Intranodal Angiomyomatous Hamartoma in a Cynomolgus Monkey.

We describe here an angiomyomatous hamartoma in the right axillary lymph node of a three-year-old male cynomolgus monkey ( Macaca fascicularis), used as a control subject in a short-term toxicity study. This is a very rare lesion that has been reported almost exclusively in inguinal lymph nodes, and to date only in human beings. In the present case, light microscopy revealed partial replacement of the lymph node parenchyma by a disorganized, irregular vascular network, sparsely distributed smooth muscle cells, and a fibro-adipocytic stroma. This was considered to be fortuitous given the age of the animal, with no clinical or toxicological significance. To the best of our knowledge, this is the first report of an intranodal angiomyomatous hamartoma in a nonhuman animal species.

Biochemical and Electroretinographic Characterization of the Minipig Eye in the Context of Drug Safety Investigations.

Minipigs are an emerging nonrodent alternative for ocular toxicology owing to anatomical similarities in the minipig eyes when compared to humans. Ocular structures and components from Göttingen minipigs were characterized and compared to species commonly used in toxicology. Ocular reference data from Göttingen minipig including intraocular pressure, vitreous electrolyte and thiol concentration, and electroretinography (ERG) data are essential to model characterization and data interpretation during drug safety assessments. Intravitreal positive control agents including gentamicin, indocyanine green, and glycine were used to demonstrate ERG alterations caused by retinal cell toxicity, light transmission obstruction, or neurotransmission interferences, respectively. Electrolyte concentrations of the aqueous and vitreous humors from Göttingen minipigs were similar to other species including humans. The reference data presented herein supports the use of the Göttingen minipig as an alternate nonrodent species in ocular toxicology.

Interspecies Comparison of Control Data From Embryo-Fetal Development Studies in Sprague-Dawley Rats, New Zealand White Rabbits, and Göttingen Minipigs.

Species-dependent differences in relative incidence of spontaneous variations and malformations should be considered in the assessment of the translational value of reproductive and developmental safety assessments. The objective of this evaluation was to compare litter parameters and the frequency of external, visceral, and skeletal malformations and variations across species in the Sprague-Dawley rat, New Zealand White rabbit, and Göttingen minipig and to determine whether notable differences exist. Pregnant female rats (n = 824), rabbits (n = 540), and minipigs (n = 70) from vehicle control groups were included in the analysis, equating to 10,749 rat, 5,073 rabbit, and 378 pig fetuses collected at term by cesarean delivery. Preimplantation loss was more frequent than postimplantation loss in the rat and rabbit, whereas the opposite was observed in the minipig. Several external and visceral malformations and variations such as domed head, bent tail, abdominal edema, and anal atresia were observed in all 3 species. Visceral malformations of the heart and major blood vessels were remarkably more frequent in the minipig and rabbit, respectively; ventricular and atrium septum defects were observed in 1.9% and 2.1%, respectively, for the minipig fetuses, whereas they were observed in equal or less than 0.02% among the rat and rabbit fetuses evaluated in this study. Understanding species-dependent differences in spontaneous variations and malformations can be useful for the interpretation of embryo-fetal development study results. The current analysis identified relevant differences between commonly used species in reproductive toxicology with potential implications for data assessment.

Assessment of phototoxicity in pigmented Long-Evans rat: sparfloxacin and 8-methoxypsoralen.

The aim of the present work was to evaluate the effects of photo-activated toxicity induced after administration of two known melanin-binding phototoxic compounds, sparfloxacin (SPX) and 8-methoxypsoralen (8-MOP), followed or not by UVA/Vis exposure, in pigmented rats (Long Evans: LE) and albino rats (Sprague Dawley: SD). Groups of three rats were treated with SPX or 8-MOP by oral gavage for six consecutive days. Irradiated animals were submitted to a UVA/Vis light dose standardized to 10 J/cm2 UVA daily. Clinical signs, cutaneous reactions and body weight were monitored throughout the study period. Ear biopsy weight, lymph node weight and lymph node cell count were determined at necropsy. Ophthalmologic examinations were performed before the first treatment and on the day of sacrifice. Microscopic examinations were performed on skin biopsies and eyes. Phototoxicity was demonstrated for both SPX and 8-MOP in the pigmented and albino strains, in terms of auricular irritation, lymph node weight and proliferation index, cutaneous reactions and ocular histopathology. LE rats were less sensitive than SD rats, especially at the ocular level, supporting the notion that pigmentation may provide protection against photo-activation. The pigmented rat may be a more relevant model than the albino rat for human safety evaluation.

