Long-term outcomes of newly diagnosed POEMS syndrome patients treated with bortezomib-based therapies.

Abstract

POEMS syndrome is a rare hematologic condition with no established standard of therapy. Bortezomib, a proteasome inhibitor, has shown potential to offer significant clinical benefits for patients with newly diagnosed POEMS syndrome. However, comprehensive data on its long-term efficacy remain scarce. This study aimed to assess the long-term efficacy of bortezomib-based regimens for newly diagnosed POEMS syndrome. A total of 53 patients were enrolled in this study. Fluorescence in situ hybridization analysis was performed on CD138-selected bone marrow samples. All patients received bortezomib-based regimens as first-line therapy. Hematologic responses, vascular endothelial growth factor (VEGF) levels, neurological response rates, and long-term survival outcomes were evaluated. Patients received a median of four treatment cycles, with a median follow-up time of 92.4 months. Hematologic responses were evaluable in 42 patients, yielding an overall response rate was 85.7%, including a complete response rate of 64.3%. VEGF responses were assessed in 44 patients, with an overall response rate of 88.6% and a complete response rate of 56.8%. Median VEGF levels decreased from 944.4 pg/mL to 137.8 pg/mL. Neurological improvements were observed in 90.6% of patients, with 24.5% achieving a complete neurological response. Median overall survival (OS) and progression-free survival were not reached. The 5-year OS and progression-free survival rates were 83.0% and 67.4%, respectively. Fluorescence in situ hybridization analysis identified 1q21 gain as the most frequent abnormality in this cohort, and it was an independent prognostic factor for OS. Bortezomib-based regimens were effective and achieved favorable long-term survival outcomes for patients with newly diagnosed POEMS syndrome.