Anagrelide for the Treatment of Essential Thrombocythemia: Real‐World Observational Study in a Cohort of Colombian Patients

Objective To evaluate the effectiveness and safety of anagrelide in Colombian patients with essential thrombocythemia (ET) treated under routine clinical practice conditions. Materials and Methods A prospective, multicenter, real‐world observational study was conducted across 15 departments in Colombia. Adult patients diagnosed with ET were included. Patients initiated treatment with anagrelide and were followed for 12 months. The primary outcome was the change in platelet count. Secondary outcomes included changes in hemoglobin, leukocyte counts, and reporting of adverse events. Response was classified as complete ( 600,000/μL), adapted from ELN/IWG‐MRT criteria. Results Of the 103 patients recruited, 53 met the inclusion criteria. The mean age was 62.2 years, and 69.8% were female. Anagrelide was used as second‐line therapy in 88.7% of patients. At 12 months, 22.0% achieved complete response ( 600,000/μL ( p < 0.001). No significant changes were identified in hemoglobin or leukocytes. Most adverse events were mild and consistent with the known profile of the drug: headache (39.6%), gastrointestinal symptoms (37.7%), and palpitations (26.4%). No serious treatment‐related events were reported. Conclusions In real‐world settings, anagrelide was effective and safe for the treatment of ET, yielding sustained platelet reduction and a favorable tolerability profile. Active dose titration was associated with higher response rates, underscoring the need for close monitoring in clinical practice.