Treatments for Myelofibrosis Based on Platelet Counts

EP: 1.Diagnosis and Risk Stratification of Myelofibrosis

EP: 2.Differences Between Types of Myelofibrosis

EP: 3.The JAK/STAT Pathway and Myelofibrosis

EP: 4.Clinical Scenario: Patient with Primary Myelofibrosis

EP: 5.Approved Treatments for Myelofibrosis

EP: 6.Therapy Strategies for Primary Myelofibrosis

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EP: 7.Treatments for Myelofibrosis Based on Platelet Counts

EP: 8.Clinical Scenario: Myelofibrosis Treatment in the Second-Line Setting

EP: 9.Approaches to Switching Treatments for Myelofibrosis

EP: 10.Considering Toxicities when Choosing Appropriate Treatment for Myelofibrosis

EP: 11.Assessing Response to Treatment in Myelofibrosis

EP: 12.Sequencing Treatments for Myelofibrosis

EP: 13.Unmet Needs in Myelofibrosis Treatment

EP: 14.Clinical Pearls for Community Oncologists Treating Myelofibrosis

John Mascarenhas, MD: Maybe we could focus on this as a group. Pacritinib has a label of 50,000 or fewer platelets [per mm3], but the reality is that when patients show up, they’ll have platelet counts of 67,000 [per mm3]. If you were to try to introduce ruxolitinib and titrate up—as you’re saying, Raajit [Rampal, MD, PhD]—you’re going to get on-target expected myelosuppression, and that might limit the ability to fully benefit from that JAK inhibitor. Keeping that in mind, what do you do? I’ll go around and ask. Aaron, you’re on the NCCN [National Comprehensive Cancer Network] panel and you write those guidelines. You try to be black and white when you put things into guidelines, but the reality is the world isn’t black and white. If you have that patient with a platelet count of 67,000 [per mm3], what do you do?

Aaron Gerds, MD: It’s almost never black and white. That’s the challenge with writing a guideline. It’s a guideline. It is not a law. That’s the first key piece. The other piece is that we live in a medical system that’s difficult to navigate sometimes. We have to consider the cost of these medications, how much patients have to pay out of pocket, and what’s covered. That’s the other hard piece to navigate. If you have a patient with a platelet count of 55,000 [per mm3], you may be stuck because the FDA label says 50,000 [per mm3]. There are payers that have already picked up on that. I can speak from experience. I’ve had pacritinib denials due to that threshold.

A lot of data support pacritinib’s use in that setting. Prospective randomized controlled data show the benefit there, but the challenge is navigating that system. That might be an instance where you may have to try ruxolitinib at a low dose for a little while and see how it goes. If you get a response, great. If the platelets slide down to less than 50,000 [per mm3], then you have another option. That’s the reality of practicing medicine in the United States. As you said, there are data to support its use, and we’re trying to use the guidelines to broaden the use of all these medications and give guidance to prescribers, the people taking care of these patients. We’re also trying to add a little more leverage for when they go to third-party payers to get these medications for patients for whom it may be appropriate.

John Mascarenhas, MD: You brought up an excellent point. There are data, as you pointed out. In PERSIST-2 [NCT02055781], with patients with less than 100,000 platelets [per mm3], there were responses in patients who had above 50,000 platelets [per mm3], both from a symptom- and spleen-response perspective. The safety data are there too. But the label is less than 50,000 [per mm3] and the guidelines restrict it to less than 50,000 [per mm3]. One could be in a situation where the platelet count is 55,000 [per mm3] and the payer is saying, “No, we’re going to reject it.” Srdan, in that case, when you’re using low-dose ruxolitinib, 5 mg twice a day, what has been your general impression and experience? Do you find that you can achieve optimal or adequate spleen and symptom response? Or do you find that you’re then moving on to the next line of therapy?

Srdan Verstovsek, MD, PhD: I’m sorry that we have to talk about the payers here, because we would like to talk about the best care without the payers’ roles. That’s the problem. Because if you’re talking about platelets between 50,000 and 100,000 [per mm3], the lower the platelet number—67,000 [per mm3], as you said—the less of a chance for me to be able to go to 10 mg twice a day when I start ruxolitinib. Ten mg twice a day is pretty satisfactory. It can control the quality of life well—spleen not so well—but 5 mg daily or 5 mg twice a day isn’t really good.

In patients who are below 50,000 [per mm3], if I have no choices—so far, there was no choice—I would use ruxolitinib 5 mg twice a day or 5 mg daily as intent to do something, without expecting too much. I told the patients at that time, “We don’t have much to choose from.” Now we do. Pacritinib is a standard practice for patients with platelets below 50,000 [per mm3]. When we go above 50,000 [per mm3], payers aside, the lower the platelets, the more likely I would think about changing from ruxolitinib 5 mg daily or 5 mg twice a day to full-dose pacritinib, because as Raajit said, dose intensity matters. If the platelets are 89,000 [per mm3], I may go with ruxolitinib because that’s closer to 100,000 [per mm3] and I can possibly get patients on 10 mg twice a day. It’s an individualized approach with a little flexibility, knowing that we’re talking about the guidelines. Putting payers aside is the best approach.

Transcript edited for clarity.