GI-102 (CD80-IgG4 Fc-IL2v3) in Combination With Pasritamig in Patients With Metastatic Castration-resistant Prostate Cancer (mCRPC) (JET-201)

November 4, 2026 updated by: GI Innovation, Inc.

A Phase 1b/2, Open-label, Multi-center Study to Evaluate the Anti-cancer Activity, Safety and Tolerability of GI-102 (CD80-IgG4 Fc-IL2v3) in Combination With Pasritamig [T-CELL-Redirecting Agent Targeting Human Kallikrein 2 (KLK2)] in Patients With Metastatic Castration-resistant Prostate Cancer (mCRPC) Who Progressed on Previous Novel Hormonal Therapy (NHT) (JET-201)

The purpose of this clinical trial is to evaluate the safety, tolerability, and preliminary anti-cancer activity of GI-102 in combination with pasritamig in adult men with metastatic castration-resistant prostate cancer (mCRPC) whose cancer has progressed after previous treatment with a novel hormonal therapy (NHT).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

107

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

  • South Korea
      • Seoul, South Korea, 05505
        • Recruiting
        • Asan Medical Center
        • Principal Investigator:
          • Jae Lyun Lee, M.D., Ph.D.
      • Seoul, South Korea, 03722
        • Recruiting
        • Yonsei University Health System, Severance Hospital
        • Principal Investigator:
          • Sang Joon Shin, M.D., Ph.D.
    • Banpo-daero
      • Seoul, Banpo-daero, South Korea, 06591
        • Recruiting
        • The Catholic University of Korea Seoul ST.MARY'S Hospital
        • Principal Investigator:
          • In Ho Kim
    • Seongbuk-gu
      • Seoul, Seongbuk-gu, South Korea, 02841
        • Recruiting
        • Korea University Anam Hospital
        • Principal Investigator:
          • Jwa Hoon Kim, M.D.
    • Yangcheon-gu
      • Seoul, Yangcheon-gu, South Korea, 07985
        • Recruiting
        • Ewha Womans University Mokdong Hospital
        • Principal Investigator:
          • Jeong Min Cho
  • United States
    • New York
      • New York, New York, United States, 10032
        • Not yet recruiting
        • Columbia University Medical Center
        • Principal Investigator:
          • Mark N. Stein, M.D.

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

Key Inclusion Criteria:

  • Male participants aged ≥18 years (or ≥19 years according to local regulatory requirements).
  • ECOG performance status of 0 to 1.
  • Histologically confirmed advanced prostate adenocarcinoma with measurable or evaluable disease. Adenocarcinoma with small cell or neuroendocrine (NE) features is permitted. However, primary small cell carcinoma, carcinoid tumor, mixed NE carcinoma, or large cell NE carcinoma (or pathologic evidence of conversion to) is disallowed.
  • Metastatic castration-resistant prostate cancer (mCRPC) with documented disease progression following at least one line of novel androgen receptor-targeted therapy.
  • PSA ≥2 ng/mL at screening.
  • No more than 2 prior taxane regimens and no prior cytotoxic chemotherapy other than taxane therapy.
  • Prior orchiectomy or ongoing androgen deprivation therapy with castrate testosterone levels.
  • Adequate organ and marrow function and adequate cardiovascular function.
  • Adequate recovery from prior anticancer therapy-related adverse events.
  • Willingness and ability to comply with study procedures and protocol-specified contraception requirements.

Key Exclusion Criteria:

  • Active or prior CNS metastases, carcinomatous meningitis, or clinically unstable spinal cord compression.
  • Significant uncontrolled cardiovascular, pulmonary, hepatic, autoimmune, infectious, or other systemic disease.
  • Active or recent clinically significant infection, including active tuberculosis, hepatitis B, or hepatitis C.
  • Active pneumonitis or interstitial lung disease (ILD), or history of clinically significant pneumonitis/ILD.
  • Recent treatment with investigational products, prohibited immunomodulating agents, radiotherapy, major surgery, or other protocol-defined prohibited therapies.
  • Prior treatment with CD3-directed therapies, including KLK2-CD3 bispecific antibodies or other CD3-targeting T-cell engagers.
  • Known hypersensitivity to GI-102, pasritamig, or their excipients, or any other condition that may interfere with study participation or interpretation of results.

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: Safety run-in: GI-102 + pasritamig (Schedule A)

Participants receive GI-102 in combination with pasritamig during the Safety run-in phase. Dose escalation is guided by a Bayesian Optimal Interval (BOIN) design.
Drug: GI-102

GI-102 will be administered in accordance with the procedures specified in the study protocol.

Drug: Pasritamig

Pasritamig will be administered in accordance with the procedures specified in the study protocol.
Experimental: Safety run-in: GI-102 + pasritamig (Schedule B)

Participants receive GI-102 in combination with pasritamig during the Safety run-in phase. Dose escalation is guided by a Bayesian Optimal Interval (BOIN) design.
Drug: GI-102

GI-102 will be administered in accordance with the procedures specified in the study protocol.

Drug: Pasritamig

Pasritamig will be administered in accordance with the procedures specified in the study protocol.
Experimental: Expansion

Participants enrolled in the Expansion phase will receive the combination recommended Phase 2 regimen (cRP2R) of GI-102 and pasritamig, determined based on the safety and dose-escalation results from the Safety run-in phase.
Drug: GI-102

GI-102 will be administered in accordance with the procedures specified in the study protocol.

