European Commission Approves KEYTRUDA (pembrolizumab) Plus Padcev (enfortumab vedotin-ejfv) as Perioperative Treatment for Adults With Resectable Muscle-Invasive Bladder Cancer (MIBC)

First and only PD-1 inhibitor plus antibody-drug conjugate regimen approved in the European Union (EU) for patients with MIBC regardless of cisplatin eligibility

RAHWAY, N.J.--(BUSINESS WIRE)--Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced the European Commission (EC) has approved KEYTRUDA^® (pembrolizumab), Merck’s anti-PD-1 therapy, in combination with Padcev^® (enfortumab vedotin-ejfv), as neoadjuvant treatment and then continued after radical cystectomy as adjuvant treatment for adults with resectable muscle-invasive bladder cancer (MIBC). This approval, which also covers KEYTRUDA SC^® [known as KEYTRUDA QLEX^TM (pembrolizumab and berahyaluronidase alfa-pmph) in the U.S.], marks the first and only PD-1 inhibitor plus antibody-drug conjugate (ADC) regimen available for patients with MIBC regardless of cisplatin eligibility in the European Union (EU).

“Although cisplatin-based chemotherapy has been a standard treatment approach for many patients with muscle-invasive bladder cancer, recurrence remains a significant challenge,” said Dr. Alfonso Gómez de Liaño, Hospital Universitario Insular de Gran Canaria, and KEYNOTE-B15 primary investigator. “Based on results from the KEYNOTE-B15 trial, today’s approval is a meaningful advance for patients with muscle-invasive bladder cancer in the European Union, extending this chemotherapy-free perioperative treatment option to patients regardless of cisplatin eligibility.”

“Building on the previous approval of KEYTRUDA plus Padcev in the European Union less than six months ago, we’re pleased to bring this important treatment option to a broader patient population as the first PD-1 inhibitor plus antibody-drug conjugate regimen approved for people with muscle-invasive bladder cancer regardless of cisplatin eligibility,” said Dr. Marjorie Green, senior vice president and head of oncology, global clinical development, Merck Research Laboratories. “This approval represents encouraging progress in bladder cancer care and underscores our commitment to addressing the needs of people who are living with this disease.”

The EC approval is based on results from the Phase 3 KEYNOTE-B15 trial (also known as EV-304), which was conducted in collaboration with Pfizer and Astellas. In the study, KEYTRUDA plus Padcev, as perioperative treatment, demonstrated a statistically significant improvement in event-free survival (EFS), reducing the risk of EFS events (defined as disease progression, recurrence or death) by 47% (HR=0.53 [95% CI, 0.41-0.70]; p<0.0001; 87/405 [21%] versus 146/403 [36%]) in patients with MIBC who are eligible for cisplatin-based chemotherapy compared to neoadjuvant chemotherapy (gemcitabine and cisplatin) and surgery. KEYTRUDA plus Padcev also demonstrated a statistically significant improvement in overall survival (OS), reducing the risk of death by 35% (HR=0.65 [95% CI, 0.48-0.89]; p=0.0029; 69/405 [17%] versus 99/403 [25%]) in these patients when compared to neoadjuvant chemotherapy and surgery. The trial showed KEYTRUDA plus Padcev demonstrated a statistically significant improvement in pathologic complete response (pCR) rate compared to neoadjuvant chemotherapy (55.8% [95% CI: 50.8, 60.7] versus 32.5% [95% CI: 28.0, 37.3]; p<0.0001). The approval follows a positive recommendation issued by the European Medicines Agency’s Committee for Medicinal Products for Human Use in September 2026.

This approval authorizes 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 July 2026, KEYTRUDA in combination with Padcev was approved by the U.S. Food and Drug Administration (FDA) as neoadjuvant treatment and then continued after cystectomy as adjuvant treatment for the treatment of adult patients with MIBC based on the Phase 3 KEYNOTE-B15 trial. This also represented the first and only PD-1 inhibitor plus ADC regimen approved in the U.S. for adults with MIBC regardless of cisplatin eligibility.

