Enzalutamide bests abiraterone in treatment of castration-resistant prostate cancer

Enzalutamide is a more effective therapy than abiraterone for patients with metastatic castration-resistant prostate cancer, but it appears to significantly increase the risk of side effects, particularly fatigue, suggests a study.

The investigators systematically reviewed the efficacy and safety of abiraterone and enzalutamide in metastatic castration-resistant prostate cancer in real-world practice. They searched the databases of PubMed, Web of Science, Cochrane, and Embase up to 6 March 2019, as well as available articles from conferences.

Outcomes measured were prostate-specific antigen (PSA) response, overall survival, progression-free survival, and number of patients with any adverse event.

Fourteen cohort studies including a total of 3,469 participants met the eligibility criteria. Pooled results showed a higher PSA response for patients on enzalutamide than abiraterone (n=790; odds ratio [OR], 0.47, 95 percent confidence interval [CI], 0.29–0.77; p=0.003; I², 59 percent).

Enzalutamide significantly correlated with a higher rate of adverse events compared to abiraterone (n=730; OR, 0.35, 95 percent CI, 0.13–0.92; I², 65 percent). No statistically significant between-group difference was noted in perceived cognitive impairments (n=1,856; OR, 0.90, 95 percent CI, 0.29–2.76; p=0.85; I², 5 percent).

Of note, enzalutamide showed a significant association with increased risk of fatigue compared with abiraterone (n=2,477; OR, 0.46, 95 percent CI, 0.34–0.63; p<0.00001; I², 0 percent).

“Two new drugs, abiraterone and enzalutamide, had recently shown beneficial effects on survival in patients with metastatic castration-resistant prostate cancer,” the investigators said.