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

NCT04898634 | Active Not Recruiting Phase 1 FDA Drug

• 4 other identifiers: CR10895878278343PCR10012020-005970-832023-506585-31-00
• Study Type: interventional
• Target: 216
• Locations: 6 countries
• Sites: 17

Brief Summary

The purpose of this study is to determine the recommended phase 2 dose(s) (RP2Ds) of JNJ-78278343 in Part 1 (Dose Escalation) and the safety at the RP2Ds in Part 2 (Dose Expansion).

Conditions

Prostatic Neoplasms

Keywords

Metastatic castration-resistant prostate cancer (mCRPC); Advanced prostate cancer

Outcome Measures

Primary Outcomes (3)

• 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.

  Up to 1 year and 10 months

• 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.

  Up to 1 year and 10 months

• 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.

  Up to 1 year and 10 months

Secondary Outcomes (8)

• Serum Concentration of JNJ-78278343

  Up to 1 year and 10 months

• Systemic Cytokine Concentrations

  Up to 1 year and 10 months

• Serum Prostate Specific Antigen (PSA) Concentration

  Up to 1 year and 10 months

• Number of Participants With Anti-JNJ-78278343 Antibodies

  Up to 1 year and 10 months

• Objective Response Rate (ORR)

  Up to 1 year and 10 months

Study Arms (1)

JNJ-78278343

EXPERIMENTAL

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 (dose escalation). In Part 2 (dose expansion), participants will receive JNJ-78278343 at recommended phase 2 dose (RP2D) as determined in Part 1. Participants who are still on study treatment (i.e., who are in Treatment Phase) at the time of the long term extension (LTE) will continue to receive study treatment until they reach a reason for discontinuation of treatment or until further notification by the sponsor of a different means for continued supply of study treatment, whichever occurs first.

Drug: JNJ-78278343

Interventions

JNJ-78278343 DRUG

JNJ-78278343 will be administered.

JNJ-78278343

Eligibility Criteria

• Age: 18 Years+
• Sex: male
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Janssen Research & Development, LLC: lead

Study Sites (17)

Columbia University Medical Center Herbert Irving Pavilion

New York, New York, 10032, United States

Location

Memorial Sloan Kettering Cancer Center

New York, New York, 10065, United States

Location

University of Washington

Seattle, Washington, 98195-9472, United States

Location

Peking University Third Hospital

Beijing, 100191, China

Location

Chongqing University Cancer Hospital

Chongqing, 400030, China

Location

Sun Yat Sen University Cancer Center

Guangzhou, 510710, China

Location

First Affiliated Hospital Of Wenzhou Medical College

Wenzhou, 325399, China

Location

Centre Leon Berard

Lyon, 69373, France

Location

APHM Hopital Timone

Marseille, 13005, France

Location

Institut Gustave Roussy

Villejuif, 94800, France

Location

National Cancer Center Hospital East

Kashiwa, 277 8577, Japan

Location

Yokohama City University Medical Center

Yokohama, 232 0024, Japan

Location

Antoni van Leeuwenhoek

Amsterdam, 1066 CX, Netherlands

Location

Erasmus MC

Rotterdam, 3015 GD, Netherlands

Location

Hosp Univ Fund Jimenez Diaz

Madrid, 28040, Spain

Location

Hosp Univ Hm Sanchinarro

Madrid, 28050, Spain

Location

Hosp Virgen de La Victoria

Málaga, 29010, Spain

Location

Related Publications (1)

• Stein MN, Vinceneux A, Robbrecht D, Doger B, Autio KA, Schweizer MT, Calvo E, Medina L, Van Dongen M, Deville JL, Bernard-Tessier A, Ghosh D, Shotts K, Shen F, Jaiprasart P, Chaudhary R, Wu S, Cartee L, Schnepp R, Gaut D, Lauring J, Wang SC, Villalobos VM, Baldini C. Pasritamig, a First-in-Class, Bispecific T-Cell Engager Targeting Human Kallikrein 2, in Metastatic Castration-Resistant Prostate Cancer: A Phase I Study. J Clin Oncol. 2025 Aug;43(22):2515-2526. doi: 10.1200/JCO-25-00678. Epub 2025 Jun 1.

  PMID: 40450573 DERIVED

MeSH Terms

Conditions

Prostatic Neoplasms

Condition Hierarchy (Ancestors)

Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Prostatic Diseases; Male Urogenital Diseases

Study Officials

• Janssen Research & Development, LLC Clinical Trial

  Janssen Research & Development, LLC

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 20, 2021
• First Posted: May 24, 2021
• Study Start: July 13, 2021
• Primary Completion (Estimated): February 10, 2027
• Study Completion (Estimated): February 10, 2027
• Last Updated: April 13, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will share

Locations

CN (4); FR (3); US (3); ES (3); JP (2); NL (2)