Prostatic NeoplasmsPhase 1NCT07082920
A Study of JNJ-78278343 in Combination With JNJ-95298177 for Treatment of Prostate Cancer
A Phase 1 study testing JNJ-78278343, JNJ-95298177 and JNJ-87189401 in people with Prostatic Neoplasms, run by Janssen Research & Development, LLC at 6 sites in 2 countries.
Trial 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 of JNJ-7827834 and JNJ-95298177 with or without JNJ-87189401 is for treatment of… Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- Prostatic Neoplasms
- What is being tested?
- JNJ-78278343, JNJ-95298177 and JNJ-87189401
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 140 participants
- Where
- 6 sitesin 2 countries
- Study dates
- 7 Jul 2025to 30 Dec 2027
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Histologically confirmed adenocarcinoma of the prostate. Primary small cell carcinoma, carcinoid tumor, neuroendocrine (NE) carcinoma, or large cell NE carcinoma arising in the prostate are not allowed; however, adenocarcinomas with NE features (for example [e.g.], immunohistochemistry [IHC] with both androgen receptor [AR]- and NE-marker positivity) are allowed
- Must have metastatic castration-resistant prostate cancer (mCRPC)
- PSA must measure at least 2 nanograms per milliliters (ng/mL) at screening
- Measurable or evaluable disease
- Prior orchiectomy or medical castration; or, for participants who have not undergone orchiectomy, must be receiving ongoing androgen deprivation therapy with a gonadotropin-releasing hormone (GnRH) analog (agonist or antagonist) prior to the first dose of study drug and must continue this therapy throughout the treatment phase
- Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
Who cannot join
- Toxicity related to prior anticancer therapy that has not returned to grade less than or equal to (<=) 1 or baseline levels (except for alopecia and vitiligo)
- Known allergies, hypersensitivity, or intolerance to any of the components (e.g., excipients) of JNJ-78278343, JNJ-95298177, or JNJ-87189401
- Participants with leptomeningeal disease or brain metastases, with the exception of participants with definitively, locally treated brain metastases that are clinically stable and asymptomatic greater than (>) 2 weeks, and who are off corticosteroid treatment for at least 2 weeks prior to first dose of study treatment
- Treatment with any anti-cancer or investigational agents within 14 days prior to the first dose of study treatment; specific requirements for certain anti-cancer therapies are as follows:
- 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
Show all 11Show fewer
- 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)
- Any serious underlying medical conditions or other issue that would impair the ability of the participant to receive or tolerate the planned treatment at the investigational site to understand the informed consent, or any condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant or that could prevent, limit, or confound the protocol-specified assessments
Trial locations and contacts
6 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
6 sites in 2 countries
United States4 sites, 4 recruiting
- Recruiting
University Hospitals Cleveland Medical Center
Cleveland, Ohio, 44106
- Recruiting
Columbia University Medical Center
New York, New York, 10032
- Recruiting
Florida Cancer Specialists
Sarasota, Florida, 34232
- Recruiting
Fred Hutchinson Cancer Center
Seattle, Washington, 98109
United Kingdom2 sites, 2 recruiting
- Recruiting
The Christie Nhs Foundation Trust
Manchester, M20 4BX
- Recruiting
Royal Marsden Hospital (Sutton)
Sutton, SM2 5PT
About this study
Official title: A Phase 1b Study of JNJ-78278343, a T-cell Redirecting Agent Targeting Human Kallikrein 2 (KLK2), in Combination With JNJ-95298177, an Antibody Drug Conjugate Targeting Prostate Specific Membrane Antigen, for Prostate Cancer
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 of JNJ-7827834 and JNJ-95298177 with or without JNJ-87189401 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.
- Conditions
- Prostatic Neoplasms
- Being tested
- JNJ-78278343, JNJ-95298177, JNJ-87189401
- Medical subject headings
- Prostatic Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
JNJ-78278343Drug
Also called Pasritamig
JNJ-78278343 will be administered intravenously.
JNJ-95298177Drug
Also called ARX517
JNJ-95298177 will be administered intravenously.
JNJ-87189401Drug
JNJ-87189401 will be administered.
| Study group | Role | What they receive |
|---|---|---|
| Part 1: Dose Confirmation | Experimental | Participants will receive JNJ-78278343 in combination with JNJ-95298177 in a dose de-escalation schedule in accordance with the Bayesian Optimal Interval Design (BOIN) design to determine the recommended phase 2 combination dose (RP2CD) regimen. Receives: Drug: JNJ-78278343; Drug: JNJ-95298177 |
| Part 2: Dose Expansion | Experimental | Participants will receive JNJ-78278343 in combination with JNJ-95298177 at the RP2CD as determined in Part 1 of the study with or without JNJ-87189401 to confirm the safety and anti-tumor activity. Receives: Drug: JNJ-78278343; Drug: JNJ-95298177; Drug: JNJ-87189401 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With Adverse Events (AEs) by Severity
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. 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 and ocular events will be graded using the alternative scale provided in the protocol.
