FDA grants fast track designation to nuvisertib for the treatment of myelofibrosis

On June 12, 2025, the U.S. Food and Drug Administration (FDA) granted fast track designation to nuvisertib, an oral, investigational, highly selective inhibitor of PIM1 kinase, for the treatment of patients with intermediate or high-risk myelofibrosis (MF).¹ 

The FDA granted orphan drug designation to nuvisertib for the treatment of patients with MF in May 2022, followed by the same designation by the Ministry of Health, Labour and Welfare of Japan (MHLW) in November 2024.¹  

The efficacy and safety of nuvisertib are currently under evaluation in a phase I/II trial (NCT04176198) in patients with intermediate- and high-risk MF.^1,2 Updated data from the ongoing trial of nuvisertib in patients with relapsed/refractory MF were presented at the EHA Congress on June 12, 2025.²  

These preliminary data suggest that nuvisertib monotherapy is well tolerated, with no dose-limiting toxicities. Clinical activity included a ≥25% spleen volume reduction (SVR25) in 22.2% of evaluable patients and a ≥50% reduction in total symptom score (TSS50) in 44.4% of evaluable patients. Improvements in bone marrow fibrosis, platelet counts, and hemoglobin levels were also demonstrated. Treatment with nuvisertib led to significant cytokine modulation and significant correlation with symptom and spleen responses (p < 0.001).