A Phase 1/2 interventional study of PF-08634404 and Enfortumab Vedotin in Urothelial Cancer, Advanced/Metastatic Urothelial Cancer and Urothelial Carcinoma, sponsored by Pfizer. Recruiting at 173 sites in 6 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-28.
Sponsored by Pfizer · Phase 1/2, Interventional, and Treatment
This study is being done to learn more about a new medicine called PF-08634404. It is for adults with a type of bladder cancer called locally advanced or metastatic urothelial cancer (LA/mUC), meaning the cancer has spread to nearby tissues or other parts of the body.
The purpose of the study is to see if PF-08634404 is safe, how well it works, how it moves through the body, and how it affects the cancer. The study will also look at how the medicine may change certain markers in the body that are linked to cancer.
To join the study, participants must:
The study has two groups:
Everyone in the study will get the study medicine through a vein (IV infusion) with or without enfortumab vedotin. Treatment will continue as long as it helps and side effects are manageable.
Before starting, participants will go through a screening period to check if they are eligible. During the study, they will have regular visits for treatment, health checks, and tests to see how the cancer is responding. Scans will be done regularly to monitor the cancer.
If the cancer gets worse but the treatment is still helping and side effects are manageable, participants may be allowed to continue treatment with their doctor's and the sponsor's agreement.
Exclusion Criteria:
Participants will be excluded if they meet any of the following:
Participants with previously treated LA/mUC will receive PF-08634404 administered intravenously as monotherapy.
Biological: PF-08634404
Participants with untreated LA/mUC will receive PF-08634404 in combination with enfortumab vedotin
Biological: PF-08634404 · Biological: Enfortumab Vedotin
Concentrate for solution for Infusion.
Also known as: SSGJ-707
Powder for concentrate for solution for infusion
Also known as: PF-08046042, ASG-22CE, PADCEV
Confirmed Objective Response Rate (ORR) by investigator
ORR is defined as the proportion of participants in the analysis population having a BOR of confirmed CR or confirmed PR according to RECIST v1.1 as assessed by investigator.
Time frame: Up to approximately 3 years
Number of Participants with Treatment Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)
AEs as characterized by type, frequency, severity (as graded by NCI CTCAE version 5.0), timing, seriousness and relationship to study intervention.
Time frame: Through 90 days after the last study intervention; Up to approximately 3 years
Number of participants with dose limiting toxicity (DLT) in Part 1 of Cohort B
The number of participants who experienced DLTs in participants receiving PF-08634404 in combination with EV.
Time frame: Through 90 days after the last study intervention; Up to approximately 3 years
Duration of Response (DOR) per RECIST v1.1 by investigator
DOR is defined as the time from the first documentation of objective response (CR or PR that is subsequently confirmed) to the date of first documented disease progression per RECIST v1.1 or death due to any cause, whichever occurs first.
Time frame: Up to approximately 3 years
Progression Free Survival (PFS) per RECIST v1.1 by investigator
Progression-free survival is defined as the time from the date of randomization to the date of the first documentation of objective PD assessed by investigator per RECIST v1.1, or death due to any cause, whichever occurs first.
Time frame: Up to approximately 3 years
Overall Survival (OS)
Overall survival defined as the time from the date of C1D1 to the date of death due to any cause.
Time frame: Up to approximately 3 years
Number of Participants With Clinical Laboratory Abnormalities
Laboratory abnormalities as characterized by type, frequency, severity (as graded by NCI CTCAE version 5.0)
Time frame: Through 90 days after the last study intervention; Up to approximately 3 years
Pharmacokinetics (PK): Serum concentration of PF-08634404
To characterize the pharmacokinetics (PK) of PF-08634404 as monotherapy in participants with previously treated LA/mUC and in combination with EV in participants with previously untreated LA/mUC.
Time frame: Up to 37 days after the last dose of treatment
Incidence of Anti-Drug Antibody (ADA) against PF-08634404
To evaluate the immunogenicity of PF-08634404 as monotherapy in participants with previously treated LA/mUC and in combination with EV in participants with previously untreated LA/mUC.
Time frame: Up to 37 days after the last dose of treatment
Showing the first 100 of 173 sites across 6 countries.
Plan to share: No — Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.
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