European LeukemiaNet criteria for safety and efficacy evaluation of new drugs for myelofibrosis

Most myelofibrosis (MF) drug approvals by Health Authorities are based on 1 or 2 outcome measures such as spleen volume reduction and/or improved quality of life. This 1–2 dimensional approach fails to capture the clinical complexity of MF. A European LeukemiaNet (ELN) task force developed a composite endpoint that allows multiple outcomes to be simultaneously measured. The panel used the Desirability Of Outcome Ranking (DOOR) method to assign 25 outcomes into 4 quartiles based on a multi-dimensional desirability score and build a 5-layer composite outcome named Desirability of Myelofibrosis Outcomes (DEMYO). Outcome operational definitions were tested by Delphi consensus, and correlations with survival were validated by a literature review. The outcomes assigned to the first two quartiles were negatively correlated with leukemia-free survival and survival. DEMYO comprehensively captures relevant MF clinical features and meaningful endpoints. Despite DEMYO requiring validation based on available trial data, it is expected to improve the quality of Health Authority approvals for new drugs for MF.