A human relevance investigation of PPARα-mediated key events in the hepatocarcinogenic mode of action of propaquizafop in rats.

Propaquizafop is an herbicide with demonstrated hepatocarcinogenic activity in rodents. A rodent-specific mode of action (MOA) in the liver via activation of peroxisome proliferator-activated receptor α (PPARα) has been postulated based on existing data. Experience with PPARα-inducing pharmaceuticals indicates a lack of human relevance of this MOA. The objective of the present investigation was to evaluate the dependency of early key events leading to liver tumors on PPARα activation in wildtype (WT) compared to PPARα-knockout (KO) rats following 2 weeks exposure to 75, 500 and 1000 ppm propaquizafop in the diet. In WT rats, both WY-14643 (50 mg/kg bw/day) and propaquizafop (dose-dependently) induced marked increases in liver weights, correlating with liver enlargement and hepatocellular hypertrophy, along with increased CYP4A and acyl-CoA oxidase mRNA expression and enzyme activities versus controls, while in KO rats liver weight was mildly increased only at the high dose with minimal microscopic correlates and without any changes in liver peroxisomal or CYP4A activities. In addition, BrdU labeling resulted in higher numbers and density of positive hepatocytes versus controls in WT but not in KO rats, indicating increased mitotic activity and cell proliferation only in WT rats, thus confirming the PPARα-dependency of the biochemical and histological changes in the liver. Based on an assessment of the results of this investigation, together with existing propaquizafop data according to the MOA-Human Relevance Framework, we conclude that liver tumors observed in rodents after dietary administration of propaquizafop do not pose a relevant health risk to humans.

Carcinogenicity testing of eliglustat in mice and rats.

Eliglustat is a novel glucosylceramide synthase inhibitor for long-term oral treatment of type 1 Gaucher disease (GD1), an inherited metabolic disorder. The carcinogenic potential of this drug has been evaluated in lifetime carcinogenicity bioassays in mice and rats. Administration of eliglustat to Swiss CD-1 mice at 0, 10, 25 or 75 mg/kg/day for 104 weeks by dietary admixture did not influence survival or bodyweight evolution, or produce any clinical indication of poor condition. At histopathology, no increases in tumor incidence for any tumor type were attributed to treatment with eliglustat. Systemic exposure to eliglustat was confirmed by a reduction in circulating levels of glucosylceramide. Administration of eliglustat to Sprague-Dawley rats by oral gavage for 105 weeks at 0, 10, 25 or 75 mg/kg/day (males) or 103 weeks at 0, 5, 15 or 50 mg/kg/day (females) did not affect survival rates, but resulted in reduced bodyweight evolution in male rats (-18% at high dose), indicating that the MTD had been achieved. At histopathology, no increases in tumor incidence were attributed to treatment with eliglustat. Systemic exposure was confirmed by toxicokinetic analyses. In conclusion, eliglustat was not carcinogenic to mice or rats in standard lifetime bioassays.

Non-clinical safety evaluation of single and repeated intramuscular administrations of MAGE-A3 Cancer Immunotherapeutic in rabbits and cynomolgus monkeys.

