Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced that the European Commission (EC) has approved KEYTRUDA, Merck’s anti-PD-1 therapy, in combination with platinum-containing chemotherapy as neoadjuvant treatment, then continued as monotherapy as adjuvant treatment, for resectable non-small cell lung cancer (NSCLC) at high risk of recurrence in adults.

This approval by the EC follows the positive recommendation from the Committee for Medicinal Products for Human Use received in February 2024 and was based on results from the Phase 3 KEYNOTE-671 trial. At a median follow-up of 29.8 months (range, 0.4 to 62.0 months), KEYTRUDA plus chemotherapy in the neoadjuvant setting followed by KEYTRUDA as monotherapy after surgical resection significantly improved overall survival (OS), reducing the risk of death by 28% (HR=0.72 [95% CI, 0.56-0.93]; one-sided p=0.00517) in patients with resectable stage II, IIIA or IIIB NSCLC versus placebo plus chemotherapy in the neoadjuvant setting followed by placebo after surgical resection, regardless of PD-L1 expression. For patients who received the KEYTRUDA-based regimen, median OS was not reached (95% CI, NR-NR) versus 52.4 months (95% CI, 45.7-NR) for patients who received the chemotherapy-placebo regimen. The KEYTRUDA-based regimen also improved event-free survival (EFS), reducing the risk of disease recurrence, progression or death by 41% (HR=0.59 [95% CI, 0.48-0.72]) compared to the chemotherapy-placebo regimen. For patients who received the KEYTRUDA-based regimen, median EFS was improved by nearly two and a half years compared to the chemotherapy-placebo regimen (47.2 months [95% CI, 32.9-NR] versus 18.3 months [95% CI, 14.8-22.1], respectively).

“Despite the clinical advances for patients with metastatic lung cancer, lung cancer continues to be the leading cause of cancer death in Europe, reinforcing the need to treat these patients in earlier stages of their disease, where we may have the most impact,” said Dr. Solange Peters, chair of the medical oncology and thoracic malignancies department, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland. “The approval of this KEYTRUDA-based regimen is an important milestone for patients diagnosed with resectable non-small cell lung cancer at high risk of recurrence, regardless of PD-L1 expression, providing a new option for these patients that has shown, through the results of the Phase 3 KEYNOTE-671 trial, the potential to help extend their lives.”

This approval allows marketing of this KEYTRUDA regimen for this indication in all 27 EU member states, as well as Iceland, Liechtenstein, Norway and Northern Ireland. KEYTRUDA is now approved for six indications in NSCLC, and for 27 indications overall in the EU. In October 2023, KEYTRUDA was approved in the U.S. for the treatment of patients with resectable (tumors ≥4 cm or node positive) NSCLC in combination with platinum-containing chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery.

“Today’s approval of the first anti-PD-1/L1 therapy as part of a treatment regimen in Europe for the neoadjuvant followed by adjuvant treatment of resectable NSCLC based on positive overall survival results demonstrates our continued progress to advance treatments in earlier stages of lung cancer,” said Marjorie Green, senior vice president and head of oncology, global clinical development, Merck Research Laboratories. “We are eager to build on this momentum as we plan to seek additional approvals of this regimen around the world, and to work together with the cancer community to help drive earlier diagnoses of lung cancer, an urgent need.”

About the KEYNOTE-671 study design

KEYNOTE-671 is a randomized, double-blind Phase 3 trial (ClinicalTrials.gov, NCT03425643) evaluating KEYTRUDA in combination with neoadjuvant chemotherapy, followed by surgery and continued adjuvant treatment with KEYTRUDA as a single agent, versus placebo plus neoadjuvant chemotherapy, followed by resection and adjuvant placebo, in patients with resectable stage II, IIIA or IIIB (T3-4N2) NSCLC (per the eight edition of the American Joint Committee on Cancer [AJCC] Cancer Staging Manual). The trial’s dual primary endpoints are EFS, per RECIST v1.1 by investigator assessment, and OS. Key secondary endpoints include pathologic complete response (pCR) and major pathological response (mPR). The study enrolled 797 patients who were randomly assigned (1:1) to receive either:

• KEYTRUDA (200 mg intravenously [IV] every three weeks [Q3W]) plus chemotherapy (cisplatin [75 mg/m², IV; given on Day 1 of each cycle] and either gemcitabine [1,000 mg/m², IV; given on Days 1 and 8 of each cycle] or pemetrexed [500 mg/m², IV; given on Day 1 of each cycle]) for up to four cycles as neoadjuvant therapy prior to surgery. Within 4-12 weeks following surgery, KEYTRUDA (200 mg) was administered every three weeks for up to 13 cycles, or;
• Placebo (saline IV Q3W) plus chemotherapy (cisplatin [75 mg/m², IV; given on Day 1 of each cycle] and either gemcitabine [1,000 mg/m², IV; given on Days 1 and 8 of each cycle] or pemetrexed [500 mg/m², IV; given on Day 1 of each cycle]) for up to four cycles as neoadjuvant therapy prior to surgery. Within 4‑12 weeks following surgery, placebo was administered every three weeks for up to 13 cycles.

