Thriving With MPNs: Your Role in Managing Your Treatment and Care

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Transcript:

Katherine Banwell:

Hello and welcome. I’m Katherine Banwell, your host for today’s program. Today, we’re going to talk about how to live and thrive with an MPN. We’re going to discuss MPN treatment goals and how you can play an active role in your care. Before we get into the discussion, please remember that this program is not a substitute for seeking medical advice. Please refer to your healthcare team about what might be best for you. 

Well, joining us today is Dr. Jeanne Palmer. Dr. Palmer, welcome. Would you please introduce yourself? 

Dr. Jeanne Palmer:

Thank you so much. I am so happy to be here and to help participate in this. My name is Jeanne Palmer. I am a hematologist at Mayo Clinic in Arizona. I specialize in MPNs as well as bone marrow transplant, and I am thrilled to be here. 

Katherine Banwell:

Thank you for taking the time out of your busy schedule to join us today, Dr. Palmer. We start all of the webinars in our Thrive series with the same question and that is, what does it mean to you to thrive with an MPN? 

Dr. Jeanne Palmer:

I think living with an MPN can be very difficult. I think there is a number of things. First of all, there’s always the worry of what’s going to happen in the future. Many of these MPNs can start as fairly, for lack of a better term, as benign issues and can convert to something much more serious. So, I think living with that sort of timebomb in the back it can be extremely stressful. So, figuring out how to live with the fact that there is some degree of uncertainty. 

I think the other thing is making sure to understand your disease. These are very rare disorders and even if you go to a hematologist-oncologist specialist, a lot of times they don’t have all the information because they don’t see a lot of them every year. So, it’s really important to make sure that above and beyond that you understand what’s going on in your body so that when new things happen, new symptoms happen, you’re able to really address them as opposed to sort of living with something that may make you feel poorly that’s not being addressed.  

So, again, I think the biggest piece of this is seeing how do you live with uncertainty, and how do you make sure you understand your disease well enough that you know what’s going on in your own body. 

Katherine Banwell:

Yeah. That’s helpful to understand, especially as we move through today’s program, and we’re going to cover the three classic MPNs, polycythemia vera, essential thrombocythemia and myelofibrosis. One part of thriving with an MPN is managing the symptoms of the disease. Would you walk us through the common symptoms of each of the MPNs? Let’s start with essential thrombocythemia. 

Dr. Jeanne Palmer:

Right. So, there are a number of shared symptoms throughout all the diseases and when we start to figure out how to categorize them, they call into several different categories. The first one is inflammation-related symptoms. We know that the inherent pathway that’s dysregulated or that causes these diseases to happen can also result in significant inflammation in a person, that can result in things like fevers, night sweats, weight loss, and overall feeling really fatigued and poorly, which is something that it seems to be much more prevalent in patients with MPNs, all sorts of them, actually. 

The next set of symptoms is related to microvasculature, so all the little blood vessels. And sometimes we think, oh, maybe that’s because there’s too many red blood cells or platelets and the blood become viscous. It’s probably more related to the actual dysregulation of that JAK2 pathway, which is inherent to all the myeloproliferative diseases and as a result, the little blood vessels can clamp down and that can give people headaches, visual changes, numbness and tingling in the hands and feet, and even can cause sort of a painful rash called erythromelalgia in the body. 

So, these are things that can happen that are probably less appreciated side effects of the disease. And finally, there’s spleen-related symptoms. The spleen is in the left upper quadrant of the abdomen and it’s an organ that generally is about 12 centimeters in length, 10 to 12, but in patients with myeloproliferative diseases it can be enlarged. And as a result of an enlarged spleen people can have feeling like they get fuller early. So, if you’re eating a meal, all of the sudden you can only eat half of that meal versus the whole meal.  

