Merck announced that the Phase 3 KEYNOTE-091 trial, also known as EORTC-1416-LCG/ETOP-8-15 – PEARLS, investigating KEYTRUDA, Merck’s anti-PD-1 therapy, met one of its dual primary endpoints of disease-free survival (DFS) for the adjuvant treatment of patients with stage IB-IIIA non-small cell lung cancer (NSCLC) following surgical resection regardless of PD-L1 expression. Based on an interim analysis review conducted by an independent Data Monitoring Committee, adjuvant treatment with KEYTRUDA resulted in a statistically significant and clinically meaningful improvement in DFS compared with placebo in the all-comer population of patients with stage IB-IIIA NSCLC.

At the interim analysis, there was also an improvement in DFS for patients whose tumors express PD-L1 (tumor proportion score [TPS] ≥50%) treated with KEYTRUDA compared to placebo; however, this dual primary endpoint did not meet statistical significance per the pre-specified statistical plan. The trial will continue to analyze DFS in patients whose tumors express high levels of PD-L1 (TPS ≥50%) and evaluate overall survival (OS), a key secondary endpoint.

The safety profile of KEYTRUDA in this study was consistent with that observed in previously reported studies. Results will be presented at an upcoming medical meeting and will be submitted to regulatory authorities.

“KEYTRUDA has become foundational in the treatment of metastatic non-small cell lung cancer and we continue to advance research to explore its potential to help fight cancer earlier,” said Dr. Roy Baynes, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories. “We are encouraged by these results supporting the potential role of KEYTRUDA in stage IB-IIIA non-small cell lung cancer. We thank the patients, investigators and our partners at EORTC and ETOP for their important contributions to this study and look forward to sharing these results with the medical community as soon as possible.”

“Surgery is widely considered the first and most important intervention for most patients with early-stage non-small cell lung cancer; however, an estimated 43% of those who undergo surgery will see their disease return,” said Professor Mary O’Brien, The Royal Marsden, NHS Foundation Trust, and Imperial College, London, UK and co-principal investigator. “Data from KEYNOTE-091 suggest adjuvant KEYTRUDA reduced the risk of disease recurrence or death after surgery in the overall population of patients with stage IB-IIIA non-small cell lung cancer.”

“Globally, lung cancer is the leading cause of cancer death and it remains critically important to detect and treat lung cancer early,” said Dr. Luis Paz-Ares, chair of the medical oncology department, Hospital Universitario Doce de Octubre, Madrid, Spain and co-principal investigator. “The goal of adjuvant treatment is to lower the risk of cancer returning after surgery. By moving KEYTRUDA into earlier stages of non-small cell lung cancer, we may be able to reduce the risk of disease recurrence after surgery for patients with stage IB-IIIA non-small cell lung cancer.”

Merck has an extensive clinical development program in lung cancer and is advancing multiple registration-enabling studies with KEYTRUDA in combination with other treatments and as monotherapy for the treatment of lung cancer. The results from KEYNOTE-091 are a first for KEYTRUDA in the adjuvant treatment setting in patients with stage IB-IIIA NSCLC.