Lucía Pérez-Lamas, Adrián Segura Diaz, Regina García Delgado, Alberto Álvarez-Larrán, María Alicia Senin, Elvira Mora, María Laura Fox, Irene Pastor Galan, Gemma Azaceta, et al.
Standard treatment for symptomatic myelofibrosis (MF) patients includes JAK inhibitors (JAKi) like ruxolitinib and fedratinib [1,2,3,4], but their effectiveness is often limited by transient responses and the development of cytopenias [5]. Recently, momelotinib received FDA and EMA approval for treating splenomegaly and disease-related symptoms in adult patients with MF and anemia. In addition to JAK1/JAK2 inhibition, momelotinib targets the activin A receptor type 1 (ACVR1), which regulates iron metabolism through hepcidin, contributing to its unique therapeutic profile [6]. The efficacy of momelotinib in improving symptoms, reducing spleen size, increasing hemoglobin (Hb) levels, and reducing transfusion dependency in both JAKi naïve and JAKi exposed MF patients has been demonstrated in several clinical trials [7,8,9,10,11].
Given its recent approval, real-world data on momelotinib use is still limited. To gather evidence on its efficacy and safety in routine practice, the Spanish Group of Philadelphia-negative Myeloproliferative Neoplasms (GEMFIN) initiated the MOMGEMFIN study, analyzing MF patients treated with momelotinib through a managed access program.
This study was a multicenter, retrospective analysis of adult patients treated with momelotinib (JAK-naïve or JAK-exposed) from March 2023 to July 2024. Eligible participants had primary or secondary MF with anemia and disease-related symptoms or symptomatic splenomegaly. Anemia was defined as Hb values less than 11 g/dL for men and less than 10 g/dL for women. Anemia response was based on the 2024 IWG-ELN criteria [12]. Transfusion dependency was classified as requiring at least one red blood cell (RBC) unit per month or three or more units over 12 weeks. Spleen evaluation followed the 2013 ELN (IWG-MRT) criteria [13]. Adverse events (AEs) were graded per CTCAE version 5.0.