Phase III Study of Abiraterone Acetate (II) Versus Abiraterone Acetate in Patients with MCRPC

Inclusion Criteria:

1. Age≧ 18 years old, male;

2. Physical condition ECOG score 0~1 points;

3. Expected survival of at least 6 months;

4. Prostate adenocarcinoma confirmed by histological or cytological examination, and nodiagnosis of neuroendocrine carcinoma or small cell carcinoma;

5. Ongoing luteinizing hormone-releasing hormone-releasing hormone (LHRHA) therapy (medical castration) or prior bilateral orchiectomy (surgical castration); Subjectswho have not undergone bilateral orchiectomy must plan to maintain effective LHRHAtherapy throughout the study;

6. Testosterone at castration level (≦50 ng/dL or 1.73 nmol/L) at screening;

7. Disease progression at the time of study enrollment. Disease progression is definedas the occurrence of one or more of the following 3 items while the subject isreceiving castration therapy: (1) PSA progression, defined as PSA > 1 ng/mL with aPSA interval of 1 week, 2 consecutive episodes of >50% increase from the baselinevalue; In patients treated with flutamide or bicalutamide, PSA must also progressafter discontinuation (≧ 4 weeks and ≧6 weeks, respectively); (2) diseaseprogression as defined in RECIST 1.1; (3) Bone disease progression as defined byPCWG3 criteria, i.e., more than ≧2 new lesions found on bone scan;

8. Subjects who have been treated with one endocrine drug and/or one cytotoxicchemotherapeutic drug in the hormone-sensitive stage, such as novel androgenreceptor antagonists (such as enzalutamide, apalutamide, ODM-201, revilutamide,HC-1119 and proxalutamide) or ADT (such as goserelin), etc., subjects who have beentreated ≤with more than one treatment (bicalutamide for 4 weeks in the mCRPC stagecan be included, and subjects who are on a triple regimen of new endocrine therapycombined with docetaxel can be included, Dual subjects with docetaxel in combinationwith ADT may be included);

9. Metastatic lesions confirmed by CT/MRI or radioactive bone scan (99mTc) imagingexamination;

10. The functional level of the organ must meet the following requirements (no bloodtransfusion or hematopoietic growth factor therapy within 2 weeks prior to routineblood screening):

• ANC≧1.5×10*9/L；

• PLT≧100×10*9/L；

• Hb≧80 g/L；

• TBIL≦1.0×ULN；

• ALT and AST ≦2.5×ULN;

• BUN and Cr≦1.5×ULN.

11. As judged by the investigator, be able to comply with the test protocol;

12. Male subjects whose partner is a female of childbearing potential, should besurgically sterile or agree to use effective contraception during the trial and forat least 3 weeks after the last administration of abiraterone acetate tablets (Ecente) or abiraterone acetate (II), sperm donation is not allowed during thestudy;

13. Voluntarily participate in this clinical trial, understand the study procedures andhave signed informed consent.

Exclusion Criteria:

1. Previous treatment with abiraterone acetate for prostate cancer;

2. Have received ≥2-line systemic drug therapy in the hormone-sensitive stage in thepast;

3. Prior treatment with novel androgen receptor antagonists (such as enzalutamide,apalutamide, ODM-201, revilutamide, HC-1119 and proxalutamide), any cytotoxicchemotherapy drug therapy, molecularly targeted therapy (patients with HRR mutationswho refuse or are unable to use PARP inhibitors can be enrolled) or immunotherapy inthe mCRPC stage;

4. The washout period of any prior anti-tumor therapy (including radiotherapy, surgery,molecularly targeted therapy, immunotherapy, and first-generation androgen receptorantagonists) to the end of the randomization date of this study is < 4 weeks (exceptfor the bicalutamide washout period < 6 weeks);

5. Participate in other drug clinical trials as subjects, and the last test drugadministration is within 4 weeks from the randomization date of the drug in thisstudy;

6. Plan to receive any other anti-tumor therapy during this trial;

7. Known untreated central nervous system (CNS) metastases. Patients with a history ofsurgery or radiotherapy for brain metastases, if the disease has been stable for atleast 8 weeks after treatment prior to enrollment and corticosteroid-free for atleast 2 weeks prior to enrollment;

8. Severe bone injury caused by tumor bone metastasis judged by the investigator,including severe bone pain with poor control, pathological fractures and spinal cordcompression of important parts that occurred in the past 6 months or are expected tooccur in the near future;

9. Presence of contraindications to prednisone (corticosteroid) use, such as activeinfection or other conditions;

10. Presence of any chronic condition requiring treatment with corticosteroidsadministered at doses greater than "prednisone 5 mg, BID";

11. Habitual constipation or diarrhea, irritable bowel syndrome, inflammatory boweldisease; Abdominal fistula, gastrointestinal perforation, or intra-abdominal abscesswithin 6 months prior to the first dose of the drug; Those with abnormalgastrointestinal function, which may affect drug absorption as judged by theinvestigator;

12. Have a history of epilepsy, or have had diseases that can induce seizures within 12months before C1D1 (including a history of transient ischemic attack, cerebralstroke, traumatic brain injury with impaired consciousness requiringhospitalization);

13. Uncontrolled hypertension. Subjects with a history of hypertension are allowed toparticipate in this study if they can effectively control their blood pressurethrough antihypertensive therapy;

14. Presence of active cardiac disease within 6 months prior to the randomization dateof the study, including: severe/unstable angina, myocardial infarction, symptomaticcongestive heart failure, left ventricular ejection fraction <50%, and ventriculararrhythmias requiring medication;

15. Other malignant tumors within 5 years before the randomization date of the study (except for carcinoma in situ that has been in complete remission and malignanttumors that have been judged to have progressed slowly by the investigator);

16. Patients with active HBV or HCV infection (HBV virus copy number≧ 104 copies/mL,HCV virus copy number≧103 copies/mL);

17. History of immunodeficiency (including HIV test positive, other acquired andcongenital immunodeficiency diseases) or organ transplantation;

18. Presence of inability to swallow, chronic diarrhea, intestinal obstruction or otherfactors affecting drug taking and absorption;

19. Known allergy or intolerance to abiraterone acetate or its excipients;

20. According to the judgment of the investigator, there are concomitant diseases (suchas severe diabetes, peripheral neuropathy, thyroid diseases and psychiatricdisorders, etc.) or any other conditions that seriously endanger the safety of thepatient or affect the completion of the study.