Inside the Clinic: Myeloproliferative Neoplasms: Current and Future Standards of Care - Episode 11

Use of Ruxolitinib in Myelofibrosis

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Expert perspectives on the role of ruxolitinib in patients who require systemic therapy for myelofibrosis.


Stephen T. Oh, MD, PhD: Covering ruxolitinib and its role in myelofibrosis, ruxolitinib was originally approved in 2011 for treatment of patients with myelofibrosis. Let me back up and say that ruxolitinib is a JAK1/JAK2 inhibitor. There are other JAK inhibitors now, 2 others that are officially FDA approved for treatment of myelofibrosis, but ruxolitinib was the first in its class to be approved, now more than a decade ago. This was on the basis of the COMFORT-I and COMFORT-II phase 3 studies. In the COMFORT-I study, patients were randomized to treatment with ruxolitinib versus placebo, and in COMFORT-II, patients were randomized to treatment with ruxolitinib versus best available therapy. With the studies, there were similar results in that the primary end point, spleen volume reduction of at least 35%, was achieved in about 30% to 40% of the patients treated with ruxolitinib versus close to 0% in either the placebo or best available therapy arms. There was a similar kind of response in terms of symptoms in both of these studies. Over the course of the decade-plus since we’ve been able to use ruxolitinib, I think that most of my colleagues in the field and I would agree that our experience has been quite similar to what was reported in those studies, which is that ruxolitinib pretty reliably provides at least some degree of spleen and symptom benefit for patients with myelofibrosis.

What I tend to say to patients is, it’s not really a question of yes or no, will a patient respond to ruxolitinib? It’s a question of how much will they respond? Their spleen will almost invariable shrink, at least to some extent, it’s just a question of how much. Thus, it has become quite commonly utilized, in particular for those issues, for an enlarged spleen and the symptoms that come with that, and for other symptoms that can be present in patients with myelofibrosis. Hence, it’s a very effective agent, in particular for symptoms, and that has been a very useful addition to the available treatment options for patients with myelofibrosis.

As far as what are the limitations of ruxolitinib, we do certainly recognize that ruxolitinib does not ameliorate cytopenias. For patients with myelofibrosis who typically have at least some degree of anemia, this does not improve with ruxolitinib. In fact, it may often get a little worse. The drug also tends to cause some degree of thrombocytopenia. These are things that come along with ruxolitinib. Like with any treatment, you have to consider what is the net benefit? And the reality is that for most patients, the symptom benefit with ruxolitinib is still worthwhile, even considering these potential negative effects in terms of cytopenias. It has been a very useful and helpful option for patients with myelofibrosis.

Transcript edited for clarity.