Low dose versus standard dose of corticosteroids in the management of adverse events of special interest from abiraterone acetate: data from a literature-based meta-analysis.

Abiraterone acetate is a CYP-17 inhibitor approved for the treatment of prostate cancer. Abiraterone acetate (AA) therapy is associated with toxicities, including hypokalemia, hypertension, liver function test abnormalities and cardiac events. These adverse events are traditionally managed with a standard dose of corticosteroids. However, preliminary data are available on the use of a lower dose of corticosteroids. The aim of this report is to perform a pooled analysis evaluating the risk ratio (RR) of AA-related adverse events of special interest associated with low or standard dose of corticosteroids. A total of 5374 cases from 4 randomized clinical trials were included. Subgroup analysis according to corticosteroids dosage revealed a higher RR of adverse events associated with a dose of 5 mg, compared to 10 mg. In particular, there was a statistically significant higher RR of hypokalemia and ALT/AST increase, and only a modest risk increase for cardiac disorders and hypertension. In conclusion, given the limitations of a literature-based study, in comparison with a meta-analysis based on individual patients' data, our study identified a relatively small increase in RR for hypertension and cardiac disorders and a bigger increase of RR for hypokalemia and ALT/AST toxicity when 5 mg, rather than 10 mg of corticosteroids were administered to manage adverse events of special interest from AA. Further studies with specified end-points are awaited to confirm these results.