• Male participants who are at least 18 years of age on the day of signing informed consent

• Histologically confirmed diagnosis of adenocarcinoma and/or neuroendocrine carcinoma of the prostate will be enrolled in this study

• Presence of metastatic disease documented on imaging studies (bone scan, computed tomography (CT) and/or magnetic resonance imaging (MRI) scans

• At least one of the following Aggressive Variant Prostate Cancer (AVPC) Criteria

‣ Histologically proven small cell (neuroendocrine) prostate cancer

⁃ Exclusive visceral metastases

⁃ Predominantly lytic bone metastases

⁃ Bulky lymph nodes (≥ 5 cm in longest dimension) or high-grade pelvic/prostatic masses

⁃ Low PSA (≤10 ng/ml) at initial presentation in the presence of extensive disease (≥20 metastases)

⁃ Elevated serum Lactate Dehydrogenase (LDH) (≥2 x ULN) or carcinoembryonic antigen (CEA) (≥2 x Upper limit (UL))

⁃ Short time to castration-resistance (≤6 months).

• Male participants: a male participant must agree to use a contraception as detailed in Appendix 3 of the protocol during the treatment period and for at least after the last dose of study treatment and refrain from donating sperm during this period

• The participant (or legally acceptable representative if applicable) provides written informed consent for the trial.

• Have measurable disease based on RECIST 1.1. Lesions situated in a previously irradiated area are considered measurable if progression has been demonstrated in such lesions.

• Have provided archival tumor tissue sample obtained in the previous year since or newly obtained core or excisional biopsy of a tumor lesion not previously irradiated. Formalin-fixed, paraffin embedded (FFPE) tissue blocks are preferred to slides. Newly obtained biopsies are preferred to archived tissue.

• Have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1. Evaluation of ECOG is to be performed within 7 days prior to the first dose of study intervention.

• Have adequate organ function as defined in the table 1 of the protocol. Specimens must be collected within 10 days prior to the start of study intervention.

• Criteria for known Hepatitis B (HBV) and C (HCV) positive subjects

‣ Hepatitis B and C screening tests are not required unless:

• Known history of HBV or HCV infection

∙ As mandated by local health authority

⁃ Hepatitis B positive subjects

• Participants who are HBsAg positive are eligible if they have received HBV antiviral therapy for at least 4 weeks and have undetectable HBV viral load prior to randomization.

∙ Participants should remain on anti-viral therapy throughout study intervention and follow local guidelines for HBV anti-viral therapy post completion of study intervention.

⁃ Participants with history of HCV infection are eligible if HCV viral load is undetectable at screening. • Participants must have completed curative anti-viral therapy at least 4 weeks prior to randomization.