No pathogenic responses in rat lung upon exposure to ground granulated blast furnace slag (GGBS).

Objective: Granulated blast furnace slag (GBS) is a by-product of the manufacture of iron by thermochemical reduction in a blast furnace. Blast furnace slag is generated at temperatures above 1500 °C. If the liquid slag is quenched very rapidly with water, a glassy slag is generated (GBS). It is used - after grinding <100 µm - [ground granulated blast furnace slag (GGBS)] for cement and concrete production. A small particulate fraction of GGBS might be accessible to the pulmonary alveoli, where it could settle down and induces physiological inflammatory responses. Within the scope of the 'Registration, Evaluation, Authorization and Restriction of Chemicals' (REACH), GGBS was already tested in rats in an acute toxicity inhalation study, as well as in a dose range finding study as a predecessor study for this study. Both did not show systemic and local toxic effect in rats upon inhalation of high-dose GGBS.Material and methods: In this study, low (4.3 mg/m3), intermediate (9.5 mg/m3), and high-dose (24.9 mg/m3) repetitive exposure of GGBS to rats was tested over a period of 4 weeks with 6 h exposure per day for 5 days per week. Results and conclusion: Even at high doses, GGBS was inactive and did not induce clinically relevant phenotypic changes in rats compared to concomitant controls.Together with both the previous acute toxicity and the dose range finding study in rats, it was shown that the exposure to the tested GGBS was unable to induce any severe pathogenic responses.

Oncolytic H-1 Parvovirus Shows Safety and Signs of Immunogenic Activity in a First Phase I/IIa Glioblastoma Trial.

Oncolytic virotherapy may be a means of improving the dismal prognosis of malignant brain tumors. The rat H-1 parvovirus (H-1PV) suppresses tumors in preclinical glioma models, through both direct oncolysis and stimulation of anticancer immune responses. This was the basis of ParvOryx01, the first phase I/IIa clinical trial of an oncolytic parvovirus in recurrent glioblastoma patients. H-1PV (escalating dose) was administered via intratumoral or intravenous injection. Tumors were resected 9 days after treatment, and virus was re-administered around the resection cavity. Primary endpoints were safety and tolerability, virus distribution, and maximum tolerated dose (MTD). Progression-free and overall survival and levels of viral and immunological markers in the tumor and peripheral blood were also investigated. H-1PV treatment was safe and well tolerated, and no MTD was reached. The virus could cross the blood-brain/tumor barrier and spread widely through the tumor. It showed favorable pharmacokinetics, induced antibody formation in a dose-dependent manner, and triggered specific T cell responses. Markers of virus replication, microglia/macrophage activation, and cytotoxic T cell infiltration were detected in infected tumors, suggesting that H-1PV may trigger an immunogenic stimulus. Median survival was extended in comparison with recent meta-analyses. Altogether, ParvOryx01 results provide an impetus for further H-1PV clinical development.

Bioavailability, biodistribution, and CNS toxicity of clinical-grade parvovirus H1 after intravenous and intracerebral injection in rats.

The autonomous parvovirus H1 (H1PV) is transmitted in rodent populations. The natural host is the rat, in which H1PV infection is pathogenic only in fetuses and newborns. H1PV infection of human cancer cells leads to strong oncolytic effects in preclinical models. In preparation for a clinical trial of H1PV injection in patients with malignant brain tumors, H1PV had to be prepared to Good Manufacturing Practice standards, including extensive toxicology testing in rats. Because the trial involves direct intracerebral injection of H1PV into the tumor and around the resection cavity, possible toxicity to CNS tissue had to be investigated. In addition, quantitative blood levels and the tissue distribution of H1PV after single intracerebral or intravenous injection were measured. Direct injection of H1PV into rat brain at 3 dose levels (maximum, 7.96 × 107 pfu) did not cause any macroscopic or histologic pathology. Furthermore, H1PV infection of the brain did not alter central or autonomous nervous system function. H1PV DNA was detected in almost all organs at 6 h, 48 h, and 14 d after intravenous and intracerebral injection, with the highest levels in liver and spleen. H1PV concentrations in most organs were similar after intravenous and intracerebral injection, indicating high permeability of the blood-brain barrier for this small virus. The current results demonstrate wide organ distribution of H1PV after intravenous or intracerebral injection, confirm that H1PV is nonpathogenic in adult rats even after direct injection into the brain, and form the basis for the ongoing ParvOryx01 clinical trial.

