NCT06842498

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

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
75

participants targeted

Target at P50-P75 for phase_2

Timeline
24mo left

Started Feb 2026

Geographic Reach
1 country

15 active sites

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress10%
Feb 2026Mar 2028

First Submitted

Initial submission to the registry

February 19, 2025

Completed
5 days until next milestone

First Posted

Study publicly available on registry

February 24, 2025

Completed
12 months until next milestone

Study Start

First participant enrolled

February 22, 2026

Completed
2.1 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 31, 2028

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

March 31, 2028

Last Updated

March 20, 2026

Status Verified

March 1, 2026

Enrollment Period

2.1 years

First QC Date

February 19, 2025

Last Update Submit

March 19, 2026

Conditions

Metastatic Castration-Resistant Prostate Cancer

Keywords

FG-3246FOR46mCRPCCRPCCD46Prostate cancerAntibody-drug conjugateMetastatic prostate cancerFibroGenADC

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 30 months)

  • Number of Participants With Treatment-emergent Adverse Events (TEAEs)

    From first dose until 28 days after last dose (up to approximately 30 months)

  • Maximum Plasma Concentration (Cmax) of FG-3246, Total Anticluster 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 30 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 30 months

  • Duration of Response (DoR) Per RECIST v1.1 and PCWG3 Criteria

    From first dose up to approximately 30 months

  • Confirmed PSA50 Response Rate: Percentage of Participants Achieving a Decline in Prostate-specific Antigen (PSA) ≥50% From Baseline

    Up to approximately 30 months

  • +8 more secondary outcomes

Study Arms (3)

FG-3246 1.8 mg/kg

EXPERIMENTAL

Participants 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 FibroGen decision to close the study.

Drug: FG-3246

FG-3246 2.4 mg/kg

EXPERIMENTAL

Participants 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 FibroGen decision to close the study.

Drug: FG-3246

FG-3246 2.7 mg/kg

EXPERIMENTAL

Participants 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 FibroGen decision to close the study.

Drug: FG-3246

Interventions

FG-3246DRUG

FG-3246 will be administered per schedule specified in the arm description.

Also known as: FOR46
FG-3246 1.8 mg/kgFG-3246 2.4 mg/kgFG-3246 2.7 mg/kg

Eligibility Criteria

Age18 Years+
Sexmale
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Participant must have histological, and/or cytological confirmation of prostate adenocarcinoma.
  • Participant with safely accessible tumor lesion must agree to biopsy of a primary or metastatic lesion during screening. Alternatively, participant may provide an archival biopsy of a primary or metastatic lesion that was taken after castration resistance developed and within 1 year prior to randomization.
  • Participant must have serum testosterone levels \<50 nanograms (ng)/deciliter (dL) during screening.
  • Participant is required to have progressed on 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 and reconfirmed on Study Day -1 or Day 1.

You may not qualify if:

  • Participant has received previous treatment with a therapeutic targeting CD46.
  • Participant has small cell neuroendocrine carcinoma (pure or mixed) or any other non-adenocarcinoma component on prior or current histologic evaluation of primary or metastatic lesion.
  • Participant has received more than one prior second-generation ARSI in any setting.
  • Participant has received any systemic anticancer therapy (for example, hormonal therapy, chemotherapy, immunotherapy, radioligand therapy, or biological therapy \[including monoclonal antibodies\], including investigational therapy) within 28 days prior to randomization.
  • Participant has received any prior radiation therapy within 28 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

Study Sites (15)

The University of Arizona Cancer Center - North Campus

Tucson, Arizona, 85719, United States

RECRUITING

UCLA Clark Urology Center

Los Angeles, California, 90095, United States

RECRUITING

University of California San Francisco

San Francisco, California, 94143, United States

RECRUITING

Bioresearch Partner

Aventura, Florida, 33180, United States

RECRUITING

Bioresearch Partner

Hialeah, Florida, 33013, United States

RECRUITING

Winship Cancer Institute, Emory University

Atlanta, Georgia, 30322, United States

RECRUITING

New Mexico Oncology Hematology Consultants, Ltd.

Albuquerque, New Mexico, 87109, United States

RECRUITING

UNC Hospitals, The University of North Carolina at Chapel Hill

Chapel Hill, North Carolina, 27514, United States

RECRUITING

Duke University Medical Center - Duke Cancer Center

Durham, North Carolina, 27710, United States

RECRUITING

University Hospitals Cleveland Medical Center

Cleveland, Ohio, 44106, United States

RECRUITING

Carolina Urologic Research Center

Myrtle Beach, South Carolina, 29572, United States

RECRUITING

University of Texas Southwestern Medical Center

Dallas, Texas, 75390, United States

RECRUITING

Oncology Consultants

Houston, Texas, 77030, United States

RECRUITING

University of Virginia Comprehensive Cancer Center

Charlottesville, Virginia, 22903, United States

RECRUITING

Fred Hutchinson Cancer Center

Seattle, Washington, 98109, United States

RECRUITING

MeSH Terms

Conditions

Prostatic Neoplasms

Condition Hierarchy (Ancestors)

Genital Neoplasms, MaleUrogenital NeoplasmsNeoplasms by SiteNeoplasmsGenital Diseases, MaleGenital DiseasesUrogenital DiseasesProstatic DiseasesMale Urogenital Diseases

Central Study Contacts

Javier Moreno

CONTACT

415-978-1466jmoreno@kyntrabio.com

Mairead Carney

CONTACT

415-978-1337mcarney@kyntrabio.com

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

March 20, 2026

Record last verified: 2026-03

Locations

US(15)