Decision Time - After Xtandi

[GDeG]

Meeting with MO next week and am preparing for treatment option changes which he is likely to suggest. Having PET scan previous day to see if mets remain in bones and how far they have progressed. Switched to Xtandi from Enzaludimide last April. very limited positive apparent psa impact from Xtandi as psa rising at annual tripling rate. MO previously indicated that he might recommend switching to Zytiga (with /without steriods). No other options previously discussed.

I know LU-177, XOFIGO, Zytiga are other approaches.

Can anyone offer other options or recommended approaches? Thanks

My profile should be complete.

[Tall_Allen]

" Switched to Xtandi from Enzaludimide last April." Xtandi is the brand name for enzalutamide. Did you mean bicalutamide (Casodex)? But it is hard to see why you wouldn't have started with Zytiga or Xtandi if you were diagnosed with bone metastases.

At any rate, the next best therapy is docetaxel. Xofigo, if there is bone pain is also an option.

(There's nothing in your profile)

[AlanMeyer Moderator]

"Xtandi" is a brand name for the same drug known generically as "enzalutamide", so I'm not sure what to make of a switch from one to the other. Perhaps it was a change in your insurance?

Xtandi and Zytiga have different mechanisms of action but aim at the same goal, i.e., to prevent testosterone ("T") or its more powerful derivative dihydrotestosterone ("DHT") from reaching and influencing the mechanisms inside the prostate tumors that stimulate cell division that increases the number of cancer cells. When patients become resistant to the effects of Zytiga they can sometimes benefit from Xtandi and vice versa, but the benefit is not usually very long lasting. It is my impression that Xtandi is the more powerful of the two drugs so men who have failed Zytiga may get more benefit from trying Xtandi than the reverse direction (Zytiga after Xtandi). Still, even a few months of benefit is not worthless and Zytiga may work for some time for you. You won't know for sure without trying.

Whether or not you try Zytiga it's time to start investigating other treatments.

Here are my thoughts about some of the other treatments:

1. Lu-177 PSMA.

This treatment can work for men, and only for men, who have significant amounts of Prostate Specific Membrane Antigen ("PSMA") on the surfaces of their cancer cells. It uses an artificially constructed antibody molecule that is combined with a radioactive atom (Lutetium-177 in this case) to deliver radiation directly to the cancer cells that have PSMA - allowing very high doses of radiation to the cancer, wherever it may be, with only very small doses to other cells. It only works for men who are "PSMA avid", and not for all of them. However there are a small percentage of men who get a spectacular response to the drug, clearing up cancer all over their bodies. It has an advantage too in that the doctors can give you a PSMA test scan that tells them whether or not you are PSMA avid, so if you're not, you don't have to go through a complicated and expensive drug procedure only to find out that it never had a chance of working. I think it's worth investigating.

2. Xofigo.

Xofigo is a brand name for the radioactive atom Radium 223 bonded to some other ingredients. Radium is similar to calcium in its chemical surface structure and is taken up by bones that are actively growing - which in an adult is often caused by prostate cancer in the bones. It won't do any good for cancer in the lungs, stomach, bladder, brain, etc., only for cancer in the bones. It can be used to reduce pain in the bones and/or, for patients whose cancer is all or mostly all in the bones, it can provide life extension. Bone scans and other scans may help determine whether or not you are a good candidate for Xofigo. If it is determined that your most dangerous cancer is in "soft tissue" (lungs, brain, etc.) then it won't do any good except to relieve bone pain if you have that.

3. Docetaxel chemotherapy.

You didn't mention chemo as an option. A lot of men are afraid of it but It can actually be a very good option. As with other prostate cancer drugs, your mileage may vary. Some men find the side effects to be very tolerable while others find them to be intolerable. Some men get great benefit while others don't. I don't know if there's any way to find out without trying it.

Finally, I'd like to make two other recommendations:

1. Join the HealthUnlocked "Advanced Prostate Cancer" forum and post your questions there. You've got "advanced" prostate cancer and there are many more folks on that forum who will have ideas about how to help you.

2. Make sure that you're seeing a doctor who specializes in medical treatment of prostate cancer. That means a "medical oncologist", not a urologist or radiation oncologist. Since there are literally hundreds of kinds of cancer and no one can be expert in all of them, try to find someone who specializes in it and knows a lot about all of these treatments, not just about Zytiga and Xtandi. I always recommend looking at one of the hospitals and research institutions recommended by the National Cancer Institute on the following web page:

cancer.gov/research/infrast... .

I wish you the best of luck.

Alan

[GDeG in reply to AlanMeyer]

Thank you for your replies. Tall Allen: yes, it bicalutamide then later, and now, Xtiga that I took/take after chemo. Also the chemo I had before both was Docetaxel.

Alan, yes I'll switch this discussion to the Advanced Prostate Cancer group. Also, just wanted to be sure my profile, which I just updated, is showing.

Thanks again

[rscic]

Consider a PSMA scan if your PSA is high enough (your MO should know what PSA is currently thought to be the minimum level to do a PSMA scan). PSMA can be more sensitive than PET. However, if the results of the PET scan are such that treatment would not be changed if more mets were detected, then the PSMA scan would be useless. Just a thought.

[GDeG in reply to rscic]

Thanks rscic.

I see the FDA approved the PSMA scan 12/20 and after searching I see UCSF is one of two sites in US that provides it (according to UCSF website). I also understand that this is not Medicare covered not sure about Supplemental plans.

So in my case I am classified as M1 CRPC but not sure about the bone met count but probably "High" versus "Low".

My understanding that if it is High but no soft tissue the either XOFIGO or Lu177 could help but if we find soft tissue Lu177 could help.

If it is low then either XOFIGO or Lu177 could help.

Is it true that Lu177 is indicated when PSMA readings are "high" whereas it is not necessary to have "high" PSMA with XOFIGO. Since PSMA scans were only approved last year in th US, the their must be some other criteria for Lu177 vs XOFIGO.

BTW I am using the "NCCN Guidelines for Patients" to describe my classification, above.

This link was provided by Tall Allen in another post.

nccn.org/patients/guideline...

[rscic in reply to GDeG]

PSMA is just an option if the detection of more metastasis would make a difference in treatment.