Merck Announces FDA Grants Priority Review For Keytruda And Keytruda Qlex Each With Padcev For Cisplatin-Eligible Patients With Muscle-Invasive Bladder Cancer

Published: 2026-04-20 12:38:53 ET MRK

Published on 04/20/2026 at 12:38 pm EDT

Merck announced that the U.S. Food and Drug Administration (FDA) granted priority review for two supplemental Biologics License Applications (sBLA) for KEYTRUDA (pembrolizumab) and KEYTRUDA QLEX (pembrolizumab and berahyaluronidase alfa-pmph), each in combination with Padcev (enfortumab vedotin-ejfv), for the treatment of patients with muscle-invasive bladder cancer (MIBC) who are eligible for cisplatin-based chemotherapy. The FDA set a Prescription Drug User Fee Act (PDUFA), or target action, date of August 17, 2026. Applications are supported by the Phase 3 KEYNOTE-B15 results, which showed that KEYTRUDA plus Padcev demonstrated a statistically significant and clinically meaningful improvement in event-free survival and overall survival in study participants.

If approved, these regimens would be the first and only perioperative treatments for patients with MIBC regardless of cisplatin eligibility, marking potential new standards of care. If approved, these indications would expand the use of KEYTRUDA and KEYTRUDA QLEX, each in combination with Padcev, as the first perioperative treatments for patients with MIBC regardless of cisplatin eligibility and build on the previously approved indications of the combination for the treatment of patients with MIBC who are ineligible for cisplatin-based chemotherapy. The sBLAs are based on data from the Phase 3 KEYNOTE-B15 trial (also known as EV-304), which was conducted in collaboration with Pfizer and Astellas, which were presented at the recent American Society of Clinical Oncology (ASCO) Genitourinary (GU) Cancers Symposium.

The companies plan to share these results with regulatory authorities worldwide for potential regulatory filings. KEYTRUDA plus Padcev is currently approved for the treatment of adult patients with locally advanced or metastatic urothelial cancer (la/mUC) in the U.S., the European Union (EU), Japan and several other countries around the world. KEYTRUDA plus Padcev is also approved in the U.S. for the treatment of adult patients with MIBC who are ineligible for cisplatin-based chemotherapy.

KEYTRUDA as a monotherapy is also approved in the U.S., EU, Japan and other countries for the treatment of certain patients with la/mUC or a type of non-muscle-invasive bladder cancer (NMIBC). KEYTRUDA plus Padcev has now demonstrated an overall survival (OS) benefit across three Phase 3 trials in bladder cancer. In addition to KEYNOTE-B15, these trials include previously announced positive results from KEYNOTE-905 for the treatment of patients with MIBC who are not eligible for or declined cisplatin-based chemotherapy and positive results from KEYNOTE-A39 for the treatment of adult patients with la/mUC.

Three additional Phase 3 studies are currently evaluating KEYTRUDA across all stages of bladder cancer, including non-muscle-invasive, muscle-invasive and metastatic disease. Two of these studies are in MIBC including KEYNOTE-866 (NCT03924856) and KEYNOTE-992 (NCT04241185). KEYTRUDA is also being evaluated in combination with Bacillus Calmette-Guerin (BCG) in patients with NMIBC in KEYNOTE-676 (NCT03711032).

KEYNOTE-B15 is one of six Phase 3 studies of a KEYTRUDA-based regimen in an earlier stage of cancer to demonstrate an OS benefit. It was also the 15th positive pivotal trial for a KEYTRUDA-based regimen in earlier-stage cancers. KEYNOTE-B15, also known as EV-304, is an open-label, randomized Phase 3 trial evaluating perioperative KEYTRUDA in combination with Padcev and surgery (radical cystectomy and pelvic lymph node dissection) versus neoadjuvant chemotherapy (gemcitabine plus cisplatin) and surgery in patients with MIBC who are cisplatin-eligible.

The trial enrolled 808 patients who were randomized to receive either: Four cycles (each cycle length is 21 days) of neoadjuvant KEYTRUDA intravenous (IV) infusion plus enfortumab vedotin IV infusion, followed by surgery, followed by 13 cycles of adjuvant KEYTRUDA IV infusion plus five cycles of enfortumab vedotin IV infusion, or; Four cycles (each cycle is 21 days) of standard of care neoadjuvant chemotherapy followed by surgery. The primary endpoint is event-free survival (EFS), defined as the time from randomization to the first occurrence of the following events: radiographic disease progression precluding radical cystectomy and pelvic lymph node dissection, failure to undergo surgery in participants with residual disease, gross residual disease left behind at time of surgery, local or distant recurrence based on blinded independent central review or death due to any cause. The key secondary endpoints are OS and pathologic complete response rate.

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