Discomfort or pain in the left upper quadrant. Sometimes it’s much more noticeable when you like bend over to tie your shoes. And then sometimes people can actually, when the spleen gets really big, the blood flow can be impaired towards the end of it which can cause some of the spleen tissue to die, and that can be painful. So, these are things that if somebody does start to notice that they’re having fullness in the left upper quadrant, pain, stuff like that, that that may be related to spleen symptoms. 

Katherine Banwell:

What about PV or polycythemia vera, what are the symptoms? 

Dr. Jeanne Palmer:

So, all of these sorts of relate to all of the myeloproliferative diseases. So, one other one that I didn’t mention, and this is actually more in PV than others, is itching. Itching can be absolutely unbearable when somebody has PV. It’s particularly noticeable after taking a shower. So, a lot of times I’ve met patients who are like I haven’t been able to take a shower in years, because it causes such a high degree of itching. 

Katherine Banwell:

Why a shower? Is it different from having a bath?  

Dr. Jeanne Palmer:

Water on the body that can cause the problem. So, if people take hot showers, it’s even worse. Although I think that people sort of react to it differently. Usually what patients end up doing is more like sponge bath type of things, rather than actually being exposed to the water. 

Taking colder showers or cooler showers can sometimes help mitigate that. But the itching, and even in the absence of a shower, people can have pretty severe itching, and that can also be one of the major side effects. 

Katherine Banwell:

Much of the time the chosen treatment for MPNs manages the symptoms of the condition. I’d like to review the different types and classes of treatment for the three MPNs. So, let’s start with essential thrombocythemia again. When is it time to treat, and what are the options available?  

Dr. Jeanne Palmer:

Right. So, with essential thrombocythemia, that’s the disease that sometimes we don’t need to treat. 

So, we basically have a risk stratification system and this risk is based on age, history of a blood clot, the presence or absence of a JAK2 mutation. So, for example, if somebody is 28, does not have a JAK2 mutation, which is again one of those driver mutations, and never had a blood clot, they actually don’t necessarily need to do anything and just be monitored.  

Somebody who is less than 60 and has a JAK2 mutation or who is greater than 60 and does not have a JAK2 mutation, in that setting, a lot of times you can use aspirin. Now, it gets a little bit gray in terms of that over 60 without the JAK2 mutation with regards to whether at that point you really should start taking some medicine to lower the platelets. 

Now, if somebody has a JAK2 mutation, is greater than 60 or has had a blood clot, hands down they need to take medicine to lower the platelets, in addition to aspirin or whatever blood thinner they may need. So, for example, if you have a blood clot in a vein, a lot of times you need to take a blood thinner and that will be a lifelong thing. And again, we do these risk stratifications because we know there is a certain risk of clotting associated with the risk of essential thrombocythemia. 

So, for example, somebody who is less than 60 and does not have a JAK2 mutation, never had a clot, their risk of clotting is probably very close to that of the normal population. Whereas if you’re higher risk and have a JAK2 mutation and greater than 60 or have had a history of a clot, the risk of clot is probably about 4 percent per year. So, this is something that can vary quite widely, and even though that 4 percent per year on the short-term doesn’t sound like a lot, if you take it additive over years, that’s why we generally try to be aggressive about lowering the platelets.  

In lowering the platelets, the goal is to get less than 400 and doing that can be done through several different medications. The most commonly used medications is a drug called hydroxyurea, which has been around for a number of years, and a drug called anagrelide which is probably a little less commonly used, because it has some more GI side effects and headaches associated with it. 

In some cases, especially in younger patients with this disease, we can consider using interferon, which is an injection of a cytokine, which are one of the chemicals that regulates the immune system within the body. But this interferon can actually help lower the platelets and there is a question of whether it may affect the biology of the disease as well. 

Katherine Banwell:

Let’s turn to polycythemia vera or PV, what are the different options available for treating it? 

Dr. Jeanne Palmer:

So, for polycythemia vera, everyone needs to be on aspirin. 

