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A Study of JNJ-78278343, a T-Cell-Redirecting Agent Targeting Human Kallikrein 2 (KLK2), for Advanced Prostate Cancer

A Phase 1 Study of JNJ-78278343, a T-Cell-Redirecting Agent Targeting Human Kallikrein 2 (KLK2), for Advanced Prostate Cancer

Status
Active, not recruiting
Phases
Phase 1
Study type
Interventional
Source
JPRN
Registry ID
JPRN-jRCT2031240484
Enrollment
216
Registered
2024-11-14
Start date
2025-01-22
Completion date
Unknown
Last updated
2026-05-25

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Prostatic Neoplasms

Interventions

Experimental: JNJ-78278343 Participants will receive JNJ-78278343. The dose levels will be escalated based on the dose limiting toxicities (DLT) evaluation by the study evaluation team (SET) in Part 1

Sponsors

Fujikawa Ei
Lead Sponsor

Eligibility

Sex/Gender
Male

Inclusion criteria

Inclusion criteria: - Confirmed adenocarcinoma of the prostate which has spread to other body parts - Part 1: Prior treatment with at least 1 prior novel androgen receptor (AR)-targeted therapy or chemotherapy - Measurable or evaluable disease - Concurrent use of any other anticancer treatment must be discontinued for at least 2 weeks before the first dose of study drug - Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 - Prior surgical removal of testicles; or, for participants who have not undergone surgical removal of testicles, must be receiving ongoing androgen deprivation therapy (ADT) with a gonadotropin releasing hormone analog

Exclusion criteria

Exclusion criteria: Disease conditions - Active central nervous system (CNS) involvement - Toxicity related to prior anticancer therapy has not adequately recovered Prior/Concomitant Therapy - Prior treatment with human kallikrein (KLK) 2-targeted therapy - Received, or are receiving, medications that suppress the immune system within 3 days prior to the first dose of study drug - Received or plans to receive any live, attenuated vaccine within 4 weeks prior to the first dose of study drug Prior/Concurrent Medical Conditions - Diagnosis of cancer other than prostate cancer within 2 years prior to the first dose of study drug - Solid organ or bone marrow transplantation - Major clotting diseases within one month prior to the first dose of study drug - Active autoimmune disease within 12 months prior to the first dose of study drug - Active infection - Major diseases of heart and blood vessels within 6 months prior to the first dose of study drug - Clinically significant lung diseases - Active or chronic hepatitis B or hepatitis C infection - Known positive test result for human immunodeficiency virus (unless stable on antiretroviral therapy with undetectable viral load) - Any serious underlying medical conditions or other issue that would impair the ability of the participant to receive or tolerate the planned treatment

Design outcomes

Primary

MeasureTime frame
1. Part 1 and 2: Number of Participants With Adverse Events (AEs) An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/ biological agent under study. [Time Frame: Up to 1 year and 10 months] 2. Part 1 and 2: Number of Participants With AEs by Severity Severity will be graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) version 5.0. Severity scale ranges from Grade 1 (Mild) to Grade 5 (Death). Grade 1= Mild, Grade 2= Moderate, Grade 3= Severe, Grade 4= Life-threatening and Grade 5= Death related to adverse event. Cytokine release syndrome (CRS) and immune effector cell associated neurotoxicity syndrome (ICANS) will be graded according to the American Society for Transplantation and Cellular Therapy (ASTCT) guidelines. [Time Frame: Up to 1 year and 10 months] 3. Part 1: Number of Participants With Dose-Limiting Toxicity (DLT) Number of participants with DLT will be reported. The DLTs are specific adverse events and are defined as any of the following: high grade non-hematologic toxicity, or hematologic toxicity. [Time Frame: Up to 1 year and 10 months]

Secondary

MeasureTime frame
4. Serum Concentration of JNJ-78278343 Serum concentrations of JNJ-78278343 will be determined. [Time Frame: Up to 1 year and 10 months] 5. Systemic Cytokine Concentrations Cytokine concentrations will be determined for biomarker assessment. [Time Frame: Up to 1 year and 10 months] 6. Serum Prostate Specific Antigen (PSA) Concentration Serum PSA concentration will be measured. [Time Frame: Up to 1 year and 10 months] 7. Number of Participants With Anti-JNJ-78278343 Antibodies Serum samples will be analyzed for the detection of anti-JNJ-78278343 antibodies using a validated assay method. [Time Frame: Up to 1 year and 10 months] 8. Objective Response Rate (ORR) ORR is defined as the percentage of participants who have a partial response (PR) or better according to the response evaluation criteria in solid tumors (RECIST) version 1.1 response criteria without evidence of bone progression according to prostate cancer working group 3 (PCWG3). [Time Frame: Up to 1 year and 10 months] 9. Radiographic Progression-free Survival (rPFS) rPFS is defined as time from the date of first dose of JNJ-78278343 until the date of objective disease progression or death, whichever comes first. [Time Frame: Up to 1 year and 10 months] 10. PSA Response Rate PSA response rate is defined as the percentage of participants with a decline of PSA of 50 percent (%) or more from baseline. The maximum reduction from baseline in PSA will also be calculated during the treatment. [Time Frame: Up to 1 year and 10 months] 11. Duration of Response (DOR) DOR will be calculated among responders (PR or better) from the date of initial documentation of a response (PR or better) to the date of first documented evidence of progressive disease, as defined in the PCWG3 or RECIST version 1.1 response criteria, or death due to any cause, whichever occurs first. [Time Frame: Up to 1 year and 10 months]

Countries

China, France, Japan, Netherlands Kingdom Of The, Spain, United States Of America

Contacts

Public ContactMedical Information Center

Janssen Pharmaceutical K.K.

DL-JANJP-JCO_TL_TSG_EMP@its.jnj.com+81-120-183-275

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: May 30, 2026