When choosing a treatment for myelofibrosis (MF), where do you start? Dr. Laura Michaelis reviews the available options for MF therapy, including a discussion of stem cell transplant.
Dr. Laura Michaelis is hematologist specializing in myeloproliferative neoplasms (MPNs) at Froedtert & the Medical College of Wisconsin, where she also serves as Associate Professor of Medicine. Learn more about Dr. Michaelis here.
So, myelofibrosis is among the most aggressive of the myeloproliferative neoplasms. And yet, it still has a broad swath of risk associated with it. And that means that compared to essential thrombocythemia and polycythemia vera, myelofibrosis – primary myelofibrosis tends to be more aggressive and needs to be treated more aggressively.
There are a group of patients who have what we call low-risk or even intermediate 1 risk myelofibrosis who don’t need treatment – who can be followed, whose blood counts can be checked, who can be regularly seen by their doctor, and who can avoid treatment for some period of time, depending on their risk factors.
And so, if you’re diagnosed with primary myelofibrosis, the first question is do I need treatment? And the second question – if the answer to that is yes, then you have to figure out why you need treatment. There is currently only one intervention that is known to be curative in myelofibrosis, and that’s the use of stem cell transplant.
Stem cell transplant, which is also called bone marrow transplant or allogeneic hematopoietic stem cell transplant, is basically a procedure where a donor is able to have their stem cells collected. And then the recipient, who’s the person with the myelofibrosis, undergoes a series of chemotherapy treatments to basically wipe out the bone marrow that they have. And it’s then replaced, using basically a blood transfusion of the stem cells of someone else, which then grow up into the recipient.
This has been shown to be safe in myelofibrosis – well, relatively safe – if done in the right person, who’s relatively fit, and done at the right stage of disease. It’s not a procedure that everybody can tolerate. People need to be pretty fit. And it should be performed at a place that has done numerous transplants for myelofibrosis since it’s a relatively complicated form of stem cell transplant. That being said, in the right person at the right time, it’s an excellent opportunity and option for these patients.
Now in patients who can’t tolerate transplant or where that’s not the right step to go, we have medications. And those medications can sometimes delay the worsening of symptoms. They can certainly control spleen size, improve people’s quality of life, and often improve survival. And the medications that we’re talking about here are called JAK-STAT inhibitors.
And the first approved, and the one that’s most commonly used, is a medicine called ruxolitinib.
This is an oral pill – a pill that you take twice a day and has excellent data that supports that it shrinks the spleen in people with myelofibrosis, that it improves symptoms. And in people with advanced polycythemia vera, decreases the blood count without leading to iron deficiency and also improves symptoms and spleen size.
There’s another JAK-STAT inhibitor that’s approved. That’s a medicine called fedratinib. And it was recently approved in people who had progressed off of myelofibrosis or even in people – or after ruxolitinib or in people who – instead of taking ruxolitinib.
Now in essential thrombocythemia, polycythemia vera, and other times even myelofibrosis, we have other treatments that are commonly used that can be exceedingly helpful in controlling symptoms and blood counts. Those include, for example, hydroxyurea, pegylated interferon, and sometimes treatments aimed at helping anemia, like steroids or derivatives of thalidomide.
And finally, I don’t want to let this end without saying that clinical trials are often an excellent possibility for patients with these conditions, like myelofibrosis.
So, when you are contemplating starting a treatment, it’s really important to ask your physician whether or not there’s any clinical trials that are right for you.