And additionally, everyone needs to make sure to keep their blood count low, to manage their hematocrit, which is one of the measures of red blood cells. So, in men it’s generally recommended to keep below 45 and in women it’s recommended to keep below 42 percent.  Now, the studied number was 45 percent and that was a study that was done, I don’t know, it was probably about 10 plus years ago, that actually showed that by keeping the blood hematocrit less than 45 percent you reduce the risk of having negative events like cardiovascular events and heart attacks. Because women tend to run with a lower blood count than men, it’s been extrapolated that 42 percent should be the number used for women. 

Now, this can be done by phlebotomy, which essentially is bloodletting. It’s kind of like donating blood except for that the blood unfortunately can’t be donated to anybody, it has to be discarded. But the phlebotomy is one way to do that, and the reason that works is because it makes somebody iron deficient. So, whereas if this is normal, if you’re iron deficient you become anemic. If your baseline hematocrit is here, making you iron deficient brings you back to normal. So, even though we always associate iron deficiency with anemia, iron deficiency in the setting of polycythemia vera is actually kind of a treatment of sorts. 

Now, once somebody gets above 60 and 60 seems to be sort of the magic age in these diseases, once somebody gets above 60, it is recommended that cytoreductive therapy is used, which means therapy or treatment that will bring down the red count. And again, for this one, hydroxyurea is an option as well as interferon. And there is recently an approval, actually FDA approval for a newer interferon called ropeginterferon or Besremi, which can help just bring down the red blood cells but it is the first interferon that’s actually been FDA approved for this indication. 

Katherine Banwell:

Are JAK inhibitors used as well? 

Dr. Jeanne Palmer:

They are. So, if somebody doesn’t respond well to hydroxyurea, the approval for ruxolitinib is actually for patients who have failed hydroxyurea. Although it’s something that we often consider especially in people who have a lot of symptoms. So, the itching, one of the things that can really help itching actually is Jakafi. If people have night sweats, they have weight loss, spleen related symptoms, those are the patients that will benefit from Jakafi. Additionally, if they are on hydroxyurea and can’t seem to get control of their blood count, Jakafi is a good option to help control the blood counts as well. 

Interferon is a very nice option because there’s great data that shows that you may actually be able to lower the percentage of JAK2 burden. 

So, we’d look at something called an allele burden, which is the percentage of cells that are involved – have the JAK2 mutation. Now, we don’t know whether lowering this percentage necessarily translates to long-term better survival, but I think there is enough data out there, and there is a good biologic underpinning for saying that this actually can help. But yes, Jakafi is another thing. 

And the really exciting thing is that there is a newer agent called rusfertide, which is a hepcidin mimetic, which is basically taking a protein in your body that helps metabolize iron and by making it externally and giving it to somebody that it can actually help bring down the hematocrit without having some of the other side effects we know with some of the other medications. That is currently in Phase III studies, so hopefully in the next couple of years we’ll see approval for that. 

Katherine Banwell:

Oh, that’s great news. And finally, how is myelofibrosis treated? 

Dr. Jeanne Palmer:

So, myelofibrosis is a little bit of a different animal. When you have something like essential thrombocythemia or PV, a lot of this is managing symptoms, preventing blood clots, but if you do appropriate treatment and management of these diseases you could probably live close to a normal life expectancy.  

So, I never typically pin a survival on it. With myelofibrosis, it’s a little bit different because there is a survival. Instead of saying you can live close to normal life expectancy, it backs up to saying how many years do I think you can live with this disease. Now, of course, we are horrible at predicting how many years anyone can live, so we have to take that all with a grain of salt. But we can at least sort of risk stratify people. 

And the first thing that’s really important is to figure out whether somebody is a transplant candidate or not and if, based on age, disease risk features, stuff like that, or whether we think they ever will be a transplant candidate. So, that kind of helps us sort of think about what your path moving forward is.  

Now, the current FDA-approved treatment for myelofibrosis, there are three JAK inhibitors approved, which is like Jakafi, which was the first approved one but there is also Inrebic or fedratinib and Vonjo or pacritinib and these have all been approved over the years. 

