Texas MPN Workshop 2021 | Updates on the treatment of pediatric and AYA patients with MPNs

When thinking about treating young patients with MPNs, I think there’s a few different questions that physicians debate in their minds about how best to treat these patients. And I think probably one of the biggest questions is when to start treatment. So, I think in an older adult, it might be very straightforward, but in a young person, potentially exposing them to the risks of cytoreductive treatment and the thought of being on medication for long periods of time is maybe a little more controversial and challenging.

So, the question of when to treat, I think is really one of the most difficult ones to answer and I don’t think there’s a right answer. If you ask some folks, they’ll say we should treat everyone because we want to try to decrease risk of disease progression and complications. If you ask some doctors, they’ll say we should only treat young patients who have had a significant event, like a blood clot or a major bleeding event, or some patients who really don’t do well just on phlebotomy and aspirin. If they have PV or they might have a lot of hard to control symptoms, maybe those are the patients who need cytoreduction.

Sometimes in kids also, we really want to focus on quality of life. So, let’s say there’s a young patient who is an athlete and is very involved in sports and has acquired Von Willebrand’s disease because of an extremely high platelet count, and they’re unable to participate in sports because of the bleeding risk. Maybe that’s a patient who should be put on cytoreductive therapy. So, at least for me, I think of all of those possibilities when I meet new patients and I think one of the most important things is really speaking to families and discussing risks and benefits of medication versus not treating and really seeing what would work for that particular patient and their family. And then as far as medications for young patients, I think the question of which medication to use upfront is also not totally clear.

I think historically hydroxyurea has been the most commonly used medication. It’s something that people in the adult medicine world have very strong opinions about. I think in pediatrics, it’s pretty universally loved for our experience using it with patients with sickle cell disease. But there are quite a few young patients with MPNs who have used hydroxyurea and have been on it for many years and have done very well. So, it’s certainly something that I include in discussions with families as one of the frontline agents to use.

And then I think the other drug that is not always used by pediatricians but is starting to be thought about more is pegylated interferon. I think historically folks saw a lot of side-effects and young patients didn’t tolerate that well, but I think with the new pegylated forms, many young patients are really tolerating it quite well. So, I think it’s a medication that is really of interest to a lot of people because it has truly the ability to slow disease progression and actually put patients into remission. So, I think that’s something that’s really valuable, and certainly for parents of young patients talking about a cure or something to stop the disease from advancing is really appealing to them.

So personally, when I speak to families about treatment, I usually discuss hydroxyurea and interferon and depending on the case, I may recommend one or the other based on the specifics of that case. But I think they’re both appropriate drugs to have in the pediatric armamentarium, and I think we can use both of them in young patients. I think the more we use interferon in young people, the more pediatricians will get comfortable with it. So, that is I think something that is helpful. Our group worked with colleagues at other institutions, and we wrote up a case series of pediatric and adolescent and young adult patients using interferon and I think the more we share that data and the more we talk about interferon use, the more comfortable pediatricians will be with that drug since it’s not something we had historically used for a lot of things in pediatrics.