We’re researching a study medicine for gastroesophageal cancer
The Symbiotic-GI-16 clinical trial is evaluating a study medicine for people with gastroesophageal cancer. There are two parts to this clinical trial called ‘Phase 2’ and ‘Phase 3’. We are currently looking for participants to join Phase 2.
Phase 2 of this clinical trial will help researchers learn if a study medicine combined with chemotherapy can be used as a safe and effective treatment for people with gastroesophageal cancer.
All participants will receive the study medicine with chemotherapy – there is no placebo or comparator medicine in this phase of the trial. Your physician will decide which chemotherapy treatment plan is best for you (one of two standard of care chemotherapy treatment plans) and will tell you what you are receiving.
If you choose to take part in this clinical trial, you could help us continue to make progress in gastroesophageal cancer treatments.
Who may participate
You may be eligible to participate if you are aged 18 or older and:
- have been diagnosed with locally advanced or metastatic stomach and/or esophageal cancer
- have not received prior treatment for advanced or metastatic cancer
- your tumor has been diagnosed as “HER2-negative” and “PD-L1 positive”*
*These cancer biomarkers are specific proteins, genes, or other markers that can give you more information about your cancer.
This is not a complete list of the eligibility criteria for this clinical trial. The study doctor will review all eligibility criteria with you.
Condition
Gastroesophageal cancer
Age
18+ years
Sex
Male or Female
Each clinical study has its own guidelines for who can participate, called eligibility criteria. However, only the research study staff can determine if you qualify to enroll in the study.
What to expect
If this clinical trial is a good fit for you and you decide to participate, you will receive the study medicine in combination with standard chemotherapy treatment. Your physician will decide which chemotherapy treatment plan is best for you (one of two standard of care chemotherapy treatment plans) and will tell you what you are receiving.
You will have regular study visits while receiving the study treatment. Most study visits are expected to last approximately 4 to 7 hours and will consist of different types of tests, procedures, and assessments.
- You will have clinic visits every 2 or 3 weeks (depending on which chemotherapy plan your doctor chooses).
- You will have assessments at each visit, which may include physical exams, blood/urine tests, questionnaires, electrocardiograms, and tumor imaging scans. Your doctor can answer any questions you may have.
Participants will have an in-person follow-up visit or phone call every 12 weeks after the end-of-treatment visit, until the study ends.
The total length of this clinical trial depends on how long you receive the study treatment and have follow-up visits. You may continue to take the study treatment for as long as the clinical trial is open and your cancer is stable or has improved, or until the trial doctor decides to stop treatment. You may choose to stop taking the study treatment and leave the clinical trial at any time.
Length of study treatment
Until the cancer is stable, or you or the study doctor decides to stop
Number of study visits
Participants will attend visits every 2-3 weeks during the Treatment Period
Long-term follow up
In person visits or phone calls every 12 weeks after the end-of-treatment visit
Each clinical study has its own guidelines for who can participate, called eligibility criteria. However, only the research study staff can determine if you qualify to enroll in the study.
About the study medicine
The study medicine is a bispecific antibody designed to target two different proteins, PD-1 and VEGF, at the same time. These proteins can play a role in how the cancer grows and how the immune system responds to it. It is thought that by binding (or connecting) to these two proteins, the study medicine may help the immune system find and attack the cancer cells while also potentially slowing down tumor growth, which may be more effective for treating gastroesophageal cancer.
The study medicine is given as intravenous (IV) infusions, meaning directly into the bloodstream through a small tube inserted into a vein. The chemotherapy treatment plan (every 2 weeks or 3 weeks) will be decided by the study doctor based on your cancer and your health.

Potential risks and benefits of taking part in the clinical trial
People who take part in clinical studies are key to advancing medical research. By taking part in this clinical trial, you will be helping to advance research which may help yourself and others with gastroesophageal cancer in the future.
This clinical trial offers the opportunity to explore if a potential study medicine may work when combined with chemotherapy, for people with gastroesophageal cancer.
Participant safety is the top priority of this clinical trial. It is possible your condition or health may improve, worsen, or stay the same. Your study doctor will discuss all the possible risks and benefits of participating with you if you qualify and choose to enroll.
In addition:
- The study team will monitor your health closely during the clinical trial
- The study treatment and any study-related procedures will be provided at no cost
- Travel support may also be available
- You will help advance research for the future of gastroesophageal cancer treatments

Frequently asked questions
Gastroesophageal cancers, meaning cancers in the esophagus (food pipe) and/or stomach, remain a leading cause of death worldwide despite recent advances. Many patients eventually develop resistance to current standard treatments. There is an urgent need for new targeted/personalized therapies to help improve long-term survival and provide better options for those whose cancer has progressed.
The study treatment and any study-related procedures are generally covered at no cost. You may be paid back (reimbursed) for reasonable expenses that you and your caregiver have as a result of taking part in this study. This may include parking, meals, or other travel-related expenses. Please speak with the study doctor if you have any questions about costs resulting from being in this study. Participants do not need health insurance to take part in this study.
As part of this study, we will analyze your blood samples and a small portion of your tissue sample to examine various biological indicators known as biomarkers. These biomarkers will help us understand how the study drug interacts with your body and what factors may influence its effectiveness. By studying these markers, we aim to identify which patients are most likely to benefit from this treatment in the future.



