Summary
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.