Metastatic Castration-resistant Prostate Cancer Cancer
Conditions
Interventions
Arm 1: Pasritamig with Best Supportive Care (BSC)
Participants in this arm receive pasritamig (JNJ-78278343), a bispecific antibody, administered as a solution for infusion using a step-up dosing sche
Sponsors
Janssen-Cilag International NV
Eligibility
Sex/Gender
Male
Age
18 Years to 99 Years
Inclusion criteria
Inclusion criteria: Current key inclusion criteria as of 01/07/2026: 1. Be 18 years of age or more at the point of informed consent. 2. Histologically confirmed adenocarcinoma of the prostate. 3. Metastatic castration-resistant prostate cancer (mCRPC): Disease that is metastatic either to bone, any lymph node, or both without clear evidence of other metastatic sites at the time of screening by conventional imaging with CT or MRI (chest, abdomen, and pelvis) and 99mTc bone scan. 4. Prostate specific antigen (PSA) greater than or equal to 2 ng/mL at screening. 5. In the opinion of the investigator, the next best treatment option is a clinical trial. 6. Participants should have had all life-prolonging therapies for which they are clinically eligible in the opinion of the investigator and to which they have access. Prior therapies could have been given in any disease setting (not limited to mCRPC). Prior treatment specifications are specified in full within the study protocol. 7. Use of any other anticancer therapy or investigational agent must be discontinued for at least 2 weeks before the first dose of study treatment. 8. Prior orchiectomy or medical castration (receiving ongoing androgen deprivation therapy [ADT] with a gonadotropin-releasing hormone [GnRH] analog [agonist or antagonist]) prior to the first dose of study treatment and must continue this therapy throughout the treatment phase. 9. Must be sufficiently recovered from any recent surgery or trauma. 10. Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2. 11. Have an eGFR greater than or equal to 30 mL/min, calculated with the CKD-epi formula, before randomisation. Participants with obstructive uropathy should have treatment prior to randomisation. 12. Participants must meet the protocol specified hepatic function measures. 13. Participants must meet the protocol specified haematological value measures. 14. Participant must agree, while on study treatment and for 3 months after the last dose of study treatment, to not donate gametes (i.e., sperm) or freeze for future use for the purposes of assisted reproduction and to wear an external condom, when transmission of sperm/ejaculate can occur. If able to produce sperm and their partner is of childbearing potential, the partner must practice a highly effective method of contraception. 15. Must sign an Informed Consent Form (ICF) indicating that the participant understands the purpose of, and procedures required for, the study and is willing to participate in the study. 16. Participant must be willing and able to adhere to the lifestyle restrictions specified in this protocol. Previous key inclusion criteria: 1. Be 18 years of age or more at the point of informed consent. 2. Histologically confirmed adenocarcinoma of the prostate. 3. Metastatic castration-resistant prostate cancer (mCRPC): Disease that is metastatic either to bone, any lymph node, or both without clear evidence of metastasis to visceral organs at the time of screening. Local-regional invasion (rectum, bladder) can be included. 4. Prostate specific antigen (PSA) greater than or equal to 2 ng/mL at screening. 5. In the opinion of the investigator, the next best treatment option is a clinical trial. 6. Participants should have had all life-prolonging therapies for which they are clinically eligible in the opinion of the investigator and to which they have access. Prior therapies could have been given in any disease setting (not limited to mCRPC). Prior tr
Exclusion criteria
Exclusion criteria: Current key exclusion criteria as of 01/07/2026: 1. Solid organ or bone marrow transplantation. 2. Venous thromboembolic events within 1 month prior to the first dose of study treatment. 3. Active autoimmune disease within the 12 months prior to signing consent that requires systemic immunosuppressive medications. 4. Participants with Grade 1 or higher fever (>=38ºC) or active infection requiring systemic treatment within 7 days prior to randomization are ineligible. Participants must be afebrile (<38ºC) at the time of study treatment dosing unless approved by medical monitor. 5. Clinically significant pulmonary compromise, particularly a requirement for supplemental oxygen use (greater than 2 L/min by nasal cannula) to maintain adequate oxygenation. 6. Suspected or known allergies, hypersensitivity, or intolerance to excipients of pasritamig. 