A Novel Recombinant Modified Vaccinia Ankara Virus expressing Interleukin-13 Receptor α2 Antigen for Potential Cancer Immunotherapy.

BACKGROUND: Genetically altered recombinant poxviruses hold great therapeutic promise in animal models of cancer. Poxviruses can induce effective cell-mediated immune responses against tumor-associated antigens. Preventive and therapeutic vaccination with a DNA vaccine expressing IL-13Rα2 can mediate partial regression of established tumors in vivo, indicating that host immune responses against IL-13Rα2 need further augmentation. OBJECTIVE: The aim of the study is developing a recombinant modified vaccinia Ankara (MVA) expressing IL-13RΑ2 (rMVA-IL13RΑ2) virus and study in vitro infectivity and efficacy against IL-13Rα2 positive cell lines. METHODS: We constructed a recombinant MVA expressing IL-13Rα2 and a green fluorescent protein (GFP) reporter gene. Purified virus titration by infection of target cells and immunostaining using anti-vaccinia and anti-IL-13Rα2 antibodies was used to confirm the identity and purity of the rMVA-IL13Rα2. RESULTS: Western Blot analysis confirmed the presence of IL-13Rα2 protein (~52 kDa). Flow cytometric analysis of IL-13Rα2 negative T98G glioma cells when infected with rMVA-IL13Rα2 virus demonstrated cell-surface expression of IL-13Rα2, indicating the infectivity of the recombinant virus. Incubation of T98G-IL13α2 cells with varying concentrations (0.1-100 ng/ml) of interleukin-13 fused to truncated Pseudomonas exotoxin (IL13-PE) resulted in depletion of GFP+ fluorescence in T98G-IL13Rα2 cells. IL13-PE (10-1000 ng/ml) at higher concentrations also inhibited the protein synthesis in T98G-IL13Rα2 cells compared to cells infected with the control pLW44-MVA virus. IL13-PE treatment of rMVA-IL13Rα2 infected chicken embryonic fibroblast and DF-1 cell line reduced virus titer compared to untreated cells. CONCLUSION: rMVA-IL13Rα2 virus can successfully infect mammalian cells to express IL-13Rα2 in a biologically active form on the surface of infected cells. To evaluate the efficacy of rMVA-IL13Rα2, immunization studies are planned in murine tumor models.

Regenerative Medicine Therapies for Rare Diseases.

The field of regenerative medicine is growing rapidly with the introduction of new therapies that have the potential to treat and cure serious medical conditions, including rare diseases, for which there are no available treatments. In the United States, the development of novel medical products is regulated and guided by the Food and Drug Administration (FDA). As scientific and technological advances are discovered and adopted by the medical industrial enterprise, the FDA's implementation of policies that create a climate conducive to safe development and rapid availability of novel medical products is one of the pillars which support the Agency's mission of protecting and promoting the public health. With advancements in cell modifications and tissue engineering, innovative creation of biomaterials, adoption of three-dimensional bioprinting, and rapid development of human genome editing technologies, the need for Agency's work in ensuring that its science-based policies remain relevant and helpful in facilitating the availability of new treatments to the most vulnerable populations of patients becomes more pressing than ever before. In December 2016, Congress amended section 506 of the Food, Drug, and Cosmetic (FD&C) Act [21 U.S.C. 356] by adding a new section 506(g), which defines the categories of products considered to be regenerative medicine therapies. As further described by FDA [1], regenerative medicine therapies are considered to include cell therapies, therapeutic tissue engineering products, human cell and tissue products, and combination products using any such therapies, as well as gene therapies, including genetically modified cells that lead to a durable modification of cells or tissues. The development and approval of regenerative medicine therapies are regulated by FDA's Office of Tissues and Advanced Therapies (OTAT) in the Center for Biologics Evaluation and Research (CBER). In this review article, we present practical considerations for investigating regenerative medicine therapies intended for the treatment of rare diseases. The material presented may be useful to researchers who are undertaking the challenging task of finding and delivering new treatments for those in need.

Regulation of immunotherapeutic products for cancer and FDA's role in product development and clinical evaluation.

Immunotherapeutics include drugs and biologics that render therapeutic benefit by harnessing the power of the immune system. The promise of immune-mediated therapies is target specificity with a consequent reduction in off-target side effects. Recent scientific advances have led to clinical trials of both active and passive immunotherapeutic products that have the potential to convert life-ending diseases into chronic but manageable conditions. Clinical trials investigating immunotherapeutics are ongoing with some trials at advanced stages of development. However, as with many products involving novel mechanisms of action, major regulatory and scientific issues arising with clinical use of immunotherapeutic products remain to be addressed. In this review, we address issues related to different immunotherapeutics and provide recommendations for the characterization and evaluation of these products during various stages of product and clinical development.