Recent Updates
Recently added Catalysts

Coformulated favezelimab/pembrolizumab

Phase 1

Metastatic Urothelial Carcinoma | Monoclonal antibody | Oncology |Merck & Company, Inc.|Last Updated: Sep 10, 2025

Success Probability

Subscribe to view

Market & Valuation

Subscribe to view

Trial Design

RandomizedACTIVE_CONTROLLED
Total Trials1
Total Enrollment390

FDA Designations

No designations recorded

Clinical trial landscape

Coformulated favezelimab/pembrolizumab · 1 trial · 2 indications

Phase 1 1
NCT05845814A Study of Efficacy and Safety of Pembrolizumab Plus Enfortumab Vedotin (EV) +/- Investigational Agents in First-Line Metastatic Urothelial Carcinoma (mUC) (MK-3475-04B/KEYMAKER-U04)Metastatic Urothelial Carcinoma
ACTIVE NOT_RECRUITING390 Analytics
PHASE1ACTIVE NOT_RECRUITING
A Study of Efficacy and Safety of Pembrolizumab Plus Enfortumab Vedotin (EV) +/- Investigational Agents in First-Line Metastatic Urothelial Carcinoma (mUC) (MK-3475-04B/KEYMAKER-U04)
Metastatic Urothelial CarcinomaUnlock trial analytics

Study Endpoints

Primary Endpoints

Part 1: Objective Response Rate (ORR)
Up to ~4 years

ORR is defined as the percentage of participants who achieve a confirmed complete response (CR) or partial response (PR) per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 as assessed by blinded independent central review (BICR). ORR will be reported for participants in Part 1.

Part 1: Percentage of Participants experiencing an Adverse Event (AE)
Up to ~4 years

An AE is defined as any untoward medical occurrence in a participant administered study drug, which does not necessarily have to have a causal relationship with the study drug. The number of participants experiencing an AE in Part 1 will be reported.

Part 1: Percentage of Participants who Discontinue study interventions due to an AE
Up to ~4 years

An AE is defined as any untoward medical occurrence in a participant administered study drug, which does not necessarily have to have a causal relationship with the study drug. The number of participants who discontinue study interventions due to an AE in Part 1 will be reported.

Part 1: Percentage of Participants with Dose-limiting toxicities (DLT)
Up to 21 days

A DLT is defined as an event with toxicity including the type, severity, time of onset, time of resolution, and the probable association with study treatment that are not due to pre-existing conditions as defined by the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events, Version 5.0 (CTCAE 5.0). The number of participants who experience a DLT in Part 1 will be reported.

Part 2: Progression Free Survival (PFS)
Up to ~4 years

PFS is defined as the time from randomization to the first documented disease progression per RECIST 1.1 by BICR or death due to any cause, whichever occurs first. PFS will be reported for participants in Part 2.

Secondary Endpoints

Part 1: PFS
Up to ~4 years
Part 1: Duration of Response (DOR)
Up to ~4 years
Part 2: Overall Survival (OS)
Up to ~4 years
Unlock Study Endpoints

Study Design & Arms

AllocationRANDOMIZED
MaskingNONE
ModelPARALLEL
PurposeTREATMENT

Treatment Arms

ArmTypeDescription
Arm A: Coformulated favezelimab/pembrolizumab plus EVEXPERIMENTALParticipants will receive coformulated favezelimab/pembrolizumab (800 mg/200 mg) as an intravenous (IV) infusion on Day 1 of every 3-week cycle for up to \~2 years (35 cycles) and EV at 1.25 mg/kg, administered as an IV infusion on Days 1 and 8 of every 3-week cycle until disease progression, intolerable toxicity, or investigator decision.
Arm B: Coformulated vibostolimab/pembrolizumab plus EVEXPERIMENTALParticipants will receive coformulated vibostolimab/pembrolizumab (200 mg/200 mg) as an IV infusion on Day 1 of every 3-week cycle, for up to \~2 years (35 cycles) and EV at 1.25 mg/kg, administered as an IV infusion on Days 1 and 8 of every 3-week cycle until disease progression, intolerable toxicity, or investigator decision.
Arm C: Pembrolizumab plus EVACTIVE_COMPARATORParticipants will receive 200 mg pembrolizumab as an IV infusion on Day 1 of every 3-week cycle for up to \~2 years (35 cycles) and EV at 1.25 mg/kg, administered as an IV infusion on Days 1 and 8 of every 3-week cycle, until disease progression, intolerable toxicity, or investigator decision.

Interventions

NameTypeDescription
Coformulated favezelimab/pembrolizumabBIOLOGICALCoformulated favezelimab/pembrolizumab (800 mg/200 mg) IV infusion
Coformulated vibostolimab/pembrolizumabBIOLOGICALCoformulated vibostolimab/pembrolizumab (200 mg/200 mg) IV infusion
EVCOMBINATION_PRODUCT1.25 mg/kg IV infusion
PembrolizumabBIOLOGICAL200 mg IV infusion
Unlock Study Design Details

Eligibility Criteria

Age Range18 Years to N/A
SexALL
Healthy VolunteersNo
Study Sites47

Inclusion Criteria: * Must have histologically documented, locally advanced/metastatic urothelial carcinoma (la/mUC). * Participants with mixed histology are eligible provided the urothelial component is ≥50% (and \<10% plasmacytoid component) * Participants whose tumors contain any neuroendoc...

Countries:United StatesAustraliaCanadaChileFranceIsraelItalyNetherlandsSouth KoreaSpainTaiwanUnited Kingdom
Unlock Eligibility Criteria

Frequently asked questions about Coformulated favezelimab/pembrolizumab

What is Coformulated favezelimab/pembrolizumab used for?

Coformulated favezelimab/pembrolizumab is an investigational monoclonal antibody combination being studied for the treatment of metastatic urothelial carcinoma. It is currently in Phase 1 clinical development for this indication, with an active trial evaluating its efficacy and safety in first-line metastatic urothelial carcinoma.

Who makes Coformulated favezelimab/pembrolizumab?

Coformulated favezelimab/pembrolizumab is being developed by Merck & Company, Inc., which trades under the ticker symbol MRK. The company is conducting clinical trials to evaluate this investigational combination therapy for metastatic urothelial carcinoma.

What phase is Coformulated favezelimab/pembrolizumab in?

Coformulated favezelimab/pembrolizumab is in Phase 1 clinical development. It is an investigational drug and has not been approved by regulatory authorities. The ongoing Phase 1 trial is active but not recruiting participants, and is studying the combination in first-line metastatic urothelial carcinoma.

What clinical trials is Coformulated favezelimab/pembrolizumab in?

Coformulated favezelimab/pembrolizumab is being studied in clinical trial NCT05845814, titled 'A Study of Efficacy and Safety of Pembrolizumab Plus Enfortumab Vedotin (EV) +/- Investigational Agents in First-Line Metastatic Urothelial Carcinoma (mUC) (MK-3475-04B/KEYMAKER-U04)'. This Phase 1 trial has an enrollment of 390 participants and is active but not recruiting.

Is Coformulated favezelimab/pembrolizumab the same as pembrolizumab?

Coformulated favezelimab/pembrolizumab is a combination product that includes pembrolizumab along with favezelimab in a coformulated form. It is distinct from pembrolizumab alone, as it combines two monoclonal antibodies into a single formulation for investigational use in metastatic urothelial carcinoma.