Pomalidomide improves the effectiveness of CAR-T treatment in the relapsed and refractory multiple myeloma or B-cell leukemia/lymphoma with extramedullary disease

Relapsed and refractory multiple myeloma (RRMM) and B-cell leukemia/lymphoma with extramedullary disease (EMD) have poor prognosis and high mortality, lack of effective therapeutic approaches. We reported for the first time that 6 patients with malignant hematological diseases with EMD received chimeric antigen receptor (CAR)-T treatment combined with pomalidomide, and CAR-T cells were treated with pomalidomide in vitro to determine its killing activity and cytokine secretion. Three patients with RRMM were given B cell maturation antigen (BCMA)-CAR-T therapy. All 3 patients with B-cell leukemia/lymphoma received CD19/22-CAR-T sequential infusion. There were no treatment-related deaths. The maximum overall response rate (ORR) was 100%. Median follow-up was 211.5 days (75-407 days). Three patients (50%) experienced cytokine release syndrome, all of which were grade 1, and no neurotoxicity was observed. In vitro experiments showed that the killing activity did not differ significantly between BCMA-CAR-T cells with and without pomalidomide (10, 25, or 50 μg/mL) in 8226/U266 cell cocultures (