Front-line systemic treatment outcomes in POEMS syndrome

Polyradiculoneuropathy, organomegaly, endocrinopathy, M-protein and skin changes (POEMS) syndrome is a rare plasma cell dyscrasia. Questions remain regarding the use of induction therapy, given the known efficacy of melphalan autologous stem cell transplant (ASCT), as well as the optimal management of transplant-ineligible patients. We describe the outcomes of 105 patients with POEMS syndrome and systemic disease, with a median follow-up of 68 months. Median age at diagnosis was 55 years and 75 were male. Front-line ASCT was performed in 67 patients, 61 melphalan 200 mg/m² and six 140 mg/m². Upfront ASCT was delivered in 28 and 39 patients received prior induction. ASCT was highly efficacious, with a median overall survival (OS) not reached; 5- and 10-year OS of 100% and 90.7%, respectively, with progression-free survival (PFS) of 76.5% and 60.0%. No significant difference was seen in OS, PFS, depth of response or improvement in mobility status with induction therapy. Outcomes were inferior for non-ASCT patients with a median OS of 11.4 years, 5-year OS of 72.8% and 10-year OS of 64.7%. Median PFS for this cohort was 5.6 years, with 5- and 10-year PFS of 57.2% and 31.8% respectively. Attainment of complete vascular endothelial growth factor (p < 0.001) and/or haematological response (p = 0.01) following front-line therapy was associated with a lower risk of relapse.