RecruitingPhase 1

A Study of JNJ-78278343 in Combination With JNJ-95298177 for Treatment of Prostate Cancer

United States, United Kingdom140 participantsStarted 2025-07-07

Plain-language summary

The purpose of this study is to identify the recommended phase 2 combination dose (RP2CD) of JNJ-78278343 in combination with JNJ-95298177 in Part 1 (Dose confirmation) of the study and to determine how safe and tolerable the RP2CD is for treatment of participants with metastatic castration-resistant prostate cancer (mCRPC; a stage of prostate cancer where the cancer has spread beyond the prostate and is resistant to hormonal therapy) in Part 2 (Dose expansion) of study.

Who can participate

Age range

18 Years

Sex

MALE

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Exclusion criteria

. Any T-cell redirecting treatment (e.g., CD3-directed bispecific or Chimeric Antigen Receptor T-cell \[CAR-T\] therapy) within 90 days prior to the first dose of study treatment
. Immune checkpoint inhibitors within 6 weeks prior to the first dose of study treatment
. Radium (Ra) 223 dichloride within 28 days prior to the first dose of study treatment
. Any prior treatment with kallikrein-related peptidase 2 (KLK2)-targeted therapy
. Any prior prostate-specific membrane antigen (PSMA)-targeting therapy (that is \[i.e.\], participants who received PSMA-targeting radioconjugates are excluded) \[Parts 2A and 2B only\]. Prior PSMA RLT is allowed in Part 1 and required for Part 2C and Part 2D but last dose must be \>3 months prior to the first dose of study treatment
. Any prior antibody drug conjugates (ADCs) with microtubule inhibitor payloads (e.g., auristatins, maytansinoids, tubulysins)

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Number of Participants With Adverse Events (AEs) by Severity

Timeframe: Up to 2 years 2 months

Part 1: Number of Participants With Dose-Limiting Toxicity (DLT)

Timeframe: Up To Day 22

Trial details

NCT IDNCT07082920

SponsorJanssen Research & Development, LLC

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2027-01-28

Contact for this trial

Study Contact

844-434-4210 Participate-In-This-Study1@its.jnj.com

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