A Study of JNJ-87189401 Combined With JNJ-78278343 for Advanced Prostate Cancer

A Phase 1 Study of JNJ-87189401 (PSMA-CD28 Bispecific Antibody) Combined With JNJ-78278343 (KLK2-CD3 Bispecific Antibody) for Advanced Prostate Cancer

The purpose of Parts 1, 2A, and 2B of the study is to determine the recommended regimen for Phase 2 (RP2Rs) of combination of JNJ-87189401 with JNJ-78278343 and the purpose of Part 2C of this study is to determine how safe the RP2R(s) of the combination of JNJ-87189401 and JNJ-78278343 is, with or without apalutamide. Part 3 of this study evaluates the safety of the triplet combination of JNJ-87189401 and JNJ-78278343 with standard of care (SOC) lutetium Lu-177 vipivotide tetraxetan. Part 4 of this study further evaluates the safety of the triplet combination of JNJ-87189401 and JNJ-78278343 with JNJ-101556143 in participants with advanced prostate cancer.

Inclusion Criteria:

• Histologically confirmed adenocarcinoma of the prostate. Adenocarcinoma with small cell or neuroendocrine (NE) features is permitted. However, small cell carcinoma, carcinoid tumor, mixed NE carcinoma, or large cell NE carcinoma is disallowed
• Measurable or evaluable disease per PCWG3 criteria
• Part 1, Parts 2A, 2B, 3 and 4: Prior orchiectomy or medical castration; 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
• Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

Exclusion Criteria:

• History of an autoimmune disease within the 12 months prior to signing consent
• Any of the following within 6 months prior to signature of informed consent: a. myocardial infarction, b. severe or unstable angina, c. clinically significant ventricular arrhythmias, d. congestive heart failure (New York Heart Association [NYHA] class II to IV), e. transient ischemic attack, and f. Cerebrovascular accident