Prostate cancer Cancer Prostatic neoplasms
Conditions
Interventions
The study will be conducted in 2 Parts:
Part 1: Dose Confirmation Participants will receive JNJ-78278343 (Pasritamig) in combination
with JNJ-95298177 (ARX517) in a dose de-escalation schedule in ac
Sponsors
Janssen-Cilag International NV
Eligibility
Sex/Gender
Male
Inclusion criteria
Inclusion criteria: 1. 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 NEmarker positivity) are allowed 2. Must have metastatic castration-resistant prostate cancer (mCRPC) 3. PSA must measure at least 2 nanograms per milliliters (ng/mL) at screening 4. Measurable or evaluable disease 5. 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 6. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
Exclusion criteria
Exclusion criteria: Current key exclusion criteria as of 16/04/2026: 1. 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) 2. Known allergies, hypersensitivity, or intolerance to any of the components (e.g., excipients) of JNJ-78278343 or JNJ-95298177 3. 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 4. 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: 4.1. 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 4.2. Immune checkpoint inhibitors within 6 weeks prior to the first dose of study treatment 4.3. Radium (Ra) 223 dichloride within 28 days prior to the first dose of study treatment 4.4. Any prior treatment with kallikrein-related peptidase 2 (KLK2)-targeted therapy 4.5. Any prior prostate-specific membrane antigen (PSMA)-targeting therapy (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 4.6. Any prior antibody drug conjugates (ADCs) with microtubule inhibitor payloads (e.g., auristatins, maytansinoids, tubulysins) 5. 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. _____ Previous key exclusion criteria: 1. 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) 2. Known allergies, hypersensitivity, or intolerance to any of the components (e.g., excipients) of JNJ-78278343 or JNJ-95298177 3. 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 4. 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: 4.1. 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 4.2. Immune checkpoint inhibitors within 6 weeks prior to the first dose of study treatment 4.3. Radium (Ra) 223 dichloride within 28 days prior to the first dose of study treatment 4.4. Any prior treatment with kallikrein-re
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| 1. 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. Up to 2 years 2 months. 2. 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. Up to Day 22. | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. 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 2 years 2 months] 2. 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. [Time Frame: Up to 2 years 2 months] 3. Radiographic Progression-Free Survival (rPFS) rPFS is defined as the time from the date of first dose of JNJ-78278343 or JNJ-95298177 until the date of radiographic disease progression or death, whichever comes first. [Time Frame: Up to 2 years 2 months] 4. 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. [Time Frame: Up to 2 years 2 months] 5. 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 2 years 2 months] 6. Serum Concentration of JNJ-78278343 Serum samples will be analyzed to determine concentrations of JNJ-78278343. [Time Frame: Up to 2 years 2 months] 7. Serum Concentration of JNJ-95298177 Serum samples will be analyzed to determine concentrations of JNJ-95298177 (including ADC, total antibody and payload pAF-AS269). [Time Frame: Up to 2 years 2 months] 8. 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 2 years 2 months] 9. Number of Participants With Anti-JNJ-95298 | — |
Countries
England, United Kingdom, United States of America
Contacts
Public ContactLarissa Bates
Outcome results
None listed