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KEYTRUDA monotherapy now approved as neoadjuvant treatment, continued as adjuvant treatment combined with radiotherapy with or without concomitant cisplatin then as monotherapy
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Based on results of KEYNOTE-689, this represents the first and only approval in the European Union for an anti-PD-1 treatment option for adults with resectable LA-HNSCC whose tumors express PD-L1 (CPS >1)
October 29, 2025--RAHWAY, N.J.--(BUSINESS WIRE)-- Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced that the European Commission (EC) has approved KEYTRUDA® (pembrolizumab), Merck’s anti-PD-1 therapy, as monotherapy for the treatment of resectable locally advanced head and neck squamous cell carcinoma (LA-HNSCC) as neoadjuvant treatment, continued as adjuvant treatment in combination with radiation therapy with or without concomitant cisplatin and then as monotherapy in adults whose tumors express PD-L1 with a Combined Positive Score (CPS) ≥1. This approval marks the first and only anti-PD-1 treatment option for certain patients with resectable LA-HNSCC in the European Union (EU) and the third approval for KEYTRUDA in HNSCC in the EU.
“This approval brings a promising advancement to patients in Europe with resectable locally advanced head and neck squamous cell carcinoma,” said Dr. Marjorie Green, senior vice president and head of oncology, global clinical development, Merck Research Laboratories. “We’re proud of the continued progress we’re making to broaden the impact of KEYTRUDA in head and neck cancers and remain focused on working to deliver innovative approaches that have the potential to make a meaningful difference for patients.”
The EC approval is based on results from the pivotal Phase 3 KEYNOTE-689 trial. At the trial’s first pre-specified interim analysis, the KEYTRUDA-based perioperative regimen demonstrated a statistically significant and clinically meaningful improvement in event-free survival (EFS), the study’s primary endpoint, compared to adjuvant radiotherapy (with or without cisplatin) alone in patients with tumors expressing PD-L1 (CPS ≥1). The KEYTRUDA-based perioperative regimen reduced the risk of EFS events (defined as disease recurrence, disease progression or death) by 30% (HR=0.70 [95% CI, 0.55-0.89]; p=0.00140) in patients with tumors expressing PD-L1 (CPS ≥1) compared to adjuvant radiotherapy (with or without cisplatin) alone. Among the patients with tumors expressing PD-L1 (CPS ≥1), median EFS was doubled to 59.7 months (95% CI, 37.9-not reached) in the KEYTRUDA arm versus 29.6 months (95% CI, 19.5-41.9) in the comparator arm. The approval follows the positive recommendation from the Committee for Medicinal Products for Human Use received in September 2025.
This approval allows marketing of this KEYTRUDA treatment regimen for this indication in all 27 EU member states, as well as Iceland, Liechtenstein and Norway. Timing for commercial availability of KEYTRUDA for this indication in individual EU countries will depend on multiple factors, including the completion of national reimbursement procedures.
In June 2025, KEYTRUDA was approved in the U.S. for the treatment of adult patients with resectable LA-HNSCC whose tumors express PD-L1 (CPS ≥1) as determined by a U.S. Food and Drug Administration (FDA)-approved test, as a single agent as neoadjuvant treatment, continued as adjuvant treatment in combination with radiotherapy with or without cisplatin and then as a single agent. Based on the results from the Phase 3 KEYNOTE-689 trial KEYTRUDA was also approved in Canada, Brazil, Switzerland and several other countries around the globe as a perioperative treatment option for certain patients with resectable LA-HNSCC.
