[Bendamustine Combined with Pomalidomide and Dexamethasone in Relapsed Multiple Myeloma with Extramedullary Disease: a Multicenter Study].

Objective: To evaluate the efficacy and safety of bendamustine combined with pomalidomide and dexamethasone (BPD regimen) in the treatment of relapsed multiple myeloma (MM) with extramedullary disease. Methods: This open, single-arm, multicenter prospective cohort study included 30 relapsed MM patients with extramedullary disease diagnosed in seven hospitals including Qingdao Municipal Hospital. The patients were treated with BPD regimen from February 2021 to November 2022. This study analyzed the efficacy and adverse reactions of the BPD regimen. Results: The median age of the 30 patients was 62 (47-72) years, of which 18 (60% ) had first-time recurrence. The overall response rate (ORR) of the 18 patients with first-time recurrence was 100%, of which three (16.7% ) achieved complete remission, 10 (55.5% ) achieved very good partial remission (VGPR), and five (27.8% ) achieved partial remission (PR). The ORR of 12 patients with recurrence after second-line or above treatment was 50%, including zero patients with ≥VGPR and six patients (50% ) with PR. Three cases (25% ) had stable disease, and three cases (25% ) had disease progression. The one-year progression free survival rate of all patients was 65.2% (95% CI 37.2% -83.1% ), and the 1-year overall survival rate was 90.0% (95% CI 76.2% -95.4% ). The common grade 3-4 hematology adverse reactions included two cases (6.7% ) of neutropenia and one case (3.3% ) of thrombocytopenia. The overall adverse reactions are controllable. Conclusions: The BPD regimen has good efficacy and tolerance in relapsed MM patients with extramedullary disease.