Merck announced the first-time presentation of overall survival (OS) results from the Phase 3 KEYNOTE-522 trial evaluating KEYTRUDA (pembrolizumab), Merck’s anti-PD-1 therapy, in combination with chemotherapy as pre-operative (neoadjuvant) treatment and then continuing as a single agent after surgery (adjuvant) for the treatment of patients with high-risk early-stage triple-negative breast cancer (TNBC).

These late-breaking data are being presented for the first time today during a Presidential Symposium session at the European Society for Medical Oncology (ESMO) Congress 2024 (presentation #LBA4) and were selected for an official Press Briefing. These data are also being simultaneously published in the New England Journal of Medicine . KEYTRUDA is the first and only immunotherapy-based regimen to show a statistically significant and clinically meaningful improvement in OS as neoadjuvant treatment with chemotherapy and then continued as a single agent as adjuvant treatment compared to placebo plus chemotherapy followed by placebo after surgery in patients with high-risk early-stage TNBC.

In pre-specified exploratory subgroup analyses of OS, the benefit of the KEYTRUDA regimen was consistent across pre-specified subgroups, including those defined by PD-L1 expression, tumor size and nodal status.

“These impactful overall survival results add to the previously reported pathological complete response and event-free survival data from the KEYNOTE-522 trial,” said Dr. Peter Schmid, lead, Centre for Experimental Cancer Medicine, Barts Cancer Institute in London, England. “In this study, pembrolizumab plus chemotherapy as neoadjuvant treatment and continued as a single agent after surgery reduced the risk of death by more than one-third compared to neoadjuvant chemotherapy, reinforcing the important role this regimen plays in the treatment of high-risk early-stage triple-negative breast cancer.”

“KEYTRUDA is the first and only immunotherapy-based regimen to show a statistically significant and clinically meaningful improvement in overall survival compared to chemotherapy alone in patients with high-risk early-stage triple-negative breast cancer,” said Dr. Gursel Aktan, vice president, global clinical development, Merck Research Laboratories. “This is an important milestone and represents the fourth KEYTRUDA study to demonstrate a significant overall survival benefit in an earlier stage of cancer, highlighting our efforts to help extend the lives of patients with certain cancers across different stages of disease.”