A Study of Pasritamig (JNJ-78278343) in Combination With Other Agents for Metastatic Prostate Cancer

A Phase 1b Study of JNJ-78278343, Targeting Human Kallikrein 2 (KLK2) in Combination With Other Agents for Metastatic Prostate Cancer

The purpose of this study is to identify the recommended phase 2 regimen(s) RP2R(s) of pasritamig and combination regimens in Part 1 (dose escalation) and to determine safety at the putative RP2R(s) of pasritamig with the combination regimens in Part 2 (dose expansion).

Inclusion Criteria:

• Part 1 A-G, 1I, 1J, and 1K (all combination treatments) and Parts 2B-C (cabazitaxel, docetaxel): Metastatic castration-resistant prostate cancer (mCRPC) with confirmed adenocarcinoma of the prostate as defined by prostate cancer working group 3 (PCWG3); Parts 2D-G, 2I, 2J, and 2K (apalutamide, enzalutamide, darolutamide, abiraterone acetate + prednisone [AAP], lutetium Lu-177 vipivotide tetraxetan, JNJ-101556143): mCRPC: Histologically confirmed adenocarcinoma of the prostate as defined by PCWG3, with a minimum PSA of 2 nanogram [ng]/milliliter (mL); Part 2H (apalutamide): metastatic hormone-sensitive prostate cancer(mHSPC) with PSA greater than (>) 0.2 ng/mL on 6 to 24 months of treatment with a next generation ARPI (apalutamide, enzalutamide, darolutamide, or abiraterone)
• Measurable or evaluable disease, except for Part 2H
• (a) Part 1A (cetrelimab) - Prior treatment for mCRPC with at least 1 prior androgen receptor pathway inhibitors (ARPI) (that is, abiraterone acetate, apalutamide, enzalutamide, darolutamide), or chemotherapy (example, docetaxel). (b) Part 1C and 2C (docetaxel), Part 1D (apalutamide), Part 1E and 2E (enzalutamide), Part 1F and 2F (darolutamide), and Part 1G, 2G (AAP), and Part 1K & 2K (JNJ-101556143)- Prior treatment with at least 1 prior ARPI (that is, apalutamide, enzalutamide, darolutamide, or abiraterone acetate). (C) Part 1B and 2B (cabazitaxel) - Prior treatment with at least 1 prior ARPI (ie, abiraterone acetate, apalutamide, enzalutamide, darolutamide) and docetaxel. (d) Part 2D (apalutamide) - Prior treatment with at least 1 prior ARPI (e) Part 2H (apalutamide)- Participant may have received up to 6 cycles of docetaxel. The last dose of docetaxel must be administered at least 2 months prior to enrollment (f) Parts 1I, 1J, 2I & 2J (lutetium Lu-177 vipivotide tetraxetan)- Prior treatment with at least 1 ARPI (abiraterone acetate, enzalutamide, darolutamide, or apalutamide). Participant must not have received prior cytotoxic chemotherapy or prior radioligand therapy (RLT) for mCRPC
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
• Adequate organ functions

Exclusion Criteria:

• Active autoimmune disease within the 12 months prior to signing consent that requires systemic immunosuppressive medications
• Toxicity related to prior anticancer therapy that has not returned to Grade less than or equal to (<=) 1 or baseline levels (except for alopecia, vitiligo, Grade <=2 peripheral neuropathy)
• Solid organ or bone marrow transplantation
• Known allergies, or intolerance to any of the components (example, excipients) of pasritamig, cetrelimab (Part 1A), cabazitaxel, Part 1B and 2B , docetaxel Part 1C and 2C , apalutamide (Part 1D and 2D and Part 2H), enzalutamide (Part 1E and 2E), darolutamide (Part 1F and 2F), or AAP (Part 1G and 2G), lutetium Lu-177 vipivotide tetraxetan (Parts 1I, 1J, 2I, and 2J), or JNJ-101556143 (Parts 1K & 2K)
• Significant infections or serious lung, heart or other medical conditions