News from ESMO 2017.

[pjoshea13]

Johann de Bono from Royal Marsden gives a summary of the PCa sessions at the European Society for Medical Oncology [ESMO] meeting [1]. de Bono is at the center of things these days. For instance, his name is on numerous Abiraterone & Enzalutamide papers.

The summary is intended for doctors, but many here will know enough to be able to follow much of it. And the text is useful for those who missed something in the first pass - it is on 2 pages.

As of now, "for patients with M1 {metastatic} prostate cancer at diagnosis, we have two standards of care: LHRH analog and docetaxel, and LHRH analogs and abiraterone. The data presented at this meeting would indicate that both are entirely satisfactory options, and I think that the patient should have the data explained to them and be allowed to choose whether to have one drug or the other at diagnosis."

Interestingly, he says that "I do not endorse giving both abiraterone and enzalutamide." I wonder why?

-Patrick

[1] medscape.com/viewarticle/88...

[Dan59]

Thank You Patrick,Interesting I was on both zand x for at least 2.5 years, after being on z only for at least a year. It was my understanding that it was more of a complete blockade. I did not need lupron at that time

Dan

[Hidden in reply to Dan59]

Dan, excuse my lack of comprehension ability but, are you saying that you used both Xtandi and Zytiga for 2.5 years after failing Zytiga after one year?

[Dan59 in reply to Hidden]

Yes , I am saying that exactly, and before I started zytiga, I was pretreated for a year and a half with ketoconazole. I was lucky to have good insurance.

[Hidden]

Have any studies/trials been conducted using abiraterone and enzalutamide simultaneously? It seems to me that using both would not only reduce the production of testosterone from three sources: the adrenal glands, the testes, and the prostate tumor, but also interrupt the ability of the testosterone that survives abiraterone to bind to prostate cancer cells. Could this result in additional survival time?

Of course what do I know?

[Dan59 in reply to Hidden]

It did seem to do just that for me. I was on zytiga alone first(after being on high dose Ketococonazole for over a 1.5 years.), on progression added xtandi. You know an awful lot through your research on this disease. That alone will add years to your survival.

[pjoshea13 in reply to Hidden]

I don't know why de Bono is against Zytiga & Xtandi together - morbidity? - but it makes perfect sense to me. When I asked about that a few years ago, my doctor said good luck getting insurance approval for $16,000 / month.

The alternative to Xtandi is Casodex. Why not combine Lupron, Zytiga, Casodex, Avodart & a statin, to block as many escape pathways as possible?

-Patrick

[Dan59 in reply to pjoshea13]

You could add nilandron if casodex was not working or bad SE. I wonder how long until zytiga and xtandi go Generic?

Your research helps us all Patrick.

Dan

[BigRich in reply to Dan59]

Dan,

I read that Zytiga could go generic in 2 Years.

Rich

[pjoshea13 in reply to Hidden]

MD Anderson Phase II trial ends soon:

clinicaltrials.gov/ct2/show...

"A Study to Determine Safety and Tolerability of Enzalutamide (MDV3100) in Combination With Abiraterone Acetate in Bone Metastatic Castration-Resistant Prostate Cancer Patients"

Here's another:

clinicaltrials.gov/ct2/show...

"Enzalutamide With or Without Abiraterone and Prednisone in Treating Patients With Castration-Resistant Metastatic Prostate Cancer"

&:

clinicaltrials.gov/ct2/show...

"Enzalutamide/Leuprolide +/- Abiraterone/Pred in Prostate"

"This study is comparing the effectiveness of enzalutamide with or without abiraterone acetate for men with high-risk, localized prostate cancer."

-Patrick

[Neal-Snyder]

Patrick,

Your question is certainly important from my viewpoint. I've been on continuous lupron for a decade, following the failure of a RP & then EBRT. First it was lupin alone, then with casodex, then with Zytiga, then Provenge & now Xtandi. The head of gennitourinal oncology at my hospital trained & then worked at UCSF, & she follows the advice of her mentor, Eric Small, which is to do 1 thing at a time. (I also take a statin & metformin.)

So I'd really like to know why he doesn't recommend taking both Z & X together or separately at any time, & why he says not to delay taxanes after taking 1 or the other. That's obviously not happening for me. I'm not asking you to pursue the answers--you spend so much of your time providing us with very useful info as it is. Thank you for this post.

Neal

[chascri]

Thanks Patrick. Excellent article. Gives me confidence my medical oncologist Is following the latest standard of Care. I am currently on Xtandi. He says when Xtandi stops working we should probably start doxetaxel. As you can see from the summary treatments in my profile he has been guiding me through all the latest treatments.

[RLSharp]

For those of you who are/were on Zytiga and Xtandi at the same time, I have a question. Were the doses and/or frequency adjusted to comply with the different metabolism rates of the two drugs when given together or were you treated with the standard doses of each drug? My Oncologist told me that he could not prescribe both drugs at the same time because they interact adversely with their metabolism rates. I believe he said that the blood serum level of one goes up and one goes down. I do not remember which one went up and which one went down.

From the Full Prescribing Information under Drug Interactions for Xtandi and Zytiga is the following information.

From the Full Prescribing Information for Xtandi - Drug Interactions:

Avoid CYP3A4, CYP2C9 and CYP2C19 substrates with a narrow therapeutic index, as XTANDI may decrease the plasma exposures of these drugs.

From the Full Prescribing Information for Zytiga - Drug Interactions:

CYP3A4 Inducers: Avoid concomitant strong CYP3A4 inducers during ZYTIGA treatment. If a strong CYP3A4 inducer must be co-administered, increase the ZYTIGA dosing frequency.

CYP3A4 is also known as Cytochrome P450 3A4.

Richard

[pjoshea13 in reply to RLSharp]

Hi Richard,

The problem with posting to an old thread is that the originator might be the only person notified. I think you should post it again, but as a new thread.

-Patrick