A Study of FG-3246 in Participants With Metastatic Castration-Resistant Prostate Cancer (mCRPC)
A Phase 2 Dose Optimization Trial Evaluating a CD46-Targeted Antibody-Drug Conjugate (FG-3246) in Patients With Metastatic Castration-Resistant Prostate Cancer
1 other identifier
interventional
75
1 country
20
Brief Summary
The purpose of this study is to evaluate the safety, efficacy, tolerability, and pharmacokinetics (PK) of FG-3246, a cluster of differentiation 46 (CD46) targeting antibody-drug conjugate (ADC), in the treatment of participants with mCRPC who have progressed following treatment with one prior second-generation androgen receptor signaling inhibitor (ARSI) in any setting and no prior taxane therapy in the mCRPC setting.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for phase_2
Started Feb 2026
20 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
February 19, 2025
CompletedFirst Posted
Study publicly available on registry
February 24, 2025
CompletedStudy Start
First participant enrolled
February 22, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
March 31, 2028
ExpectedStudy Completion
Last participant's last visit for all outcomes
March 31, 2028
May 22, 2026
May 1, 2026
2.1 years
February 19, 2025
May 19, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (3)
Radiographic Progression-free Survival (rPFS) By Investigator Assessment Per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 and Prostate Cancer Clinical Trials Working Group 3 (PCWG3) Criteria
Until radiographic progression is noted (up to approximately 25 months)
Number of Participants With Treatment-emergent Adverse Events (TEAEs)
From first dose until 28 days after last dose (up to approximately 25 months)
Maximum Plasma Concentration (Cmax) of FG-3246, Total Anti-cluster of Differentiation 46 Antibody (CD46), and Free Monomethyl Auristatin E (MMAE)
Within each 21 day treatment cycle from Cycle 1 through 28 days post last dose (up to approximately 25 months)
Secondary Outcomes (13)
rPFS Rate at 6 Months (rPFS6) Per RECIST v1.1 and PCWG3 Criteria
Month 6
rPFS Rate at 12 Months (rPFS12) Per RECIST v1.1 and PCWG3 Criteria
Month 12
Confirmed Objective Response Rate (ORR) Per RECIST v1.1 and PCWG3 Criteria
From first dose up to approximately 25 months
Duration of Response (DoR) Per RECIST v1.1 and PCWG3 Criteria
From first dose up to approximately 25 months
Confirmed PSA50 Response Rate: Percentage of Participants Achieving a Decline in Prostate-specific Antigen (PSA) ≥50% From Baseline
Up to approximately 25 months
- +8 more secondary outcomes
Study Arms (3)
FG-3246 1.8 mg/kg
EXPERIMENTALParticipants will receive FG-3246 1.8 milligrams (mg)/kilogram (kg) administered via intravenous (IV) infusion on Day 1 of each 21-day treatment cycle (every 3 weeks \[Q3W\]) until radiographic progression, unacceptable safety and tolerability, participant or investigator decision to stop treatment, other withdrawal criteria are met, or sponsor decision to close the study.
FG-3246 2.4 mg/kg
EXPERIMENTALParticipants will receive FG-3246 2.4 mg/kg administered via IV infusion on Day 1 of each 21-day treatment cycle (Q3W) until radiographic progression, unacceptable safety and tolerability, participant or investigator decision to stop treatment, other withdrawal criteria are met, or sponsor decision to close the study.
FG-3246 2.7 mg/kg
EXPERIMENTALParticipants will receive FG-3246 2.7 mg/kg administered via IV infusion on Day 1 of each 21-day treatment cycle (Q3W) until radiographic progression, unacceptable safety and tolerability, participant or investigator decision to stop treatment, other withdrawal criteria are met, or sponsor decision to close the study.
Interventions
FG-3246 will be administered per schedule specified in the arm description.
Eligibility Criteria
You may qualify if:
- Participant must have histological, and/or cytological confirmation of prostate adenocarcinoma on all prior tumor biopsies.
- Participant with soft tissue disease and a safely accessible soft tissue tumor lesion(s) must agree to biopsy of a primary or metastatic lesion during screening. Alternatively, participant may provide a suitable archival biopsy of a primary or metastatic lesion.