About KEYNOTE-B15

KEYNOTE-B15, also known as EV-304, is an open-label, randomized, multicenter, active-control Phase 3 trial (ClinicalTrials.gov, NCT04700124) evaluating perioperative KEYTRUDA in combination with Padcev and surgery (radical cystectomy [RC] and pelvic lymph node dissection [PLND]) versus neoadjuvant chemotherapy (gemcitabine plus cisplatin) and surgery in patients with previously untreated MIBC who are eligible for cisplatin-based chemotherapy. The trial enrolled 808 patients who were randomized 1:1 to receive either:

• Neoadjuvant KEYTRUDA 200 mg intravenously on Day 1 and Padcev 1.25 mg/kg intravenously on Days 1 and 8 of each 21-day cycle for four cycles prior to surgery, followed by adjuvant KEYTRUDA 200 mg on Day 1 of each 21-day cycle for 13 cycles and adjuvant Padcev 1.25 mg/kg on Days 1 and 8 of each 21-day cycle for five cycles (n=405), or;
• Neoadjuvant gemcitabine 1000 mg/m² on Days 1 and 8 and cisplatin 70 mg/m² on Day 1 of each 21-day cycle for four cycles prior to surgery, followed by observation (n=403).

The major efficacy outcome measure was EFS as assessed by blinded independent central review (BICR), defined as the time from randomization to the first occurrence of the following events: disease progression preventing curative surgery, failure to undergo surgery for participants with muscle invasive residual disease, incomplete surgical resection, local or distant recurrence after surgery or death. Additional efficacy outcome measures were OS and pCR rate as assessed by blinded independent pathology review.

About bladder cancer

Bladder cancer is the eighth most common cancer worldwide, diagnosed in more than 635,000 patients each year globally. In Europe, it is estimated there were approximately 208,291 patients diagnosed with bladder cancer and more than 67,000 deaths from the disease in 2024. According to some clinical practice guidelines, about 25% of newly diagnosed bladder cancer cases are MIBC. The standard of care for patients with MIBC is neoadjuvant cisplatin-based chemotherapy followed by surgery, which is shown to prolong survival. However, nearly half of patients who undergo this standard treatment experience recurrence. Additionally, up to half of patients with MIBC are not eligible to receive cisplatin and face limited treatment options, typically undergoing surgery alone.

About Merck’s research in genitourinary cancers

Merck is advancing research aimed at helping transform the treatment landscape and broaden options for people with genitourinary (GU) cancers, including bladder, kidney and prostate cancers. Globally, GU cancers account for an estimated 2.6 million new cancer diagnoses each year, equaling over 1 in 8 of all cancer incidences. Through a robust clinical development program with more than 50 ongoing clinical trials evaluating more than 22,000 patients around the world, Merck is investigating the potential of several portfolio medicines and pipeline assets, leveraging multiple novel combination strategies, across various stages of disease, to help address unmet needs in GU cancers.

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 more than 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 2,800 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.

About KEYTRUDA QLEX™ (pembrolizumab and berahyaluronidase alfa-pmph) injection for subcutaneous use, 165 mg + 2,000 units/mL

KEYTRUDA QLEX is a fixed-combination drug product of pembrolizumab and berahyaluronidase alfa. Pembrolizumab is a programmed death receptor-1 (PD-1) blocking antibody and berahyaluronidase alfa enhances dispersion and permeability to enable subcutaneous administration of pembrolizumab. KEYTRUDA QLEX is administered as a subcutaneous injection into the thigh or abdomen, avoiding the 5 cm area around the navel, over one minute every three weeks (2.4 mL) or over two minutes every six weeks (4.8 mL).

Selected Indications in the U.S. for KEYTRUDA^® (pembrolizumab) and KEYTRUDA QLEX™ (pembrolizumab and berahyaluronidase alfa-pmph)

Urothelial Cancer

KEYTRUDA and KEYTRUDA QLEX are each indicated, in combination with enfortumab vedotin-ejfv, for the treatment of adult patients with locally advanced or metastatic urothelial cancer.

KEYTRUDA and KEYTRUDA QLEX, as single agents, are each indicated for the treatment of adult patients with locally advanced or metastatic urothelial carcinoma:

• who are not eligible for any platinum-containing chemotherapy, or
• who have disease progression during or following platinum-containing chemotherapy or within 12 months of neoadjuvant or adjuvant treatment with platinum-containing chemotherapy.

