Academic BCMA CAR-T (ARI0002h) achieves MRD-negative remission with sBCMA biomarker response in relapsed POEMS...

Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal gammopathy, and Skin changes (POEMS) syndrome is a rare plasma cell disorder with diverse multisystem manifestations. Autologous stem cell transplantation (ASCT) is the preferred front-line therapy when feasible, but relapsed/refractory (RR) cases after ASCT failure lack effective salvage options. B-cell maturation antigen (BCMA)-directed CAR-T cell therapy has revolutionised multiple myeloma (MM) treatment. Given the shared BCMA expression on clonal plasma cells between MM and POEMS, CAR-T cell therapy is also a biologically compelling strategy for POEMS syndrome [1]. However, there are only two previous case reports of CAR-T cell therapy in POEMS [3,4], none involving patients with prior ASCT failure. We report a 54-year-old male with RR-POEMS progressing after two previous ASCT failures who received an academic point-of-care BCMA-directed CAR-T cell therapy (ARI0002h) via fractionated infusion. No cytokine release syndrome (CRS) or neurotoxicity (ICANS) occurred. At 3 months, the patient achieved a measurable residual disease (MRD)-negative complete haematological response (CR_H) by Next Generation Flow (NGF) with a sensitivity of 10⁻⁶ and a radiological CR. Responses have been sustained for 10 months. Serum BCMA (sBCMA) levels declined dynamically in parallel with haematological response, suggesting potential utility as a novel monitoring biomarker in POEMS. This case supports BCMA-directed CAR-T therapy as a safe and effective salvage strategy in RR-POEMS following ASCT failure, even in an aggressive disease context. Clinical trial registration: Not aplicable.