Measured: Up to 2 years 2 months
Part 1: Number of Participants With Dose-Limiting Toxicity (DLT)
High grade hematologic or non-hematologic toxicities with exceptions and/or toxicities leading to treatment discontinuation will be regarded as DLT.
Measured: Up To Day 22
Secondary outcomes (11)
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).
Measured: Up to 2 years 2 months
Prostate-Specific Antigen (PSA) Response Rate
PSA response rate is defined as the percentage of participants with a decline of PSA of 50% or more from baseline.
Measured: Up to 2 years 2 months
Radiographic Progression-Free Survival (rPFS)
rPFS 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.
Measured: Up to 2 years 2 months
Time to Response (TTR)
TTR is defined for the responders as the time from the date of first dose of any study treatment to the date of first documented response.
Measured: Up to 2 years 2 months
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.
Measured: Up to 2 years 2 months
Serum Concentration of JNJ-78278343
Serum samples will be analyzed to determine concentrations of JNJ-78278343.
Measured: Up to 2 years 2 months
Serum Concentration of JNJ-95298177
Serum samples will be analyzed to determine concentrations of JNJ-95298177 (including ADC, total antibody and payload pAF-AS269).
Measured: Up to 2 years 2 months
Serum Concentration of JNJ-87189401
Serum samples will be analyzed to determine concentrations of JNJ-87189401.
Measured: Up to 2 years 2 months
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.
Measured: Up to 2 years 2 months
Number of Participants With Anti-JNJ-95298177 Antibodies
Serum samples will be analyzed for the detection of anti-JNJ-95298177 antibodies using a validated assay method.
Measured: Up to 2 years 2 months
Number of Participants With Anti-JNJ-87189401 Antibodies
Serum samples will be analyzed for the detection of anti-JNJ-87189401 antibodies using a validated assay method.
Measured: Up to 2 years 2 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jul 2025
- Study start7 Jul 2025
- Primary completion30 Nov 2027 (estimated)
- Study completion30 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Prostatic NeoplasmsStudies of the same condition, open and under way.
- More trials run by Janssen Research & Development, LLCThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 140 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Janssen Research & Development, LLC
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Janssen Research & Development, LLC Clinical trial, Study director, Janssen Research & Development, LLC
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07082920
- Sponsor's protocol ID
- 78278343PBPCR1004
- Status last verified
- Nov 2026
- First submitted
- 22 Jul 2025
- Last updated
- 3 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: The data sharing policy of Johnson \& Johnson Innovative Medicine is available at www.innovativemedicine.jnj.com/our-innovation/clinical-trials/transparency. As noted on this site, requests for access to the study data can be submitted through Yale Open Data Access (YODA) Project site at yoda.yale.edu.
Study at a glance
From the registry record, last updated by the sponsor on 3 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1b Study of JNJ-78278343, a T-cell Redirecting Agent Targeting Human Kallikrein 2 (KLK2), in Combination With JNJ-95298177, an Antibody Drug Conjugate Targeting Prostate Specific Membrane Antigen, for Prostate Cancer
- ClinicalTrials.gov ID
- NCT07082920
- Acronym / sponsor ID
- 78278343PBPCR1004
- Conditions
- Prostatic Neoplasms
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 140 participants (estimated)
- Lead sponsor
- Janssen Research & Development, LLCIndustry (pharma, biotech, devices)
- Study start
- 7 Jul 2025 (actual)
- Primary completion
- 30 Nov 2027 (estimated)
- Study completion
- 30 Dec 2027 (estimated)
- First posted
- 24 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 of JNJ-7827834 and JNJ-95298177 with or without JNJ-87189401 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.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Part 1: Dose Confirmation | Experimental | Drug: JNJ-78278343, Drug: JNJ-95298177Participants will receive JNJ-78278343 in combination with JNJ-95298177 in a dose de-escalation schedule in accordance with the Bayesian Optimal Interval Design (BOIN) design to determine the recommended phase 2 combination dose (RP2CD) regimen. |
| Part 2: Dose Expansion | Experimental | Drug: JNJ-78278343, Drug: JNJ-95298177, Drug: JNJ-87189401Participants will receive JNJ-78278343 in combination with JNJ-95298177 at the RP2CD as determined in Part 1 of the study with or without JNJ-87189401 to confirm the safety and anti-tumor activity. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Histologically confirmed adenocarcinoma of the prostate. Primary small cell carcinoma, carcinoid tumor, neuroendocrine (NE) carcinoma, or large cell NE carcinoma arising in the prostate are not allowed; however, adenocarcinomas with NE features (for example [e.g.], immunohistochemistry [IHC] with both androgen receptor [AR]- and NE-marker positivity) are allowed
