Future drug developments in multiple myeloma: an overview of novel lenalidomide-based combination therapies

The tale of lenalidomide clinical superiority over thalidomide and regulatory and cost-effectiveness issues

In April 2017, the National Sanitary Surveillance Agency (ANVISA-Brazil) approved lenalidomide (LEN) for multiple myeloma (MM) and myelodysplastic syndrome. ANVISA had rejected the first application in 2010, and denied a request for reconsideration in 2012. The reason for rejection was the lack of comparative effectiveness studies proving that LEN was more effective than thalidomide (THAL), a strictly controlled drug regulated by Federal law 10.651/2003 and dispensed to patients (at no costs) through public health system units and hospitals. ANVISA unexplained retreat on the LEN approval for marketing was an unquestionable triumph of the lobbying that ensued the denial, at the forefront of which were politicians, Congress members, patient organizations and medical societies. Two randomized (phase III) trials and three observational (case-control and population-based cohort) compared the effectiveness of THAL- versus LEN-based therapies in MM. Overall, these studies showed no difference in efficacy between LEN- and THAL-based therapies. LEN caused less neuropathy, and more severe hematologic adverse effects. It is much costlier than THAL, and substitution of THAL by LEN shall raise considerably public healthcare costs in Brazil.

Targeting interlukin-6 to relieve immunosuppression in tumor microenvironment

Immunotolerance is one of the hallmarks of malignant tumors. Tumor cells escape from host immune surveillance through various mechanisms resulting in tumor progression and therapeutic resistance. Interlukin-6 is a proinflammatory cytokine involved in many physiological and pathological processes by integrating with multiple intracellular signaling pathways. Aberrant expression of interlukin-6 is associated with the growth, metastasis, and chemotherapeutic resistance in a wide range of cancers. Interlukin-6 exerts immunosuppressive capacity mostly by stimulating the infiltrations of myeloid-derived suppressor cells, tumor-associated neutrophils, and cancer stem-like cells via Janus-activated kinase/signal transducer and activator of transcription 3 pathway in tumor microenvironment. On this foundation, blockage of interlukin-6 signal may provide potential approaches to novel therapies. In this review, we introduced interlukin-6 pathways and summarized molecular mechanisms related to interlukin-6-induced immunosuppression of tumor cell. We also concluded recent clinical studies targeting interlukin-6 as an immune-based therapeutic intervention in patients with cancer.

MDX-1097 induces antibody-dependent cellular cytotoxicity against kappa multiple myeloma cells and its activity is augmented by lenalidomide

MDX-1097 is an antibody specific for a unique B cell antigen called kappa myeloma antigen (KMA) that consists of cell membrane-associated free kappa light chain (κFLC). KMA was detected on kappa human multiple myeloma cell lines (κHMCLs), on plasma cells (PCs) from kappa multiple myeloma (κMM) patients and on κPC dyscrasia tissue cryosections. In primary κMM samples, KMA was present on CD38+ cells that were CD138 and CD45 positive and/or negative. MDX-1097 exhibited a higher affinity for KMA compared to κFLC and the latter did not abrogate binding to KMA. MDX-1097-mediated antibody-dependent cellular cytotoxicity (ADCC) and in vitro exposure of target cells to the immunomodulatory drug lenalidomide resulted in increased KMA expression and ADCC. Also, in vitro exposure of peripheral blood mononuclear cells (PBMCs) to lenalidomide enhanced MDX-1097-mediated ADCC. PBMCs obtained from myeloma patients after lenalidomide therapy elicited significantly higher levels of MDX-1097-mediated ADCC than cells obtained prior to lenalidomide treatment. These data establish KMA as a relevant cell surface antigen on MM cells that can be targeted by MDX-1097. The ADCC-inducing capacity of MDX-1097 and its potentiation by lenalidomide provide a powerful rationale for clinical evaluation of MDX-1097 alone and in combination with lenalidomide.

Gene of the month: Interleukin 6 (IL-6)

The Interleukin 6 (IL-6) gene encodes the classic proinflammatory cytokine IL-6. It is also known as interferon-β2 (IFN-β2), B cell stimulatory factor-2 and hybridoma/plasmacytoma growth factor. IL-6 is a multifunctional cytokine with a central role in many physiological inflammatory and immunological processes. Due to its major role in initiation as well as resolving inflammation, deregulation of IL-6 is a mainstay of chronic inflammatory and autoimmune diseases. Additionally, IL-6 has been shown to be implicated in pathogenesis of many human malignancies. Thus, a better understanding of IL-6 and its role in various pathological conditions could enable the development of strategies to use it as a therapeutic target. This short review focuses on the structure, regulation and biological activities of IL-6. In addition we discuss the role of IL-6 in diseases with inflammatory background and cancer and also the therapeutic applications of anti-IL-6 agents.

