will Genetic Testing tell me if Xandi will work (zytiga stopped)

[Racer26]

on Xofigo first shot 2 weeks ago no side effects, 10/16/19 first shot of Xgiva no effects yet. need help very confused Been off Zytiga since August 2019 MO said take your choice start on Xtandi now and see if it works . Do I need Genetic testing first to see if it will work ? Or Mo said I can go on clinical trial at the end of six months of Xofigo I cannot take Xtandi ahead of time for this trial. Psa at 12 and I am nervous not taking a back up for six months ? I appreciate everyones help. Stage 4 9mets in bones nothing anywhere else yet. Don't want it to spread.

[Tall_Allen]

A genomic test for AR-V7 can predict if Xtandi won't work (not if it will work or for how long), but there are other reasons that may limit its effectiveness. IMO, the best way is to just try it. But with your bone mets, it may be a better strategy to take Xofigo first. The reason is because Xofigo is given every 4 weeks for a total of 6 injections. So after 20 weeks you can start Xtandi. However, if you start with Xtandi and it remains effective for a year or two, it will be a long time before you can get to Xofigo.

[Racer26 in reply to Tall_Allen]

Allen my wife and are worried that the cancer might spread into the soft tissue (liver etc.) I have not been on Zytiga since may thants when psa went to 4.8 and took last pill Aug 3rd. psa was 8.3 Was thinking starting Xtandi after 2nd shot of Ofigo to help stop spread to soft tissues. Thank you very much You help to get my mind straighter.. Also any suggestions I've lost 20 lbs in 2 months not much appetite and I know I have to gain some weight. Thank you Allen

[Tall_Allen in reply to Racer26]

There is an ongoing trial of Xtandi+Xofigo+Zometa/Xgeva to see if adding the bone-preserving agent will prevent the excess mortality seen when Zytiga was combined with Xofigo. I think that Provenge with Xofigo may be a superior combination.

[Peterd110 in reply to Tall_Allen]

Is there just one shot at xofigo or can it be rechallenged later on. Just curious

[Tall_Allen in reply to Peterd110]

I haven't seen any studies where men are re-challenged. There may be cumulative radiation toxicity. Most men don't use it early enough.

[tango65]

Genetic testing could identified AR-V7 variants which are related to abiraterone and enzalutamide failure. When this variant is present adding another anti androgen is associated with short term efficacy.

nejm.org/doi/full/10.1056/N...

When an anti androgen fails the sequence with chemo (docetaxel or cabazitaxel) could be more effective than using another anti androgen.

ascopost.com/news/october-2...

ncbi.nlm.nih.gov/pubmed/302...

One option could be to study the possibility of a clinical trial with modified niclosamide which could resensitize the cancer to abiraterone or enzalutamide:

clinicaltrials.gov/ct2/resu...

[Hidden]

I will eventually be in the same situation and my plan is to rechallenge Docetaxel chemotherapy first, then try another androgen blocker such as Xtandi. I'm hoping to gain back some hormone sensitivity with chemo. Something to consider.

[Racer26 in reply to Hidden]

it's a tough rode ahead hard on the mind , body and family. try to keep strong . Thanks

[j-o-h-n]

You got that right... A hard road to race on.... But just put your pedal to the metal and full speed ahead.

Good Luck, Good Health and Good Humor.

j-o-h-n Thursday 10/24/2019 5:03 PM DST