About KEYNOTE-689
KEYNOTE-689 is a randomized, active-controlled, open-label Phase 3 trial (ClinicalTrials.gov, NCT03765918) evaluating KEYTRUDA as neoadjuvant treatment and KEYTRUDA in combination with standard of care radiotherapy (with or without cisplatin) as adjuvant treatment in treatment-naïve patients with newly diagnosed, stage III or IVA resectable LA-HNSCC. Efficacy outcomes are classified by PD-L1 status. The primary endpoint is EFS, which is defined as the time from randomization to the first occurrence of radiographic disease progression; local or distant progression or recurrence; or death due to any cause. The secondary endpoints include overall survival, major pathological response, pathological complete response and safety. The study enrolled 714 patients who were randomized 1:1 to receive:
KEYTRUDA (200 mg intravenously [IV] every three weeks [Q3W] for two cycles) as neoadjuvant therapy prior to surgery, followed by either KEYTRUDA (200 mg IV Q3W for 15 cycles) plus standard of care radiotherapy with cisplatin (100 mg/m 2 IV Q3W for three cycles) as adjuvant therapy following surgery for high-risk patients or KEYTRUDA (200 mg IV Q3W for 15 cycles) plus standard of care radiotherapy without cisplatin as adjuvant therapy following surgery for low-risk patients; or
No neoadjuvant therapy prior to surgery, followed by adjuvant standard of care radiotherapy with cisplatin (100 mg/m 2 IV Q3W for three cycles) as adjuvant therapy following surgery for high-risk patients or standard of care radiotherapy without cisplatin as adjuvant therapy following surgery for low-risk patients.
About head and neck cancer
Head and neck cancer describes a number of different tumors that develop in or around the throat, larynx, nose, sinuses and mouth. It is estimated there were more than 947,200 new cases of head and neck cancer diagnosed and more than 482,400 deaths from the disease in 2022 globally. In Europe, it is estimated there were approximately 161,900 new cases of head and neck cancer and more than 72,500 deaths from the disease in 2022. These data include cancers of the oral cavity, pharynx and larynx. Most head and neck cancers are squamous cell carcinomas, which begin in the flat, squamous cells that make up the thin mucosal lining of the head and neck. Locally advanced head and neck squamous cell carcinoma is cancer that has spread from where it started to nearby tissue or lymph nodes but has not yet spread to distant parts of the body. There are several factors that greatly increase the risk of developing head and neck cancer, including tobacco and alcohol use and human papillomavirus.
About Merck’s early-stage cancer clinical program
Finding cancer at an earlier stage may give patients a greater chance of long-term survival. Many cancers are considered most treatable and potentially curable in their earliest stage of disease. Building on the strong understanding of the role of KEYTRUDA in later-stage cancers, Merck is evaluating our portfolio of medicines and pipeline candidates in earlier disease states, with approximately 30 ongoing registrational studies across multiple types of cancer.
About KEYTRUDA® (pembrolizumab) injection for intravenous use, 100 mg
KEYTRUDA is an anti-programmed death receptor-1 (PD-1) therapy that works by increasing the ability of the body’s immune system to help detect and fight tumor cells. KEYTRUDA is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes which may affect both tumor cells and healthy cells.
Merck has the industry’s largest immuno-oncology clinical research program. There are currently more than 1,600 trials studying KEYTRUDA across a wide variety of cancers and treatment settings. The KEYTRUDA clinical program seeks to understand the role of KEYTRUDA across cancers and the factors that may predict a patient's likelihood of benefitting from treatment with KEYTRUDA, including exploring several different biomarkers.
Merck’s focus on cancer
Every day, we follow the science as we work to discover innovations that can help patients, no matter what stage of cancer they have. As a leading oncology company, we are pursuing research where scientific opportunity and medical need converge, underpinned by our diverse pipeline of more than 25 novel mechanisms. With one of the largest clinical development programs across more than 30 tumor types, we strive to advance breakthrough science that will shape the future of oncology. By addressing barriers to clinical trial participation, screening and treatment, we work with urgency to reduce disparities and help ensure patients have access to high-quality cancer care. Our unwavering commitment is what will bring us closer to our goal of bringing life to more patients with cancer.
About Merck
At Merck, known as MSD outside of the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We aspire to be the premier research-intensive biopharmaceutical company in the world – and today, we are at the forefront of research to deliver innovative health solutions that advance the prevention and treatment of diseases in people and animals. We foster a diverse and inclusive global workforce and operate responsibly every day to enable a safe, sustainable and healthy future for all people and communities.