Drug: Pasritamig

Pasritamig will be administered in accordance with the procedures specified in the study protocol.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence and nature of DLTs (Safety run-in phase)
Time Frame: From Day -14 to Cycle 1 Day 22 (35 days)

A DLT is defined as a clinically significant AE (classified according to the NCI CTCAE version 6.0) or significant laboratory abnormality that occur during the DLT assessment periods, and is considered by the Investigator to be related to the study drug(s).
From Day -14 to Cycle 1 Day 22 (35 days)
Incidence, nature, and severity of AEs graded according to CTCAE v6.0 (Safety run-in phase)
Time Frame: Up to 2 years

An adverse event (AE) is any untoward medical occurrence in a participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with the treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a pharmaceutical product, whether or not considered related to the pharmaceutical product. Preexisting conditions which worsen during a study are also considered as AEs. All AE events will be graded according to National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) version 6.0.
Up to 2 years
PSA response rate (≥ 50% decline from baseline) per PCWG3 (Expansion phase)
Time Frame: Up to 2 years

PSA response rate is defined as the percentage of participants with a decline of PSA of 50% or more from baseline.
Up to 2 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
PSA response rate (≥ 50% and ≥ 90% decline from baseline) per PCWG3 (Safety run-in phase)
Time Frame: Up to 2 years

PSA response rate is defined as the percentage of participants with a decline of PSA of 50% (or 90%) or more from baseline.
Up to 2 years
Radiographic PFS per PCWG3
Time Frame: Up to 2 years

Radiographic PFS is defined as the time from the date of first dose of any study treatment until the date of radiographic disease progression or death, whichever comes first.
Up to 2 years
Time to PSA progression
Time Frame: Up to 2 years

Time to PSA progression, defined as the time from baseline to the first date of documented PSA progression per PCWG3 criteria.
Up to 2 years
Overall Response Rate (ORR) per RECIST v1.1
Time Frame: Up to 2 years

Among participants with measurable disease, ORR is defined as the percentage of participants who achieve a partial response (PR) or complete response (CR) according to RECIST v1.1.
Up to 2 years
Duration of Response (DoR) per RECIST v1.1
Time Frame: Up to 2 years

Among participants with measurable disease who achieve a CR or PR, DoR is defined as the time from the first documented CR or PR until the first documented disease progression according to RECIST v1.1 or death from any cause, whichever occurs first.
Up to 2 years
Disease Control Rate (DCR) per RECIST v1.1
Time Frame: Up to 2 years

Among participants with measurable disease, DCR is defined as the percentage of participants who achieve a CR, PR, or stable disease (SD) according to RECIST v1.1.
Up to 2 years
Incidence, nature, and severity of AEs graded according to CTCAE v6.0 (Expansion phase)
Time Frame: Up to 2 years

An adverse event (AE) is any untoward medical occurrence in a participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with the treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a pharmaceutical product, whether or not considered related to the pharmaceutical product. Preexisting conditions which worsen during a study are also considered as AEs. All AE events will be graded according to National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) version 6.0.
Up to 2 years
PK profile: peak plasma concentration (Cmax) of GI-102 when combined with pasritamig
Time Frame: Up to 2 years

Plasma concentrations of GI-102 will be measured at specified time points following administration of GI-102 in combination with pasritamig to determine the maximum observed plasma concentration (Cmax).
Up to 2 years
PK profile: half-life (T1/2) of GI-102 when combined with pasritamig
Time Frame: Up to 2 years

Plasma concentrations of GI-102 will be measured at specified time points following administration of GI-102 in combination with pasritamig to determine the terminal half-life (T1/2) of GI-102.
Up to 2 years
PK profile: area under the plasma concentration-time curve (AUC) of GI-102 when combined with pasritamig
Time Frame: Up to 2 years

Plasma concentrations of GI-102 will be measured at specified time points following administration of GI-102 in combination with pasritamig to determine the area under the plasma concentration-time curve (AUC) of GI-102.
Up to 2 years

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Immune cell phenotyping in peripheral blood
Time Frame: Up to 2 years

Immune cell populations and their changes following study treatment will be assessed in peripheral blood using flow cytometry.
Up to 2 years
Overall Response Rate (ORR) per iRECIST
Time Frame: Up to 2 years

ORR is defined as the percentage of participants who achieve a partial response (PR) or complete response (CR) according to the iRECIST criteria.
Up to 2 years
Overall Survival (OS)
Time Frame: Up to 2 years

Overall survival (OS) is defined as the time from the first dose of study treatment to death from any cause.
Up to 2 years
Incidence of anti-GI-102 antibody (ADA)
Time Frame: Up to 2 years

Serum samples will be analyzed using a validated assay to determine the incidence of anti-GI-102 antibodies (ADA).
Up to 2 years
Incidence of Neutralizing Antibody (Nab) Against GI-102
Time Frame: Up to 2 years

Serum samples that are positive for anti-GI-102 antibodies (ADA) will be further analyzed using a validated assay to determine the incidence of neutralizing antibodies (Nab).
Up to 2 years

Collaborators and Investigators

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

Sponsor

GI Innovation, Inc.

Collaborators

Janssen Research & Development, LLC

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 (Estimated)

October 12, 2026

Primary Completion (Estimated)

March 31, 2029

Study Completion (Estimated)

September 30, 2029

Study Registration Dates

First Submitted

October 1, 2026

First Submitted That Met QC Criteria

October 6, 2026

First Posted (Actual)

October 13, 2026

Study Record Updates

Last Update Posted (Actual)

November 9, 2026

Last Update Submitted That Met QC Criteria

November 4, 2026

Last Verified

November 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • GII-102-P201 (JET-201)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

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.

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