Pathology, organ distribution, and immune response after single and repeated intravenous injection of rats with clinical-grade parvovirus H1.

Parvovirus H1 (H1PV) is an autonomous parvovirus that is transmitted in rodent populations. Its natural host is rats. H1PV infection is nonpathogenic except in rat and hamster fetuses and newborns. H1PV infection of human cancer cells caused strong oncolytic effects in preclinical models. For a clinical trial of H1PV in patients with brain tumors, clinical-grade H1PV was produced according to Good Manufacturing Practices. This report focuses on results obtained after a single high-dose intravenous injection of highly purified H1PV in 30 rats and multiple (n = 17) intravenous injections at 3 dose levels in 223 rats. In both studies, no virus-related mortality or macroscopic organ changes related to H1PV occurred. Histopathology after multiple virus injections revealed minimal diffuse bile duct hyperplasia in livers of animals of the highest dose group and germinal center development in spleens of animals from the high-dose group. Liver changes were reversible within a 2-wk recovery period after the last injection. Hematology, blood chemistry, and coagulation analyses did not reveal significant toxicologic changes due to H1PV. Virus injection stimulated the production of IgG antibodies but did not alter mononuclear cell function or induce cytokine release. PCR analysis showed dose-dependent levels of viral genomes in all organs tested. The virus was excreted primarily through feces. These data provide important information regarding H1PV infection in its natural host. Due to the confirmation of the favorable safety profile of H1PV in a permissive animal model, a phase I/IIa clinical trial of H1PV in brain tumor patients could be initiated.

Atu027, a liposomal small interfering RNA formulation targeting protein kinase N3, inhibits cancer progression.

We have previously described a small interfering RNA (siRNA) delivery system (AtuPLEX) for RNA interference (RNAi) in the vasculature of mice. Here we report preclinical data for Atu027, a siRNA-lipoplex directed against protein kinase N3 (PKN3), currently under development for the treatment of advanced solid cancer. In vitro studies revealed that Atu027-mediated inhibition of PKN3 function in primary endothelial cells impaired tube formation on extracellular matrix and cell migration, but is not essential for proliferation. Systemic administration of Atu027 by repeated bolus injections or infusions in mice, rats, and nonhuman primates results in specific, RNAi-mediated silencing of PKN3 expression. We show the efficacy of Atu027 in orthotopic mouse models for prostate and pancreatic cancers with significant inhibition of tumor growth and lymph node metastasis formation. The tumor vasculature of Atu027-treated animals showed a specific reduction in lymph vessel density but no significant changes in microvascular density.

Local tolerance testing of parenteral drugs: how to put into practice.

Notwithstanding that there are national and international guidelines about local tolerance testing of parenteral drugs in animals, in particular to mention CPMP/SWP/2145/00 (Note for Guidance on Non-Clinical Local Tolerance Testing of Medicinal Products), very heterogeneous study designs have been established in the past. A working group including experts of the leading pharmaceutical industry from German-language countries, named "Arbeitskreis Lokale Verträglichkeit," has been intensively discussing the experimental procedures in detail for a period of six years and has been considering their pros and cons. This team of experts now feels confident to give some recommendations for study conduct besides describing different materials and methods for this type of toxicological study. Special knowledge from toxicologists as well as pathologists from our working group has been taken into account. This paper deals with choice of species, number of animals used, controls, administration sites, volumes, rate and frequency, length of observation period, termination, clinical, macroscopic and histopathological examinations and, finally, overall assessment criteria and conclusion. Our purpose is that this paper may be of value for: *The study director who is inexperienced in the conduction of local tolerance testing and who may need a standard design as his first step into this new field. *The well-versed study director who would like to know how others have done in the past, who may examine self-critically his own practice and who is open to our team's recommendations, tips and tricks from practice. *The specialist at a regulatory authority who, finally, reviews study reports, assesses their format and content and, above all, decides on the approval of a drug product.