Merck (MSD) has reported that the Phase III KEYNOTE-756 clinical trial of Keytruda plus chemotherapy for breast cancer met the primary endpoint of pathological complete response (pCR) rate.

The double-blind, randomised trial is assessing Keytruda, an anti-PD-1 therapy, plus chemotherapy as a neoadjuvant therapy subsequent to adjuvant treatment, comprising Keytruda, in combination with endocrine therapy.

Discover B2B Marketing That Performs

Combine business intelligence and editorial excellence to reach engaged professionals across 36 leading media platforms.

Find out more

The trial enrolled 1,240 individuals with early-stage, high-risk, oestrogen receptor-positive, human epidermal growth factor receptor 2-negative (ER+/HER2-) breast cancer.

Dual primary endpoints of the study are event-free survival (EFS) and pCR rate while overall survival and safety comprise the secondary endpoints.

According to data from an interim assessment conducted by the independent Data Monitoring Committee (DMC), the Keytruda regimen was shown to offer a statistically significant pCR improvement rate versus a neoadjuvant placebo and chemotherapy.

Keytruda’s safety profile in the trial was in line with that seen in earlier trials, and no new safety signals were detected.

GlobalData Strategic Intelligence

US Tariffs are shifting - will you react or anticipate?

Don’t let policy changes catch you off guard. Stay proactive with real-time data and expert analysis.

By GlobalData

As per the DMC guidance, the trial will be progressed without any modifications to analyse EFS.

Merck Research Laboratories global clinical development vice-president Dr Gursel Aktan said: “This is the first positive Phase III study evaluating an immunotherapy-based regimen for patients with high-risk, early-stage ER-positive, HER2-negative breast cancer, and an important milestone in our efforts to advance research in early-stage breast cancer.”

Keytruda has received approval in the US for two indications to treat triple-negative breast cancer patients.

Prior to this development, Merck reported positive topline findings from two Phase III trials of its investigational 21-valent pneumococcal conjugate vaccine, V116.

Clinical Trials Arena Excellence Awards - Nominations Closed

Nominations are now closed for the Clinical Trials Arena Excellence Awards. A big thanks to all the organisations that entered – your response has been outstanding, showcasing exceptional innovation, leadership, and impact.

Excellence in Action
YPrime won the Innovation award for AI in Clinical Trials and the Environmental award for Sustainable Trials, thanks to its eCOA, IRT and eConsent platforms. Explore how purpose-built AI, paperless workflows and circular hardware practices are reshaping timelines, data quality and ESG performance in clinical research.

Discover the Impact