7. Participant has a prior or concurrent second malignancy (other than the disease under study) for which natural history or treatment could likely interfere with any study endpoints of safety or the efficacy of the study treatment(s). 8. Any of the protocol-specified cardiac dysfunctions within 6 months prior to first dose of study treatment. 9. Has known history of either brain or leptomeningeal prostate cancer metastases. 10. Participants who are HIV-positive and meet any of the criteria specified in the study protocol. 11. Active or chronic HBV or HCV infection, as specified in the study protocol. 12. Prior treatment with KLK2-targeted therapy. 13. Prior treatment with any CD3-directed therapy. 14. Received immunosuppressive doses of systemic medications within 3 days prior to the first dose of study treatment. A single course of glucocorticoids is permitted as prophylaxis for imaging contrast. If glucocorticoids were used to treat immune-related adverse events associated with prior therapy, 7 or more days must have elapsed since the last dose of corticosteroid. 15. Received or plans to receive any live, attenuated vaccine within 4 weeks before the first dose of study treatment. Live, attenuated influenza vaccines are permitted as late as 7 days before the study treatment. 16. 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 study 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. Solid organ or bone marrow transplantation. 2. Venous thromboembolic events within 1 month prior to the first dose of study treatment. 3. Active autoimmune disease within the 12 months prior to signing consent that requires systemic immunosuppressive medications. 4. Active infection or condition that requires treatment with systemic antibiotics within 7 days prior to the first dose of study treatment. Prophylactic anti-infective agents are allowed. 5. Clinically significant pulmonary compromise, particularly a requirement for supplemental oxygen use (greater than 2 L/min by nasal cannula) to maintain adequate oxygenation. 6. Suspected or known allergies, hypersensitivity, or intolerance to excipients of pasritamig. 7. Participant has a prior or concurrent second malignancy (other than the disease under study) for which natural history or treatment could likely interfere with
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Overall Survival, defined as the time from randomisation to date of death from any cause. Participants alive at the time of analysis will be censored on the last date the participant was known to be alive. After the primary endpoint achieves statistical significance, the a will be passed to the key secondary endpoints of rPFS, time to symptomatic progression, time to skeletal-related events, and PFS | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Radiographic progression-free survival is measured using investigator-assessed RECIST v1.1 and PCWG3 criteria at baseline and every 8 weeks until radiographic progression or death 2. Time to symptomatic progression is measured using protocol-specified clinical criteria at baseline and every scheduled clinical assessment until first occurrence 3. Time to skeletal-related event is measured using protocol-specified criteria based on clinical and imaging assessments at baseline and every scheduled visit until first occurrence 4. Progression-free survival is measured using radiographic imaging, clinical assessment, and survival status at baseline and every 8 weeks until radiographic or clinical progression or death 5. Time to prostate-specific antigen progression is measured using serum PSA levels assessed per PCWG3 criteria at baseline and every 4 weeks until progression 6. Time to pain progression is measured using the Brief Pain Inventory-Short Form (BPI-SF) item 3 “worst pain in 24 hours” at baseline and every 4 weeks until first observation of pain progression 7. Time to deterioration in fatigue is measured using the EORTC QLQ-C30 fatigue scale at baseline and every 4 weeks until first observation of deterioration 8. Incidence and severity of adverse events are measured using investigator assessment and graded per CTCAE v5.0 at baseline and throughout the treatment period until 30 days after last dose 9. Clinical laboratory test results are measured using standard haematology, biochemistry, and urinalysis panels at baseline and every 4 weeks during treatment | — |
Countries
Australia, Belgium, Brazil, Canada, China, England, France, Germany, Italy, Japan, Netherlands, Northern Ireland, Poland, Spain, Sweden, Taiwan, United Kingdom
Contacts
Public ContactPeter;. Chatfield;Study Team
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Outcome results
None listed