Xtandi beneficial in reducing radiographic progression-free survival (rPFS) in men with metastatic hormone-sensitive PC

[Tall_Allen]

Not FDA-approved yet. The FDA has recently accepted rPFS as a surrogate endpoint for overall survival. It remains to be seen if they will accept it for this indication. No data yet:

investors.pfizer.com/invest...

[dentaltwin]

Yeah, just saw this on my news feed. I know that using PFS as a surrogate for OS is controversial (in any case I know it is in lung cancer). I really don't understand why, unless it turns out improved PFS does not lead to improved overall survival.

[Tall_Allen in reply to dentaltwin]

Yes, that's why. It's not at all clear that delaying the detection of new metastases prolongs survival. The FDA has just issued new guidance on surrogate endpoints:

fda.gov/downloads/drugs/Gui...

They suggest that drug companies consult with them before designing clinical trials. They approved Erleada and Xtandi for non-metastatic CRPC based on rPFS, but that's a different situation.

[dentaltwin in reply to Tall_Allen]

Thanks!

[COG1 in reply to Tall_Allen]

The trial my husband is on is using radiographic progression free survival as an endpoint. this is interesting.

[Tall_Allen]

If you have had any PSA progression while taking a GnRH agonist (e.g., lupron) and you've been previously diagnosed with metastases, I think most insurance would approve Xtandi or Zytiga for you.

[cesanon]

What am I missing? I thought xtandi was already approved for use with androgen deprivation therapy?

[Tall_Allen in reply to cesanon]

It's approved for castration-resistant PC (both metastatic and non-metastatic) but not for metastatic hormone-sensitive PC.