KEYNOTE-522 Phase 3 Results - Was Pembrolizumab a Win in Triple-Negative Breast Cancer?

By. Peter Schmid, FRCP, MD, PhD

Date. 10/11/2023

KEYNOTE-522 Phase 3 Results - Was Pembrolizumab a Win in Triple-Negative Breast Cancer?

In this interview, Peter Schmid, FRCP, MD, PhD, from Barts Cancer Institute, London, UK, delves into the compelling 5-year follow-up data emanating from the Phase III KEYNOTE-522 (NCT03036488) trial. The trial was designed to investigate the efficacy of combining pembrolizumab with chemotherapy as neoadjuvant therapy and pembrolizumab as adjuvant therapy in patients grappling with the challenges of triple-negative breast cancer.

The previously reported findings from the trial had already indicated noteworthy and statistically significant improvements in both pathological complete response (pCR) and event-free survival (EFS) with the administration of the pembrolizumab regimen. Building upon these promising results, the 5-year follow-up data, presented at the European Society for Medical Oncology (ESMO) 2023 Congress in Madrid, Spain, serve to validate and fortify the robustness of these earlier outcomes.

The 60-month EFS rates, a pivotal marker of the treatment's long-term impact, were unveiled, showcasing a substantial advantage in the pembrolizumab and chemotherapy arm with rates reaching 81.3%, compared to 72.3% in the chemotherapy and placebo arm. What makes these results particularly compelling is the consistency of the observed benefit across pre-specified subgroups, affirming the broad applicability and efficacy of the pembrolizumab-based approach.

Dr. Schmid's insights underscore the clinical significance of these findings, highlighting not only the sustained impact on pathological complete response rates but, more crucially, the enduring benefit in event-free survival rates.

The remarkable 37% reduction in the risk of recurrence over the 5-year period positions pembrolizumab as a promising and enduring component in the therapeutic arsenal against triple-negative breast cancer.

The interview not only elucidates the scientific and clinical implications of the 5-year follow-up data but also underscores the potential paradigm shift these results signify in the management of triple-negative breast cancer. As a beacon of progress in the field, the study sets the stage for further exploration and refinement of immunotherapeutic strategies in the ongoing pursuit of improved outcomes for patients facing this challenging malignancy.

KEYNOTE-522 Phase 3 Results - Was Pembrolizumab a Win in Triple-Negative Breast Cancer?

KEYNOTE-522 reveals pembrolizumab's 5-year success in triple-negative breast cancer, with a remarkable 81.3% event-free survival rate, showcasing its transformative potential in long-term patient outcomes.