Expert perspectives on monitoring patients receiving therapy for myelofibrosis, with additional considerations for when it is appropriate to switch therapy.
Stephen T. Oh, MD, PhD: As far as frequency of monitoring in patients with myelofibrosis, it’s somewhat specific with regard to the treatment the patient is on and their issues, in terms of their blood counts and things like that. For instance, if I have a patient who’s not being actively treated with anything but is following an observation approach, then I’d generally see the patient every 3 to 6 months with CBC [complete blood count] monitoring in that time frame. If they don’t require transfusions or anything that requires any more frequent monitoring, that’s potentially sufficient.
For a patient who’s just started treatment with ruxolitinib, depending on their baseline hemoglobin and platelet count, we’d check their CBC at least every 2 to 4 weeks initially. Further monitoring would be dependent on stability of their counts and whether we’re adjusting the dose of the ruxolitinib. For patients who are transfusion dependent or close to that, we may be checking their CBC as frequently as every 2 to 4 weeks. In the absence of that, when a patient is on a stable dose of ruxolitinib, it may be as infrequent as every 2 to 3 months. It depends on the context of their baseline counts and how they might be changing and deciding their treatment.
Regarding office visits, I’ll see patients with myelofibrosis every 3 to 4 months, depending on if they have problematic symptoms or things are changing. In the best-case scenario, if the patient has minimal symptoms and they’re very stable, I might see them only every 6 months, but at least every 3 to 4 months for most patients.
As far as things that we’re monitoring that may provoke change in therapy, we’re looking at symptoms—night sweats, fatigue, abdominal pain related to splenomegaly. If the patient has been on treatment with ruxolitinib for some time and is noticing more satiety or abdominal pain, this suggests that their spleen has begun to re-enlarge. That would prompt us to see them in the clinic and potentially get imaging if we need to assess the spleen size more accurately. If it’s changed in a big way and is causing problematic symptoms, that would potentially provoke a change in therapy.
The other scenario where a change in therapy may be necessary is if there’s a change in the counts. For instance, I mentioned earlier that with ruxolitinib, if patients have a low platelet count, and this gets worse on treatment with ruxolitinib, there may be a point that we have to lower the dose of the ruxolitinib. Or it may become unsafe to use ruxolitinib. With availability of pacritinib, that might be a scenario in which we change treatments in patients who are in particular developing severe thrombocytopenia.
As far as logistics with switching therapies, this question just came up for me this morning. Let’s say you’ve got a patient on ruxolitinib and you’re considering switching to fedratinib. Do you need to have some tapering-off period with ruxolitinib, which is generally recommended? If you’re switching from 1 JAK inhibitor to another, whether you need a tapering or a washout period isn’t as clear, because most of the clinical trials weren’t conducted in that way. They generally required a washout period, well in advance of starting the new therapy. It’s not entirely clear what to do there, but some degree of either overlap or switching directly to the new treatment is my general recommendation.
Transcript edited for clarity.