Daratumumab, Elotuzumab, and the Development of Therapeutic Monoclonal Antibodies in Multiple Myeloma

There has been substantial progress in clinical outcomes for patients with multiple myeloma (MM). This encouraging trend derives in large part from the increasing number of effective therapeutic options and the ability because of this to achieve higher quality responses to treatment. The approval of both daratumumab and of elotuzumab in combination with lenalidomide and dexamethasone, in late 2015, was a notable achievement in the field, as daratumumab and elotuzumab represent the first monoclonal antibodies available for use in MM. Given their unique mechanisms of action and favorable side effect profiles, daratumumab and elotuzumab have considerable potential as therapeutic partners with agents in other drug classes and in different clinical settings ranging from newly diagnosed to relapsed disease. This review discusses the development of daratumumab and elotuzumab as well as other monoclonal antibodies currently being evaluated for use in MM.

The use of novel agents in the treatment of relapsed and refractory multiple myeloma

Although outcomes for patients with multiple myeloma (MM) have improved over the past decade, the disease remains incurable and even patients who respond well to induction therapy ultimately relapse and require additional treatment. Conventional chemotherapy and high-dose therapy with stem cell transplantation (SCT) have historically been utilized in the management of relapsed MM, but in recent years the immunomodulatory drugs (IMiDs) thalidomide and lenalidomide, as well as the proteasome inhibitor bortezomib, have assumed a primary role in this setting. This review focuses on the role of thalidomide, lenalidomide and bortezomib in relapsed and refractory MM, with additional discussion dedicated to emerging drugs in relapsed MM that may prove beneficial to patients with this disease.

Cooperation between core binding factor and adjacent promoter elements contributes to the tissue-specific expression of interleukin-3

Tissue-specific expression of interleukin-3 (IL-3) is mediated via cis-acting elements located within 315 base pairs of the transcription start. This is achieved in part through the positive activities of the AP-1 and Elf-1 sites in the IL-3 promoter. The contribution to T cell-specific expression by other promoter sites was assessed in a transient expression assay with IL-3 promoter constructs linked to a luciferase gene, focusing initially on the core binding factor (CBF) site, which is footprinted in vivo upon T cell activation. Activity of the CBF site is shown to be critically dependent on the adjacent activator site Act-1. Together the Act-1 and CBF sites form a functional unit (AC unit) with dual activity. The AC unit is demonstrated to enhance basal activity of promoters both in fibroblasts and T cells. This activity is further inducible in activated T cells, but not in fibroblasts. In addition to the already identified NIP repressor site, evidence is presented for a second repressor region that restricts promoter activity in fibroblasts. Finally, a novel positive regulatory element has been mapped in the IL-3 promoter between nucleotide -180 and -210 that leads to increased expression in T cells. Together these results demonstrate that T cell expression of IL-3 is not specified by the activity of a single tissue-specific element, but instead involves multiple interacting elements that provide both specific positive regulation in T cells and specific negative regulation in fibroblasts.