How is the effectiveness of MPN treatment determined? Dr. Naveen Pemmaraju describes key factors to monitor treatment effectiveness to ensure optimal patient care and to determine when it may be time to consider a change in therapy.
Dr. Naveen Pemmaraju is Director of the Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) Program in the Department of Leukemia at The University of Texas MD Anderson Cancer Center. Learn more about Dr. Pemmaraju, here.
Once on therapy, how is the disease monitored and how do you know if the treatment is working?
So, it differs from each disease, but let’s take polycythemia vera for a good example. So, let’s suppose you have polycythemia vera. I think there’s three markers here that you can check. One is the blood counts, right?
So, you want to make sure that the blood counts are controlled. New England Journal, five or six years ago now, our Italian colleagues published a very seminal paper which shows that the goal of therapy should be that the hematocrit should be below 45. So, that’s actually a very nice number to have. So, not just waiting for symptoms of the disease but keep the number low. And if you do that, that correlates with decreased cardiac events, thromboembolic events.
Number two, I think that, besides the blood count, the spleen. The spleen and liver size also is a nice surrogate for how the disease is doing. So, if that’s enlarging or getting out of control, that may be time to stop what you’re doing, reassess. The disease may be progressing to myelofibrosis, for example.
And then I think, lastly, the absence of stuff actually helps, too. So, the absence of major bleeding, the absence of blood clots, the absence of transformation to MF. I think if the quality of life is good, you’re decreasing blood clots and bleeding, you’re not going to a more advanced disease state, these are all wins for us with P vera.
You touched on this briefly, but I’m wondering when a patient should consider changing treatments.
Yeah, changing treatments is more art than science, I would say. So, it does – that’s one of those that is kind of specific from patient to patient. In general, what we just talked about gives you that guidance. So, in polycythemia vera, since we brought that up earlier, uncontrolled blood counts despite maximum medication intervention, the phlebotomy requirement being untoward and impossible to keep up with, the spleen size growing out of control, the quality of life being impossible – these are some aspects to look into changing therapy and/or clinical trial.
But remember, it’s not a one-size-fits-all, right? So, some patients, the counts – some of these things may or may not actually play out. So, it has to be more of a gestalt, more of a total picture there.