Mascarenhas J, Komrokji RS, Palandri F, et al. - Given poor clinical results in patients with myelofibrosis who are relapsed or refractory (R/R) to Janus-associated kinase inhibitors (JAKis), researchers undertook this phase II multicenter study to assess imetelstat (a telomerase inhibitor) in patients with intermediate-2 or high-risk myelofibrosis R/R to JAKi. They randomized patients to receive either imetelstat 9.4 mg/kg or 4.7 mg/kg intravenously once every 3 weeks. Spleen and symptom response rates observed at week 24 were 10.2% and 32.2% in the 9.4-mg/kg arm and 0% and 6.3% in the 4.7-mg/kg arm. Findings revealed clinical benefits in symptom response rate were conferred by imetelstat 9.4 mg/kg once every 3 weeks; along with an acceptable safety profile for this poor-risk JAKi R/R population. Selective impacts on the malignant clone were indicated by biomarker and bone marrow fibrosis evaluations.