Rezvilutamide in Patients With Biochemical Recurrence After Radical Prostatectomy for Prostate Cancer

Main Inclusion Criteria:

1. Age ≥ 40 years, male.
2. Patients with histologically-confirmed diagnosis of prostate adenocarcinoma.
3. pathologically node-negative (pN0) or pathologically node cannot be assessed (pNx);
4. Patients with PSA \< 0.1ng/ml within 8 weeks after radical prostatectomy (RP) and maintained for at least 6 months;
5. Biochemical recurrence (two consecutive rises in PSA with absolute values \> 0.2ng/ml, the time interval ≥ 2 weeks apart ) and no local recurrence or distant metastatic lesions on conventional imaging (bone scan and CT/MRI scan);
6. Eastern Cooperative Oncology Group (ECOG) performance status score of 0 to 1;
7. Estimated life expectancy \>10 year;
8. Adequate laboratory parameters

   * Absolute Neutrophil Count (ANC) ≥ 1.5 x 10\^9/L
   * Platelet count (PLT) ≥ 100 x 10\^9/L
   * Haemoglobin (Hb) ≥ 90 g/L
   * Serum creatinine (Cr) ≤ 1.5 x upper limit of normal(ULN) or creatinine clearance \> 50 ml/min.
   * Total bilirubin (TBIL) ≤ 1.5 x ULN.
   * Glutamic oxaloacetic transaminase (AST/SGOT) or glutamic alanine transaminase (ALT/SGPT) levels ≤ 2.5 x ULN.
   * International normalised ratio (INR) ≤1.5, prothrombin time (PT) and activated partial thromboplastin time (APTT)≤1.5 x ULN .
   * Left ventricular ejection fraction (LVEF) ≥ 50%.
9. Patients able to comply with the protocol. Arm 1 subjects are proposed to receive salvage radiation therapy, while arm 2 subjects are not suitable for or refuse radiation therapy.
10. Signed informed consent.

Main Exclusion Criteria:

1. Prior hormonal therapy (antiandrogens or gonadotropin releasing hormone) or prior radiotherapy to pelvic .
2. Postoperative biochemical recurrence with PSA \> 2 ng/ml.
3. Postoperative pathology containing neuro-endocrine differentiation or small cell features.
4. Prior malignancy other than prostate cancer in the past three years.
5. History of any of the following:

   * Seizure or known condition that may pre-dispose to seizure
   * Severe or unstable angina, myocardial infarction, symptomatic congestive heart failure, arterial or venous thromboembolic events (eg, pulmonary embolism, cerebrovascular accident including transient ischemic attacks), or clinically significant ventricular arrhythmias within 6 months prior to entry.
   * Active infection (eg, human immunodeficiency virus \[HIV\] or viral hepatitis)
6. Any other serious or uncontrolled illness which in the opinion of the investigator makes it undesirable for the patient to enter the trial.