About lung cancer

Lung cancer is the leading cause of cancer death worldwide. In 2022 alone, there were approximately 2.4 million new cases and 1.8 million deaths from lung cancer globally. Non-small cell lung cancer is the most common type of lung cancer, accounting for about 80% of all cases. In recent decades, the overall five-year survival rate for patients diagnosed with lung cancer increased from 11% to 15% on average across EU countries. Improved survival rates are due, in part, to earlier detection and screening, reduction in smoking, advances in diagnostic and surgical procedures, as well as the introduction of new therapies. Early detection and screening remain an important unmet need, as 44% of lung cancer cases are not found until they are advanced.

About Merck’s research in lung cancer

Merck is advancing research aimed at transforming the way lung cancer is treated, with a goal of improving outcomes for patients affected by this deadly disease. Through nearly 200 clinical trials evaluating more than 36,000 patients around the world, Merck is at the forefront of lung cancer research. In NSCLC, KEYTRUDA has six approved U.S. indications (see indications below) and is approved for advanced disease in more than 95 countries. Among Merck’s research efforts are trials focused on evaluating KEYTRUDA in earlier stages of lung cancer as well as identifying new combinations and coformulations with KEYTRUDA.

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 studying KEYTRUDA in earlier disease states, with more than 25 ongoing registrational studies across multiple types of cancer.

About KEYTRUDA^® (pembrolizumab) injection, 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.

Selected KEYTRUDA^® (pembrolizumab) Indications in the U.S.

Non-Small Cell Lung Cancer

KEYTRUDA, in combination with pemetrexed and platinum chemotherapy, is indicated for the first-line treatment of patients with metastatic nonsquamous non-small cell lung cancer (NSCLC), with no EGFR or ALK genomic tumor aberrations.

KEYTRUDA, in combination with carboplatin and either paclitaxel or paclitaxel protein-bound, is indicated for the first-line treatment of patients with metastatic squamous NSCLC.

KEYTRUDA, as a single agent, is indicated for the first-line treatment of patients with NSCLC expressing PD-L1 [tumor proportion score (TPS) ≥1%] as determined by an FDA-approved test, with no EGFR or ALK genomic tumor aberrations, and is:

• stage III where patients are not candidates for surgical resection or definitive chemoradiation, or
• metastatic.

KEYTRUDA, as a single agent, is indicated for the treatment of patients with metastatic NSCLC whose tumors express PD-L1 (TPS ≥1%) as determined by an FDA-approved test, with disease progression on or after platinum-containing chemotherapy. Patients with EGFR or ALK genomic tumor aberrations should have disease progression on FDA-approved therapy for these aberrations prior to receiving KEYTRUDA.

KEYTRUDA is indicated for the treatment of patients with resectable (tumors ≥4 cm or node positive) NSCLC in combination with platinum-containing chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery.

KEYTRUDA, as a single agent, is indicated as adjuvant treatment following resection and platinum-based chemotherapy for adult patients with stage IB (T2a ≥4 cm), II, or IIIA NSCLC.

See additional selected KEYTRUDA indications in the U.S. after the Selected Important Safety Information.

Selected Important Safety Information for KEYTRUDA

Severe and Fatal Immune-Mediated Adverse Reactions

KEYTRUDA is a monoclonal antibody that belongs to a class of drugs that bind to either the programmed death receptor-1 (PD-1) or the programmed death ligand 1 (PD-L1), blocking the PD-1/PD-L1 pathway, thereby removing inhibition of the immune response, potentially breaking peripheral tolerance and inducing immune-mediated adverse reactions. Immune-mediated adverse reactions, which may be severe or fatal, can occur in any organ system or tissue, can affect more than one body system simultaneously, and can occur at any time after starting treatment or after discontinuation of treatment. Important immune-mediated adverse reactions listed here may not include all possible severe and fatal immune-mediated adverse reactions.

Monitor patients closely for symptoms and signs that may be clinical manifestations of underlying immune-mediated adverse reactions. Early identification and management are essential to ensure safe use of anti–PD-1/PD-L1 treatments. Evaluate liver enzymes, creatinine, and thyroid function at baseline and periodically during treatment. For patients with TNBC treated with KEYTRUDA in the neoadjuvant setting, monitor blood cortisol at baseline, prior to surgery, and as clinically indicated. In cases of suspected immune-mediated adverse reactions, initiate appropriate workup to exclude alternative etiologies, including infection. Institute medical management promptly, including specialty consultation as appropriate.

