A Phase 1b Study of Pasritamig (JNJ-78278343), a T-cell Redirecting Agent Targeting Human Kallikrein 2 (KLK2), in Combination With JNJ-86974680, an A2a Receptor (A2aR) Antagonist, for Prostate Cancer
The purpose of this study is to identify the recommended phase 2 combination dose (RP2CD) of Pasritamig in combination with JNJ-86974680 in Part 1 (Dose finding) of the study and to determine how safe and tolerable the RP2CD is for treatment of participants with advanced prostate cancer in Part 2 (Dose expansion) of study.
• 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