How I treat elderly patients with plasma cell dyscrasias

Uncommon Haematological Transformation: Chronic Myeloid Leukaemia Transitioning Into Plasma Cell Leukaemia in a Single Patient

A 40-year-old male patient who was a known case of chronic myeloid leukaemia (CML) was diagnosed two years back on tab imatinib 400 mg/day; he came with complaints of easy fatigability, syncopal attacks, and bone pain associated with low-grade fever for 15 days. Repeat haematological profile and a peripheral smear of the patient suggested features of plasma cell leukaemia (PCL)/plasma cell dyscrasia (PCD). A definitive treatment protocol of lenalidomide, bortezomib, and dexamethasone for PCL was prescribed to the patient. This medical case study emphasizes the rare possibility of the transformation of CML into PCL and the possible trigger of tyrosine kinase inhibitor for the same.

Shutting off the fuel supply to target metabolic vulnerabilities in multiple myeloma

Pathways that govern cellular bioenergetics are deregulated in tumor cells and represent a hallmark of cancer. Tumor cells have the capacity to reprogram pathways that control nutrient acquisition, anabolism and catabolism to enhance their growth and survival. Tumorigenesis requires the autonomous reprogramming of key metabolic pathways that obtain, generate and produce metabolites from a nutrient-deprived tumor microenvironment to meet the increased bioenergetic demands of cancer cells. Intra- and extracellular factors also have a profound effect on gene expression to drive metabolic pathway reprogramming in not only cancer cells but also surrounding cell types that contribute to anti-tumor immunity. Despite a vast amount of genetic and histologic heterogeneity within and between cancer types, a finite set of pathways are commonly deregulated to support anabolism, catabolism and redox balance. Multiple myeloma (MM) is the second most common hematologic malignancy in adults and remains incurable in the vast majority of patients. Genetic events and the hypoxic bone marrow milieu deregulate glycolysis, glutaminolysis and fatty acid synthesis in MM cells to promote their proliferation, survival, metastasis, drug resistance and evasion of immunosurveillance. Here, we discuss mechanisms that disrupt metabolic pathways in MM cells to support the development of therapeutic resistance and thwart the effects of anti-myeloma immunity. A better understanding of the events that reprogram metabolism in myeloma and immune cells may reveal unforeseen vulnerabilities and advance the rational design of drug cocktails that improve patient survival.

Development of plasma cell dyscrasias in a patient with chronic myeloid leukemia: A case report

BACKGROUND

Chronic myeloid leukemia (CML) is a clonal hematopoietic stem cell disorder. Plasma cell dyscrasias are a rare heterogeneous group of hematological disorders. The co-occurrence of CML and plasma cell dyscrasias in the same patient is an extremely rare incident and has been reported in several cases in the literature.

CASE SUMMARY

In the present report, we described a rare case of the co-occurrence of CML and plasma cell dyscrasias in a 48-year-old man, and we discussed the reason why monoclonal gammopathy of undetermined significance progressed to smoldering multiple myeloma and eventually to multiple myeloma while being treated with dasatinib for CML. The tyrosine kinase inhibitor treatment and cytogenetic change may contribute to this phenomenon, and clonal hematopoiesis of indeterminate potential may lead to both CML and multiple myeloma cells in a patient. Future studies are warranted to further explain the hidden reasons.

CONCLUSION

This case highlights that gene translocation may contribute to initiation and sustainability of clonal proliferation. Moreover, the treatment with tyrosine kinase inhibitor and cytogenetic change may contribute to progression from monoclonal gammopathy of undetermined significance to smoldering multiple myeloma and eventually to multiple myeloma.

Non-selective proteasome inhibitors in multiple myeloma and future perspectives

INTRODUCTION

: The ubiquitination system is the most important cascade of protein degradation independently of lysosomal function. The proteasome system is actively involved in cell cycle regulation. Therefore, proteasome inhibition can lead to inhibition of tumor cell proliferation, and therefore it constitutes a potential therapeutic anticancer approach especially in the therapeutic algorithm of patients with multiple myeloma.

AREAS COVERED

Three different proteasome inhibitors are currently approved, bortezomib, carfilzomib and ixazomib, and they have been investigated in multiple myeloma and other hematological malignancies. Multiple myeloma cells are extremely sensitive to this inhibition which leads to accumulation of proteins and endoplasmic reticulum stress, leading finally to apoptosis. However, these agents lack specificity, since they target both the constitutive proteasome and the immunoproteasome. Targeting the constitutive proteasome is the main reason for side toxicity due to the effect on normal tissues. In contrary, immunoproteasome inhibition may reduce the adverse events while maintaining the therapeutic efficacy. In this review the authors present the role of the available proteasome inhibitors in myeloma therapeutics and future perspectives of both selective and non-selective proteasome inhibitors.

