Regulatory Aspects for Approval of Advanced Therapy Medicinal Products in the EU.

In the European Union (EU), advanced therapy medicinal products (ATMPs) undergo evaluation by the European Medicines Agency's (EMA) Committee for Advanced Therapies (CAT) to obtain marketing authorization under the centralized procedure. Because of the diversity and complexity of ATMPs, a tailored approach to the regulatory process is required that needs to ensure the safety and efficacy of each product. Since ATMPs often target serious diseases with unmet medical need, the industry and authorities are interested in providing treatment to patients in a timely manner through optimized and expedited regulatory pathways. EU legislators and regulators have implemented various instruments to support the development and authorization of innovative medicines by offering scientific guidance at early stages, incentives for small developers and products for rare diseases, accelerated evaluation of marketing authorization applications, different types of marketing authorizations, and tailored programs for medicinal products with the orphan drug designation (ODD) and the Priority Medicines (PRIME) scheme. Since the regulatory framework for ATMPs was established, 20 products have been licenced, 15 with orphan drug designation, and 7 supported by PRIME. This chapter discusses the specific regulatory framework for ATMPs in the EU and highlights previous successes and remaining challenges.

Physicians prefer greater detail in the biosimilar label (SmPC) - Results of a survey across seven European countries.

In the European Union, labels (Summaries of Product Characteristics, SmPCs) of biosimilars and their reference products are in many instances almost identical (following a generic approach) despite different data requirements for the authorization of biosimilars and generics. To understand physicians' preferences on type and detail of information in the biosimilar label and their use of information sources when prescribing biologics including biosimilars, EuropaBio surveyed 210 physicians across seven European countries. Among surveyed physicians, 90.5% use the label frequently or occasionally as an information source and 87.2% deemed a clear statement on the origin of data helpful or very helpful. When comparing excerpts from the label of an authorized biosimilar and modified texts with additional information, 78.1-82.9% preferred the samples with additional information. This survey shows that the label is an appropriate vehicle for providing physicians with information about biologics and that physicians prefer more product-specific information in the biosimilar label.

Comparison of structure, strength and cytocompatibility of a fibrin matrix supplemented either with tranexamic acid or aprotinin.

Fibrin sealants are used as hemostats, sealants, tissue adhesives, and as matrix for substances/cells in a number of surgical and tissue engineering procedures. Main characteristics of fibrin are high tensile strength, adhesive strength, biocompatibility, and resorption. A major adverse event would be premature fibrin lysis and recurrent bleeding. This must be prevented by fibrinolysis inhibitors. The most common fibrinolysis inhibitors used are aprotinin and tranexamic acid (t-AMCA). Comparison of commercially available fibrin sealants utilizing aprotinin or t-AMCA revealed a lower sealing efficacy in an in vivo lung resection model for a t-AMCA containing product. Therefore, we compared the influence of t-AMCA and aprotinin on structure, mechanical properties, and cytocompatibility of a fibrin matrix. In our experiments, we found that substitution of aprotinin with t-AMCA reduced the tensile strength and formation of fibrin fibers and affected viability of a fibroblast cell-line. In conclusion, t-AMCA negatively affects physical and biological properties of fibrin relevant for clinical application as well as tissue regeneration.

Expression and purification of biologically active rat bone morphogenetic protein-4 produced as inclusion bodies in recombinant Escherichia coli.

Rat bone morphogenetic protein-4 (rBMP-4) cDNA was cloned from rat osteoblasts by RT-PCR and expressed in E. coli. Monomeric, dimeric and polymeric forms of recombinant rat BMP-4 (rrBMP-4) were obtained from inclusion bodies after solubilization with urea. The dimer was separated from the remaining polymer and host cell contaminants using size exclusion chromatography. Furthermore, purified rrBMP-4 was stabilized at low urea concentration (40 mM) and at pH 8.5 through the addition of bovine serum albumin. Both, rrBMP-4 dimer and polymer were biologically active as tested by the induction of alkaline phosphatase activity in MC3T3-E1 cells.

Release of the mitochondrial enzyme carbamoyl phosphate synthase under septic conditions.

