Mechanistic Insights into Off-the-Shelf vs. Personalized mRNA Cancer Vaccines: A Comparative Review of BNT111 and BNT122

mRNA vaccines are a relevant approach in cancer immunotherapy, using messenger RNA to induce immune responses against tumor-associated antigens. In this review, BNT111 and BNT122 are compared as representative off-the-shelf and personalized models. BNT111 is a fixed mRNA vaccine that has demonstrated significant antitumor efficacy against shared melanoma antigens, particularly when combined with immune checkpoint inhibitors. It allows a standardized production via in vitro transcription (IVT) in a cell-free system. Conversely, BNT122 is a personalized vaccine designed to match an individual’s tumor mutations by targeting patient-specific neoantigens to elicit more robust immune responses. It has significant suitability in the adjuvant setting to target minimal residual disease. Despite favorable safety and immunogenicity, the effectiveness of these vaccines is influenced by various factors, including tumor heterogeneity, differences in antigen expression, off-target effects on mRNA-LNP distribution, molecular instability, and complex manufacturing constraints. Neither approach can be directly considered as the definitive optimal vaccine. A comprehensive analysis of their strengths and limitations is vital for a balanced and objective future research direction. Collectively, this emphasizes the need for further improvements in vaccine design and strategies, prioritizing high-quality, safe, and accessible treatments for every cancer-based patient and ensuring their successful integration into healthcare.