Abstract PS2-06-20: Fr-popea: French real-world-data of peri-operative pembrolizumab KN522 regimen in extreme ages subgroups (<30 y.o and >70 y.o) with high-risk TNBC

Abstract Background: The current standard of care for early triple-negative breast cancer (eTNBC) patients is peri-operative pembrolizumab, as demonstrated by the improved pathological response and survival outcomes in the KEYNOTE-522 trial. However, the youngest and oldest patients are underrepresented in randomized clinical trials. Methods: The FR-POPEA study is a prospective, observational, subgroup cohort analysis of high-risk TNBC patients who were treated with perioperative pembrolizumab in the French KN522 Early Access Program (EAP) from April 2022 to November 2024. Eligible patients were adults with confirmed stage II-III TNBC (including ER 1-9% according to the French guidelines). Real-world data were collected through EAP forms completed by physicians. Clinical and safety data were collected until the end of the EAP or the end of the treatment. The oldest group was ≥70 years old (the control group was