To identify sepsis-related dysregulations of protein expression in the liver, we used a baboon model of acute endotoxemia and performed comparative proteome analysis. Treatment with lipopolysaccharide (LPS) was followed by an early but long-lasting (5-48 h) generation of N-terminal fragments of carbamoyl phosphate synthase-1 (CPS-1), an abundant enzyme of the hepatic urea cycle, which is normally located in the mitochondrial matrix. In addition, we developed a new sandwich immunoassay to determine circulating CPS-1 in human and baboons. We found CPS-1 to be induced by LPS and to be released into the circulation of healthy humans and baboons as early as 4 to 5 h after stimulation. Similarly, CPS-1 levels increased after injection of gram-positive bacteria in another baboon model. Enhanced CPS-1 levels were also detected in serum of patients with sepsis. Our data demonstrate fragmentation of CPS-1 in the liver and early increase in circulating CPS-1 levels under septic conditions. We suggest that circulating CPS-1 might serve as a novel serum marker indicating mitochondrial impairment of the liver and/or the small intestine in critically ill patients.

Release of glutaraldehyde from an albumin-glutaraldehyde tissue adhesive causes significant in vitro and in vivo toxicity.

BACKGROUND: A two-component sealant composed of bovine serum albumin and glutaraldehyde (BioGlue) is used to treat aortic dissections. Although glutaraldehyde guarantees strong adherence to tissues and synthetic materials, its toxic potential should be considered. The aim of this study was to determine the amount of glutaraldehyde released from BioGlue, its cytotoxic effects on cultured cells, and the local reaction of lung, liver, and aortic tissues to BioGlue. METHODS: BioGlue was prepared according to the product insert, allowed to polymerize, and then overlaid with saline solution. The supernatant was analyzed for its content of glutaraldehyde. The cytotoxic effect of BioGlue was evaluated by adding the supernatants to either cultured human embryo fibroblasts (MRC5) or mouse myoblasts (C2C12). In vivo toxicity was assessed on three different tissues by applying BioGlue onto a partial lung resection, a liver abrasion, or an intact abdominal aorta in rabbits. Tissue samples were histologically evaluated 2 and 7 days after application. RESULTS: Saline supernatants from polymerized BioGlue contained 100 to 200 mug/mL glutaraldehyde and were cytotoxic to both cell lines tested. Application of BioGlue to lung and liver tissue evoked serious adverse effects consisting of high-grade inflammation, edema, and toxic necrosis. Intact aortic tissue showed only low-grade or medium-grade inflammation. CONCLUSIONS: Polymerized BioGlue releases amounts of glutaraldehyde that are capable of inducing cytotoxic effects both in vitro and in vivo. Use of BioGlue should be restricted to the aortic dissection procedure, as other tissues are sensitive to the amounts of glutaraldehyde released from the glue.

Lipopolysaccharide dose response in baboons.

A lipopolysaccharide (LPS) dose-response study in an experimental baboon endotoxemia model is presented to define the relevance of this model compared with human endotoxemia. We describe acute and subacute endotoxemic models in baboons, the first evoked by bolus injection of LPS (1 mg, 0.1 mg, or 4 ng per kg of Escherichia coli LPS), and the second evoked by infusion of 1.5 mg/kg of E. coli LPS over 30 min. We report the analysis of LPS clearance, the kinetics of tumor necrosis factor, interleukin (IL) 6, and IL-8 expression on the protein as well as on the mRNA level, change in blood counts (white and red blood cells and circulating platelets), and several hemodynamic parameters such as temperature, cardiac index, heart rate, and mean arterial pressure via multiple sampling. The resulting data are compared with previously published human data. Our results show that the LPS-induced kinetics of cytokine release, as well as of hemodynamic and hematologic changes in baboons, were similar to those observed in humans, even though baboons required a approximately 104-fold higher initial LPS dose to develop these manifestations. Hence, we demonstrate that endotoxemia in baboons qualitatively, yet not quantitatively, resembles endotoxemia in humans and, therefore, proves to constitute a useful model for studying the pathogenic mechanisms of sepsis in relation to humans.

Modulation of toll-like receptor 4 expression on human monocytes by tumor necrosis factor and interleukin-6: tumor necrosis factor evokes lipopolysaccharide hyporesponsiveness, whereas interleukin-6 enhances lipopolysaccharide activity.