EXPERT OPINION

The available non-selective proteasome inhibitors have changed the therapeutics of multiple myeloma the last 10 years and have significantly improved the clinical outcomes of the patients. Furthermore, selective proteasome inhibitors are now under preclinical investigation and there is hope that their optimization will come with an improved safety profile with at least comparable efficacy.

Metabolic Disorders in Multiple Myeloma

Multiple myeloma (MM) is the second most common hematological malignancy and is attributed to monoclonal proliferation of plasma cells in the bone marrow. Cancer cells including myeloma cells deregulate metabolic pathways to ensure proliferation, growth, survival and avoid immune surveillance, with glycolysis and glutaminolysis being the most identified procedures involved. These disorders are considered a hallmark of cancer and the alterations performed ensure that enough energy is available for rapid cell proliferation. An association between metabolic syndrome, inflammatory cytokinesand incidence of MM has been also described, while the use of metformin and statins has been identified as a positive prognostic factor for the disease course. In this review, we aim to present the metabolic disorders that occur in multiple myeloma, the potential defects on the immune system and the potential advantage of targeting the dysregulated pathways in order to enhance antitumor therapeutics.

Anti-tumor activities of the new oral pan-RAF inhibitor, TAK-580, used as monotherapy or in combination with novel agents in multiple myeloma

Many RAS pathway inhibitors, including pan-RAF inhibitors, have shown significant anti-tumor activities in both solid and hematological tumors. The pan-RAF inhibitor, TAK-580, is a representative of the novel RAF inhibitors that act by disrupting RAF homo- or heterodimerization. In this study, we examined the anti-tumor effects of TAK-580 used as monotherapy or in combination with bortezomib, lenalidomide, or other novel agents in multiple myeloma (MM) cells in vitro. TAK-580 monotherapy potently targeted proteins in the RAS-RAF-MEK-ERK signaling pathway and induced potent cytotoxicity and apoptosis in MM cell lines and myeloma cells from patients with newly diagnosed and relapsed and/or refractory MM, compared with a representative RAF inhibitor, dabrafenib. Normal donor peripheral blood B lymphocytes and cord blood CD34-positive cells were not affected. Importantly, TAK-580 significantly inhibited phospho-FOXO3 and induced upregulation of Bim_L and Bim_S in a dose-dependent manner, finally leading to apoptosis in MM cells. Moreover, TAK-580 enhanced bortezomib-induced cytotoxicity and apoptosis in MM cells via the FOXO3-Bim axis and the terminal unfolded protein response. Importantly, TAK-580 also enhanced lenalidomide-induced cytotoxicity and apoptosis in MM cells. Taken together, our results provide the rationale for TAK-580 monotherapy and/or treatment in combination with novel agents to improve outcomes in patients with MM.

Clinical Utility of Selinexor/Dexamethasone in Patients with Relapsed or Refractory Multiple Myeloma: A Review of Current Evidence and Patient Selection

Multiple myeloma (MM) is one the most common hematological malignancies, and despite the survival prolongation offered by proteasome inhibitors (PIs), immunomodulatory drugs (IMiDs) and anti-CD38 monoclonal antibodies, the need for novel agents is prominent. Selinexor is a first-in-class, oral, selective inhibitor of exportin-1 (XPO1), a vital protein for the exportation of more than 200 tumor suppressor proteins from the nucleus. Both in solid tumors and hematologic malignancies, selinexor-mediated inhibition of nucleus export seems to effectively lead to cancer cell death. Selinexor in combination with dexamethasone (Sd) received an accelerated FDA approval on July 2019 for heavily pretreated patients with relapsed/refractory MM (RRMM) based on the promising results of the Phase II STORM trial. The preliminary results of the randomized Phase III BOSTON trial have shown a 47% increase in progression-free survival among PI-sensitive, RRMM patients who received selinexor with bortezomib-dexamethasone compared with bortezomib-dexamethasone alone. Several different selinexor-containing triplet regimens are currently being tested in the RRMM setting in an umbrella trial, and the preliminary results seem promising. Furthermore, the addition of selinexor in other anti-myeloma agents seems to overcome drug-acquired resistance in preclinical studies. The main toxicities of selinexor are gastrointestinal disorders and hematologic toxicities (mainly thrombocytopenia); however, they are manageable with proper supportive measures. In conclusion, selinexor is a new anti-myeloma drug that seems to be effective in patients who have no other therapeutic options, including patients who have received novel cellular therapies such as CAR-T cells. Its potential role earlier in the therapeutic algorithm of MM is currently under clinical investigation.