Merck Keytruda Plus Chemo Ups Response V. Chemo in Early Breast Cancer

Interim Results from Pivotal Neoadjuvant/Adjuvant Phase 3 KEYNOTE-522 Trial Presented for the First Time at ESMO 2019 Congress During Presidential Symposium

As Previously Announced, KEYTRUDA Plus Chemotherapy Has Been Granted Breakthrough Therapy Designation by US FDA for Neoadjuvant Treatment of High-Risk, Early-Stage TNBC

Merck (NYSE: MRK), known as MSD outside the United States and Canada, today announced results from the pivotal neoadjuvant/adjuvant Phase 3 KEYNOTE-522 trial in patients with early-stage triple-negative breast cancer (TNBC). The trial investigated a regimen of neoadjuvant KEYTRUDA, Merck’s anti-PD-1 therapy, plus chemotherapy, followed by adjuvant KEYTRUDA as monotherapy (the KEYTRUDA regimen) compared with a regimen of neoadjuvant chemotherapy followed by adjuvant placebo (the chemotherapy-placebo regimen). Interim findings – which are from the first randomized trial of an anti-PD-1 therapy in the neoadjuvant/adjuvant setting for TNBC – are being presented today during the Presidential Symposium at the European Society for Medical Oncology (ESMO) 2019 Congress (Abstract #LBA8).

In the neoadjuvant phase, KEYTRUDA plus chemotherapy (n=401) resulted in a statistically significant increase in pathological complete response (pCR) versus chemotherapy (n=201), from 51.2% with neoadjuvant chemotherapy to 64.8% for neoadjuvant KEYTRUDA plus chemotherapy, in patients with early-stage TNBC (p=0.00055). Pathological complete response, one of the dual primary endpoints was defined as ypT0/Tis ypN0 (i.e., no invasive residual cancer in breast and lymph nodes). The improvement seen when adding KEYTRUDA to neoadjuvant chemotherapy was observed regardless of PD-L1 expression. In the other dual primary endpoint of event-free-survival (EFS), with a median follow-up of 15.5 months, the KEYTRUDA regimen reduced the risk of progression in the neoadjuvant phase and recurrence in the adjuvant phase by 37% – a favorable trend for EFS – compared with the chemotherapy-placebo regimen (HR=0.63 [95% CI, 0.43-0.93]). The safety profiles of KEYTRUDA and chemotherapy in KEYNOTE-522 were consistent with previous studies.

“This innovative trial is the first to employ combined neoadjuvant and adjuvant treatment with KEYTRUDA in patients with early-stage TNBC,” said Dr. Roger M. Perlmutter, president, Merck Research Laboratories. “The results of the KEYNOTE-522 study, reported today, are very encouraging and have the potential to change the treatment of patients diagnosed with TNBC.”

https://www.marketscreener.com/MERCK-AND-COMPANY-13611/news/Merck-s-KEYTRUDA-pembrolizumab-Plus-Chemotherapy-Showed-Statistically-Significant-Increase-in-P-29274967/