Myelofibrosis treatment in a real-world setting: Argentine data from the international study METER

Abstract

Introduction: JAK1/JAK2 inhibitors (JAKi), such as ruxolitinib, are valuable in the management of splenomegaly and the improvement of symptoms in patients with myelofibrosis, although their use as first-line therapy is not always direct or universal. However, the real-world treatment patterns and impact of JAKi are not precisely known. Our aim was to describe the results of the Argentine cohort of the international METER study (Multi-Country, Real- World Chart Review Study to Explore Treatment Patterns, Effectiveness and Healthcare Resource Utilization for Patients with Myelofibrosis). Methods: The retrospective METER study included 928 adult patients with primary or secondary myelofibrosis. The primary objective was to describe real-world treatment patterns. Secondary objectives included assessment of overall treatment effectiveness and description of health resource use. Results: data from 51 patients were collected for Argentina; most were male (58.8%); median age: 67 years (interquartile range [IQR]: 60-74); 84.3% with primary myelofibrosis; 56.3% (9/16) had no mutations associated with high molecular risk; 51.2% were defined as intermediate-1 risk. Most had grade 3 fibrosis. The median time between diagnosis and first-line treatment was 8.47 months (ICER: 1.03-23.2), exceeding one year in 41.2% of cases. In all lines of treatment, ruxolitinib was the most commonly used drug. The median treatment duration was 53.5 months (95% confidence interval [95%CI]: 17.7-84.3) for the first line; 9.1 months (3.2-29.6) for the second line, 2.4 months (1.1-not reached) for the third line, 2.5 months for the fourth line (0.6-not reached) and 10.4 months for the fifth line. The proportion of discontinuation was 56.9%, 85%, 73.3%, 80% and 50%, respectively. Inadequate response was the most frequent cause of discontinuation. A therapeutic procedure was performed in 19.6% of participants after a median of 9.27 months (IQR: 5.13-11.9) from the first treatment. The median overall survival was 88 months (95%CI: 62.6-169.5), with an estimated 36-month rate of 91.5% (95%CI: 78.8-96.7). From the first treatment, Argentine participants required a median of 5 transfusions (IQR: 0-19). Discussion: in the Argentine cohort of the international METER study, most patients were at intermediate risk and had a high proportion of grade 3 fibrosis. The median time from diagnosis to first treatment was 8.47 months. Ruxolitinib was the most widely used drug in all therapeutic lines, consistent with the overall results.