A Dose Finding Study of Debio 4228 in Participants With Advanced Prostate Cancer

Prior treatment

• Previous ADT (neoadjuvant or adjuvant hormonal therapy) for ≥6 months duration and \<6 months treatment-free interval before start of screening.
• Participant requires combination with androgen deprivation therapy with the exception of enzalutamide.
• Received chemotherapy or cryotherapy within 8 weeks prior to the start of screening for the treatment of prostate cancer.
• Use of exogenous testosterone within 6 months before the start of screening.
• Major surgery within 4 weeks before the start of screening.

Other illness

• History of bilateral orchiectomy, adrenalectomy, or hypophysectomy.
• Abnormal cardiovascular function or diabetes.
• Cancer disease within the last two years except for prostate cancer and some skin cancers.
  • \[Note: Other protocol and subprotocol-defined criteria apply\]

• Participant with histologically confirmed diagnosis of prostate cancer, with one of the following:
  • Newly diagnosed androgen-sensitive locally advanced or metastatic disease; or
  • Localized disease not suitable for local primary intervention with curative intent.
• Participant judged by the Study Investigator to be candidate for continuous androgen deprivation therapy (ADT).
• Baseline morning serum testosterone levels \>150 ng/dL at screening visit.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.
• Life expectancy of at least 6 months.
• Adequate bone marrow, hepatic, and renal function at the screening visit.
  • \[Note: Other protocol and subprotocol-defined criteria apply\]