Safety and Efficacy of TAK-385 for Patients With Localized Prostate Cancer

Inclusion Criteria

• Is male, 18 years of age or older.
• Has histologically confirmed diagnosis of localized prostate adenocarcinoma of intermediate risk for which 6-month neoadjuvant and adjuvant androgen deprivation therapy (ADT) to EBRT is indicated. Intermediate risk per National Comprehensive Cancer Network (NCCN) guidelines includes one of the following:
• T2b-T2c disease, or
• Gleason score 7, or
• Prostate-specific antigen (PSA) 10-20 nanogram per milliliter (ng/mL).
• Is scheduled for EBRT to begin greater than or equal to (>=) 12 weeks after the Baseline visit.
• Has serum testosterone at screening greater then (>) 150 nanogram per deciliter (ng/dL) (5.2 nanomoles per liter [nmol/L]).
• Has screening serum PSA concentration >2 ng/mL.
• Has body mass index (BMI) >=18.0 at screening or baseline.
• Has Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 at screening or baseline.
• Is a male participant, even if surgically sterilized (that is, status postvasectomy), who: Agrees to practice effective barrier contraception during the entire study treatment period and through 4 months after the last dose of study drug, or, Agrees to practice true abstinence, when this is in line with the preferred and usual lifestyle of the participant. (Periodic abstinence [example, calendar, ovulation, symptothermal, postovulation methods for the female partner] and withdrawal are not acceptable methods of contraception.).
• Has given voluntary written consent before performance of any study-related procedure not part of standard medical care, with the understanding that consent may be withdrawn by the participant at any time without prejudice to future medical care.
• Has suitable venous access for the study-required blood sampling, including pharmacokinetic (PK) and pharmacodynamic sampling.

Exclusion Criteria

• Has metastatic disease (based on investigator evaluation and assuming no likely metastatic pelvic lymph nodes >1.0 cm in long axis diameter).
• Had prior or current use of a gonadotropin-releasing hormone (GnRH) analog or androgen receptor antagonist as first-line hormone therapy, unless total use was less than 6 months and not more recently than 1 year before the planned baseline visit.
• Had diagnosis of or treatment for another malignancy within 2 years before the first dose of study drug, or previous diagnosis of another malignancy with evidence of residual disease. Participants with nonmelanoma skin cancer or carcinoma in situ of any type are not excluded if they have undergone complete resection.
• Has abnormal screening and/or baseline laboratory values that suggest a clinically significant underlying disease, or the following laboratory values:
• Alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) >1.5 * institutional upper limit of the normal range (ULN);
• Serum creatinine >2.0 milligram per deciliter (mg/dL);
• Total bilirubin >2.0 * institutional ULN (unless documented Gilbert's disease);
• Uncontrolled diabetes (Hemoglobin A1c [HbA1c] >10 [percent] %) or previously undiagnosed diabetes mellitus with HbA1c >8%.
• Has history of myocardial infarction, unstable symptomatic ischemic heart disease, any ongoing cardiac arrhythmias of Grade >2 (chronic stable atrial fibrillation on stable anticoagulant therapy is allowed), thromboembolic events (example, deep vein thrombosis, pulmonary embolism, or symptomatic cerebrovascular events), or any other significant cardiac condition (example, pericardial effusion, restrictive cardiomyopathy) within 6 months before receiving the first dose of study drug.
• Has electrocardiogram (ECG) abnormalities of:
• Q-wave infarction, unless identified 6 or more months before screening;
• Heart rate-corrected QT interval millisecond (msec) (QTcF interval) >480 msec. If QTcF is prolonged in a participant with a pacemaker, the participant may be enrolled in the study upon discussion with the project clinician;
• If the QT