PURPOSE: A combination of anti–B-cell maturation antigen (BCMA) and anti-CD19 chimeric antigen receptor (CAR) T cells induced high response rates in patients with relapsed or refractory (R/R) multiple myeloma (MM), but long-term outcomes have not been assessed yet. PATIENTS AND METHODS: In this single-arm, phase II trial, patients with R/R MM received a combination of anti-BCMA CAR T cells and anti-CD19 CAR T cells at a dose of 1 × 10⁶ cells/kg, after receiving a conditioning chemotherapy consisting of cyclophosphamide and fludarabine. The overall response, long-term outcomes, and safety were assessed, as were their associations with clinical and disease characteristics. RESULTS: Of 69 enrolled patients, 62 received the combined infusion of anti-BCMA and anti-CD19 CAR T cells with a median follow-up of 21.3 months. The overall response rate was 92% (57/62), and complete response or better was observed in 37 patients (60%). Minimal residual disease–negativity was confirmed in 77% (43/56) of the patients with available minimal residual disease detection. The estimated median duration of response was 20.3 months (95% CI, 9.1 to 31.5). The median progression-free survival was 18.3 months (95% CI, 9.9 to 26.7), and the median overall survival was not reached. Patients with extramedullary disease had significantly inferior survival. Fifty-nine patients (95%) had cytokine release syndrome, with 10% grade 3 or higher. Neurotoxic events occurred in seven patients (11%), including 3% grade 3 or higher. Late adverse effects were rare, except for B-cell aplasia, hypogammaglobulinemia, and infections. CONCLUSION: The combination of anti-BCMA and anti-CD19 CAR T cells induced durable response in patients with R/R MM, with a median progression-free survival of 18.3 months and a manageable long-term safety profile.

Despite the high therapeutic response achieved with B-cell maturation antigen (BCMA)-specific chimeric antigen receptor (CAR) T-cell therapy in relapsed and refractory multiple myeloma (R/R MM), primary resistance and relapse exist with single-target immunotherapy. Here, we design bispecific BC19 CAR T cells targeting BCMA/CD19 and evaluate antimyeloma activity in vitro and in vivo. Preclinical results indicate that BC19 CAR specifically recognize target antigens, and BC19 CAR T cells mediate selective killing of BCMA or CD19-positive cancer cells. BC19 CAR T cells also exhibit potent antigen-specific anti-tumor activity in xenograft mouse models. We conduct an open-label, single-arm, phase I/II study of BC19 CAR T cells in 50 patients with R/R MM (ChiCTR2000033567). The primary endpoint was safety. BC19 CAR T cells are well tolerated with grade 3 or higher cytokine release syndrome in 8% of patients and grade 1 neurotoxic events in 4% of patients, which meet the pre-specified primary endpoint. Secondary endpoints include overall response rate (92%), median progression-free survival (19.7 months), median overall survival (19.7 months) and median duration of response (not reached). Our study demonstrates that bispecific BC19 CAR T cells are feasible, safe and effective in treating patients with R/R MM.

Primary myelofibrosis (PMF) is a type of cloned myeloproliferative neoplasm stemming from haematopoietic stem cells, and tends to transform to acute myeloid leukaemia (AML) in approximately 10–20% of cases over a 10-year period. The transformation into AML has a poor prognosis, with a median overall survival of only 2.6 months in patients receiving supportive treatment. To date, treatment of AML transformation remains poor. The case of a 58-year-old female patient with AML transformed from PMF, who was treated with decitabine combined with all-trans retinoic acid, is reported. The patient had complete remission and a 17-month overall survival from initial diagnosis of transformed AML, with tolerated haematologic toxicity during the treatment period.

Erbin has been shown to have significant effects on the development of solid tumors. However, little is known about its function and regulatory mechanism in hematological malignancies. The biological function of Erbin on cell proliferation was measured in vitro and in vivo. The predicted target of Erbin was validated by dual-luciferase reporter assay and rescue experiment. We found that overexpression of Erbin could inhibit the cell proliferation and promote the cell differentiation of acute myeloid leukemia (AML) cells, whereas depletion of Erbin could enhance the cell proliferation and block the cell differentiation in AML cells in vitro and in vivo. Besides, miR-183-5p was identified as the upstream regulator that negatively regulated the Erbin expression. The results were confirmed by dual-luciferase reporter and RNA pull-down assay. Furthermore, we found that miR-183-5p negatively regulated Erbin, resulting in enhanced cell proliferation of AML cells via activation of RAS/RAF/MEK/ERK and PI3K/AKT/FoxO3a pathways. The activation of RAS/RAF/MEK/ERK and PI3K/AKT/FoxO3a pathways was mediated by Erbin interacting with Grb2. These results were also validated by rescue experiments in vitro and in vivo. All above-mentioned findings indicated that the miR-183-5p/Erbin signaling pathway might represent a novel prognostic biomarker or therapeutic target for treatment of AML.