Dr Prithviraj Bose on Treating Progression in Myelofibrosis

Prithviraj Bose, MD, of MD Anderson Cancer Center discusses treatment options for patients progressing with myelofibrosis.

How do you treat progression in myelofibrosis?

So, it’s a lot of things, and currently there is not a whole lot that is available for these patients. Ruxolitinib is our standard first-line drug for most patients with myelofibrosis and progression to me generally mean progression on ruxolitinib. So, we just had the FDA approve fedratinib, so that is a new option now, which certainly would be a valid option in a good number of patients who progress on ruxolitinib. There is data from the JAKARTA-2 study supporting fedratinib’s use in the post-ruxolitinib setting.

But where it gets interesting is that you have to look at the definitions used in various trials that have studied agents in the post-ruxolitinib setting. So, JAKARTA-2, for example, originally had a fairly loose definition and then the data were reanalyzed using a stringent definition, which I hope is becoming more of a consensus because the recent trial of pacritinib, PAC203—pacritinib is another JAK 2 inhibitor—used the same definitions as they used in the revised analysis of JAKARTA-2. So, hopefully some sort of a consensus is emerging in the field.

And what was interesting was when they used the revised definition, the response rates dramatically changed. They originally reported spleen response rate was 55% and with the new definition it was 30%. Symptom response rate was virtually identical, 26% and 27% on the original and the reanalysis.