A Study of the Clinical Activity and Safety of JNJ-64041809, a Live Attenuated Listeria Monocytogenes Immunotherapy, in Combination With Apalutamide Versus Apalutamide in Subjects With Metastatic Castration-resistant Prostate Cancer

An Open-label, Randomized, Phase 2 Study of the Clinical Activity and Safety of JNJ-64041809, a Live Attenuated Listeria Monocytogenes Immunotherapy, in Combination With Apalutamide Versus Apalutamide in Subjects With Metastatic Castration-resistant Prostate Cancer

The purpose of this study is to evaluate if the anti-tumor activity of JNJ-809 combined with apalutamide is improved compared with apalutamide alone for subjects with metastatic castration-resistant prostate cancer (mCRPC).

Inclusion Criteria:

• Adenocarcinoma of the prostate
• Metastatic disease as documented by technetium-99m (99mTc) bone scan or metastatic lesions by computed tomography (CT) or magnetic resonance imaging (MRI) scans
• Surgically or medically castrated, with testosterone levels of less than (<)50 nanogram per deciliter (ng/dL)
• Castration-resistant prostate cancer documented by time to prostate-specific antigen (PSA) increase during continuous treatment with androgen deprivation therapy (ADT) OR radiographic progression of soft tissues OR radiographic progression of bone according to PCWG3

Exclusion Criteria:

• Predominately small cell or neuroendocrine carcinoma of the prostate
• Known brain metastases (even if treated) or untreated epidural spread
• Prior chemotherapy for prostate cancer, except if administered in the adjuvant/neoadjuvant setting, or up to 6 cycles of docetaxel for metastatic hormone-sensitive prostate cancer
• Treatment with medications known to lower the seizure threshold or any investigational agent that were not discontinued or substituted greater than or equal to (>=)28 days prior to randomization