Toll-like receptors (TLR) play a pivotal role in the innate immune response, and the expression levels of these receptors may reflect the sensitivity of immune cells to infections. The binding of lipopolysaccharide (LPS) to TLR-4 triggers human monocytes to produce cytokines, which play a dominant role in the inflammatory response, as can be observed during sepsis and after polytrauma. Here, we evaluated TLR-4 expression of isolated monocytes in the presence of tumor necrosis factor (TNF)-alpha, interleukin (IL) 6, IL-8, and IL-10, and we investigated cellular activation of this treatment. TNF-alpha significantly down-regulated TLR-4 mRNA expression after 6 h (100% vs. 38.5% +/- 4%; P < 0.05). This down-regulation was followed by a dose- and time-dependent diminished expression of TLR-4 surface protein (100% vs. 8.0% +/- 5%; P < 0.01). Forty-eight hours after TNF-alpha treatment, a reduced nuclear factor (NF)-kappaB translocation and a diminished IL-6 secretion after LPS stimulation were found (100% vs. 42.0% +/- 23%; P < 0.05). In contrast, IL-6 incubation upregulated TLR-4 cell surface protein (100% vs. 165.8% +/- 24%; P < 0.05) and increased the ability to activate NF-kappaB and AP-1 after LPS stimulation. Stimulation with IL-8 or IL-10 had no significant effects. We conclude that not only LPS but also TNF-alpha and IL-6 have the potency to regulate the immune response via TLR-4. Down-regulation of TLR-4 by TNF-alpha is associated with LPS hyporeactivity for NF-kappaB formation, whereas upregulation of TLR-4 via IL-6 can increase the responsiveness of mononuclear phagocytes.

Increased plasma D-lactate is associated with the severity of hemorrhagic/traumatic shock in rats.

D-lactate is produced by indigenous bacteria in the gastrointestinal tract. Mammals do not have the enzyme systems to metabolize D-lactate rapidly. The present study was designed to determine the kinetics of circulating D-lactate levels and to examine whether the severity of shock affects circulating D-lactate levels in rats subjected to hemorrhagic/traumatic shock. Anesthetized rats underwent midline laparotomy (duration 30 min) and were bled to 30-35 mmHg mean arterial pressure (MAP). After the onset of decompensation, MAP was either increased to 40-45 mmHg immediately by administration of Ringer's solution (moderate shock) or after 40% of shed blood volume had been re-infused as Ringer's solution (severe shock). MAP was then maintained at 40-45 mmHg for 40 min by further administration of Ringer's solution (inadequate resuscitation). Subsequently, adequate resuscitation was performed for 60 min with shed blood and additional Ringer's solution. Metabolic acidosis was significantly more pronounced in severe than in moderate hemorrhagic/traumatic shock. Plasma D-lactate levels were already significantly increased at the end of severe hemorrhagic/traumatic shock and remained high during inadequate resuscitation. D-lactate levels were significantly higher after severe than after moderate shock. Endotoxin levels did not correlate with shock severity. Damage to the intestinal mucosa was more profound in severe shock than in moderate shock. Our data suggest that hemorrhagic/traumatic shock is associated with mucosal damage and increased plasma D-lactate levels. The severity of shock affects D-lactate concentrations in plasma. Plasma D-lactate may be a useful marker of intestinal injury after hemorrhagic/traumatic shock.

Identification and characterization of 9D7, a novel human protein overexpressed in renal cell carcinoma.

With the objective of discovering novel tumor-associated antigens of the cancer/testis type, we compared the transcriptional profiles of renal cell carcinoma (RCC) and non-tumorous kidney and further screened for genes expressed in RCC and testis, but not other normal tissues. In a first step, a representational difference analysis library consisting of approximately 1,900 RCC cDNA clones was generated. Clones were then spotted onto filters and hybridized with cDNA probes derived from a testis-specific cDNA library, a pool of RCCs and a pool of 10 healthy normal tissues, respectively. Based on strong hybridization signals with both RCC and testis, but not normal tissue probes, 185 clones were sequenced and annotated. After EST-database comparison, 35 clones were selected for experimental analysis, including conventional and quantitative RT-PCR as well as Northern blotting. Clone 9D7 showed strong mRNA expression in RCC as well as in several other major tumor types. In normal tissues there was little or no mRNA expression with the exception of heart. 9D7 was cloned to full-size and found to represent a novel human gene containing 5 exons residing on chromosome 14. Alternative splicing within exon 1 generates 2 open-reading-frames consisting of 717 or 435 bp corresponding to predicted proteins of 239 or 145 amino acids. 9D7 shows high homology (227/239 amino acids or 95% identity) to a growth factor-inducible gene of Rattus norvegicus involved in apoptosis. In situ hybridization as well as immunohistochemical analysis using 9D7-specific antisera confirmed overexpression of 9D7 in RCCs as compared to normal kidney tissue.