Recent Advances Provide More Options for the Treatment of Myelofibrosis

With updated clinical trials, newly approved drugs, and a further understanding from oncologists, the past decade has welcomed a number of new advances which have changed the treatment landscape for patients with myelofibrosis.

At the Miami Cancer Institute’s Third Annual Summit of the Americas on Immunotherapies for Hematologic Malignancies, Raajit K. Rampal, MD, PhD, gave a presentation on treating patients with myelofibrosis, including when to treat, who to treat, and the current standards of care.

There are 3 FDA approved JAK inhibitors helping to reduce symptoms in this patient population. These drugs include, ruxolitinib(Jakafi),fedratinib (Inrebic), and most recently pacritinib (Vonjo), which was approved for the treatment of patients with myelofibrosis and severe thrombocytopeniaat the end of February 2022.

Although there are plenty of emerging treatments in this space, unmet needs still exist. Rampal notes that while new JAK inhibitors have been approved, there is nothing that he would consider to be a disease modifying therapy. The current therapies available for patients work well to control symptoms, including shrinking the spleen, but more is needed to provide patients with a higher response rate and provide further care.

In an interview with Targeted Oncology^TM, Rampal, hematologic oncologist at Memorial Sloan Kettering Cancer Center, further discussed the recent advances in the field and what his hopes are for the future of this space.

TARGETED ONCOLOGY: How have updates in the myelofibrosis field improved the quality of life for patients?

Rampal: During the Third Annual Summit of the Americas on Immunotherapies for Hematologic Malignancies, we discussed the treatment overview of myelofibrosis in regard to when to treat, who to treat, and what are the current standards of care as well as the things that are emerging. The drugs that we have currently FDA approved, ruxolitinib, fedratinib, and pacritinib, which was just approved this year, all do a good job of reducing symptoms in patients with myelofibrosis and reducing the size of the spleen. I think all of them do make a difference in how patients feel.

That being said, there also is potentially data to indicate that ruxolitinib may confer a survival advantage based on some ad hoc analyses.

What does the current treatment landscape of myelofibrosis look like?

The treatment of the disease depends on what the situation is or what problems the patient is facing. In other words, JAK inhibitors are not necessarily the only tool that we should employ, it really depends on what the patient's dealing with. If a patient has anemia, for example, there are a variety of other medications that can be used, things like immunomodulatory agents like danazol or steroids. For patients who have constitutional symptoms, or an enlarged spleen, JAK inhibitors are really the mainstay of therapy.

Again, we have now 3 FDA approved JAK inhibitors with another that is in a phase 3 trial currently. For our patients who have progressive disease and are progressing, we do use hypomethylating agents. At the end of the day, the only treatments that we have that can change the course of the disease and cure the disease is stem cell transplant.

How has this treatment landscape changed over the past decade?

It has changed remarkably, and is changing more now, in the last couple of years, than it has in the last 10 years. In the span of the last few years, we've had fedratinib approved, and pacritinib approved only weeks ago, so that has been a dramatic change.

Right now, there are a number of agents that are in phase 3 trials, which you know, all earlier phases of study have looked really good. Those agents, if they are successful in their phase 3 trials, are going to completely change the landscape of how we treat this disease. I think that change will come within the next 2 to 3 years.

What unmet needs still exist in this space?

At this point, we don’t really have what I would call a disease modifying therapy. All of the drugs that we have are good at controlling symptoms, shrinking spleen, and all of those things are important, but none of them I would at this point characterize as a disease modifying intervention. Will any of the new drugs fulfill that? I don't know, [and] I think that remains to be seen. We need to see data to support that idea, [and] I think that's the biggest need.

We still need better drugs for anemia. Most of the drugs we have only have about a 30% or so response rate. For patients with low platelets, they have an especially poor prognosis, and we need to have better interventions for them. For people who have progressive disease, accelerated or blast phase disease, we have very few options for those patients. To me, that's a completely unmet need.

What would you say are the key takeaways for community oncologists who want to learn more about the emerging treatments and options for patients with myelofibrosis?

When dealing with a patient with myelofibrosis, the first thing to do is to try to figure out where they are in their disease course because patients can have a latent disease that is relatively quiet for maybe a decade or more, and then there are the patients who are going to progress within a year or 2 to leukemia. Using the existing tools that we have to try to figure out where patients are on that spectrum is key.

Then, figuring out where they fall in the risk spectrum, what is that patient's immediate risk of disease progression? What are their needs? What is the patient facing? Are they having symptoms? Is the spleen bothering them? Do they have anemia that is causing symptoms? That will then guide what you do in terms of therapy.

For therapy decisions, do they need medications to deal with any of those symptoms, JAK inhibitors or other drugs? Second, are these patients at relatively high risk of their disease progressing? If they are and we think they're a transplant candidate, then should they be seen by a transplanter. I think that anytime you're starting to need to treat the patient, that is a good time to think about talking to the transplant folks.

What research in this field are you looking forward to learning more about?

The number of new drugs that are entering trials and new ideas that are entering into trials is amazing. This is just an exciting time in this field. We've got to see what the data shows us and if any of these things do pan out, but I think that in the next 2-3 years we could see a completely different paradigm and how we choose to treat these patients.