The MAGE-A3 recombinant protein combined with AS15 immunostimulant (MAGE-A3 Cancer Immunotherapeutic) is under development by GlaxoSmithKline for the treatment of lung cancer and melanoma. We performed non-clinical safety studies evaluating potential local and systemic toxic effects induced by MAGE-A3 Cancer Immunotherapeutic in rabbits (study 1) and cynomolgus monkeys (study 2). Animals were allocated to two groups to receive a single (rabbits) or 25 repeated (every 2 weeks) injections (monkeys) of MAGE-A3 Cancer Immunotherapeutic (treatment groups) or saline (control groups). All rabbits were sacrificed 3 days post-injection and monkeys 3 days following last injection (3/5 per gender per group) or after a 3-month treatment-free period (2/5 per gender per group). Local and systemic reactions and MAGE-A3-specific immune responses (monkeys) were assessed. Macroscopic and microscopic (for rabbits, injection site only) post-mortem examinations were performed on all animals. No systemic toxicity or unscheduled mortalities were recorded. Single (rabbits) and repeated (monkeys; up to four times at the same site) injections were well tolerated. Following five to seven repeated injections, limb circumferences increased up to 26% (5 h post-injection), but returned to normal after 1-8 days. Three days after the last injection, enlargements of iliac, popliteal, axillary and inguinal lymph nodes, and increased incidence or severity of mononuclear inflammatory cell infiltrates was observed in injected muscles of treated monkeys. No treatment-related macroscopic findings were recorded after the treatment-free period. MAGE-A3-specific antibody and T-cell responses were raised in all treated monkeys, confirming test item exposure. Single or repeated intramuscular injections of MAGE-A3 Cancer Immunotherapeutic were well tolerated in rabbits and monkeys.

New challenges and opportunities in nonclinical safety testing of biologics.

New challenges and opportunities in nonclinical safety testing of biologics were discussed at the 3rd European BioSafe Annual General Membership meeting in November 2013 in Berlin: (i)Approaches to refine use of non-human primates in non-clinical safety testing of biologics and current experience on the use of minipigs as alternative non-rodent species.(ii)Tissue distribution studies as a useful tool to support pharmacokinetic/pharmacodynamic (PKPD) assessment of biologics, in that they provide valuable mechanistic insights at drug levels at the site of action.(iii)Mechanisms of nonspecific toxicity of antibody drug conjugates (ADC) and ways to increase the safety margins.(iv)Although biologics toxicity typically manifests as exaggerated pharmacology there are some reported case studies on unexpected toxicity.(v)Specifics of non-clinical development approaches of noncanonical monoclonal antibodies (mAbs), like bispecifics and nanobodies.

Safety evaluation of a whey protein fraction containing a concentrated amount of naturally occurring TGF-ß2.

TM0601p is a whey protein isolate derived from cow milk, containing a concentrated amount of transforming growth factor ß2 (TGF-ß2), and is intended for nutritional use in infants and adults. In vivo and in vitro studies have been performed to evaluate the safety of this product. In a 13-week toxicity study, treatment of adult Sprague-Dawley rats by gavage at up to 2000mg/kg/day did not result in any significant findings other than minor non-adverse changes in urinary parameters in females. The no-observed-adverse-effect level (NOAEL) was established as 2000mg/kg/day. In a juvenile toxicity study, rat pups received 600mg/kg/day by gavage from postnatal day (PND) 7 to PND 49. Transient lower bodyweight gain in the pre-weaning period was attributed to gastrointestinal effects of the viscous test material; following weaning, bodyweight gain was comparable to the vehicle controls. Reduced eosinophil counts and changes in urinary parameters (females) were recorded in treated pups at PND 49, and higher thymus weights were recorded in males only at the end of the recovery period (Day 77). None of the findings were considered adverse. There were no other significant findings and the NOAEL was established as 600mg/kg/day. No evidence of genotoxicity was seen in the bacterial reverse mutation test or the in vitro micronucleus test. Overall the results obtained present a reassuring safety profile for TM0601p.

Recording of the full-field electroretinogram in minipigs.

