Real-Life Experience With First-Line Therapy Bortezomib Plus Melphalan and Prednisone in Elderly Patients With Newly Diagnosed Multiple Myeloma Ineligible for High Dose Chemotherapy With Autologous Stem-Cell Transplantation

Development of a novel Bruton's tyrosine kinase inhibitor that exerts anti-cancer activities potentiates response of chemotherapeutic agents in multiple myeloma stem cell-like cells

Despite recent improvements in multiple myeloma (MM) treatment, MM remains an incurable disease and most patients experience a relapse. The major reason for myeloma recurrence is the persistent stem cell-like population. It has been demonstrated that overexpression of Bruton's tyrosine kinase (BTK) in MM stem cell-like cells is correlated with drug resistance and poor prognosis. We have developed a novel small BTK inhibitor, KS151, which is unique compared to other BTK inhibitors. Unlike ibrutinib, and the other BTK inhibitors such as acalabrutinib, orelabrutinib, and zanubrutinib that covalently bind to the C481 residue in the BTK kinase domain, KS151 can inhibit BTK activities without binding to C481. This feature of KS151 is important because C481 becomes mutated in many patients and causes drug resistance. We demonstrated that KS151 inhibits in vitro BTK kinase activities and is more potent than ibrutinib. Furthermore, by performing a semi-quantitative, sandwich-based array for 71-tyrosine kinase phosphorylation, we found that KS151 specifically inhibits BTK. Our western blotting data showed that KS151 inhibits BTK signaling pathways and is effective against bortezomib-resistant cells as well as MM stem cell-like cells. Moreover, KS151 potentiates the apoptotic response of bortezomib, lenalidomide, and panobinostat in both MM and stem cell-like cells. Interestingly, KS151 inhibits stemness markers and is efficient in inhibiting Nanog and Gli1 stemness markers even when MM cells were co-cultured with bone marrow stromal cells (BMSCs). Overall, our results show that we have developed a novel BTK inhibitor effective against the stem cell-like population, and potentiates the response of chemotherapeutic agents.

Ixazomib combined with lenalidomide and dexamethasone chemotherapy for newly diagnosed multiple myeloma in China-Compared with bortezomib/lenalidomide/dexamethasone

BACKGROUND

To compare the response and safety of Ixazomib/Lenalidomide/Dexamethasone (IRd) and Bortezomib/Lenalidomide/Dexamethasone (VRd) treatment in newly diagnosed multiple myeloma (MM).

METHODS

This was a single-center retrospective analysis in Xiangtan Central Hospital. A total of 52 newly diagnosed MM patients from June 2019 to June 2021 were enrolled and divided into the IRd (n = 21) and VRd (n = 31) groups. After 4 cycles of chemotherapy, the best response and adverse events were recorded. Moreover, the progression-free survival (PFS) and overall survival (OS) were calculated.

RESULTS

Patients in IRd group and VRd group showed similar PFS (Log-rank p = 0.70), OS (Log-rank p = 0.61) and overall response rate (83.87% vs 90.48%, p = 0.803). In addition, patients in VRd group showed lower Eastern Cooperative Oncology Group scores (p = 0.047), and higher incidence of peripheral sensory neuropathy (0.00% vs 19.35%, p = 0.032) than that of patients in IRd group.

CONCLUSION

Compared to VRd regimen, IRd had the similar efficacy, better safety, and may be more convenient for patients with poor basic condition for newly diagnosed MM. This study provides an insight for physicians to use IRd as first-line treatment in MM.

Cellular Interaction Analysis Characterizing Immunosuppressive Microenvironment Functions in MM Tumorigenesis From Precursor Stages

Cell–cell interaction event (CCEs) dysregulation may relate to the heterogeneity of the tumor microenvironment (TME) and would affect therapeutic responses and clinical outcomes. To reveal the alteration of the immune microenvironment in bone marrow from a healthy state to multiple myeloma (MM), scRNA-seq data of the four states, including healthy state normal bone marrow (NBM) and three disease states (MGUS, SMM, and MM), were collected for analysis. With immune microenvironment reconstruction, the cell types, including NK cells, CD8⁺ T cells, and CD4⁺ T cells, with a higher percentage in disease states were associated with prognosis of MM patients. Furthermore, CCEs were annotated and dysregulated CCEs were identified. The number of CCEs were significantly changed between disease states and NBM. The dysregulated CCEs participated in regulation of immune cell proliferation and immune response, such as MIF-TNFRSF14 interacted between early B cells and CD8⁺ T cells. Moreover, CCE genes related to drug response, including bortezomib and melphalan, provide candidate therapeutic markers for MM treatment. Furthermore, MM patients were separated into three risk groups based on the CCE prognostic signature. Immunoregulation-related differentiation and activation of CD4⁺ T cells corresponded to the progression status with moderate risk. These results provide a comprehensive understanding of the critical role of intercellular communication in the immune microenvironment over the evolution of premalignant MM, which is related to the tumorigenesis and progression of MM, which moreover, suggests a way of potential target selection for clinical intervention.