A Clinical Study of Ifinatamab Deruxtecan Based Treatment Combinations or as Monotherapy to Treat Metastatic Castrate Resistant Prostate Cancer (mCRPC) (MK-2400-01A/IDeate-Prostate02)

Inclusion Criteria

• Inclusion Criteria: The main inclusion criteria include but are not limited to the following: - Has histologically- or cytologically-confirmed adenocarcinoma of the prostate without small cell histology - Has prostate cancer progression while on androgen deprivation therapy (ADT) (or post bilateral orchiectomy) within 6 months before Screening - Has current evidence of distant metastatic disease - Has received prior treatment with 1 or 2 androgen receptor pathway inhibitors (ARPIs) and progressed during or after treatment - Participants receiving bone resorptive therapy (including, but not limited to bisphosphonate or denosumab) must have been on stable doses for ≥4 weeks before allocation/randomization - An Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1 assessed within 10 days before allocation/randomization - Has prior treatment with poly-ADP-ribose polymerase inhibitors (PARPi) if indicated by local approved regimen or were deemed ineligible to receive PARPi by the investigator Exclusion Criteria: The main exclusion criteria include but are not limited to the following: - Has any history of interstitial lung disease (ILD)/pneumonitis irrespective of steroid use (except for a history of radiation pneumonitis that did not require steroids), current ILD, clinical or radiographic suspicion of ILD for which the diagnosis of ILD cannot be ruled out - Clinically severe pulmonary compromise resulting from intercurrent pulmonary illnesses - Uncontrolled or significant cardiovascular disease - History of pituitary dysfunction - Poorly controlled diabetes mellitus - History or current condition of adrenal insufficiency (eg, Addison's disease) - Has received prior treatment with taxane-based chemotherapy agent for metastatic castration-resistant prostate cancer (mCRPC). - Chronic steroid treatment (dose of >10 mg daily prednisone equivalent), except for low-dose inhaled steroids (for asthma/chronic obstructive pulmonary disease), topical steroids (for mild skin conditions), or intra-articular steroid injections - Received prior radiotherapy within 2 weeks of start of study intervention, or has radiation-related toxicities, requiring corticosteroids - Known additional malignancy that is progressing or has required active treatment within the past 3 years - Known active central nervous system (CNS) metastases and/or carcinomatous meningitis - Active autoimmune disease that has required systemic treatment in the past 2 years - History of allogeneic tissue/solid organ transplant