Hi, I'm Dr. Scholz. Let's talk about prostate cancer clinical trials.
As you know, there are a lot of different clinical trials out there, and I've always
had mixed feelings about clinical trials. The trials, many times, are set up to answer
important research questions, but they're not always designed to help patients, and
in particular, patients that have advanced prostate cancer, they don't have time to waste
doing clinical trials unless it's going to advance their survival and their quality of
life.
So I've gone through a list of clinical trials and selected one for presentation that I think
both answers an interesting clinical question, but also can help patients perhaps get a better
outcome.
In this particular clinical trial, we're talking about men that have a rising PSA after previous
surgery. This is a very common situation—probably 40-50 thousand men a year experience a PSA
relapse after surgery, and a rising PSA, of course, is the beginning of the cancer coming
back. a rising PSA after surgery or radiation, the PCRI terms "Indigo." The Indigo stage
of prostate cancer. And these men generally do very well. Historically they're treated
with either radiation, sometimes observation if the PSA is rising very slowly (doubling
time over a year), or more commonly they'll get some sort of hormonal therapy such as
Lupron. The study is looking at adding more potent hormonal agents to Lupron to determine
if you can get longer holidays, better cure rates, longer survival, and the medicines
in particular that are being studied are apalutamide (which is also known as Erleada) and Zytiga
(which is also known as abiraterone). So the question is, if you add either Erleada or
Zytiga or both to Lupron, are you going to get a better long-term outcome. In the clinical
trial they have 500 patients that will be randomly allocated to one of three groups.
Either Lupron alone, Erleada alone, or Erleada plus Zytiga. And the treatment will continue
for 12 months and then stop, and then people will be watched.
So it's, I think, a win-win situation for men with prostate cancer and rising PSA. They're
not proposing to treat men that have very indolent relapses i.e. PSA doubling times
over 9 months, but men that have shorter doubling times, less than 9 months, are very appropriate
for this kind of a treatment. So how have men done historically with just Lupron? Well,
they've done pretty well. The problem is that practically no one gets cured. I've treated
literally thousands of men with Lupron in this situation and I've only seen two that
remained in remission after the Lupron was stopped. So, got Lupron for about a year,
PSA went down to 0, and in these two individuals that I remember very distinctly, their PSA
never rose.
There is room for improvement in this group and the unanswered question is, "If we add
something more potent such as Erleada or Zytiga or both will we get some men who remain in
continuous remission after the treatment is stopped which is akin to being cured? So Janssen
pharmaceuticals is really to be commended for studying this group. The FDA, unless you
show a survival advantage, oftentimes will not approve new medications just on the basis
of better outcomes. So it's a bit risky to do a study like this because men who have
rising PSAs and go on Lupron or other agents tend to live a normal life expectancy. Lupron
alone will keep people alive for 10-15 years without much difficulty. The difference would
be, of course, that if more potent agents can put people in a durable remission they
wouldn't be dependent on Lupron to stay alive for the rest of their lives.