Phase 3 KEYNOTE-522 Trial Meets Overall Survival Endpoints in Patients With TNBC

Science and technology company Merck announced that their phase 3 KEYNOTE-522 trial evaluating pembrolizumab (Keytruda), an anti-programmed death receptor-1 (PD-1) therapy, met its overall survival (OS) endpoint when combined with chemotherapy as a neoadjuvant treatment and then when continued as adjuvant treatment for patients with high-risk early-state TNBC.

KEYNOTE-522 is a randomized, double-blind phase 3 trial with 1174 participants. The dual primary endpoints were pathologic complete response (pCR) rate and event-free survival, and the secondary endpoint was overall survival. The participants were randomized at a 2:1 ratio and were treated with one of two regimen options. One cohort (n = 784) received Keytruda plus chemotherapy (paclitaxel and carboplatin), followed by Keytruda plus chemotherapy (cyclophosphamide and either doxorubicin or epirubicin) as neoadjuvant therapy prior to surgery, followed by Keytruda monotherapy as adjuvant therapy post-surgery. The other cohort (n = 784) received a chemotherapy-placebo regimen consisting of placebo plus chemotherapy (paclitaxel and carboplatin), followed by placebo plus chemotherapy (cyclophosphamide and either doxorubicin or epirubicin) as neoadjuvant therapy prior to surgery, followed by placebo monotherapy as adjuvant therapy post-surgery.

An interim analysis conducted by an independent data monitoring committee found that patients treated with Keytruda experienced statistically significant and clinically meaningful improvement in OS compared to those who received pre-operative chemotherapy. In addition, the safety profile of Keytruda remained consistent with previous studies and no new safety signals were observed.

“To have achieved overall survival from this landmark study is highly encouraging and builds upon the positive pathological complete response and event-free survival results that led to approvals for this regimen around the world,” said Gursel Aktan, MD, PhD, vice president, global clinical development, Merck Research Laboratories.

Reference

Merck announces phase 3 keynote-522 trial met its overall survival (OS) endpoint in patients with high-risk early-stage triple negative breast cancer (TNBC). News release. Business Wire. May 28, 2024. Accessed May 22, 2024. https://www.businesswire.com/news/home/20240528354394/en/Merck-Announces-Phase-3-KEYNOTE-522-Trial-Met-its-Overall-Survival-OS-Endpoint-in-Patients-With-High-Risk-Early-Stage-Triple-Negative-Breast-Cancer-TNBC