imetelstat + fedratinib

Imetelstat + fedratinib is an experimental combination therapy under consideration for the treatment of myelofibrosis, a rare hematological malignancy characterized by bone marrow fibrosis, extramedullary hematopoiesis, and abnormal cytokine production. **Imetelstat** is a first-in-class, competitive inhibitor of telomerase, delivered as a thiophosphoramidate oligonucleotide that binds the RNA template of human telomerase, ultimately inhibiting its activity and impeding the proliferation of malignant hematopoietic progenitor cells. **Fedratinib** is an oral, selective small-molecule inhibitor of Janus kinase 2 (JAK2), curbing the JAK-STAT signaling pathway implicated in myelofibrosis pathogenesis and driving cytokine-mediated symptoms and splenomegaly. While imetelstat has primarily been investigated in JAK inhibitor–refractory or relapsed myelofibrosis, and fedratinib is approved for primary or secondary myelofibrosis post-ruxolitinib, there is currently limited to no clinical evidence specifically for their combined use. Most ongoing or published clinical research of imetelstat-based combinations in MF utilizes ruxolitinib rather than fedratinib. Nonetheless, this combination theoretically targets complementary pathogenic mechanisms in MF: telomerase-driven malignant stem cell persistence and JAK2-mediated proliferative signaling[3][4].