@brittdan You should be okay based on your chemo experience in the first round. As Jeff mentioned of the three drugs (Xtandi, Erleada, Nubeqa) most patients find Nubeqa has fewer side effects. They all do the same thing, about equally effective and expensive ($10K+ mth in USA). Your doctor probably will not mind the substitution. The chemo with the carbon platinum is required for effective treatment and you have already exhausted almost every treatment.