comparative study of abiraterone acetate tablets (i) or zytiga® in patients with metastatic castration-resistant prostate cancer

Conditions: Metastatic Castration-resistant Prostate Cancer (mCRPC)

Summary: to evaluate whether the efficacy of the abiraterone acetate tablets (i) is comparable to that of the zytiga®) by comparing the serum testosterone concentrations on day 9 and/or day 10 after oral administration of the two formulations in patients with metastatic castration-resistant prostate cancer (mcrpc).


Eligibility criteria:
inclusion criteria: 1. males, ≥ 18 years old; 2. histologically or cytologically diagnosed with prostate adenocarcinoma, without neuroendocrine or small cell characteristics, and having metastatic lesions with imaging evidence (such as positive bone scan or metastatic lesions on ct/mri); 3. serum testosterone level \< 50 ng/dl or 1.7 nmol/l at the screening; subjects who have not undergone bilateral orchidectomy must plan to continue medication throughout the study to maintain therapy with effective gnrh agonist or antagonist; 4. progression of prostate cancer as confirmed by diagnostic files, meeting one of the conditions for disease progression: 1) biochemistry evidence of recurrence: continuous 3 rises of psa (taken a minimum of 1 week apart) from a baseline measurement of at least 2 ng/ml, greater than 50% of the minimum value in 2 rises; 2) radiographic progression: a clear evidence of new lesion; 2 or more new bone lesions appearing on bone scan; ct or mri showing lesion progression (recist 1.1); 5. ecog performance status score of ≤ 1; 6. life expectancy of ≥ 6 months; 7. major organs are functioning well exclusion criteria: 1. history of pituitary or adrenal dysfunction; 2. have used flutamide within 4 weeks before the first dose of study treatment, and bicalutamide or nilutamide within 6 weeks before the first dose of study treatment; 3. prior therapy with cyp17 inhibitors (such as abiraterone acetate, ketoconazole, tak-700, etc.) or investigational drugs or marketed drugs of new androgen receptor antagonists (such as enzalutamide, apalutamide, shr3680, odm-201, and proxalutamide); 4. have received 5-reductase inhibitors (such as finasteride and dutasteride), estrogen, progesterone, any herbal products (such as saw palmetto) that may decrease psa levels, and radiotherapy within 4 weeks prior to the start of study medication; 5. have previously received biotherapy or cytotoxic chemotherapy for mcrpc; patients who have completed docetaxel treatment for at least 1 year before enrollment can participate in screening; 6. prostate cancer with moderate to severe pain symptoms, with a score of \> 3 for question 3 (the worst pain in the last 24 hours, 0-1 point means asymptomatic, 2-3 points mean mild symptoms) of the brief pain inventory-short form (bpi-sf); 7. with contraindications to the use of glucocorticoids, such as uncontrolled persistent infections or other conditions; 8. chronic diseases that require systemic corticosteroid therapy (\> 10 mg/day prednisone or equivalent). patients who have discontinued the administration or reduced the dose to \< 10 mg within 14 days prior to the start of study treatment are eligible; 9. presence of abdominal fistula, gastrointestinal perforation, abdominal abscess, or other abnormal gastrointestinal function within 6 months before the first dose of study treatment, which may affect drug absorption as judged by the investigator; 10. presence of active heart disease within 6 months prior to the first dose of study treatment, including: severe/unstable angina, myocardial infarction, symptomatic congestive heart failure, left ventricular ejection fraction \< 50%, and severe arrhythmia requiring treatment or new york heart association (nyha) class iii-iv heart failure; 11. inability to swallow the whole tablet; 12. other conditions that make the patient unsuitable for the study as judged by the investigator.