PURPOSE: To test a simple electroretinographic protocol on a representative sample of minipigs. ANIMAL STUDIED: Minipig. PROCEDURES: Electroretinogram recordings were conducted on 162 healthy minipigs (81 males and 81 females) aged 4-6 months. After a 1.5-h light-adaptation period, the animals were anesthetized with general anesthesia. First, binocular full-field photopic electroretinogram recordings were conducted under photopic conditions. Subsequently, scotopic electroretinogram recordings were conducted during dark-adaptation periods every 4 min for a 20-min period. At the end of this period, the maximal combined rod-cone response was recorded by measuring the retinal response to a single high-intensity flash. We used sclerocorneal clip electrodes as active electrodes and needle electrodes as reference and ground electrodes. RESULTS: The a-wave and b-wave peak times and amplitudes have been measured and statistically analyzed. For each of the statistical comparisons, normality and homogeneity of variances were evaluated. No significant gender differences were observed, with the exception of a higher b-wave amplitude for the photopic ERG recordings observed in females when compared to males (48.14 ± 12.909 µV vs. 42.88 ± 10.666 µV; P = 0.005). The process of dark adaptation was evaluated, and the maximal combined rod-cone response was measured (a- and b-waves amplitude and peak time). CONCLUSIONS: We conducted photopic and scotopic electroretinogram recordings from a protocol based on light adaptation followed by dark adaptation using sclerocorneal clip electrodes, which allows quick assembly and examination.

Genomics Integrated Systems Transgenesis (GENISYST) for gain-of-function disease modelling in Göttingen Minipigs.

Göttingen Minipigs show several anatomical, physiological, and pathogenetical similarities to humans and serve an important role in translational studies for example as large animal models of disease. In recent years, the number of transgenic Göttingen Minipigs models has increased, as advanced genetic techniques simplify the generation of animals with precisely tailored modifications. These modifications are designed to replicate genetic alterations responsible for human disease. In addition to serving as valuable large animal disease models, transgenic Göttingen Minipigs are also considered promising donors for xenotransplantation. Current technologies for generation of transgenic minipigs demand a long development and production time of typically 2-3 years. To overcome this limitation and expand the use of Göttingen Minipigs for disease modelling and drug testing, we developed the GENISYST (Genomics Integrated Systems Transgenesis) technology platform for rapid and efficient generation of minipigs based transgenic disease models. As proof of concept, we report the successful generation of transgenic minipigs expressing green fluorescent protein (GFP) in multiple disease-relevant tissues including liver, heart, kidney, lungs, and the central nervous system (CNS). Our data demonstrates the feasibility, efficiency, and utility of GENISYST for rapid one-step generation of transgenic minipigs for human disease modelling in drug discovery and development.

Shared Learnings on the New EMA First-in-Human and Early Clinical Trial Guideline: Proceedings From a DIAlogue Session at DIA Europe 2018.

The EU is a member of the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH), and therefore adopts the ICH Guidelines, including the ICH M3 Guideline on Nonclinical Safety Studies. Following the 2016 incident in France with BIA 10-2474, and in light of the substantial evolvement of how early clinical development has been undertaken during the last 10 years, for example, conducting integrated (FIH) studies that include multiple parts (eg, single ascending doses, multiple ascending doses, food effect), EMA decided to update the existing 2007 FIH guideline. The key revisions to the 2007 guideline, now titled "Guideline on Strategies to Identify and Mitigate Risks for First-in-Human and Early Clinical Trials With Investigational Medicinal Products," include additional information. The revision reinforces the importance and impact of pharmacologic data, which supports the intended efficacy of the compound, risk assessment, and protocol design. The updates, effective February 2018, are intended to provide additional guidance and clarity for Sponsors developing FIH and early phase clinical research programs, and ultimately support subject safety. At the 2018 DIA Europe Annual Meeting in Basel, Switzerland, European regulators, industry representatives and academics convened a DIAlogue Session on April 17 to discuss how the revised 2017 guideline is being applied, and to establish recommendations for its application. Using two case studies as examples, the session participants discussed the nonclinical and clinical considerations for applying the newly revised recommendations, and interacted with a panel including regulators and industry representatives. The proceedings from this session reflect practical considerations for the implementation of the revised guideline.

In Vitro Human Placental Studies to Support Adenovirus-Mediated VEGF-DΔNΔC Maternal Gene Therapy for the Treatment of Severe Early-Onset Fetal Growth Restriction.

