Myeloproliferative (MPN) Symptom Burden Response Thresholds: Assessment Of MPN-SAF TSS Quartiles As Potential Markers Of Symptom Response

We have previously reported on the significant, but heterogeneous baseline MPN symptom burden among an international sample of MPN patients (including essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF)) utilizing the MPN Symptom Assessment Form (MPN-SAF) and the derivative Total Symptom Score (MPN-SAF TSS). Recent clinical trials have sought to determine optimal MPN symptom response criteria, such as absolute 10 point improvement in MPN SAF TSS for ET/PV (ELN Criteria, Barosi et. al. Blood2013) and 50% reduction in MPN-SAF TSS for MF (IWG-MRT, Tefferi et. al. Blood2013). We sought to determine the role of improvement in MPN-SAF TSS quartiles as potential thresholds to assess symptomatic response to therapy.