Table 2:
Prespecified secondary and exploratory efficacy endpoints
| Endpoint | Median months (95% CI) | HR or RR (95% CI) |
p Value | Events, n | ||
|---|---|---|---|---|---|---|
| Apalutamide + abiraterone- prednisone (n=492) |
Abiraterone- prednisone (n=490) |
Apalutamide + abiraterone- prednisone (n=492) |
Abiraterone- prednisone (n=490) |
|||
| Secondary endpoints | ||||||
| Overall survival | 36·2 (32·8–38·8) | 33·7 (31·2–38·3) | 0·95 (0·81–1·11)* | 0·50† | 329 | 336 |
| Time to initiation of cytotoxic chemotherapy | 36·1 (32·2–42·6) | 34·2 (29·5–39·2) | 0·94 (0·78–1·13)* | 0·51† | 231 | 239 |
| Time to chronic opioid use | 47·0 (39·2–NE) | 53·3 (42·0–NE) | 1·07 (0·87–1·32)* | 0·50† | 192 | 182 |
| Time to pain progression | 21·8 (18·0–25·7) | 26·5 (22·6–29·5) | 1·12 (0·95–1·33)* | 0·19† | 286 | 271 |
| Exploratory and post hoc endpoints | ||||||
| Time to PSA progression | 13·8 (12·0–15·6) | 12·0 (10·2–13·8) | 0·87 (0·74–1·02)* | 0·076† | 325 | 340 |
| Time to clinical progression | 16·0 (14·3–17·3) | 18·1 (16·4–19·8) | 1·10 (0·96–1·27)* | 0·18† | 398 | 389 |
| Time to first subsequent anticancer therapy | 25·6 (22·6–28·6) | 23·5 (20·4–27·3) | 0·96 (0·82–1·13)* | 0·63† | 308 | 310 |
| Time to second progression-free survival | 31·8 (28·4–36·9) | 30·2 (27·2–34·9) | 0·92 (0·78–1·08)* | 0·31† | 288 | 290 |
| Undetectable PSA (<0·2 ng/mL) at any time during treatment, n (%) | 121 (25%) | 94 (19% | 1·28 (1·01–1·62)‡ | 0·040§ | – | – |
| Confirmed decline of ≥50% in PSA level, n (%) | 391 (79% | 357 (73%) | 1·09 (1·02–1·17)‡ | 0·015§ | – | – |
| Decline of ≥90% in PSA level, n (%) | 262 (53%) | 238 (49% | 1·10 (0·97–1·24)‡ | 0·14§ | – | – |
| Objective response rate (RECIST 1·1), n (%) | n=187 | n=162 | ||||
| Number of patients with measurable disease at baseline | ||||||
| Responder (complete response or partial response)§§ | 109 (58%) | 86 (53%) | 1·10 (0·91–1·33)‡ | 0·33¶ | – | – |
| Non-responder | 78 (42%) | 76 (47%) | ||||
Intent-to-treat population. RECIST=Response Evaluation Criteria In Solid Tumors. NE=not estimable; RR=relative response.
*
Stratified proportional hazards model (HR <1 favours apalutamide + abiraterone-prednisone).
†
Log-rank test stratified by ECOG PS at screening (0, 1), presence of visceral metastases at screening (yes, no), and geographic region (North America, European Union, rest of world).
‡
Relative response (>1 favours apalutamide + abiraterone-prednisone).
§
Stratified Cochran–Mantel–Haenszel test.
§§
Complete response and partial response did not have to be confirmed.
¶
Chi-square test.