Enzalutamide (ENZ) and abiraterone acetate plus prednisone (AAP) are oral antiandrogens indicated in Europe 1 for the treatment of metastatic castration resistant prostate cancer (mCPRC). A comparative preliminary analysis of cognitive decline and mood changes in mCRPC patients receiving ENZ and AAP has been reported2. However, a meta-analysis for these adverse effects (AEs) has not been available in the literature.
Following on from the methodology presented by Ruiz et al.3 a further meta-analysis was performed to estimate the pooled Relative Risk (RR) of neuropsychiatric AEs for AAP and ENZ. A complementary analysis of the EUDRA database was performed to explore the consistency of the real world adverse drug reactions (ADR) reporting pattern with the meta-analysis.Calculation of Proportional Reporting Ratios was performed following EUDRA guidelines.
The meta-analysis results indicate that patients treated with ENZ had a statistically significant higher risk of restless leg syndrome, anxiety, headache and insomnia vs control (Table). Both ENZ and AAP showed increased significant risk for falls vs control. The Proportional Reporting Ratio (PRR)4 of suspected ADRs reported in EUDRA is higher with ENZ than with AAP for all the variables analyzed.Table:
|Source||n||Headache||Seizures||Falls||Dizziness||Hallucinations||Restless leg syndrome||Memory impairment||Anxiety||Insomnia|
|AAP||COU-AA 301 & 302||2267||1,12 (0,89-1,40)||1.0 (0.09-10,95)||1,60 (1,03-2,49)*||0.97 (0,77-1,23)||-||-||-||1,04 (0,78-1,64)||1,04 (0,83-1,30)|
|Pooled RR (95%CI)|
|AAP||EUDRA ADRs Feb 17||7498||29 (0,49)||18 (0,22)||57 (0,51)||56 (0,45)||6 (0,29)||2 (0,24)||5 (0,15)||6 (0,21)||10 (0,21)|
|ENZ||PREVAIL & AFFIRM||2914||1.7||2,20 (0,39-12,39)||2,30 (1,67-3,17)*||1,21 (0,86-1,76)||4,74 (0,76-29,67)||5,87 (2,05-16,78)*||1,21 (0,86-1,76)||1,52 (1,04-2,23)*||1,45 (1,09-1,91)*|
|Pooled RR (95%CI)||(1.31-2.19) *|
|ENZ||EUDRA ADRs Feb 17||24258||197 (2,10)||258 (4,69)||383 (2,04)||414 (2,29)||66 (3,4)||29 (4,48)||111 (6,86)||92 (4,73)||159 (4,91)|
The analysis suggests that some neuropsychiatric AEs are more prevalent with ENZ vs placebo than AAP vs prednisone. The reporting trend in EUDRA is consistent with this result.
Clinical trial identification
Legal entity responsible for the study
M. Sanchez Iznaola: Market access manager at Janssen Pharmaceuticals in Spain. R. Parra: Group Manager Hemar lead in onco-hematology at Janssen Pharmaceuticals in Spain. G. Angela: Medical affairs lead in oncology at Janssen Pharmaceuticals in Spain. J. Casariego: Medical affairs Director for solid tumors for Janssen Emea. J. Muñoz Del Toro: Medical affairs in oncology at Janssen Pharmaceuticals in Spain. P. Robinson: Hemar lead in oncology for Janssen Emea.