Cancer Immunotherapy in 2025: A Systematic Review of Clinical Effectiveness, Safety, and Real-World Outcomes
Executive Summary Cancer immunotherapy represents one of the most consequential paradigm shifts in oncology since the advent of combination chemotherapy [1–3]. By targeting immune checkpoints, tumor antigens, or immune effector cells themselves, immunotherapies have delivered durable, and in some cases curative, responses in a subset of patients across historically lethal malignancies [4–7]. However, population-level benefit remains heterogeneous. Immune checkpoint inhibitors (ICIs) consistently extend survival in several cancers, although absolute overall survival (OS) gains are often modest at a population level . Many regulatory approvals rely on surrogate endpoints rather than mature overall survival (OS) data [32,35], immune-related toxicities can be severe or permanent [28–30], and costs place substantial strain on healthcare systems [38–40]. Real-world effectiveness frequently diverges from pivotal trial results [54]. Credit: Statista 1. Introduction 1.1 Historical Context...