Zytiga and dexamethasone

[longleaf]

I am interested in learning more about switching from prednisone to dexamethasone with your zytiga as a way to get more use from the zytiga. My husband’s psa is rising and the Dr. mentioned this as a possible next step. I appreciate any information.

[Hidden]

It worked for me and more importantly, about 40% of the people who did it in a clinical trial. I've been on Zytiga for over 3 years now, PSA is still below 1.

[longleaf in reply to Hidden]

Thank you for responding. Why did you switch from prednisone to dexamethasone ? It looks like you have gotten good results.

[TeleGuy in reply to longleaf]

You switch when your PSA rises on abiraterone+prednisone. My PSA plummeted when I made the switch.

[Chrisbaird in reply to Hidden]

I’m on that combination for over a year luckily my PSA remains low only side effect is the hot sweats with the hormone 3 monthly injection added to the combination

[6357axbz]

You need a taper off schedule when you get off prednisone. I’m not sure how substituting dexamethasone may impact this.

[Hidden in reply to 6357axbz]

It's just a direct switch, the doses are equivalent. Dexamethasone is stronger per mg, but you take much less of it.

[Hidden]

There was a clinical trial to test this:

pubmed.ncbi.nlm.nih.gov/301...

The results were positive. My doctor was a bit skeptical since he had only 1 out 3 patients that got a response. But he agreed to try it and it worked. Doesn't work for everyone, but almost 1/2 get some kind of PSA response.

[dhccpa in reply to Hidden]

So your doc had a subset of patients where Zytiga failed for 100 per cent of that subset? But he's reluctant to switch because it will only help 1/3 of them?

[Hidden]

Listen to the MO and highly consider doing it. You have a great chance of the switch being successful.It amounts to extending the effective life of Zytiga. Make sure you follow your MO's instructions for weaning and adding.

[Tall_Allen]

Here's the study:

pubmed.ncbi.nlm.nih.gov/300...

[Scout4answers in reply to Tall_Allen]

From the SWITCH study conclusion:

Patients with AR gain detected in plasma circulating tumour DNA did not respond to switch, whereas patients with AR normal status benefited the most.

Is there a way to test for AR gain or for AR normal status ?

[Tall_Allen in reply to Scout4answers]

Yes. They did a cell-free DNA test, but it is very expensive. It is easier to just try it and see.

[longleaf]

Thank you everyone who replied and for the study links. I appreciate the people on this forum so much.

[PeteLG]

After 10 months on Zytiga and pragdasone PAs "skyrocketed". Within two months on dexamethasone PSA deceased to a more manageable level with no additional side affects. All can say the change worked for me and according to studies about haft of men who switched.Best of our good fortune for your husband.

[Zhyravlik]

hi. After 10 month on Zytiga fathers PSA started to rise again. All summer it stayed at 64-65 and after that it jumpet to 86. We switched to Dexa and next month it was 68. But then he probably forgot and took prednisolone again and next month it was 95... We switched to Dexamethasone again and in few days will have new results.

[Zhyravlik in reply to Zhyravlik]

I have update on PSA level and it`s 88 (95,95 month before that). So it`s lower again with dexa! I am very glad. I hope next month it will be lower.

[longleaf in reply to Zhyravlik]

Happy for you

[SeosamhM]

My experience is the similar to gregg57's. Don't think too much about it - the longer we can stay on Zytiga the better. So far, the switch from pred to dex has gotten me an extra 16 months on Zytiga (my PSA was rising over the summer of 2020). It is definitely hit or miss - my MO says I'm the only one of five of his patients that responded to the switch. Good luck. - Joe M.

[slpdvmmd]

I was switched and got a year in retrospect I would get a PSMA PET/CT at the time of the switch. I may allow for other choices or adjuvants.