Evaluating efficacy and safety of GVAX alone vs combinations in treatment of pancreatic adenocarcinoma; a single arm meta-analysis of Randomized Controlled trials

Introduction Pancreatic cancer is among the deadliest diseases, and the treatment has low success. The promising results of immunotherapy still have the problem of resistance based on immunosuppressive tumor microenvironments. This research assesses the dosage and effectiveness of GVAX/CRS-207 vaccines, paired with nivolumab in pre-treated metastatic pancreatic adenocarcinoma with the intention of increasing result by improving immunotherapeutic strategies. Methodology This systematic review and meta-analysis followed PRISMA guidelines to evaluate the efficacy and safety of GVAX and CRS-207 in treating advanced or metastatic pancreatic adenocarcinoma. A comprehensive search was conducted across multiple databases, including PubMed, Cochrane Central, and Embase, from inception to June 2025, without language or publication year limitations. Two investigators independently screened titles, abstracts, and full texts, with disagreements resolved by a third author. Included studies were randomized controlled trials involving adult patients with pancreatic adenocarcinoma previously treated with chemotherapy. Data extraction and quality assessment using the Cochrane risk of bias tool (ROB 2.0) were performed independently by two authors. Primary outcomes included overall survival, progression-free survival, and safety, while secondary outcomes included immune response, tumor response rate, and quality of life. Results The pooled risk ratios were not statistically significant: RR = 0.53 [0.06–4.79], P = 0.57; RR = 1.48 [0.86–2.52], P = 0.15. Similarly, the pooled hazard ratio was HR = 0.75 [0.30–1.92], P = 0.55. High heterogeneity was observed in two outcomes (I² = 76%, 86%), indicating substantial variability, while one showed no heterogeneity (I² = 0%). Results should be interpreted cautiously due to variability and wide confidence intervals. Limitations include potential publication bias, lack of statistical power, and differences in study design. Quality assessment and certainty in evidence must be carefully considered in drawing conclusions. Conclusion There is no significant survival improvement in established pancreatic cancer by using GVAX and CRS-207 therapies, significant heterogeneity and few data restricts conclusive results. More well-structured large-scale studies are required to determine their efficacy and safety against this logistical cancer.