Table 2.
Summary of prostate-specific antigen responses
| Abiraterone Acetate + Prednisone | |
|---|---|
| Efficacy-evaluable patients, n | 122 |
| ≥50% reduction in PSA during Cycles 1–6, n (%) |
106 (86.9) |
| 95% Cl | 80.9, 92.9 |
| P-valuea | <0.0001 |
| PSA reduction by category, n (%) | |
| 0 | 6 (4.9) |
| 0 to <30% | 5 (4.1) |
| 30 to <50% | 5 (4.1) |
| 50 to <90% | 33 (27.0) |
| ≥90% | 73 (59.8) |
| Undetectable PSA, n (%) | |
| <0.20 ng/mL | 27(22.1) |
| <0.02 ng/mL | 7 (5.7) |
| PSA progression-free rates, n | 131 |
| 12 months (%, 95% Cl) | 0.797 (0.705, 0.863) |
| 18 months (%, 95% Cl) | 0.674 (0.570, 0.758) |
| 24 months (%, 95% Cl) | 0.557 (0.449, 0.651) |
a
Response compared against the fixed proportion of 0.35 using a 1-sample and 1-sided test for a binomial proportion by normal approximation. CI, confidence interval