Many patients wondered what happened to Fedratinib, the drug Sanofi had in trials several years ago. Amid some controversy, the drug was shelved, although many patients were experience positive responses. Fedratinib is back. It is a selective JAK2 Inhibitor, whereas existing treatments target both JAK1 & 2. Spleen reduction will likely continue to be a primary endpoint. For those patients resistant to current treatments, Fedratinib could be a potential option in the near future.
In the JAKARTA phase 3 trial, fedratinib had a ≥35% reduction in spleen volume at week 24 in 46.9% of myelofibrosis patients and a ≥50% reduction in total symptom score in 37.1% of patients. The only grade >2 TEAE seen notably more often in 400mg fedratinib vs. placebo by cycle 6 placebo cross-over was anemia (common to all Jak2 inhibitors). We know there is a significant unmet need in the MF patient population and we’re working diligently to get fedratinib to market to address this unmet need. In JAKARTA 2 fedratinib had a ≥35% reduction in spleen volume at week 24 in 55.4% of myelofibrosis patients that were previously intolerant or resistant to ruxolitinib treatment.