Nonclinical aspects of biopharmaceutical development: discussion of case studies at a PhRMA-FDA workshop.

Robust assessments of the nonclinical safety profile of biopharmaceuticals are best developed on a scientifically justified, case-by-case basis, with consideration of the therapeutic molecule, molecular target, and differences/similarities between nonclinical species and humans (ICH S6). Significant experience has been gained in the 10 years ensuing since publication of the ICH S6 guidance. In a PhRMA-FDA-sponsored workshop, "Nonclinical Aspects of Biopharmaceutical Development," industry and US regulatory representatives engaged in exploration of current scientific and regulatory issues relating to the nonclinical development of biopharmaceuticals in order to share scientific learning and experience and to work towards establishing consistency in application of general principles and approaches. The proceedings and discussions of this workshop confirm general alignment of strategy and tactics in development of biopharmaceuticals with regard to such areas as species selection, selection of high doses in toxicology studies, selection of clinical doses, the conduct of developmental and reproductive toxicity (DART) studies, and assessment of carcinogenic potential. However, several important aspects, including, for example, appropriate use of homologues, nonhuman primates, and/or in vitro models in the assessment of risk for potential developmental and carcinogenic effects, were identified as requiring further scientific exploration and discussion.

Successful removal of pathogenic autoantibodies in pemphigus by immunoadsorption with a tryptophan-linked polyvinylalcohol adsorber.

BACKGROUND: Autoantibodies against the glycoproteins desmogleins 1 and 3 which are components of the desmosomal adhesion complex have been shown to be responsible for the loss of epidermal adhesion characteristic of pemphigus. Elimination of these antibodies should clinically improve the pathology of this group of severe autoimmune blistering skin disorders. OBJECTIVES: To gather information about the efficacy of immunoadsorption in the reduction of pathogenic serum autoantibodies against desmogleins 1 and 3 and to evaluate the clinical benefit of immunoadsorption in the treatment of pemphigus. PATIENTS AND METHODS: Nine patients with pemphigus and detectable circulating desmoglein antibodies were included in this open trial. Two immunoadsorption treatments separated by a 48-h interval were performed per patient. Anti-desmoglein 1 and 3 antibodies in the patients' sera were monitored by enzyme-linked immunosorbent assay and indirect immunofluorescence before and following each immunoadsorption. In addition, the efficacy of the tryptophan-linked polyvinylalcohol adsorber in removing antidesmoglein antibodies was directly evaluated. RESULTS: IgG antibodies against desmogleins 1 and 3 were effectively eliminated from the patients' plasma upon passage through the adsorber and levels of serum autoantibodies were significantly reduced by immunoadsorption. A single immunoadsorption treatment led to a reduction of antidesmoglein autoantibodies of about 30%. Clinically, mucosal and cutaneous lesions improved allowing for a reduction of the systemic immunosuppressive treatment with glucocorticoids. CONCLUSIONS: Immunoadsorption with tryptophan-linked polyvinylalcohol adsorbers holds promise as a highly effective and safe adjuvant therapeutic regimen in pemphigus.

[Local treatment of periarthropathies with the 5-HT3-receptor-antagonist tropisetron]. / Die Lokalbehandlung von Periarthropathien mit dem 5-HT3-Rezeptor-Antagonisten Tropisetron.

All substances used in the local treatment for periarthropathies, such as local anesthetics, corticosteroids or botulinum toxin A, possess certain disadvantages. Finding alternatives to these agents in the local treatment of the disease therefore seems desirable. Comparative studies proved a local injection of the 5-HT3 receptor antagonist, tropisetron (Navoban(R)), to be more effective than an injection of the local anesthetic prilocaine in treating periarthropathies of different localizations. A comparison between the local injection of 10 mg of depot dexamethasone combined with 60 mg of lidocaine and 5 mg of tropisetron showed that the two regimens had the same effect. These findings demonstrate that a local injection of 5 mg tropisetron does represent an alternative to the local treatment with corticosteriods plus local anesthetics. However, these results should be corroborated by additional studies.

