A Study of Pasritamig (JNJ-78278343) in Combination With JNJ-86974680 for Treatment of Prostate Cancer

Inclusion Criteria: * 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 * Metastatic castration-resistant prostate cancer (mCRPC) that is metastatic either to bone, any lymph node, or both without clear evidence of metastasis to visceral organs. Local-regional invasion (rectum, bladder) and bone disease with soft tissue component can be included * Prior orchiectomy or medical castration (for example, 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) * Prostate-specific antigen (PSA) greater than or equal to (\>=) 2 nanograms per milliliters (ng/mL) at screening * Measurable or evaluable disease * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 Exclusion criteria: * Toxicity related to prior anticancer therapy that has not returned to grade less than or equal to (\<=) 1 or baseline levels (except for alopecia, neuropathy \[Grade 2\] and vitiligo) * Known allergies, hypersensitivity, or intolerance to any of the components (for example, excipients) of pas…