Severe fetal growth restriction (FGR) affects 1 in 500 pregnancies, is untreatable, and causes serious neonatal morbidity and death. Reduced uterine blood flow (UBF) is one cause. Transduction of uterine arteries in normal and FGR animal models using an adenovirus (Ad) encoding VEGF isoforms increases UBF and improves fetal growth in utero. Understanding potential adverse consequences of this therapy before first-in-woman clinical application is essential. The aims of this study were to determine whether Ad.VEGF-DΔNΔC (1) transfers across the human placental barrier and (2) affects human placental morphology, permeability and primary indicators of placental function, and trophoblast integrity. Villous explants from normal term human placentas were treated with Ad.VEGF-DΔNΔC (5 × 107-10 virus particles [vp]/mL), or virus formulation buffer (FB). Villous structural integrity (hematoxylin and eosin staining) and tissue accessibility (LacZ immunostaining) were determined. Markers of endocrine function (human chorionic gonadotropin [hCG] secretion) and cell death (lactate dehydrogenase [LDH] release) were assayed. Lobules from normal and FGR pregnancies underwent ex vivo dual perfusion with exposure to 5 × 1010 vp/mL Ad.VEGF-DΔNΔC or FB. Perfusion resistance, para-cellular permeability, hCG, alkaline phosphatase, and LDH release were measured. Ad.VEGF-DΔNΔC transfer across the placental barrier was assessed by quantitative polymerase chain reaction in DNA extracted from fetal-side venous perfusate, and by immunohistochemistry in fixed tissue. Villous explant structural integrity and hCG secretion was maintained at all Ad.VEGF-DΔNΔC doses. Ad.VEGF-DΔNΔC perfusion revealed no effect on placental permeability, fetoplacental vascular resistance, hCG secretion, or alkaline phosphatase release, but there was a minor elevation in maternal-side LDH release. Viral vector tissue access in both explant and perfused models was minimal, and the vector was rarely detected in the fetal venous perfusate and at low titer. Ad.VEGF-DΔNΔC did not markedly affect human placental integrity and function in vitro. There was limited tissue access and transfer of vector across the placental barrier. Except for a minor elevation in LDH release, these test data did not reveal any toxic effects of Ad.VEGF-DΔNΔC on the human placenta.

Mutagenicity of benzyl chloride in the Salmonella/microsome mutagenesis assay depends on exposure conditions.

Benzyl chloride (BCl) is a clear yellowish, volatile liquid that is widely used as an intermediate for the production of benzyl alcohol and benzyl compounds used in perfumery, dyes and pharmaceuticals. In previous studies BCl has shown weak and inconsistent mutagenicity in the Salmonella/microsome mutagenesis assay (Ames test). The aim of the present study was to investigate the potential mutagenic activity of BCl using modifications of the standard Ames test in order to adapt the method to the volatile nature of the test compound. Tests were performed using (a) the standard plate-incorporation method, (b) incubation of the treated plates in closed containers, (c) a vaporization-diffusion method to expose Ames test plates to volatilised BCl and (d) the pre-incubation method. Using the standard plate-incorporation method, BCl showed no (in the absence of metabolic activation) or very weak (in the presence of metabolic activation) mutagenic activity in Salmonella typhimurium tester strain TA 100. The use of the pre-incubation method did not improve detection of mutagenic activity of BCl. The use of closed containers significantly increased the response, but the most marked response was obtained by testing BCl in volatilised form in the vaporization-diffusion method. Using the latter approach there appeared to be less toxicity of the BCl treatments to the tester bacteria. Our findings suggest that BCl may show greater mutagenic activity in the gaseous phase. This work underlines the importance of using appropriate methods for the evaluation of volatile compounds. The modifications described here are easy to realize in practice and should prove useful for the investigation of other volatile materials or atmospheric contaminants.

The emerging role of in vitro electrophysiological methods in CNS safety pharmacology.