Differential effects of dihalogenated and trihalogenated acetates in the liver of B6C3F1 mice.

Haloacetates are produced in the chlorination of drinking water in the range 10--100 microg l(-1). As bromide concentrations increase, brominated haloacetates such as bromodichloroacetate (BDCA), bromochloroacetate (BCA) and dibromoacetate (DBA) appear at higher concentrations than the chlorinated haloacetates: dichloroacetate (DCA) or trichloroacetate (TCA). Both DCA and TCA differ in their hepatic effects; TCA produces peroxisome proliferation as measured by increases in cyanide-insensitive acyl CoA oxidase activity, whereas DCA increases glycogen concentrations. In order to determine whether the brominated haloacetates DBA, BCA and BDCA resemble DCA or TCA more closely, mice were administered DBA, BCA and BDCA in the drinking water at concentrations of 0.2--3 g l(-1). Both BCA and DBA caused liver glycogen accumulation to a similar degree as DCA (12 weeks). The accumulation of glycogen occurred in cells scattered throughout the acinus in a pattern very similar to that observed in control mice. In contrast, TCA and low concentrations of BDCA (0.3 g l(-1)) reduced liver glycogen content, especially in the central lobular region. The high concentration of BDCA (3 g l(-1)) produced a pattern of glycogen distribution similar to that in DCA-treated and control mice. This effect with a high concentration of BDCA may be attributable to the metabolism of BDCA to DCA. All dihaloacetates reduced serum insulin levels. Conversely, trihaloacetates had no significant effects on serum insulin levels. Dibromoacetate was the only brominated haloacetate that consistently increased acyl-CoA oxidase activity and rates of cell replication in the liver. These results further distinguish the effects of the dihaloacetates from those of peroxisome proliferators like TCA.

Central role of peroxisome proliferator-activated receptors in the actions of peroxisome proliferators.

Peroxisome proliferators (PPs) are a large class of structurally dissimilar chemicals that have diverse effects in rodents and humans. Most, if not all, of the diverse effects of PPs are mediated by three members of the nuclear receptor superfamily called peroxisome proliferator-activated receptors (PPARs). In this review, we define the molecular mechanisms of PPs, including PPAR binding specificity, alteration of gene expression through binding to DNA response elements, and cross talk with other signaling pathways. We discuss the roles of PPARs in growth promotion in rodent hepatocarcinogenesis and potential therapeutic effects, including suppression of cancer growth and inflammation.

Dichloroacetate and trichloroacetate promote clonal expansion of anchorage-independent hepatocytes in vivo and in vitro.

Dichloroacetate (DCA) and trichloroacetate (TCA) are hepatocarcinogenic by-products of water chlorination and metabolites of several industrial solvents. To determine whether DCA and TCA promote the clonal expansion of anchorage-independent liver cells in vitro, a modification of the soft agar assay (over agar assay) was utilized to quantitate growth and analyze phenotype of anchorage-independent hepatocellular colonies. Hepatocytes from naïve male B6C3F1 mice were isolated and cultured with 0-2.0 mM DCA or TCA over agar for 10 days, at which time colonies of eight cells or more were scored. Both DCA and TCA promoted the formation of anchorage-independent colonies in a dose-dependent manner. Immunocytochemical analysis using a c-Jun antibody demonstrated that colonies promoted by DCA were primarily c-Jun+, whereas TCA-promoted colonies were primarily c-Jun-. This corresponds to the differences in c-Jun immunoreactivity reported in tumors induced by DCA and TCA. Neither DCA nor TCA induced c-Jun expression in hepatocyte monolayers, indicating that these haloacetates selectively affect subpopulations of anchorage-independent hepatocyts. The latency of colony formation was decreased by the concentration of DCA, although the same number of colonies appeared after 25 days in culture at all DCA concentrations used. The plating density of hepatocytes also affected colony formation. At lower cell densities, promotion of colony formation by DCA was significantly reduced. Pretreatment of male B6C3F1 mice with 0.5 g/liter DCA in drinking water resulted in a fourfold increase in in vitro colony formation above hepatocytes isolated from naïve mice, suggesting that DCA is promoting the clonal expansion of anchorage-independent hepatocytes in vivo. Results from this study indicate that DCA and TCA promote the survival and growth of initiated cells. Furthermore, results from over agar assays reflect observations made in vivo, indicating this assay provides a valid means to investigate the mechanism by which chemicals promote clonal expansion of initiated hepatocytes.

