A Study of JNJ-78278343, a T-Cell-Redirecting Agent Targeting Human Kallikrein 2 (KLK2), for Advanced Prostate Cancer
Conditions
Prostatic NeoplasmsDrugs
JNJ-78278343Summary
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).
Locations
0 locations Found with status Recruiting
Eligibility 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:
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
Study Plan
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-78278343Description:
JNJ-78278343 will be administered.
Outcome Measures
Primary Outcome Measures
Part 1 and 2: Number of Participants With Adverse Events (AEs)
Part 1 and 2: Number of Participants With AEs by Severity
Part 1: Number of Participants With Dose-Limiting Toxicity (DLT)
Secondary Outcome Measures
Serum Concentration of JNJ-78278343
Systemic Cytokine Concentrations
Serum Prostate Specific Antigen (PSA) Concentration
Number of Participants With Anti-JNJ-78278343 Antibodies
Objective Response Rate (ORR)
Radiographic Progression-free Survival (rPFS)
PSA Response Rate
Duration of Response (DOR)
Timeline
Last Updated
December 11, 2025Start Date
May 24, 2021Today
December 18, 2025Completion Date ( Estimated )
February 10, 2027
Sponsors of this trial
Lead Sponsor
Janssen Research & Development, LLC