Corticosteroid switch in heavily pre-treated castration-resistant prostate cancer patients progressed on abiraterone acetate plus prednisone.

The aim of this retrospective study is to evaluate the activity and safety of a steroidal switch from prednisone to dexamethasone in patients with advanced, heavily pre-treated, castration-resistant prostate cancer (CRPC) who progressed on abiraterone acetate. Treatment consisted of oral daily abiraterone plus dexamethasone (0.5 mg once daily) administered until disease progression or unacceptable toxicity. Thirty-six patients were evaluated: all men underwent a prior treatment with enzalutamide. A PSA decrease ≥50% was observed in 11% of patients; median progression-free survival was 10.8 weeks (95% CI: 9.2-16), and median survival was 17.6 weeks (95% CI: 15.8-28.8). Better efficacy and survival were observed in the subgroup of patients treated with abiraterone acetate prior for a period >3 months; treatment was well tolerated, and no grade 3-4 toxicities were observed. Our findings did not suggest the use of steroid switch in all CRPC who were heavily pre-treated. However, the switch could be an option for patients who responded well to prior abiraterone acetate treatment.