A Pilot Study of the Telomerase Inhibitor Imetelstat for Myelofibrosis

Imetelstat, a telomerase inhibitor, induced complete or partial responses in 21% of patients with refractory myelofibrosis. In some patients, reversal of marrow fibrosis was documented and the burden of mutant clones decreased. Myelosuppression was the key toxic effect. Allogeneic stem-cell transplantation is currently the only method of treatment for patients with myeloproliferative neoplasm–associated myelofibrosis that has been shown to induce long-term disease-free remission. 1 Unfortunately, allogeneic stem-cell transplantation is associated with a relatively high rate of treatment-related death and complications, including chronic graft-versus-host disease. Furthermore, many older patients are not eligible for this intervention. Other treatment strategies, including the use of Janus kinase (JAK) inhibitors, are palliative and lack selective anticlonal activity. 2 Ruxolitinib and other JAK inhibitors can alleviate constitutional symptoms and reduce spleen size, but they often cannot induce complete or partial remissions, reversal of bone marrow fibrosis, . . .