KEYTRUDA and KEYTRUDA QLEX are each indicated, in combination with enfortumab vedotin-ejfv, as neoadjuvant treatment and then continued after cystectomy as adjuvant treatment for the treatment of adult patients with muscle invasive bladder cancer (MIBC).

KEYTRUDA and KEYTRUDA QLEX, as single agents, are each indicated for the treatment of adult patients with Bacillus Calmette-Guerin (BCG)-unresponsive, high-risk, non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS) with or without papillary tumors who are ineligible for or have elected not to undergo cystectomy.

See additional selected indications in the U.S. for KEYTRUDA and KEYTRUDA QLEX after the Selected Safety Information.

Selected Safety Information for KEYTRUDA and KEYTRUDA QLEX

Contraindications

KEYTRUDA QLEX is contraindicated in patients with known hypersensitivity to berahyaluronidase alfa, hyaluronidase or to any of its excipients.

Severe and Fatal Immune-Mediated Adverse Reactions

KEYTRUDA and KEYTRUDA QLEX are monoclonal antibodies that belong 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 or KEYTRUDA QLEX 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 and KEYTRUDA QLEX depending on severity of the immune-mediated adverse reaction. In general, if KEYTRUDA and KEYTRUDA QLEX require 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 and KEYTRUDA QLEX 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. Immune-mediated pneumonitis occurred in 5% (13/251) of patients receiving KEYTRUDA QLEX in combination with chemotherapy, including fatal (0.4%), Grade 3 (2%), and Grade 2 (1.2%) adverse reactions.

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 and KEYTRUDA QLEX 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. Immune-mediated colitis occurred in 1.2% (3/251) of patients receiving KEYTRUDA QLEX in combination with chemotherapy, including Grade 3 (0.8%) and Grade 2 (0.4%) adverse reactions.

Hepatotoxicity and Immune-Mediated Hepatitis

KEYTRUDA and KEYTRUDA QLEX 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. Immune-mediated hepatitis occurred in 0.4% (1/251) of patients receiving KEYTRUDA QLEX in combination with chemotherapy, including Grade 2 (0.4%) adverse reactions.

KEYTRUDA With Axitinib or KEYTRUDA QLEX With Axitinib

KEYTRUDA and KEYTRUDA QLEX, when either is used 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 or KEYTRUDA QLEX 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.

Immune-Mediated Endocrinopathies

Adrenal Insufficiency

KEYTRUDA and KEYTRUDA QLEX can cause primary or secondary adrenal insufficiency. For Grade 2 or higher, initiate symptomatic treatment, including hormone replacement as clinically indicated. Withhold KEYTRUDA and KEYTRUDA QLEX depending on severity. Adrenal insufficiency occurred in 0.8% (22/2799) of patients receiving KEYTRUDA, including Grade 4 (<0.1%), Grade 3 (0.3%), and Grade 2 (0.3%) reactions. Systemic corticosteroids were required in 77% (17/22) of patients; of these, the majority remained on systemic corticosteroids. Adrenal insufficiency led to permanent discontinuation of KEYTRUDA in <0.1% (1) and withholding in 0.3% (8) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement. Adrenal insufficiency occurred in 2% (5/251) of patients receiving KEYTRUDA QLEX in combination with chemotherapy, including Grade 3 (0.4%) and Grade 2 (0.8%) adverse reactions.

Hypophysitis

KEYTRUDA and KEYTRUDA QLEX can cause immune-mediated hypophysitis. Hypophysitis can present with acute symptoms associated with mass effect such as headache, photophobia, or visual field defects. Hypophysitis can cause hypopituitarism. Initiate hormone replacement as indicated. Withhold or permanently discontinue KEYTRUDA and KEYTRUDA QLEX depending on severity.

Hypophysitis occurred in 0.6% (17/2799) of patients receiving KEYTRUDA, including Grade 4 (<0.1%), Grade 3 (0.3%), and Grade 2 (0.2%) reactions. Systemic corticosteroids were required in 94% (16/17) of patients; of these, the majority remained on systemic corticosteroids. Hypophysitis led to permanent discontinuation of KEYTRUDA in 0.1% (4) and withholding in 0.3% (7) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement.