The role of JAK inhibitors and treatment of myelofibrosis is symptoms-based. So, for example, a lot of patients with myelofibrosis will have weight loss, night sweats, big spleens, really feeling fatigued and poorly and in this setting, the JAK inhibitor can be very helpful. And you don’t have to have a JAK2 mutation, a lot of times people say, well, I don’t have the JAK2 mutation so how can a JAK inhibitor help. So, the JAK inhibitor works on this pathway, which is called the JAK/STAT pathway, irrespective of mutation. 

So, if you are having symptoms and you have myelofibrosis, JAK mutation, excuse me, the JAK2 mutation does not predict who is going to have a response. And people who, regardless of which mutation you have, may actually benefit from it. 

So, the JAK inhibitors, though, are extremely effective at reducing symptom burden as well as reducing the spleen size. And we know that if a spleen is big and we can make it shrink that, that probably is a surrogate marker for living longer, and I think it’s because inflammation does a lot of wear and tear on the body. So if you can reduce the inflammation and the spleen shrinks, which generally go hand in hand, then you might help somebody live longer. It is not changing the biology of the disease, though, however, it doesn’t change the pathway and that this disease is kind of projecting ahead in terms of creating – it changes, as it goes along, may acquire new mutations or something like that which makes the disease become more serious. 

Right now, the approved therapies for it are JAK inhibitors and the Jakafi, ruxolitinib was the first one approved. Inrebic was approved several years back, or fedratinib. 

And then the most recent one that was approved is Vonjo or pacritinib and that’s a drug that is a JAK inhibitor that is actually very good for people with low platelets. The reason I bring that up is because if we think of what’s the biggest limiter of JAK inhibitors, JAK inhibitors bring down red blood cells, and they bring down platelets. So, when somebody has low platelets it’s very hard to use a JAK inhibitor, because we’re not really able to increase the dose well enough to get that inflammatory reduction because of the fact that the blood counts will drop too low. 

So, now drugs like Vonjo exist which, due to several other mechanisms associated with the drug are actually much more tolerated in somebody with low platelets. So, if you have low platelets, you can actually take the Vonjo, hopefully get the same degree of JAK inhibition to help the spleen shrink, help the symptoms get better without necessarily making the platelets substantially worse. A lot of times they do drop, it doesn’t help bring up the platelets, but it does help people tolerate more JAK inhibition, which ultimately will help with symptoms.  

Dr. Jeanne Palmer:

So, one thing I also wanted to add about myelofibrosis treatment is sometimes people present, they don’t have a lot of symptoms, they don’t have a lot of spleen related problems but they have anemia or low blood counts and these can be incredibly hard to treat. 

Even with symptoms and low red blood cell count or anemia or low platelets, it can be challenging to treat because many of these medications lower that. To treat the anemia there are several things that we can do. One of the first ones is using erythropoietin, and so there are many agents, they go by the names of like Procrit or darbepoetin alfa, that actually stimulate red blood cell growth by – like we give a recombinant hormone that helps red blood cells grow. This is normally something produced by the kidney. 

So, one thing that’s important before going on one of these injections is to make sure that the kidney is not already producing enough. So, for example, if the kidney said, oh geez, I really need more red cells and is making lots of this hormone, erythropoietin, giving more of it is not going to help the system. But in people who don’t have a really high level it can be very beneficial. 

The other thing that can help with anemia, specifically, is a drug called danazol (Danocrine).  

It’s been around for a very long time. There are multiple presumed mechanisms of action, but one of them is that it is kind of a testosterone derivative. So, this is a medicine that can often help increase red blood cells in probably about 40 percent of people, and it’s a pill that you take twice a day. 

Another option, sometimes we use thalidomide or lenalidomide (Revlimid). These are medications that have been used quite frequently in the setting of multiple myeloma and even a little bit in myelodysplastic syndrome, so some other blood disorders.