Adverse CNS effects account for a sizeable proportion of all drug attrition cases. These adverse CNS effects are mediated predominately by off-target drug activity on neuronal ion-channels, receptors, transporters and enzymes - altering neuronal function and network communication. In response to these concerns, there is growing support within the pharmaceutical industry for the requirement to perform more comprehensive CNS safety testing prior to first-in-human trials. Accordingly, CNS safety pharmacology commonly integrates several in vitro assay methods for screening neuronal targets in order to properly assess therapeutic safety. One essential assay method is the in vitro electrophysiological technique - the 'gold standard' ion channel assay. The in vitro electrophysiological method is a useful technique, amenable to a variety of different tissues and cell configurations, capable of assessing minute changes in ion channel activity from the level of a single receptor to a complex neuronal network. Recent advances in automated technology have further expanded the usefulness of in vitro electrophysiological methods into the realm of high-throughput, addressing the bottleneck imposed by the manual conduct of the technique. However, despite a large range of applications, manual and automated in vitro electrophysiological techniques have had a slow penetrance into the field of safety pharmacology. Nevertheless, developments in throughput capabilities and in vivo applicability have led to a renewed interest in in vitro electrophysiological techniques that, when complimented by more traditional safety pharmacology methods, often increase the preclinical predictability of potential CNS liabilities.

QT interval correction for drug-induced changes in body temperature during integrated cardiovascular safety assessment in regulatory toxicology studies in dogs: A case study.

INTRODUCTION: Cardiovascular safety assessment requires accurate evaluation of QT interval, which depends on the length of the cardiac cycle and also on core body temperature (BT). Increases in QT interval duration have been shown to be associated with decreases in BT in dogs. METHODS: An example of altered QT interval duration associated with changes in body temperature observed during a 4-week regulatory toxicology study in dogs is presented. Four groups of Beagle dogs received the vehicle or test item once on Day 1, followed by a 4-week observation period. Electrocardiogram (ECG) parameters were continuously recorded on Days 1 and 26 by jacketed external telemetry (JET). Core body temperature (BT) was measured with a conventional rectal thermometer at appropriate time-points during the Day 1 recording period. RESULTS: Decreased BT was observed approximately 2h after treatment on Day 1, along with increased QT interval duration corrected according to the Van de Water formula (QTcV), but the effect was no longer observed after correction for changes in BT [QTcVcT=QTcV-14(37.5-BT)] according to the Van der Linde formula. No significant changes in QTcV were reported at the end of the observation period, on Day 26. DISCUSSION: The present study demonstrates that core body (rectal) temperature can easily be monitored at appropriate time-points during JET recording in regulatory toxicology studies in dogs, in order to correct QT interval duration values for treatment-related changes in BT. The successful application of the Van der Linde formula to correct QTc prolongation for changes in BT was demonstrated.

Reproductive safety evaluation of L-Ergothioneine.

L-Ergothioneine is a naturally occurring histidine-derived betaine (CAS No: 497-30-3) synthesized by bacteria and fungi, and found ubiquitously in plants and animals. It is present in many human foodstuffs. We evaluated the potential reproductive toxicity of L-Ergothioneine in Sprague-Dawley rats. L-Ergothioneine was administered at concentrations of 0.1, 0.3 or 0.9% in diet to F0 males (for 10 weeks before pairing and 3 weeks during pairing) and F0 females (for 13 weeks before pairing, during pairing and gestation, and until day 5 of lactation). Systemic exposure increased with dose-level, but not dose proportionally, suggesting saturation of uptake mechanisms. No clinical signs of toxicity were observed and there were no effects of L-Ergothioneine treatment on mating and reproductive performance or parameters of fertility. All animals mated within a similar number of days and pregnancy rates were uniformly high in control and treated groups. There were no effects of treatment with L-Ergothioneine on the duration of gestation, pre- and post-implantation losses, number of pups delivered and viability index, or on litter parameters (litter size, clinical signs, body weight or sex ratio) and the repartition of found dead/cannibalized pups. In conclusion, L-Ergothioneine was well tolerated and without adverse effects on the reproductive parameters evaluated.

Biodistribution and predictive hepatic gene expression of intravenous iron sucrose.