Withhold or permanently discontinue KEYTRUDA depending on severity of the immune-mediated adverse reaction. In general, if KEYTRUDA requires interruption or discontinuation, administer systemic corticosteroid therapy (1 to 2 mg/kg/day prednisone or equivalent) until improvement to Grade 1 or less. Upon improvement to Grade 1 or less, initiate corticosteroid taper and continue to taper over at least 1 month. Consider administration of other systemic immunosuppressants in patients whose adverse reactions are not controlled with corticosteroid therapy.

Immune-Mediated Pneumonitis

KEYTRUDA can cause immune-mediated pneumonitis. The incidence is higher in patients who have received prior thoracic radiation. Immune-mediated pneumonitis occurred in 3.4% (94/2799) of patients receiving KEYTRUDA, including fatal (0.1%), Grade 4 (0.3%), Grade 3 (0.9%), and Grade 2 (1.3%) reactions. Systemic corticosteroids were required in 67% (63/94) of patients. Pneumonitis led to permanent discontinuation of KEYTRUDA in 1.3% (36) and withholding in 0.9% (26) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement; of these, 23% had recurrence. Pneumonitis resolved in 59% of the 94 patients.

Pneumonitis occurred in 8% (31/389) of adult patients with cHL receiving KEYTRUDA as a single agent, including Grades 3-4 in 2.3% of patients. Patients received high-dose corticosteroids for a median duration of 10 days (range: 2 days to 53 months). Pneumonitis rates were similar in patients with and without prior thoracic radiation. Pneumonitis led to discontinuation of KEYTRUDA in 5.4% (21) of patients. Of the patients who developed pneumonitis, 42% interrupted KEYTRUDA, 68% discontinued KEYTRUDA, and 77% had resolution.

Pneumonitis occurred in 7% (41/580) of adult patients with resected NSCLC who received KEYTRUDA as a single agent for adjuvant treatment of NSCLC, including fatal (0.2%), Grade 4 (0.3%), and Grade 3 (1%) adverse reactions. Patients received high-dose corticosteroids for a median duration of 10 days (range: 1 day to 2.3 months). Pneumonitis led to discontinuation of KEYTRUDA in 26 (4.5%) of patients. Of the patients who developed pneumonitis, 54% interrupted KEYTRUDA, 63% discontinued KEYTRUDA, and 71% had resolution.

Immune-Mediated Colitis

KEYTRUDA can cause immune-mediated colitis, which may present with diarrhea. Cytomegalovirus infection/reactivation has been reported in patients with corticosteroid-refractory immune-mediated colitis. In cases of corticosteroid-refractory colitis, consider repeating infectious workup to exclude alternative etiologies. Immune-mediated colitis occurred in 1.7% (48/2799) of patients receiving KEYTRUDA, including Grade 4 (<0.1%), Grade 3 (1.1%), and Grade 2 (0.4%) reactions. Systemic corticosteroids were required in 69% (33/48); additional immunosuppressant therapy was required in 4.2% of patients. Colitis led to permanent discontinuation of KEYTRUDA in 0.5% (15) and withholding in 0.5% (13) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement; of these, 23% had recurrence. Colitis resolved in 85% of the 48 patients.

Hepatotoxicity and Immune-Mediated Hepatitis

KEYTRUDA as a Single Agent

KEYTRUDA can cause immune-mediated hepatitis. Immune-mediated hepatitis occurred in 0.7% (19/2799) of patients receiving KEYTRUDA, including Grade 4 (<0.1%), Grade 3 (0.4%), and Grade 2 (0.1%) reactions. Systemic corticosteroids were required in 68% (13/19) of patients; additional immunosuppressant therapy was required in 11% of patients. Hepatitis led to permanent discontinuation of KEYTRUDA in 0.2% (6) and withholding in 0.3% (9) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement; of these, none had recurrence. Hepatitis resolved in 79% of the 19 patients.

KEYTRUDA With Axitinib

KEYTRUDA in combination with axitinib can cause hepatic toxicity. Monitor liver enzymes before initiation of and periodically throughout treatment. Consider monitoring more frequently as compared to when the drugs are administered as single agents. For elevated liver enzymes, interrupt KEYTRUDA and axitinib, and consider administering corticosteroids as needed. With the combination of KEYTRUDA and axitinib, Grades 3 and 4 increased alanine aminotransferase (ALT) (20%) and increased aspartate aminotransferase (AST) (13%) were seen at a higher frequency compared to KEYTRUDA alone. Fifty-nine percent of the patients with increased ALT received systemic corticosteroids. In patients with ALT ≥3 times upper limit of normal (ULN) (Grades 2-4, n=116), ALT resolved to Grades 0-1 in 94%. Among the 92 patients who were rechallenged with either KEYTRUDA (n=3) or axitinib (n=34) administered as a single agent or with both (n=55), recurrence of ALT ≥3 times ULN was observed in 1 patient receiving KEYTRUDA, 16 patients receiving axitinib, and 24 patients receiving both. All patients with a recurrence of ALT ≥3 ULN subsequently recovered from the event.