Symbiotic-GU-06: A Study to Learn About PF-08634404 Alone or In Combination With Enfortumab Vedotin in Urothelial Cancer

June 3, 2026 updated by: Pfizer

AN INTERVENTIONAL PHASE 1B/2, OPEN-LABEL STUDY TO INVESTIGATE THE SAFETY, ANTITUMOR ACTIVITY, AND PHARMACOKINETICS OF PF 08634404 MONOTHERAPY OR IN COMBINATION WITH ENFORTUMAB VEDOTIN IN ADULT PARTICIPANTS WITH LOCALLY ADVANCED OR METASTATIC UROTHELIAL CANCER

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:

  • Be adults (18 years or older) and
  • Have locally advanced or metastatic urothelial cancer,

The study has two groups:

  • Cohort A: People who have already received treatment for their cancer will get the study medicine ( PF-08634404) alone.
  • Cohort B: People who have not had treatment before will get the study medicine along with another cancer medicine called enfortumab vedotin.

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.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

132

Phase

  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Australia
    • New South Wales
      • North Ryde, New South Wales, Australia, 2109
        • Recruiting
        • Macquarie University
    • Queensland
      • Auchenflower, Queensland, Australia, 4066
        • Recruiting
        • Icon Cancer Centre Wesley
    • Victoria
      • Clayton, Victoria, Australia, 3168
        • Not yet recruiting
        • Monash Health
  • China
    • Beijing Municipality
      • Beijing, Beijing Municipality, China, 100142
        • Not yet recruiting
        • Beijing Cancer Hospital
  • Japan
      • Fukuoka, Japan, 811-1395
        • Recruiting
        • National Hospital Organization Kyushu Cancer Center
      • Yamagata, Japan, 990-9585
        • Recruiting
        • Yamagata University Hospital
    • Tokyo
      • Shinjuku-ku, Tokyo, Japan, 1608582
        • Recruiting
        • Keio University Hospital
  • Puerto Rico
      • Manati, Puerto Rico, 00674
        • Recruiting
        • Pan American Center for Oncology Trials, LLC - Manati Office
      • Mayagüez, Puerto Rico, 00680
        • Recruiting
        • Pan American Center for Oncology Trials, LLC - Mayaguez Office
      • Rio Piedras, Puerto Rico, 00935
        • Recruiting
        • Pan American Center for Oncology Trials, LLC
      • Rio Piedras, Puerto Rico, 00935
        • Recruiting
        • Hospital Oncologico Dr. Isaac Gonzalez-Martinez
  • United States
    • Arkansas
      • Fayetteville, Arkansas, United States, 72703
        • Recruiting
        • Highlands Oncology Group, PA
      • Rogers, Arkansas, United States, 72758
        • Recruiting
        • Highlands Oncology Group, PA
      • Springdale, Arkansas, United States, 72762
        • Recruiting
        • Highlands Oncology Group, PA
    • California
      • Duarte, California, United States, 91010
        • Recruiting
        • City of Hope (City of Hope National Medical Center, City of Hope Medical Center)
      • Duarte, California, United States, 91010
        • Recruiting
        • City of Hope Investigational Drug Services (IDS)
      • Irvine, California, United States, 92618
        • Recruiting
        • City of Hope at Irvine Lennar
      • Irvine, California, United States, 92618
        • Recruiting
        • City of Hope Investigational Drug Service (IDS)
      • Long Beach, California, United States, 90813
        • Recruiting
        • City of Hope-Long Beach (ELM)
      • Upland, California, United States, 91786
        • Recruiting
        • City of Hope Upland
    • Colorado
      • Aurora, Colorado, United States, 80012
        • Recruiting
        • Rocky Mountain Cancer Centers, LLP
      • Denver, Colorado, United States, 80218
        • Recruiting
        • Rocky Mountain Cancer Centers, LLP
      • Lone Tree, Colorado, United States, 80124
        • Recruiting
        • Rocky Mountain Cancer Centers, LLP
    • Connecticut
