The goal of this clinical trial is to learn if Rezvilutamide works to treat high-risk prostate cancer in patients who have recently undergone surgery (radical prostatectomy). It will also learn about the safety of Rezvilutamide. The main questions it aims to answer are:

Does Rezvilutamide, when used as an add-on treatment after surgery, lower the risk of the cancer returning (biochemical recurrence) within 3 years? What is the 36-month metastasis-free survival (MFS) rate for patients receiving this treatment? What is the safety profile of Rezvilutamide combined with ADT, specifically regarding the types, grades, and incidence of Treatment-Emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), Adverse Drug Reactions (ADRs), Adverse Events of Special Interest (AESIs), and rare adverse events? What are the exploratory findings regarding the status of immune cells after using Rezvilutamide?

Researchers will evaluate the combination of Rezvilutamide and hormone therapy (ADT) to see if it helps keep patients cancer-free.

Participants will:

Take Rezvilutamide: 240 mg once daily, taken orally before or after breakfast. Each cycle is 28 days, for up to 24 cycles. Treatment continues unless biochemical recurrence, disease progression, intolerable toxicity occurs, or the participant withdraws consent, as determined by the investigator.

Receive Androgen Deprivation Therapy (ADT): Leuprorelin 3.75mg via subcutaneous injection, once every 28 days for a total of 12 cycles.

[Study Rationale & Background] High-risk prostate cancer is typically defined by factors including clinical stage (e.g., cT3-4), a Gleason score of 8 or higher, and Prostate-Specific Antigen (PSA) levels greater than 20 ng/mL. Patients meeting these criteria face a significant risk of recurrence after radical prostatectomy (RP). While adjuvant radiotherapy is a standard option, many patients cannot tolerate or choose not to undergo radiation. This study explores an intensive endocrine therapy approach using Rezvilutamide, a potent new-generation oral androgen receptor (AR) inhibitor, combined with standard Androgen Deprivation Therapy (ADT).

[Study Design & Intervention] This is an exploratory, prospective, single-arm clinical study. After enrollment, participants will receive a combination therapy of standard-dose Rezvilutamide (240 mg once daily, orally) and ADT (Leuprorelin 3.75 mg subcutaneous injection, once every 4 weeks). Each treatment cycle lasts 28 days. After completing 12 cycles of the combination therapy, participants will proceed to monotherapy with standard-dose Rezvilutamide for maintenance. The total duration of treatment will be up to 24 cycles. The primary objective is to evaluate the 3-year biochemical recurrence-free survival (BCRFS) rate.

[Safety & Exploratory Objectives] Secondary objectives focus on the 36-month metastasis-free survival (MFS) rate and a comprehensive safety profile. This includes monitoring the types, grades, and incidence of Treatment-Emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), Adverse Drug Reactions (ADRs), and Adverse Events of Special Interest (AESIs). Additionally, the study includes an exploratory analysis of immune cell status to characterize the biological impact of Rezvilutamide on the patient's immune environment during treatment.

[Quality of Life] Patient-reported outcomes and quality of life will be monitored throughout the study using standardized assessment tools, including the FACT-P, EPIC-26, and BPI-SF scales, to ensure a holistic evaluation of the treatment's impact on physical and emotional well-being.

Inclusion Criteria

Subjects must meet all of the following criteria to be eligible for entry into this study:

Age ≥ 18 years.

Histologically confirmed adenocarcinoma of the prostate following radical prostatectomy.

Evaluated by the investigator as requiring pharmacological treatment.

ECOG Performance Status of 0 or 1.

Preoperative imaging ruled out metastatic disease.

Must meet at least one of the following postoperative high-risk factors:

Positive surgical margins;

Pathological stage pT3-pT4;

Lymph node metastasis;

Preoperative PSA ≥ 20 ng/ml.

Unwilling to receive postoperative radiotherapy.

PSA < 0.1 ng/ml during the screening period.

Capable of understanding and voluntarily signing the Informed Consent Form (ICF).

Exclusion Criteria

Patients meeting any of the following criteria will be excluded from the study:

Postoperative pathology contains non-adenocarcinoma components, such as neuroendocrine differentiation or small cell features.

Known or suspected hypersensitivity to Rezvilutamide or any of its excipients.

Factors affecting drug administration or absorption, such as inability to swallow, chronic diarrhea, or intestinal obstruction.

History of seizures or presence of conditions predisposing to seizures within 12 months prior to screening (including history of transient ischemic attack, stroke, or traumatic brain injury with loss of consciousness requiring hospitalization).

Active cardiac disease within 6 months prior to screening, including: severe/unstable angina, myocardial infarction, symptomatic congestive heart failure, and ventricular arrhythmias requiring medical treatment.

History of other malignancies within 3 years prior to screening (except for completely remitted carcinoma in situ or malignancies judged by the investigator to be slow-progressing).

Active HBV or HCV infection (HBV DNA ≥ 10^4 copies/mL, HCV RNA ≥ 10^3 copies/mL).

History of immunodeficiency (including positive HIV test, other acquired or congenital immunodeficiency diseases) or history of organ transplantation.

Male subjects with female partners of childbearing potential who refuse surgical sterilization or refuse to use effective contraception during the study period.

Any other condition which, in the opinion of the investigator, may interfere with the conduct of the study, compromise protocol compliance, or pose an unacceptable risk to the subject.