FDA grants fast track designation to selinexor for MF treatment

On July 17, 2023, the U.S. Food and Drug Administration (FDA) granted fast-track designation to selinexor, a selective inhibitor of oral exportin 1 (XPO1), for the treatment of myelofibrosis (MF).¹ The mechanism of action of selinexor, as well as coverage of its previous FDA and European Commission orphan drug designations, have been covered by the MPN Hub here.

XPORT-MF-034^1,2

Selinexor is currently being investigated as part of the phase III XPORT-MF-034 (NCT04562389) clinical trial. This trial aims to evaluate the safety and efficacy of selinexor 60 mg weekly in combination with ruxolitinib in patients with Janus kinase inhibitor (JAKi)-naïve MF.
The primary endpoints include:

• Spleen volume response rate of ≥35%
• Symptom improvement of ≥50% at Week 24

The latest phase I trial data was presented at European Hematology Association (EHA) 2023 Hybrid Congress. Topline data includes:

• At Week 24, 91.7% of evaluable patients reached a spleen volume response rate of ≥35%
• At Week 24, 77.8% of patients achieved a total symptom improvement of ≥50%
• Most common treatment-emergent adverse events:
  • Nausea: 78.6%
  • Anemia: 64.3%
  • Thrombocytopenia: 64.3%
  • Fatigue: 57.1%