      • Norwich, Connecticut, United States, 06360
        • Recruiting
        • Eastern Connecticut Hematology and Oncology Associates
    • New York
      • Albany, New York, United States, 12206
        • Recruiting
        • New York Oncology Hematology
      • Clifton Park, New York, United States, 12065
        • Recruiting
        • New York Oncology Hematology
    • Tennessee
      • Nashville, Tennessee, United States, 37203
        • Recruiting
        • Sarah Cannon Research Institute
      • Nashville, Tennessee, United States, 37203
        • Recruiting
        • SCRI Oncology Partners
    • Texas
      • Austin, Texas, United States, 78758
        • Recruiting
        • Texas Oncology - Central South
      • Austin, Texas, United States, 78705
        • Recruiting
        • Texas Oncology - Central/South Texas
      • Austin, Texas, United States, 78731
        • Recruiting
        • Texas Oncology - Central/South Texas
      • Austin, Texas, United States, 78745
        • Recruiting
        • Texas Oncology - Central/South Texas
      • Beaumont, Texas, United States, 77702
        • Recruiting
        • Texas Oncology - Gulf Coast
      • Harlingen, Texas, United States, 78550
        • Recruiting
        • Texas Oncology - Central/South Texas
      • Houston, Texas, United States, 77024
        • Recruiting
        • Texas Oncology - Gulf Coast
      • Houston, Texas, United States, 77054
        • Recruiting
        • Texas Oncology - Gulf Coast
      • Irving, Texas, United States, 75063
        • Recruiting
        • US Oncology Investigational Products Center (IPC)
      • McAllen, Texas, United States, 78503
        • Recruiting
        • Texas Oncology - Central/South Texas
      • Pearland, Texas, United States, 77584
        • Recruiting
        • Texas Oncology - Gulf Coast
      • Sugar Land, Texas, United States, 77479
        • Recruiting
        • Texas Oncology - Gulf Coast
      • The Woodlands, Texas, United States, 77380
        • Recruiting
        • Texas Oncology - Gulf Coast
      • Waco, Texas, United States, 76712
        • Recruiting
        • Texas Oncology - Central/South Texas
      • Webster, Texas, United States, 77598
        • Recruiting
        • Texas Oncology - Gulf Coast
    • Virginia
      • Blacksburg, Virginia, United States, 24060
        • Recruiting
        • Oncology & Hematology Associates of Southwest Virginia, Inc.,DBA Blue Ridge Cancer Care
      • Fairfax, Virginia, United States, 22031
        • Recruiting
        • Virginia Cancer Specialists, PC
      • Low Moor, Virginia, United States, 24457
        • Recruiting
        • Oncology & Hematology Associates of Southwest Virginia, Inc.,DBA Blue Ridge Cancer Care
      • Norfolk, Virginia, United States, 23502
        • Recruiting
        • Virginia Oncology Associates
      • Roanoke, Virginia, United States, 24014
        • Recruiting
        • Oncology & Hematology Associates of Southwest Virginia, Inc.,DBA Blue Ridge Cancer Care
      • Salem, Virginia, United States, 24153
        • Recruiting
        • Oncology & Hematology Associates of Southwest Virginia, Inc.,DBA Blue Ridge Cancer Care
      • Wytheville, Virginia, United States, 24382
        • Recruiting
        • Oncology & Hematology Associates of Southwest Virginia, Inc.,DBA Blue Ridge Cancer Care

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age ≥18 years at the time of screening.
  • Histologically confirmed locally advanced or metastatic urothelial carcinoma (LA/mUC).
  • Measurable disease per RECIST v1.1 criteria.
  • ECOG performance status of 0 or 1.
  • Adequate organ function, including hematologic, hepatic, and renal parameters.
  • Willingness to comply with study procedures and provide informed consent.
  • For participants of childbearing potential: agreement to use effective contraception during the study and for a defined period after the last dose.

