Zytiga to Xtandi

[PHnerd]

Hello all! Just had my father’s latest oncology appointment today. After many years of being on Zytiga, the doc has recommended we switch to Xtandi. Radiology shows one new spot in his tailbone (which we expected as he’s been experiencing a bit of pain there). Note: his cancer metastasized in summer 2019 to the pelvic bone. PSA is at 1.1 today but has slowly been increasing from 0.03 for the past couple of years. Main reason for switching meds is radiologic progression.

Anyone have any experiences with switching to Xtandi from Zytiga? He will still be on dexamethasone and the Zoladex shots.

[LearnAll]

Rising PSA from 0.03 to 1.1 in 2 years indicates that the cancer cells are growing slowly .It is not irrational to switch from Abiraterone to Enzalutamide. These 2 medicines work by totally different mechanism. Abi just blocks all 3 sources of testosterone whereas Enza blocks the Androgen Receptor and Does Not Lower testosterone. Enza only stops the action of testosterone.

Therefore, A combination of zoladex and Enza is a good next step. I do not understand why he needs to continue with Dexamenthadone once Abi is stopped ? He does not need a steroid when he is not on Abi. Steroids like Dexameth are strong drugs with a lot of side effects. Discuss with his doctor and get Dexameth removed.

[Magnus1964]

I switched from zytiga to xtandi. I had good luck with it.

[PHnerd in reply to Magnus1964]

Magnus, what course of treatment did you pursue after Xtandi?

[Magnus1964 in reply to PHnerd]

No treatments. I have not had anything for the past year and a half.

[Muffin2019 in reply to Magnus1964]

Glad it worked for you, hoping it does the same for me but some of the posts is discouraging as to the length of time it works.

[Magnus1964 in reply to Muffin2019]

Zytiga 3 1/2 years, xtandi 4 years.

[Muffin2019 in reply to Magnus1964]

At least no steroids with xtandi , good results hopefully close to the same.

[meowlicious99 in reply to Magnus1964]

Magnus1964 Thats quite an exceptional result . congrats!

[PHnerd]

Thanks so much for this! Definitely lots of options to consider I guess and you’re right - Canada is lacking in a lot of the options the States has to offer.

PS: it’s my father, not my husband 😅 but thanks again!

[Tall_Allen]

Xtandi usually only works for a very short time after Zytiga failure. It is called "cross resistance." It is best to alternate between docetaxel and hormonal therapies. Sometimes docetaxel renews the sensitivity of the androgen receptor. This discusses the benefits of alternation:

prostatecancer.news/2019/12...

Another option is to try Xofigo now. Here are some combinations that may be useful. Note that when they combined Xofigo and docetaxel, they were able to reduce the docetaxel dose.

prostatecancer.news/2021/02...

[Muffin2019 in reply to Tall_Allen]

So no long term results, I have no bone Mets and have started xtandi after abi failed after a year and half, not to encouaging. PSA has been rising to around 8, last scans shows no disease progression in both CT and bone scans. Insurance would not pay for a PET scan and denied it. So this only lasts 6 months, I am hoping for longer ?

[CAMPSOUPS in reply to Tall_Allen]

If docetaxel with adt + Zytiga is used at initial dx is docetaxel best for hormonal "re-sensitizing".

I get a bit confused as I see the Carboplatin/Cabazitaxel combo is being used as well it seems. ( seems being a key for me lol).

Actually I have your write up on hormonal/chemo sequencing from your site I should just look it up again I guess.

[Tall_Allen in reply to CAMPSOUPS]

The article I wrote starts with docetaxel. If one has already had docetaxel, one can use Jevtana for the second round of chemo. I think carboplatin can increase the effectiveness in some cases, especially when genomics show DNA repair defects emerging, or there are signs of "lineage plasticity."

[CAMPSOUPS in reply to Tall_Allen]

Thanks. The question and answer selfishly (lol) fit a future choice I might have although others might benefit from the knowledge too.

I didnt get in on the Peace-1 regime. Had dox and adt. The effects wore off about 11 months after last dox infusion. Started Zytiga.

On Zytiga for about a year now.

Will probably switch to dexamethasone to try and get the bit of time sometimes seen with it when Zytiga + prednisone fails.

[Roscoaus2000]

I switched the other way. Enzalutamide was used after Bicalutamide stopped working after 12 months. It was very effective and my bladder control improved. My energy levels jumped amazingly. However after only 4 months it passed the blood brain barrier and I had a slight seizure. Apparently this is a rare side effect. I had both a ct scan and an mri neither of which showed any brain damage. My Oncologist then switched me to Zytiga. 4 1/2 years later my psa is only now slowly rising to 0.17.

[Muffin2019]

Just started xtandi after being on abi for the past year and half, so your assessment is that this drug will fail in 6 months ? Not very encouaging more like discouraging especially at the cost of meds for cancer.

[j-o-h-n]

I switched from chocolate chip to plain vanilla ice cream (two scoops)....

Good Luck, Good Health and Good Humor.

j-o-h-n Wednesday 06/15/2022 7:05 PM DST