prednisone dosage with abiraterone

[meowlicious99]

From the janssenlabels product insert:

"

Metastatic castration-resistant prostate cancer:

• ZYTIGA 1,000 mg orally once daily with prednisone 5 mg orally twice daily. (2.1)

Metastatic castration-sensitive prostate cancer:

• ZYTIGA 1,000 mg orally once daily with prednisone 5 mg orally once daily. (2.2)

"

I am trying to understand the logic behind why the dosage would be different based on resistance status. why does crpc need a higher glucocorticoid replacement therapy.

I understand 5 mg was the dose used for hspc in the clinical trials so i am wondering why they choose a lower does when conducting the trial.

[CAMPSOUPS]

All I can say is thank you for asking this and in the specifics you asked.I will be interested in answers/discussion.

[tango65]

I believe it is related to the doses used in the clinical trials:

nejm.org/doi/full/10.1056/n...

[Ramp7]

After a year and a half PSA has started to go up on Prednisone switched to Dexamethasone 0.5mg.

[Gearhead]

Good question. I'm alert for a valid answer. I once heard speculation that this has to do with concerns about the long-term cumulative effects of prednisone and the anticipated difference in CSPC and CRPC lifespans. I hope that's BS.