FBTA-05

Development of bispecific antibodies (BsAbs) as therapeutic agents has recently attracted significant attention, and investments in this modality have been steadily increasing. This review discusses challenges, and suggestions to overcome them, associated with the development of BsAbs, specifically those pertaining to clinical pharmacology, pharmacometrics, and bioanalysis. These challenges and possible solutions are discussed by presenting several case studies of BsAbs that have gained regulatory approval or that are currently in clinical development. BsAbs, also termed “dual‐targeting” or “dual‐specificity” antibodies, have the ability to bind two different targets on the same or different cell(s); the targets may be cell‐surface receptors or soluble ligands, as shown in Figure ​1.1. These dual‐nature antibodies have key advantages that can potentially enhance therapeutic efficacy compared with monotherapy or traditional combination therapies by: i) simultaneously blocking two different targets or mediators that have a primary role in the disease pathogenesis; ii) inducing cell signaling pathways (e.g., proliferation or inflammation); iii) retargeting to mediate antibody‐dependent cell‐mediated cytotoxicity (ADCC); iv) avoiding the development of resistance and increasing antiproliferative effects, specifically in oncology; and v) temporarily engaging a patient's own cytotoxic T cells to target cancer cells, thus activating cytotoxic T cells to cause tumor lysis (e.g., bispecific T‐cell engagers (BiTE)). Open in a separate window Figure 1 Various designs for BsAb molecules (a) Dimers inhibition: BsAbs can bind to two receptors/targets (HER2/HER3, HER2/HER4) on the same cell (e.g., MM‐111); (b) Dual inhibition: BsAbs can inhibit two different cytokines simultaneously, for example, COVA322 that inhibits TNF‐α and IL17A; (c) Triomabs: The antigen binding site binds to target cell receptors (EpCAM, HER2, or CD20) and the T‐cell receptors (CD3). The heavy chain site binds to NK cells or dendritic cells or macrophages/phagosome (e.g., catumaxomab, ertumaxomab, FBTA05); (d) Two‐ligand inactivation: two arms bind to different ligands on different cells belonging to the same population, such as DLL4 x VEGF, TNF‐α x IL17A, IL4 x IL13 (e.g., OMP‐305B83, COVA322, SAR156597); (e) Transmembrane/transcytosis: The BsAbs are designed specifically to cross the barriers/membrane via receptor transport (transferrin receptor) and bind to enzymes/receptors (BACE1) on the other side; (f) BiTE antibody construct: These are designed to bridge T cells and target cells by binding to CD3/CD28 or CD19/CD20/CD22/CEA/EpCAM, respectively (e.g., blinatumomab, MEDI‐565, MT110). The examples mentioned above can be found in Table 2 for further information. BACE1, β‐secretase 1; BiTE, bispecific T‐cell engagers; BsAbs, bispecific antibodies; DDL4, delta‐like ligand 4; EpCAM, epithelial cell adhesion molecule; HER, human epidermal growth factor receptor; IL, interleukin; NK, Natural Killer; TNF‐α, tumor necrosis factor‐alpha; VEGF, vascular endothelial growth factor.

Pediatric patients with newly diagnosed, non-Hodgkin Lymphoma (NHL) have an excellent overall survival. However, therapy regimens are associated with acute toxicity and late effects. Furthermore, patients with relapsed or refractory disease have relatively few options with proven clinical benefit. Both histologic and molecular differences exist between adult and pediatric NHL preventing simple translation of adult NHL successes into improvements in pediatric NHL treatment. This review summarizes the introduction of targeted therapies into frontline treatments for patients with anaplastic large-cell lymphoma and CD20–positive tumors, with the goal of improving overall survival while limiting both short- and long-term toxicities. In addition, newer approaches that have limited data in children but may have a significant role in how we treat pediatric NHL in the future are reviewed, which include CD19 directed therapy, Notch inhibition, the tri-functional antibody, FBTA05, and EZH2 inhibition.