- Participant must have serum testosterone levels \<50 nanograms (ng)/deciliter (dL) during screening.
- Participant is required to have progressed on no more than one prior treatment with a second generation ARSI (abiraterone acetate, enzalutamide, apalutamide, or darolutamide) initiated in either the castration-sensitive or castration-resistant setting.
- Participant must have progressive mCRPC following last treatment at screening.
- Participant must have ≥1 metastatic lesion that is present on baseline Computed Tomography (CT), Magnetic Resonance Imaging (MRI), or bone scan obtained ≤28 days prior to randomization.
- Participant must have adequate organ function during screening.
You may not qualify if:
- Participant has received previous treatment with a therapeutic targeting CD46.
- Participant has small cell neuroendocrine carcinoma (pure or mixed) on any prior histologic evaluation of primary or metastatic lesion.
- Participant has progressed on more than one prior second-generation ARSI in any setting or has received more than two prior second-generation ARSIs in any setting.
- Participants must not have received recent anticancer treatments before enrollment. Ongoing supportive or hormonal therapies are allowed if they were started well before randomization and are continued without change.
- Participant has received any prior radiation therapy within 14 days prior to randomization.
- Participant has a known actionable mutation or gene alteration, for example, BRCA1 mutation, for which approved therapies are available, for example, PARP inhibitors, unless these therapies are not appropriate for the participant as determined by the investigator or the participant refuses such therapy.
- Participant has National Cancer institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) ≥Grade 2 peripheral neuropathy at the time of screening from any etiology.
- Participant has received any prior chemotherapy; however, one prior taxane-based chemotherapy in the castration-sensitive setting is allowed if completed \>12 months before randomization.
- Participant has known hypersensitivity to the components of FG-3246 or its analogs or a history of allergic or anaphylactic reaction to human, humanized, or chimeric monoclonal antibodies.
- Participant has diagnosis with any other malignancy in the past 5 years, except for adequately treated basal cell or squamous cell carcinoma of the skin.
- Participant requires treatment with a strong cytochrome P450 3A4 (CYP3A4) inhibitor or inducer drug that cannot be safely discontinued.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Kyntra Biolead
Study Sites (20)
Western Regional Medical Center - City of Hope Phoenix Goodyear
Goodyear, Arizona, 85338, United States
HonorHealth Research Institute
Scottsdale, Arizona, 85258, United States
The University of Arizona Cancer Center - North Campus
Tucson, Arizona, 85719, United States
VA Greater Los Angeles Healthcare System
Los Angeles, California, 90073, United States
UCLA Clark Urology Center
Los Angeles, California, 90095, United States
University of California San Francisco
San Francisco, California, 94158, United States
New Haven Hospital - Yale Cancer Center
New Haven, Connecticut, 06519, United States
Bioresearch Partner - Aventura
Aventura, Florida, 33180, United States
Bioresearch Partner - Hialeah
Hialeah, Florida, 33013, United States
Winship Cancer Institute, Emory University
Atlanta, Georgia, 30322, United States
East Jefferson General Hospital Metairie
New Orleans, Louisiana, 70112, United States
New Mexico Oncology Hematology Consultants, Ltd.
Albuquerque, New Mexico, 87109, United States
Duke University Medical Center - Duke Cancer Center
Durham, North Carolina, 27710, United States
University Hospitals Cleveland Medical Center
Cleveland, Ohio, 44106, United States
Carolina Urologic Research Center
Myrtle Beach, South Carolina, 29572, United States
University of Texas Southwestern Medical Center
Dallas, Texas, 75390, United States
Oncology Consultants
Houston, Texas, 77030, United States
University of Virginia Comprehensive Cancer Center
Charlottesville, Virginia, 22908, United States
Fred Hutchinson Cancer Center
Seattle, Washington, 98109, United States
University of Washington Medical Center
Seattle, Washington, 98195, United States
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 2
- Allocation
- RANDOMIZED
- Masking
- NONE
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
February 19, 2025
First Posted
February 24, 2025
Study Start
February 22, 2026
Primary Completion (Estimated)
March 31, 2028
Study Completion (Estimated)
March 31, 2028
Last Updated
May 22, 2026
Record last verified: 2026-05