned doses.
17. Other circumstances that may increase the study-related risks or interfere with interpretation of the study results, in the opinion of the investigator.
18. Any medical or psychiatric condition including any active suicidal ideation in the past year or suicidal behavior in the past 5 years or laboratory abnormality that may increase the risk of study participation or, in the investigator’s judgment, make the participant inappropriate for the study.
9. Clinically significant cardiovascular disease, or other comorbidities, within 6 months prior to the first dose.
11. Evidence of non-infectious or drug-induced ILD pneumonitis that: -Was previously diagnosed and was managed with parenteral steroids for any duration or oral steroids for >6 weeks, or; -Had onset during or after treatment with immunotherapy, improved or resolved, then recurred after immunotherapy rechallenge, or; -Is currently diagnosed and managed with systemic therapy, or; -Is suspected on radiologic imaging at screening.
10. Participants with active autoimmune diseases requiring systemic treatment within the past 2 years prior to the first dose of study intervention (ie, with use of disease-modifying agents, corticosteroids, or immunosuppressive drugs). a) Replacement therapy (eg, thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency) is not considered a form of systemic disease modifying treatment and is permitted. b)Participants with vitiligo, psoriasis, type 1 diabetes mellitus or resolved childhood asthma/atopy are allowed. c) Participants with Sjögren’s syndrome are allowed.
2. Participants with known active CNS metastases, including leptomeningeal, brainstem, meningeal or spinal cord metastases or compression are excluded.
3. Known DPD deficiency (refer to the local 5-FU and capecitabine label or local clinical guidance for DPD status recommendation prior to starting treatment).
4. Clinically significant risk of hemorrhage or fistula.
5. Major surgery or severe trauma within 4 weeks prior to the first dose, or planned major surgery during the study; minor local surgery (excluding peripherally inserted central catheter placement and implantable central venous port placement) within 3 days prior to the first dose. Participants must have recovered adequately from the toxicity or complications from the surgery prior to starting study intervention.
6. History of allogeneic organ transplantation and allogeneic hematopoietic stem cell transplantation.

The study team makes the final eligibility decision.

Where it's taking place

Taiwan
Japan
Israel
United States
China
Canada

Questions & answers

Do participants get paid in this trial?

This listing doesn't specify compensation. Many trials still reimburse travel or offer a stipend, so it's worth asking the study team when you connect.

Is it free to join, and do I need insurance?

Searching and applying through BridgeMD is free. In clinical trials the study-related treatment and visits are generally provided at no cost to you. You usually don't need insurance to take part - confirm specifics with the study team.

How long does this study last?

The listing doesn't state an exact length. The study team walks you through the schedule and number of visits before you decide to enroll.

Who can join this trial?

This study is enrolling all sexes, 18-64 years, 65+ years. The study team makes the final eligibility decision.

Where is this trial taking place?

Study sites include Taiwan; Japan; Israel; United States; China; Canada. Enter your location above to see the nearest site and check your eligibility.

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BridgeMD is an information and trial-matching tool - not medical advice, and not the study sponsor. Details come from EU CTIS; the study team decides eligibility.