INTRODUCTION: We have examined iron biodistribution and hepatic gene expression in rats following administration of the generic Iron Sucrose Azad (ISA) or the reference iron sucrose drug Venofer®. METHODS: ISA and Venofer® were administered intravenously to normal, non-anemic, male rats at 15 mg/kg (a supra-therapeutic dose-level). To evaluate biodistribution, tissue iron levels were determined over 28 days for plasma, liver, spleen, bone marrow, heart, kidney, lung and stomach using a validated ICP-MS method. Hepatic gene expression was evaluated by microarray analysis of mRNA from samples taken 24 h after drug administration. RESULTS: Iron concentration/time profiles for plasma and tissues were quantitatively similar for ISA and Venofer. Following administration, circulating iron levels briefly exceeded transferrin binding capacity and there was a transient increase in hepatic iron. Bone marrow iron levels remained elevated throughout the study. No increases in tissue iron levels were observed in the heart, stomach or lungs. Spleen iron levels increased over the course of the study in treated and control rats. Small, transient increases were recorded in the kidneys of treated rats. The effects of ISA and Venofer® on hepatic gene transcription were similar. Principal components analysis showed that there was no systematic effect of either treatment on transcriptional profiles. Only a small number of genes showed significant modulation of expression. No transcriptional pattern matches with toxicity pathways were found in the ToxFX database for either treatment. No modulation of key genes in apoptosis, inflammation or oxidative stress pathways was detected. DISCUSSION: These findings demonstrated that the biodistribution of administered iron is essentially similar for Iron Sucrose Azad and Venofer®, that iron sucrose partitions predominantly into the liver, spleen and bone marrow, and that hepatic gene expression studies did not provide any evidence of toxicity in animals treated at a supra-therapeutic dose-level.

Study designs for the nonclinical safety testing of new vaccine products.

During the development of a new vaccine, the purpose of nonclinical studies is to provide safety information to support the clinical development and licensure of the product. In this article the study designs currently accepted for the nonclinical safety testing of new vaccines are described for single dose, local tolerance, repeat dose toxicity and safety pharmacology studies; these studies together form the basis of a typical nonclinical safety evaluation dossier. The detailed design of the preclinical package must take account of the intended clinical use, patient population, route of administration, formulation, dose level and immunisation schedule. The test item that is used for these studies must be adequately representative of the intended clinical formulation. The animal model used for these studies must be selected on criteria of relevance. Single dose toxicity studies provide information on acute actions or the potential effect of accidental overdose, but this information is often available from the repeat dose toxicity study, obviating the need for the acute study. Local tolerance studies provide information on tissue reactions at the site of administration. Evaluation of the findings must distinguish between normal tissue responses to injected material and findings indicative of undesirable pathological changes. The repeated dose toxicity studies are the principal studies that support the safety profile of the vaccines. The design of these studies must take full account of the features of the vaccine in the choice of treatment regime, dose levels, pharmacodynamic monitoring and timing of investigations and sacrifice. Safety pharmacology studies are performed to evaluate the potential for undesirable secondary pharmacological actions of vaccines if there is data to suggest that such studies are needed; this evaluation is made on a case by case basis. In the absence of specific guidance the design of studies for therapeutic vaccines follows the same general principles as those for anti-infective vaccines.

The RETHINK project on minipigs in the toxicity testing of new medicines and chemicals: conclusions and recommendations.

The objective of the RETHINK project was to evaluate the potential impact of toxicity testing in the minipig as an alternative approach in regulatory toxicity testing that can contribute to the replacement, refinement and reduction of animal testing (3Rs). Expert study groups (Working Groups) were assembled to review five different areas relating to the use of minipigs in regulatory safety testing: ethical issues, welfare and animal care, development of new medicines and chemicals, safety testing issues and emerging technologies in safety testing. The conclusions and recommendations of the projects are presented in this article. It is concluded that there are no specific areas where restrictions to the use of minipigs in toxicology are required for welfare reasons. The minipig model is generally acceptable to regulatory authorities, provided it is adequately justified. The minipig is an interesting model for safety testing since there are numerous anatomical, physiological, genetic and biochemical similarities to humans. In addition many features of the minipig make it a practical and flexible model for safety testing. The use of the minipig in development of products does not bring any financial penalty in terms of the cost of testing. Benefits in terms of 3Rs can be identified in terms of life-cycle analysis of the use of minipigs compared to dogs and non-human primates. Finally the minipig (unlike the dog) is well positioned to take advantage of genomics and gene manipulation technologies. Specific recommendations for further research are made, which could bring 3Rs benefits. To deploy the minipig to the best advantage, clear information is needed about the predictivity of the minipig for human toxicities, and focussed action to define the potential role of the minipig in testing of biologics.