Exclusion Criteria:

Participants will be excluded if they meet any of the following:

  • History of another malignancy within 3 years before the first dose of study intervention, or any evidence of residual disease from a previously diagnosed malignancy
  • Known active CNS lesions, including leptomeningeal metastasis, brainstem, meningeal, or spinal cord metastases or compression
  • Active autoimmune diseases requiring systemic treatment within the past 2 years
  • Participation in another investigational study within 30 days or 5 half-lives of the investigational product.
  • Pregnant or breastfeeding individuals.
  • Inability or unwillingness to comply with study requirements.
  • Study staff or their immediate family members directly involved in the conduct of the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Sequential Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Cohort A
Participants with previously treated LA/mUC will receive PF-08634404 administered intravenously as monotherapy.
Biological: PF-08634404
Concentrate for solution for Infusion.
Other Names:
  • SSGJ-707
Experimental: Cohort B
Participants with untreated LA/mUC will receive PF-08634404 in combination with enfortumab vedotin
Biological: PF-08634404
Concentrate for solution for Infusion.
Other Names:
  • SSGJ-707
Biological: Enfortumab Vedotin
Powder for concentrate for solution for infusion
Other Names:
  • ASG-22CE
  • PADCEV
  • PF-08046042

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Confirmed Objective Response Rate (ORR) by investigator
Time Frame: Up to approximately 3 years
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.
Up to approximately 3 years
Number of Participants with Treatment Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time Frame: Through 90 days after the last study intervention; Up to approximately 3 years
AEs as characterized by type, frequency, severity (as graded by NCI CTCAE version 5.0), timing, seriousness and relationship to study intervention.
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
Time Frame: Through 90 days after the last study intervention; Up to approximately 3 years
The number of participants who experienced DLTs in participants receiving PF-08634404 in combination with EV.
Through 90 days after the last study intervention; Up to approximately 3 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Duration of Response (DOR) per RECIST v1.1 by investigator
Time Frame: Up to approximately 3 years
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.
Up to approximately 3 years
Progression Free Survival (PFS) per RECIST v1.1 by investigator
Time Frame: Up to approximately 3 years
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.
Up to approximately 3 years
Overall Survival (OS)
Time Frame: Up to approximately 3 years
Overall survival defined as the time from the date of C1D1 to the date of death due to any cause.
Up to approximately 3 years
Number of Participants With Clinical Laboratory Abnormalities
Time Frame: Through 90 days after the last study intervention; Up to approximately 3 years
Laboratory abnormalities as characterized by type, frequency, severity (as graded by NCI CTCAE version 5.0)
Through 90 days after the last study intervention; Up to approximately 3 years
Pharmacokinetics (PK): Serum concentration of PF-08634404
Time Frame: Up to 37 days after the last dose of treatment
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.
Up to 37 days after the last dose of treatment
Incidence of Anti-Drug Antibody (ADA) against PF-08634404
Time Frame: Up to 37 days after the last dose of treatment
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.
Up to 37 days after the last dose of treatment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Pfizer

Collaborators

Astellas Pharma Inc

Investigators

  • Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 11, 2026

Primary Completion (Estimated)

December 6, 2027

Study Completion (Estimated)

September 5, 2028

Study Registration Dates

First Submitted

February 12, 2026

First Submitted That Met QC Criteria

February 12, 2026

First Posted (Actual)

February 19, 2026

Study Record Updates

Last Update Posted (Actual)

June 4, 2026

Last Update Submitted That Met QC Criteria

June 3, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • C6461006
  • 2025-523523-21-00 (Registry Identifier: CTIS (EU))
  • Symbiotic-GU-06 (Other Identifier: Pfizer)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

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.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Urothelial Carcinoma

Clinical Trials on PF-08634404

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Belarus

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe