Latest Development in Multiple Myeloma

Bone marrow adipocytes is a new player in supporting myeloma cells proliferation and survival in myeloma microenvironment

Multiple myeloma (MM) is a lethal B cell neoplasm characterized by clonal expansion of malignant plasma cells in the bone marrow and remains incurable due to disease relapse and drug resistance. Bone marrow adipocytes (BMAs) are emerging as playing active functions that can support myeloma cell growth and survival. The aim of this study is to investigate myeloma-mesenchymal stem cells (MSCs) interaction and the impact of such interactions on the pathogenesis of MM using in vitro co-culture assay. Here we provide evidence that MM cell up-regulated MSCs to express PPAR-γ and pushes MSCs differentiation toward adipocytes at the expense of osteoblasts in co-culture manner. The increased BMAs can effectively enhance MM cell to proliferation, migration, and chemoresistance via cell-cell contact and/or cytokines release regulated by PPAR-γ signal pathway. This effect was partially reversed in medium containing PPAR-γ antagonist G3335 and indicated that G3335 distorts the maturation of MSC-derived adipocytes and cytokines release by adipocytes through inhibition of PPAR-γ, a key transcriptional factor for the activation of adipogenesis, or cell to cell contact, or both. In meantime, we observed higher expression of adipocyte differentiation associated genes DLK1, DGAT1, FABP4, and FASN both in MSCs and MSC derived adipocytes, but the osteoblast differentiation-associated gene ALP was down regulated in MSCs. These finding mean that direct consequence of MM/MSC interaction that play a role in MM pathogenesis. Consistent with those in vitro results, our primary clinical observation also showed that bone marrow samples from MM patients had significantly higher bone adiposity in comparison with controls and the number of adipocytes decreased in those who were response to anti-MM therapy. Our finding suggested that BMAs may have an important contribution to MM progression, particularly in drugs resistant of MM cells, and plays an important contribution in MM bone disease and treatment failure, but more clinical studies are needed to confirm its role.

Carfilzomib, cyclophosphamide, and dexamethasone (KCd) for the treatment of triple-class relapsed/refractory multiple myeloma (RRMM)

BACKGROUND

Multiple myeloma (MM) is an incurable hematologic malignancy, and outcomes remain poor for patients with triple-class relapsed/refractory MM (RRMM). Descriptive analyses were performed on available data for patient characteristics, disease course, and outcomes of the KCd on triple-class RRMM patients at our institution.

PATIENTS AND METHODS

Twenty-three patients with triple-class RRMM treated with KCd between June 2017 and October 2020 were included in our analysis. The regimen KCd consisted of 28 days cycles of carfilzomib 20/36 mg/m² IV on days 1, 2, 8, 9, 15, and 16, cyclophosphamide 300 mg/m2 IV weekly, and dexamethasone (20-40) mg orally weekly.

RESULTS

Patients received a median of 6 (3-10) prior regimens. The median number of cycles administered was 4 (1-11) cycles. Overall response rate was 52%, 6 patients (26%) achieved very good partial response (VGPR), 6 patients (26%) achieved partial response (PR), and 5 patients (22%) achieved stable disease (SD). Progression-free survival (PFS) and Overall-survival (OS) were 4 and 11.9 months, respectively. There was no reported treatment-related mortality. The most common grade ≥3 adverse events were neutropenia (26%), thrombocytopenia (56.5%), and anemia (56.5%).

CONCLUSIONS

KCd showed clinically meaningful efficacy and manageable safety profile in patients with triple-class RRMM in real-world.

Circulating miRNAs as Auxiliary Diagnostic Biomarkers for Multiple Myeloma: A Systematic Review, Meta-Analysis, and Recommendations

Multiple myeloma (MM) is a hematologic malignancy characterized by aberrant expansion of monoclonal plasma cells with high mortality and severe complications due to the lack of early diagnosis and timely treatment. Circulating miRNAs have shown potential in the diagnosis of MM with inconsistent results, which remains to be fully assessed. Here we updated a meta-analysis with relative studies and essays published in English before Jan 31, 2021. After steps of screening, 32 studies from 11 articles that included a total of 627 MM patients and 314 healthy controls were collected. All data were analyzed by REVMAN 5.3 and Stata MP 16, and the quality of included literatures was estimated by Diagnostic Accuracy Study 2 (QUADAS-2). The pooled area under the curve (AUC) shown in summary receiver operating characteristic (SROC) analyses of circulating miRNAs was 0.87 (95%CI, 0.81–0.89), and the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were 0.79, 0.86, 5, 0.27, 22, respectively. Meta-regression and subgroup analysis exhibited that “miRNA cluster”, patient “detailed stage or Ig isotype” accounted for a considerable proportion of heterogeneity, revealing the importance of study design and patient inclusion in diagnostic trials; thus standardized recommendations were proposed for further studies. In addition, the performance of the circulating miRNAs included in MM prognosis and treatment response prediction was summarized, indicating that they could serve as valuable biomarkers, which would expand their clinical application greatly.