This week’s “Ask Dr. Durie” comes from
a gentleman who wants to know, “Is MRD testing routinely recommended?” So, this is another good question and the
simple answer to that is, “No, we are still not at the point where we recommend routine
testing for MRD, which is minimal residual disease. It’s helpful to think about, “What are
the values of doing MRD testing?” And so, there are four types of reasons to
consider testing the minimal residual disease in the bone marrow, to check the bone marrow
t
o see how much myeloma is left, MRD testing. The first one is just to indicate prognosis. And so obviously if you have MRD-negative,
if there’s been a very deep response, and there doesn’t seem to be any myeloma left
in the bone marrow, this is obviously good news. And so this is good prognosis. However, if you have a complete remission
or a stringent complete remission and you’ve been in remission for a while, we already
know that you’re doing well. And so, the MRD information just adds a littl
e
bit extra security and possibly is not essential in that setting. The second type of use of MRD testing is extremely
important, and this is the use of MRD testing within clinical trials to use MRD testing
as what we call a, “surrogate marker,” or a “surrogate endpoint.” And this means that if the FDA is reviewing
a trial and a treatment has produced MRD-negative in a high percentage of patients, then this
treatment can be considered to be better than another treatment where this MRD-negative
l
evel has not been achieved. And so, this is something that is currently
being reviewed by the I2TEAMM, which is an “Independent International Group,” collecting
together all of the trials to submit them to the FDA for review and hopefully have approval
of MRD-negative as an endpoint, but this has not been achieved yet and we will have further
follow up on this later in this year, 2019. The third category of MRD testing is to make
decisions. You do the MRD test, and if it’s positive,
some myeloma
left, or negative, no current myeloma, you try to make treatment decisions. Well, the truth is that we need more trials
about this. We really don’t know if you’re MRD-negative,
can we safely stop the treatment? And if you’re MRD-positive, should we change
the treatment? We don’t clearly know the answers to those
questions. And so, I don’t recommend making these decisions
right now until we have more follow up information. The fourth use of MRD testing is as an endpoint
within what we call “Cure
Trials.” As we develop as part of a Black Swan process,
protocols which are designed to achieve the deepest responses possible, and possibly to
achieve a cure for myeloma, we definitely need MRD testing to track how deep the response
is and if we’re getting towards this really amazing endpoint of long remissions and possible
cure. So, MRD testing is essential as part of “Cure
Trials,” of which we have two currently, the CESAR Trial, using KRd and transplant
from Spain and the ASCENT trial, the
U.S. trial, using KRd plus daratumumab, which is
just accruing patients right now. So very, very important in that setting. So, the bottom line is MRD is very important. It can be tested using a molecular method
or an immune flow method, so NGS or NGF. However, this is still not routinely recommended,
it’s still not a standardized test. And so, for the time being I think that without
careful discussion, it’s not something to immediately recommend to a patient. However, if an individual patient w
ants to
have this done, talk carefully with your doctor so that you understand and have the same expectations
of what you’ll be able to do once you have that information, if it’s negative or positive,
for the MRD test. So, very exciting, still in development. A year or two from now maybe it will be a
routine test that we can comfortably recommend.
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