The primary purpose of this study is to evaluate the efficacy of triptorelin embonate 22.5 mg 6-month formulation administered by the subcutaneous (under the skin) route in:

• achieving castrate levels of testosterone (< 1.735 nmol/L) on Day 29 [i.e., 28 days after investigational medicinal product (IMP) injection], and
• in maintaining serum testosterone castrate levels from Month 2 (Day 57) to end of Month 12 (Day 337) in participants with advanced prostate cancer.

Summary Inclusion Criteria:

• Meets protocol-specified criteria for qualification and contraception
• Is willing and able to remain confined in the study unit for the entire duration of each treatment period and comply with restrictions related food, drink and medications
• Voluntarily consents to participate and provides written informed consent prior to any protocol-specific procedures

Summary Exclusion Criteria:

• Has history or current use of over-the-counter medications, dietary supplements, or drugs (including nicotine and alcohol) outside protocol-specified parameters
• Has signs, symptoms or history of any condition that, per protocol or in the opinion of the investigator, might compromise: 1) the safety or well-being of the participant or study staff; 2) the safety or well-being of the participant's offspring (such as through pregnancy or breast-feeding); 3) the analysis of results