Thyroid Disorders

KEYTRUDA and KEYTRUDA QLEX can cause immune-mediated thyroid disorders. Thyroiditis can present with or without endocrinopathy. Hypothyroidism can follow hyperthyroidism. Initiate hormone replacement for hypothyroidism or institute medical management of hyperthyroidism as clinically indicated. Withhold or permanently discontinue KEYTRUDA and KEYTRUDA QLEX depending on severity.

Thyroiditis occurred in 0.6% (16/2799) of patients receiving KEYTRUDA, including Grade 2 (0.3%). None discontinued, but KEYTRUDA was withheld in <0.1% (1) of patients.

Hyperthyroidism occurred in 3.4% (96/2799) of patients receiving KEYTRUDA, including Grade 3 (0.1%) and Grade 2 (0.8%). It led to permanent discontinuation of KEYTRUDA in <0.1% (2) and withholding in 0.3% (7) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement. Hypothyroidism occurred in 8% (237/2799) of patients receiving KEYTRUDA, including Grade 3 (0.1%) and Grade 2 (6.2%). It led to permanent discontinuation of KEYTRUDA in <0.1% (1) and withholding in 0.5% (14) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement. The majority of patients with hypothyroidism required long-term thyroid hormone replacement. The incidence of new or worsening hypothyroidism was higher in 1185 patients with HNSCC, occurring in 16% of patients receiving KEYTRUDA as a single agent or in combination with platinum and FU, including Grade 3 (0.3%) hypothyroidism. The incidence of new or worsening hyperthyroidism was higher in 580 patients with resected NSCLC, occurring in 11% of patients receiving KEYTRUDA as a single agent as adjuvant treatment, including Grade 3 (0.2%) hyperthyroidism. The incidence of new or worsening hypothyroidism was higher in 580 patients with resected NSCLC, occurring in 22% of patients receiving KEYTRUDA as a single agent as adjuvant treatment (KEYNOTE-091), including Grade 3 (0.3%) hypothyroidism.

Thyroiditis occurred in 0.4% (1/251) of patients receiving KEYTRUDA QLEX in combination with chemotherapy, including Grade 2 (0.4%). Hyperthyroidism occurred in 8% (20/251) of patients receiving KEYTRUDA QLEX in combination with chemotherapy, including Grade 2 (3.2%). Hypothyroidism occurred in 14% (35/251) of patients receiving KEYTRUDA QLEX in combination with chemotherapy, including Grade 2 (11%).

Type 1 Diabetes Mellitus (DM), Which Can Present With Diabetic Ketoacidosis

Monitor patients for hyperglycemia or other signs and symptoms of diabetes. Initiate treatment with insulin as clinically indicated. Withhold KEYTRUDA and KEYTRUDA QLEX depending on severity. Type 1 DM occurred in 0.2% (6/2799) of patients receiving KEYTRUDA. It led to permanent discontinuation in <0.1% (1) and withholding of KEYTRUDA in <0.1% (1) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement. Type 1 DM occurred in 0.4% (1/251) of patients receiving KEYTRUDA QLEX in combination with chemotherapy.

Immune-Mediated Nephritis With Renal Dysfunction

KEYTRUDA and KEYTRUDA QLEX can cause immune-mediated nephritis.

Immune-mediated nephritis occurred in 0.3% (9/2799) of patients receiving KEYTRUDA, including Grade 4 (<0.1%), Grade 3 (0.1%), and Grade 2 (0.1%) reactions. Systemic corticosteroids were required in 89% (8/9) of patients. Nephritis led to permanent discontinuation of KEYTRUDA in 0.1% (3) and withholding in 0.1% (3) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement; of these, none had recurrence. Nephritis resolved in 56% of the 9 patients.

Immune-Mediated Dermatologic Adverse Reactions

KEYTRUDA and KEYTRUDA QLEX can cause immune-mediated rash or dermatitis. Exfoliative dermatitis, including Stevens-Johnson syndrome, drug rash with eosinophilia and systemic symptoms, and toxic epidermal necrolysis, has occurred with anti–PD-1/PD-L1 treatments.

Media Contacts:

Julie Cunningham
julie.cunningham@merck.com

Paige Carlin
paige.carlin@merck.com

Investor Contacts:

Peter Dannenbaum
(732) 594-1579

Steven Graziano
(732) 594-1583