Keytruda clinical trial: `My husband... - Advanced Prostate...

Advanced Prostate Cancer

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Keytruda clinical trial

Judymin profile image

`My husband has been on clinical trial with keytruda and xtandi for 5 months. Scans are stable but psa continues to rise now at 16.3!!! I don't think it is working, asked doctor about psma or axumin scan, said insurance doesn't pay (we are in NJ) Not sure of cost, he said it could show other mets as more sensitive and that doesn't mean they weren't there before, and doesn't mean the immunotherapy not working. I think we need to see where it is, chemo probably next step. He is not concerned with psa but it has doubled in less than 6 months which is terrible sign. I am very worried.


17 Replies

Why do you "need to see where it is?"

Kaytruda only works if you have the genetic mutations that allow it to work..Was he tested for those markers ? How long has he been on the Xtandi ? Was he on Zytiga before that ? Does the trial he is in have a name or number ? Maybe we could help you more if we knew more..

Fairwind, you are right. She wrote nine months ago:

"My husband has been on Zytiga for 4 years with great results but now failing and psa up to 6.5. His oncologist suggests switching to Xtandi. Has anyone done that? Results? side effects?"

Xtandi does not work for a long time after Zytiga. I do not know how long it takes to notice effects from Keytruda.

gvweller profile image
gvweller in reply to GP24

In my case Xtandi worked immediately when Zytiga failed, but it only worked for about a year. In my case (favorable mutation) Keytruda basically cured me after three infusions (about 9 weeks). PSA went from about 60 to undetectable in that time, and has remained undetectable for about a year and a half now. I was scheduled for the Xtandi + Keytruda trial at U of M, but took Keytruda alone when the genetic result became known.

Cmdrdata profile image
Cmdrdata in reply to gvweller

Howdy, can you be more specific in which genetic mutation are present in your case? I am trying to understand which drugs are effective with respect to which mutation. I am getting a genetic test profile in a a few eels and thus will know what I have. Thanks.

gvweller profile image
gvweller in reply to Cmdrdata

See below...


What is the name of the genetic test you did and what do they call the mutation that is necessary for Keytruda to work? Hope you can help. My PSA on the rise after on Zytiga for hardly a year.

Here is a piece that describes the situation.

There were some glitches. At first Medicare declined to cover. Turned out my oncologist had not correctly described the diagnosis. Merck called his office and explained how to do it.

Best of luck to you. George

From what I have seen here, it appears that Xtandi is a frequent next step after Zytiga fails, and vice versa. They both have the effect of depriving the tumor cells of testosterone (T), but they do so with entirely different mechanisms. If the tumors are becoming testosterone independent, i.e., they don't need T to divide and multiply, then Xtandi won't help, or won't help for long. However sometimes the resistance to one drug does not confer immediate resistance to the other and Xtandi does help.

As I understand it, there is some evidence that, for some men, chemotherapy can resensitize cells to hormone therapy and vice versa. If that works for your husband then he may find Zytiga working for him again after a course of chemo.

It's also worth looking into Lu-177 PSMA, a completely different type of therapy using radioactive atoms delivered to the tumor cells via the bloodstream. As with everything else, it only works for some men, not for all, but for a few men it can be terrific. According to what I've read, if I understand it, the failure of Zytiga and Xtandi is due to changes in the tumor cell population that can actually make it more sensitive to Lu-177. Lu-177 is only available in the U.S. via clinical trials. It is approved in Germany and Australia and some people go to one of those countries for treatment.

I know this is a very trying time. I hope that the two of you are able to take time out from the worry and anxiety and benefit from each other's company.

We all wish the best to you and your husband.


Cmdrdata profile image
Cmdrdata in reply to AlanMeyer

Alan, am I mistaken that Lu-177 is primarily effective if the cancer cells express PSMA?

AlanMeyer profile image
AlanMeyer in reply to Cmdrdata

You are not mistaken. The radioactive Lu-177 atoms are bound to an antibody molecule with a high affinity for PSMA, meaning that the molecule has a physical and electrical shape that fits perfectly into a PSMA molecule and not into anything else. When the combined Lu-177 + antibody molecule moves around through the blood stream, if it bumps into a PSMA molecule on the surface of a tumor cell, it sticks to it. Some time later the Lu-177 gives off an electron that smacks into the nearby tissue - the tumor cell, and damages it, hopefully killing the cell. With lots of PSMA on the tumor, lots of radiated electrons will likely hit it and destroy it.

So, no or little PSMA = no or little benefit. Lots of PSMA = lots of benefit.


Do you know an average cost for Lu-177 in Germany. Just started xtanda was taken off Ztega and just completed Provenge. Thanks

Sorry, I don't know the cost. However I know this has been discussed on our forum before. Type the following search into Google to bring up a list of web pages that may give you useful information: cost of lu-177 psma treatment germany

I hope that helps.


If the PSA is going up it is possible that Xtandi started to be less effective. The sequence of abiraterone and then xtandi (or viceversa) when xtandi or abiraterone fails , is probably less effective than using one or the other and when one of them fails to try chemo. The chemo initially could be taxotere and if does not work well it could be cabazitaxel (jetvana).

Other way to re sensitize the cancer to abiraterone or enzalutamide is to try these drugs along with niclosamide. The only way to try this approach, which has been useful for many, is to enter the clinical trials at Davis, in Sacramento:

Regulate niclosamide is not absorbed by the gut. The clinical trials use a special formulation of niclosamide which could achieve therapeutic levels of niclosamide in the blood.

Then there are the clinical trials for Lu 177 PSMA and Ac 225 PSMA.

If the bone scans have shown that there are bone metastases and infiltration of the bone marrow, Ac 225 PSMA could be more effective than Lu 177 PSMA

These treatments could be done outside clinical trials in Europe and Australia.

Thank you all for your responses. Zytiga was very effective for a long time, but seems Xtandi not. Will wait for next psa, he had just had colonoscopy 4 days before the last test, maybe that caused rise???? Can only hope. He is not on Medicare unfortunately. He did have gene mapping done through a blood test years ago. Thanks for the input and support. judym

Where is the trial?

Good Luck, Good Health and Good Humor.

j-o-h-n Wednesday 06/19/2019 7:32 PM DST

Dear judy min, Fairwind has this correct. My husband was tested for Keytruda and did not have the genetic markers to make it effective unfortunately. Maybe that is the case with your man. Sending positive energy and good thoughts your direction---and to us all!

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