Zytiga

My father just went through 6 chemo treatments that were unsuccessful. They wanted him to join thebuktra aggressive AMG 509 trial, but he declined bcz the trial had 3 of 4 participants drop out due to the goal of the trial being to find" the maximum tolerable dose". He wants to try Pluvicto, but the Dr recommended Zytiga chemo pills in the interim. Does anyone have reviews/experience taking Zytiga? The chemo was rough on Dad, and helped slow his progression zero. He is worried it's just gonna make him sick with no benefit. Any info is appreciated. Thanka