The study we presented yesterday at ASCO was actually a phase II investigator initiated trial looking at fedratinib in patients that have what we call MDS/MPN overlap, so myelodysplastic syndromes overlapping with myeloproliferative neoplasm, which is a rare group of patients that exhibit this kind of complex situation where they make too many blood cells but at the same time they have some dysplastic features and don’t make enough of other blood cells.

Could you outline the methodology?

This was a phase II study looking at fedratinib and essentially this enrolled 25 patients with a futility analysis performed after the first 11 patients was done. This was a really simple design in the sense that everyone received fedratinib, patients stayed on it for 24 weeks with the primary endpoint being assessed at that time. We looked at 12 weeks as well but the primary endpoint was assessed after 24 weeks.

What did you find?

What we found in this study is that fedratinib, which is an approved therapy for myelofibrosis, it’s a JAK2 inhibitor that also has some interesting activity against BRD4 as well as FLT3 and it potently suppresses c-Myc. We found in this complex patient population of MDS/MPN overlap fedratinib was able to reduce spleen size quite consistently across the board, leading to a spleen response rate of 30% but virtually everyone had a reduction in their spleen size. We also saw that 47% achieved a symptom response or 50% improvement in their total symptom score from baseline to week 24.

What impact could these findings have?

For these rare diseases unfortunately we don’t really have a standard of care approach. We extrapolate therapies from different disease entities and often these patients are excluded from clinical trials. The implications of this study are that we now know that fedratinib can lead to specific activity in these rare disease patients. What’s nice is that fedratinib is already an approved agent for myelofibrosis so this is something that we could access and leverage this information tomorrow if you had, say, a patient with MDS/MPN overlap that had features that make it likely to benefit from this type of strategy.

What is next for this study?

With this study the next steps, really this isn’t something that we plan to take to a phase III for registrational trial. Unfortunately, the feasibility of that would be quite challenging. But, as I mentioned, fedratinib is an approved agent and so this is something that we can rapidly translate and put into the clinic tomorrow if you had a patient. So we need to continue to develop clinical trials specifically for these rare disease patient populations. This isn’t something where we should be excluding these folks. Actually, these folks need direct attention and inclusion in clinical trials. So the future is very bright because we are understanding more and more about these folks and we can direct or design trials with specific implications for their disease.