A critical evaluation of pembrolizumab in addition to lenalidomide and dexamethasone for the treatment of multiple myeloma

Mesenchymal stromal cells in bone marrow niche of patients with multiple myeloma: a double-edged sword

Multiple myeloma (MM) is a hematological malignancy defined by the abnormal proliferation and accumulation of plasma cells (PC) within the bone marrow (BM). While multiple myeloma impacts the bone, it is not classified as a primary bone cancer. The bone marrow microenvironment significantly influences the progression of myeloma and its treatment response. Mesenchymal stromal cells (MSCs) in this environment engage with myeloma cells and other bone marrow components via direct contact and the secretion of soluble factors. This review examines the established roles of MSCs in multiple facets of MM pathology, encompassing their pro-inflammatory functions, contributions to tumor epigenetics, effects on immune checkpoint inhibitors (ICIs), influence on reprogramming, chemotherapy resistance, and senescence. This review investigates the role of MSCs in the development and progression of MM.

Beyond the cell: novel noncellular immunotherapy approaches to multiple myeloma

The development of novel cellular therapies and bispecific T-cell-engaging antibodies is occurring at breakneck speed in multiple myeloma (MM). While groundbreaking, these agents have their unique logistical and toxicity issues and currently do not represent a curative approach. In this context, there continues to be an urgent need to develop novel, off-the-shelf immunotherapy approaches to add to the armamentarium. This article explores novel agents being investigated in combination with standard immunomodulatory drugs as well as next-generation cereblon E3 ligase modulators. These novel agents include drugs being repurposed from their use in other diseases as well as novel monoclonal antibodies. In addition, agents under development such as immunocytokines, immunotoxins, and natural killer-cell activators/engagers are reviewed. These novel therapeutic strategies hold the promise of countermanding the immunosuppressive tumor microenvironment, leading to enhanced anti-MM activity.

Mechanisms of Immune Evasion in Multiple Myeloma: Open Questions and Therapeutic Opportunities

Multiple myeloma (MM) is the second most common hematologic malignancy, characterized by a multi-step evolutionary path, which starts with an early asymptomatic stage, defined as monoclonal gammopathy of undetermined significance (MGUS) evolving to overt disease in 1% of cases per year, often through an intermediate phase known as "smoldering" MM (sMM). Interestingly, while many genomic alterations (translocation, deletions, mutations) are usually found at early stages, they are not sufficient (alone) to determine disease evolution. The latter, indeed, relies on significant "epigenetic" alterations of different normal cell populations within the bone marrow (BM) niche, including the "evasion" from immune-system control. Additionally, MM cells could "educate" the BM immune microenvironment (BM-IM) towards a pro-inflammatory and immunosuppressive phenotype, which ultimately leads to disease evolution, drug resistance, and patients' worse outcome. Indeed, it is not a case that the most important drugs for the treatment of MM include immunomodulatory agents (thalidomide, lenalidomide, and pomalidomide) and monoclonal antibodies (daratumumab, isatuximab, and elotuzumab). On these bases, in this review, we describe the most recent advances in the comprehension of the role of the different cells composing the BM-IM, and we discuss the potential molecular targets, which could represent new opportunities to improve current treatment strategies for MM patients.

Understanding the Role of T-Cells in the Antimyeloma Effect of Immunomodulatory Drugs

Immunomodulatory drugs (IMiDs) are effective treatments for patients with multiple myeloma. IMiDs have pleotropic effects including targeting the myeloma cells directly, and improving the anti-myeloma immune response. In the absence of myeloma cells, lenalidomide and pomalidomide induce CD4⁺ T cell secretion of IL-2 and indirect activation of Natural Killer (NK) cells. In the context of T cell receptor ligation, IMiDs enhance T cell proliferation, cytokine release and Th1 responses, both in vivo and in vitro. Furthermore, combination treatment of IMiDs and myeloma-targeting monoclonal antibodies eg. daratumumab (anti-CD38) and elotuzumab (anti-SLAMF7), checkpoint inhibitors, or bispecific T cell engagers showed synergistic effects, mainly via enhanced T and NK cell dependent cellular toxicity and T cell proliferation. Conversely, the corticosteroid dexamethasone can impair the immune modulatory effects of IMiDs, indicating that careful choice of myeloma drugs in combination with IMiDs is key for the best anti-myeloma therapeutic efficacy. This review presents an overview of the role for T cells in the overall anti-myeloma effects of immunomodulatory drugs.

Monoclonal antibodies in newly diagnosed and smoldering multiple myeloma: an updated review of current clinical evidence

Introduction: Monoclonal antibodies (MoAbs) are rapidly changing the therapeutic scenario of multiple myeloma. Most of the available data, however, come from studies performed in patients with relapsed or refractory disease.Area covered: Here, the most recent results from clinical trials that have investigated (or are investigating) efficacy and safety of MoAbs as front-line treatments in both transplant-eligible and not-eligible patients with newly diagnosed multiple myeloma, as well as in smoldering myeloma, are reviewed. PubMed reported articles before 28 March 2020, and abstracts presented at the last ASCO, ASH, EHA, and IMW meetings were considered. Among others, pertinent data regarding daratumumab, isatuximab, elotuzumab, and pembrolizumab will be analyzed.Expert opinion: Introduction of MoAbs as first-line therapy will likely provide a significant improvement in the clinical outcome of patients with multiple myeloma. This will also require an appropriate re-positioning of salvage therapies. The role of MoAbs in smoldering myeloma appears to be promising, but adequate follow-up is needed.