In contrast to KEYNOTE-522 that established the addition of perioperative pembrolizumab to neoadjuvant chemo for triple-negative breast cancer improves survival, the behemoth international ALEXANDRA trial failed to demonstrate a benefit with the addition of postoperative atezolizumab. Across 2199 women receiving post-operative chemo for resected stage II-III TNBC +/- one year of atezolizumab, the primary endpoint of disease-free survival was not improved with atezo (HR 1.11) at a median of 32 months. The authors stipulate: “Because treatment stimulates immune cells close to the tumor, postoperative immune checkpoint inhibitor application, after removing the primary tumor and lymph nodes, may not represent the optimal biological context for immunotherapy.” | Ignatiadis, JAMA 2025