- Must have metastatic castration-resistant prostate cancer (mCRPC)
- PSA must measure at least 2 nanograms per milliliters (ng/mL) at screening
- Measurable or evaluable disease
- Prior orchiectomy or medical castration; or, for participants who have not undergone orchiectomy, must be receiving ongoing androgen deprivation therapy with a gonadotropin-releasing hormone (GnRH) analog (agonist or antagonist) prior to the first dose of study drug and must continue this therapy throughout the treatment phase
Key exclusion criteria (11 listed)
- Toxicity related to prior anticancer therapy that has not returned to grade less than or equal to (<=) 1 or baseline levels (except for alopecia and vitiligo)
- Known allergies, hypersensitivity, or intolerance to any of the components (e.g., excipients) of JNJ-78278343, JNJ-95298177, or JNJ-87189401
- Participants with leptomeningeal disease or brain metastases, with the exception of participants with definitively, locally treated brain metastases that are clinically stable and asymptomatic greater than (>) 2 weeks, and who are off corticosteroid treatment for at least 2 weeks prior to first dose of study treatment
- Treatment with any anti-cancer or investigational agents within 14 days prior to the first dose of study treatment; specific requirements for certain anti-cancer therapies are as follows:
- Any serious underlying medical conditions or other issue that would impair the ability of the participant to receive or tolerate the planned treatment at the investigational site to understand the informed consent, or any condition for which, in the opinion of the investigator, participation would not be in the best interest of the participant or that could prevent, limit, or confound the protocol-specified assessments
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| JNJ-78278343Also: PasritamigJNJ-78278343 will be administered intravenously. | Drug | Part 1: Dose Confirmation, Part 2: Dose Expansion |
| JNJ-95298177Also: ARX517JNJ-95298177 will be administered intravenously. | Drug | Part 1: Dose Confirmation, Part 2: Dose Expansion |
| JNJ-87189401JNJ-87189401 will be administered. | Drug | Part 2: Dose Expansion |
Primary outcome
Number of Participants With Adverse Events (AEs) by Severity
Time frame: Up to 2 years 2 months
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. 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 and ocular events will be graded using the alternative scale provided in the protocol.
Part 1: Number of Participants With Dose-Limiting Toxicity (DLT)
Time frame: Up To Day 22
High grade hematologic or non-hematologic toxicities with exceptions and/or toxicities leading to treatment discontinuation will be regarded as DLT.
11 secondary outcomes
Objective Response Rate (ORR)
Time frame: Up to 2 years 2 months
Prostate-Specific Antigen (PSA) Response Rate
Time frame: Up to 2 years 2 months
Radiographic Progression-Free Survival (rPFS)
Time frame: Up to 2 years 2 months
Time to Response (TTR)
Time frame: Up to 2 years 2 months
Duration of Response (DOR)
Time frame: Up to 2 years 2 months
Serum Concentration of JNJ-78278343
Time frame: Up to 2 years 2 months
Serum Concentration of JNJ-95298177
Time frame: Up to 2 years 2 months
Serum Concentration of JNJ-87189401
Time frame: Up to 2 years 2 months
Number of Participants With Anti-JNJ-78278343 Antibodies
Time frame: Up to 2 years 2 months
Number of Participants With Anti-JNJ-95298177 Antibodies
Time frame: Up to 2 years 2 months
Number of Participants With Anti-JNJ-87189401 Antibodies
Time frame: Up to 2 years 2 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Nov 2026.
- Individual participant dataSharing planned: Yes. The data sharing policy of Johnson \& Johnson Innovative Medicine is available at www.innovativemedicine.jnj.com/our-innovation/clinical-trials/transparency. As noted on this site, requests for access to the study data can be submitted through Yale Open Data Access (YODA) Project site at yoda.yale.edu.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Janssen Research & Development, LLC Clinical trial study director
Janssen Research & Development, LLC
6 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing JNJ-78278343, JNJ-95298177 and JNJ-87189401 in people with Prostatic Neoplasms, run by Janssen Research & Development, LLC at 6 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 3 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 6 sites in United States, United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Study Contact (844-434-4210, Participate-In-This-Study1@its.jnj.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants With Adverse Events (AEs) by Severity (time frame: Up to 2 years 2 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Nov 2026.