@jeffmarc I am not familiar with the Medicare plans since I do not live in the United States and did not sign up for Medicare Part B when I was 65. I do have a United States Blue Cross plan that covers me in most countries. That plan uses the FDA approvals to determine what ARPI drugs they will approve for each condition. Also ADT with a LHRH agonist or antagonist or a dual orchiectomy is required when an ARPI drug is used.

For example for Metastatic CSPC they will approve Erleada or Nubeqa with ADT. For Non-metastatic CRPC the will approve those same drugs. Once you reach Metastatic CRPC the approved drugs with ADT are Xtandi or Zytiga. To be able to take only Nubeqa requires that you not only have to have a doctor that is willing to prescribe that and an insurance plan that will override FDA approved standard of care.