Developing and evaluating definitions of real-world clinical endpoints for patients with early-stage triple-negative breast cancer using a United States of America secondary database

Background: The KEYNOTE-522 trial showed that neoadjuvant chemotherapy (NAC) plus adjuvant pembrolizumab improved overall survival, event-free survival (EFS), and pathological complete response (pCR) in high-risk early-stage triple-negative breast cancer. As treatments evolve, evaluating real-world (RW) effectiveness is key to understanding trial generalizability. This study benchmarked RW efficacy endpoints in early-stage triple-negative breast cancer patients treated with NAC. Materials and methods: disease) and rwEFS (time from NAC start to first event). Outcomes were compared with those from the KEYNOTE-522 control arm. Results: = 0.97). The incidence rates of first events were also similar (22.0% RW versus 23.8% trial). Conclusions: Although pCR rates were higher in the KEYNOTE-522 control arm compared with the RW cohort, rwEFS was comparable with EFS in the KEYNOTE-522 control arm. This study highlights the value of combining structured data with custom abstraction to assess RW endpoints and support future research.