Studies on drug-polymer interaction, in vitro release and cytotoxicity from chitosan particles excipient

Nonobvious controlled polymeric pharmaceutical excipient, chitosan nanoparticles (CS-NPs) for lenalidomide encapsulation were geared up by the simple ionic cross linking method to get better bioavailability and to reduce under as well as overloading of hydrophobic and sparingly soluble drug lenalidomide towards cancer cells. Lenalidomide loaded chitosan nanoparticles (LND-CS-NPs) were in the size range of 220-295 nm and characterized by DLS, TEM, FT-IR, TGA and XRD. Encapsulation of lenalidomide over chitosan nanoparticles was observed about 99.35% using UV spectrophotometry method. In vitro release and the cytotoxic studies were performed using LND-CS-NPs. This study implies the new drug delivery route for lenalidomide and illustrates that the CS-NPs serves as the effective pharmaceutical carrier for sustained delivery of lenalidomide.

Epigenetic modulating agents as a new therapeutic approach in multiple myeloma

Multiple myeloma (MM) is an incurable B-cell malignancy. Therefore, new targets and drugs are urgently needed to improve patient outcome. Epigenetic aberrations play a crucial role in development and progression in cancer, including MM. To target these aberrations, epigenetic modulating agents, such as DNA methyltransferase inhibitors (DNMTi) and histone deacetylase inhibitors (HDACi), are under intense investigation in solid and hematological cancers. A clinical benefit of the use of these agents as single agents and in combination regimens has been suggested based on numerous studies in pre-clinical tumor models, including MM models. The mechanisms of action are not yet fully understood but appear to involve a combination of true epigenetic changes and cytotoxic actions. In addition, the interactions with the BM niche are also affected by epigenetic modulating agents that will further determine the in vivo efficacy and thus patient outcome. A better understanding of the molecular events underlying the anti-tumor activity of the epigenetic drugs will lead to more rational drug combinations. This review focuses on the involvement of epigenetic changes in MM pathogenesis and how the use of DNMTi and HDACi affect the myeloma tumor itself and its interactions with the microenvironment.

Clinical utility and implementation of gene-expression profiling in myeloma: current status and challenges

SUMMARY Multiple myeloma, a neoplasm of terminally differentiated plasma cell, is the second most frequent hematological malignancy after non-Hodgkin’s lymphoma. Gene-expression profiling is a powerful and sensitive tool that can detect global transcriptional changes in cells. This technology has been applied in myeloma studies in the last decade in diverse areas such as understanding molecular pathogenesis, role of microenvironment, molecular heterogeneity, prognosis prediction and identification of novel therapeutic targets. In this review, we will briefly retrace the achievements and consider the future perspectives of gene-expression profiling in multiple myeloma research.

Inhibition of the IL-6 signaling pathway: a strategy to combat chronic inflammatory diseases and cancer

Interleukin (IL)-6 is a pro-inflammatory cytokine that produces multifunctional effects. Deregulated IL-6 production and signaling are associated with chronic inflammatory diseases, auto-immunity and cancer. On this basis, inhibition of IL-6 production, its receptors or the signaling pathways are strategies currently being widely pursued to develop novel therapies for a wide range of diseases. This survey aims to provide an updated account of why IL-6 inhibitors are shaping up to become an important class of drugs potentially useful in the treatment of ailments and in particular in inflammation and cancer. In addition we discuss the role of different agents in modulating IL-6 and also recent clinical studies targeting IL-6 in inflammation-mediated diseases and cancer.

The microenvironment and molecular biology of the multiple myeloma tumor

Multiple myeloma (MM) is a deadly plasma cell cancer that resides in the bone marrow (BM). Numerous studies have demonstrated the involvement of the BM microenvironment supporting tumor growth, angiogenesis, bone disease and drug resistance. Reciprocal interactions between the different components of the BM microenvironment and the MM cells are necessary to regulate migration, differentiation, proliferation and survival of the malignant plasma cells. In this review we focus on the interactions and molecular mechanisms by which the BM microenvironment exert these effects. Better understanding of these interactions and the study of the epigenetic changes that tumor cells undergo are necessary in order to improve current treatments and for the discovery of new therapies that may eventually lead to a potential cure.