Immunotherapy

[Annie1373]

Why doesn’t immunotherapy really work for prostate cancer?

[AlanMeyer]

Hello Annie,

I wouldn't say it doesn't work. Provenge is an immunotherapy and it was found to extend life in many men. However it's not as effective as other therapies. Still, I'm not sure we've found the best way to use it yet. Like most drugs, it was approved for use in men for which other treatments had stopped working. That was traditionally considered to be the best way to try new drugs - first try the drugs that are known to work. Only try the experimental drugs when there's no well tested and reliable options left. However we're now learning that drug combinations are often more effective than treatments given one at a time, and drugs given early in the disease process are more effective than drugs held off until late. So I'm hopeful that Provenge will be used earlier and in combination with other treatments and will make a greater contribution to prostate cancer treatment in the future.

Other immunotherapies have not been very effective, or not effective at all for prostate cancer. That's true for many cancers. Most of the immunotherapies have turned out to be effective for only a limited number of cancer types. Scientists are working hard to figure out why that's the case and whether the problems can be surmounted, but scientific research is a slow, difficult, painstaking process. All of the hundreds of complex molecules involved in the immune system are way, way smaller than human eyes, even with microscopes, can see, and watching these molecules in action in living tissue is pretty near impossible.

Nevertheless, I'm optimistic about the future of immunotherapy. It may come too late for most of the people in this group, but maybe in time for our sons and grandsons.

I wish we all had the benefit of what medicine will look like 20, 50, or 100 years from now, but that's for the future. In the meantime I'm truly thankful that we don't have to rely completely on the medicine available 20, 50, or 100 years ago.

Alan

[NPfisherman]

Hi Annie,

Basically, immunotherapy has been found to be effective in certain mutations....for the BRCA 1/2 group, PARP inhibitors have been found to be fairly effective. Keytruda is effective in about 10% of PCa--and much more in one specific mutation .... They are combining checkpoint inhibitors---see Checkmate 650 below:

ascopost.com/issues/april-1...

The NCI MATCH Trial will match specific gene mutations to specific treatments and will provide additional information. A macrophage drug is under trial in Finland which is as effective as a PD-L1 inhibitor---and could be added to a checkpoint inhibitor... so it is coming--but slowly--and will take more time... Patience is required....

All the best,

Don Pescado

[PhilipSZacarias]

Hello Annie,

Compared to other types of cancer, and particular melanomas, the mutation load and therefore immunogenicity of prostate cancer is less. In general the greater the number of mutations the greater the chance that the immune system will recognize it. This one factor, but there are probably others like the local environment of the PCa tumours, especially bone mets, that may make access difficult. Immunology is a very hairy subject.

Cheers,

Phil

[leo2634]

I'm sitting here with two needles in my arms getting immunotherapy. This is my last treatment so hopefully it will help in the Battle. I've heard pros and cons about this treatment but if it extends my life by a day it's worth it to me. I love my life, my family, my Grandkids too much not to want to live as long as possible. Never give up never surrender. Leo

[Olivia007 in reply to leo2634]

I love your response don’t give up u have too much to live for and the love of ur family may God bless you 10 times over

[The_Don5]

urotoday.com/conference-hig...

[Magnus1964]

Provenge worked for me. It has been 4 years since my treatment. I did not "cure" my Pca but the nodules in my lungs have stayed dormant.

[SeosamhM in reply to Magnus1964]

Great new, Magnus. I see Provenge in the same way - as a method to minimize growth and scavenge the cancer cells roaming the body.

[j-o-h-n]

Keytruda is working for my LUNG MELANOMA.....

Good Luck, Good Health and Good Humor.

j-o-h-n Tuesday 06/18/2019 2:36 PM DST

[FCoffey]

Prostate cancer is a "cold" tumor, meaning that there are relatively few T cells found inside the tumor. T cells an important part of the immune system. Melanoma is a hot tumor, with many T cells inside the tumor.

“Cold” tumors aren't recognized or don't provoke a strong response by the immune system. T cells can't penetrate the tumors. We still learning how T cells are excluded by the tumor microenvironment: blood vessels, structural elements, and specialized immune cells. Some of these actually secrete cytokines the suppress the immune response. The result is that the tumor defends itself against many kinds of immunotherapy.

Another aspect of immunotherapy is that it often doesn't lower PSA or visibly shrink tumors. However, men who get treatments like Provenge live longer. There is some evidence suggesting that the benefit grows with early administration. Living longer is the ultimate goal, more important than a proxy like PSA. The trouble with living longer is there is no way for any one man to know that he got that benefit. You can only see it by studying groups of men over long periods of time.