Differences in phenotype and cell replicative behavior of hepatic tumors induced by dichloroacetate (DCA) and trichloroacetate (TCA).

Dichloroacetate (DCA) and trichloroacetate (TCA) are two hepatocarcinogenic by-products of water chlorination. To compare the effects of DCA and TCA on cell replication in the nodules and tumors they induce, male B6C3F1 mice were administered 2.0 g/L DCA or TCA in their drinking water for 38 or 50 weeks, respectively. The pretreated mice were then given water containing 0, 0.02, 0.5, 1.0, or 2.0 g/L DCA or TCA for two additional weeks to determine whether cell proliferation in the normal liver or tumors that had been induced by DCA or TCA was dependent on continued treatment. Prior to sacrifice the mice were subcutaneously implanted with mini-osmotic pumps to label DNA in dividing cells with 5-bromo-2'-deoxyuridine (BrdU). Serial sections of nodules/tumors and normal liver were stained immunohistochemically for BrdU, the oncoproteins c-Jun and c-Fos, and hematoxylin and eosin (H & E); or with Periodic acid-Schiff (PAS) stain, BrdU, and H & E, respectively. DCA and TCA transiently stimulated the division of normal hepatocytes relative to rates observed in the livers of control mice. However, at 40 and 52 weeks of treatment, replication of normal hepatocytes was substantially inhibited by DCA and TCA, respectively. Cell division within DCA-induced lesions that were identified macroscopically was significantly higher with increasing dose of DCA administered in the last 2 weeks of the experiment. DCA-induced lesions were found to display immunoreactivity to anti-c-Jun and anti-c-Fos antibodies, were predominantly basophilic, and contained very little glycogen relative to surrounding hepatocytes. In contrast, rates of cell division within TCA-induced altered hepatic foci and tumors were very high and appeared to be independent of continued treatment. TCA-induced lesions did not display immunoreactivity to either c-Jun or c-Fos antibodies. Results from this study suggest that the mechanisms by which DCA and TCA induce hepatocarcinogenesis in the male B6C3F1 mouse differ.

[Changes in temporomandibular joint functions in various general anesthesia procedures]. / Untersuchungen zu Veränderungen der Kiefergelenkfunktionen unter verschiedenen Allgemeinanaesthesieverfahren.

In a clinical study conducted in 1986 on 100 patients, we were able to demonstrate that intubation leads to the occurrence of temporary disturbances of the stomatognathic system. To verify these results, a double-blind study was conducted involving 140 patients of ASA groups I and II. Further acceptance criteria were: operation outside of the head and neck area, no throat pack or gastric tube, and the requirement of dental antagonists on the left and right side. Group composition: Group A: oral intubation with a laryngoscope (n = 50); Group B: nasal intubation using a fiberoptic endoscope (n = 40); Group C: face mask (n = 50) Groups A and B were divided at random. Balanced anesthesia was performed for all patients. In group B, after nasal intubation the mandible was placed and fixed in the habitual occlusion position. The patients had a dental examination preoperatively and on 1st, 2nd and 3rd postoperative day. Parallel to this study, we also interviewed 400 patients after routine intubation anesthesia with regard to postoperative temporomandibular joint (TMJ) symptoms. Groups A, B, and C were comparable in age, sex, height, weight, preoperative values of maximal mandibular movement, and pathological findings of the TMJ (Tables 1-3); the only differences were a longer mean duration of surgery in groups A and B than in group C (P greater than 0.05) and that women described more stomatognathic disorders in the preoperative medical history than men.(ABSTRACT TRUNCATED AT 250 WORDS)