Ruben Mesa, MD: Let’s pivot in terms of, the patient is in front of us, we’ve talked about a bunch of different options. Let’s talk about how we monitor and why we might potentially change between some of these things. First in terms of monitoring, why don’t we start with the bone marrow. Angela, I had asked you regarding the diagnosis piece, in which patients are you going to be repeating a bone marrow biopsy in myelofibrosis [MF]?

Angela Fleischman, MD, PhD: I think in my practice I would reserve a follow-up bone marrow for a clinical red flag. I don’t necessarily repeat bone marrow biopsies at specific points just because it’s been a period of time since the last one. But I clearly do a bone marrow if I’m concerned about something changing, somebody’s starting to get blasts in their peripheral blood, if they have a significant change in their blood counts, if they had a good hemoglobin and hematocrit before, and now they’re horribly anemic and transfusion-dependent. Or rarely if a person has a significant change in their symptom burden and they just know something is different. Their blood counts may not reflect that, but they really do feel significantly different. I do the bone marrow to check to see whether the clinical concern is mirrored with a change in their bone marrow. In particular, what I’m most concerned about is are they progressing to an acute leukemia? That’s sort of the worst-case scenario.

Ruben Mesa, MD: Now Jamile, let’s talk spleen. We can do an examination, we can do ultrasound, we can do MR [magnetic resonance], we can do CT. Clinical trials typically will have us do an MR or a CT. What do you use clinically? Are there times that you do use imaging outside of a trial?

Jamile Shammo, MD, FACP, FASCP: Yes. I just thought about a patient I had who had been on a perfectly steady dose of a JAK inhibitor. Then he walked into the clinic one time and said, “I think my spleen is larger.” And he was right, because it was. And on exam essentially I felt that this felt larger, and of course, I had to confirm that by imaging. Certainly, that was to me the easiest way to say to somebody, “You’re failing therapy.” There’s just no other way around it, and that’s when we ended up doing the bone marrow. But perhaps examining, recording the spleen size at every point, and then supplementing that with imaging, is what I do.

Ruben Mesa, MD: Stephen, why don’t you take the final piece? If we think about blood counts, how are you monitoring blood counts? Is that weekly, is that every few weeks? Particularly in these cytopenic patients with MF, what’s the gold standard for monitoring the counts?

Stephen Oh, MD, PhD: I think it certainly is tailored to individual patients as far as how frequently they need or should have their blood counts checked. You can look at it a couple of ways. One is if there’s any concern for the potential need for transfusion, then it’s based on the frequency with which they might need transfusion. For patients who are red cell transfusion-dependent, it could be as frequent as every 2 to 4 weeks, if that might be the frequency that they need transfusions. It’s the same with platelets.

But outside of that, well, there are 2 factors. One is if they’re on treatments and I need to be monitoring their counts at a certain frequency to be able to determine whether the counts are dropping, for instance, the platelet count with ruxolitinib, the frequency would be based on that. For instance, if I start a patient on ruxolitinib, depending on the dose and their baseline counts, I might check their CBC [complete blood count] again about every 2 weeks initially, and then progressively back off from there. But if we’re talking about a patient whose counts generally are stable, it might be as infrequently as every 3 months, or in the most low-risk patients, 6 months. Then the decision-making for me is what timeframe would I need to reassure myself and the patient that there’s no significant change that we might miss if we don’t check it frequently enough, and whether there would be any indication of disease progression.

This transcript has been edited for clarity.