So, Dr. Scholz, we're covering immunotherapy today. Can you explain what it is and how
does it work in prostate cancer patients?
Yeah, you know, immunotherapy, Alex, has been sort of the holy grail of treatment ever since
the immune system was discovered many years ago. There's been a lot of false starts; there's
been a lot of false advertising. You know, over the counter stuff to stimulate the immune
system. It all sounds good on paper, but it's kind of hard to measure immune therapy outcomes
because our immune systems work so silently in the background fighting off bugs constantly.
The achievement in the last 10-15 years of actual effective immune treatment is really
quite amazing. There's only one product for prostate cancer called Provenge—Sipuleucel-T
is the generic name—that has been proven to work and it uses a system that kind of
makes sense if you have the technology to pull it off. The company goes after the immune
cells that identify cancer cells—they're called dendritic cells—and in a sort of
like a, well it's called leukapheresis, but it's sort of like dialysis where someone goes
in and they remove blood and then they put it back in, and they remove these dendritic
cells, ship them off the Seal Beach, California, and put them in a vat with a lot of prostate
cancer parts, specifically something called PAPE and some hormonal stimulating agents
and they sensitize these dendritic cells to go attack prostate cancer. They give them
hormones to make them multiply, put them in a bag, send them back to the doctor's office,
and then infuse it into the patient, and then those dendritic cells tell that patient's
immune system to attack the prostate cancer. That's called Provenge. This type of immune
therapy is really only available for prostate cancer. There are other—many other—types
of immune therapy now out for bladder cancer, lung cancer that use different methods, but
for prostate cancer, Provenge is the only type of immune therapy that we have right
now.
So, why is Provenge the only approved immunotherapy? Like, can you explain to the audience—we
hear about other types of treatments in other types of cancers how come that hasn't crossed
over to prostate cancer yet?
I think it will. Many people have heard about, you know, President Carter was almost dying
from melanoma spread to his brain and then he went on an immune-stimulating medicine
called Keytruda. There are large phase III trials looking at using Keytruda to treat
prostate cancer as well, and we have some experience with that type of immune therapy
and it does have activity in prostate cancer, although it's not FDA-approved yet. The clinical
trials need to be completed. Keytruda works by a different mechanism. Our immune system
is in a balanced state where if it gets overactive people can end up with immune illnesses like
rheumatoid arthritis or lupus, and then, of course, if the immune system is insufficiently
active, then people can catch cancers and infections. So, our immune systems are heavily
regulated. What Keytruda does is it downregulates the suppressive effect. So there are forces
that are keeping your immune system in check and Keytruda releases those forces so that
the immune system runs more freely, and this is why it's been a popular agent and now FDA-approved,
I think, in 12 different types of cancer.
What are the side effects of Provenge?
Most common side effect is none. The immune system does work quietly, but a minority of
patients, when they get their infusion, will have some fever or chills or some body aches.
Kind of like a flu-like feeling that could last for a couple of hours or maybe a day.
That responds well to things like Benadryl, Tylenol, and things like that.
Thanks so much for watching. If you would like more information about anything we discussed
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