Adenovirus 5/F35-Human Guanylyl Cyclase C-PADRE(Thomas Jefferson University)

The goal of this clinical trial is to learn whether the Ad5.F35-hGCC-PADRE vaccine is safe and can stimulate an immune response against gastrointestinal (GI) cancers in patients with pancreatic, colorectal, esophageal, gastric, or small bowel adenocarcinomas who have completed surgical resection and standard adjuvant therapy. An additional goal is to evaluate whether the vaccine may help eliminate minimal residual disease (MRD) in ctDNA-positive colon cancer patients.
The main questions it aims to answer are:
Is the Ad5.F35-hGCC-PADRE vaccine safe and tolerable at different dose levels? Does the vaccine induce GCC-specific T-cell immune responses in patients with GI malignancies? In ctDNA-positive colon cancer patients, can the vaccine promote ctDNA clearance as a marker of MRD elimination?
The investigators will compare immune responses across different vaccine dose levels (10¹¹, 10¹², and 5 × 10¹² virus particles) to determine the optimal dose.
Participants will:
Receive the Ad5.F35-hGCC-PADRE vaccine by intramuscular injection. Be assigned to one of three dose levels during the dose-finding phase or receive a prespecified dose in the dose-expansion cohort.
Undergo safety assessments, including monitoring for adverse events, injection-site reactions, and laboratory test abnormalities.
Have blood samples collected to evaluate GCC-specific T-cell immune responses. For ctDNA-positive colon cancer patients, undergo ctDNA testing to assess clearance of minimal residual disease.