BSH 2024 | Current and emerging treatment options for patients with MF who are ineligible for ruxolitinib

So for patients who are ineligible for ruxolitinib, generally they are ineligible because they’ve got too early of a stage of disease. So in many health economies, for example the UK, it is for intermediate II or high-risk disease only. In general, in my practice, I would try to get around that by looking at multiple different prognostic scores, trying to make a patient intermediate II risk, because ruxolitinib is clearly a very effective therapy and mainstay of treatment. So generally, you know, just trying to be a bit more pragmatic.

But there are certain aspects of a disease which can make a patient ineligible for ruxolitinib as well. Principally, that would be severe thrombocytopenia. And so it’s an emerging therapy. For example, there is pacritinib, which we’ve known about for a long time being trialed in the PACIFICA study. There’s also momelotinib, which has recently been approved in the UK and Europe, as well as by the FDA, which is similar to ruxolitinib – a JAK1, JAK2, ACVR1 inhibitor – but also can be used for patients who are thrombocytopenic and helps us with transfusion dependance. So an on target effect of JAK inhibition is anemia, so some of us are reluctant and, you know, struggle to manage anemia for patients on ruxolitinib. 

So those are the main elements that are sort of JAK inhibitor based, and then there are some combination strategies, but for the most part these involve ruxolitinib. Some strategies targeting anemia, I mentioned the KER-050, there are also LOXL2 inhibitors, and also some of the CALR-directed therapies as well (vaccination, monoclonal antibody, bispecific, etc.) are being used for patients who can’t have a JAK inhibitor or who have become refractory or intolerant. So there’s a few, not as many as we would like, agents around for these patients, but there are some.