Test article specifications

Test Article Specifications. In general, the product that is used in the definitive pharmacology and toxicology studies should be comparable to the product proposed for the initial clinical studies. 

If there are any identifiable gross lesions, they often differ between animals that die, and those that survive to the end of the observation period. The reason for these differences is very simple. An animal that dies less than 24 hours after chemical exposure probably has not had sufficient time to develop a well-defined lesion. As mentioned earlier, most deaths occur within 24 hours. Animals that survive for the two-week observation period have probably totally recovered and rarely have apparent lesions. Hence, the animals that provide the best chance to identify test-article-specific lesions are those that die in the region of 24 to 96 hours postdosing. 

AUCo oo is obtained from the rat pharmacokinetic data, and the test article specific activity is derived from analysis of the dose formulation administered to the rats. 

To assay specifically the afferent arm of the DTH response, the proliferation of the popliteal lymph node cells to SRBCs can also be measured (White et al., 1985). As described, mice treated with the test article are sensitized to SRBCs by inoculation of SRBCs into the hind footpad. However, 1.5 h later they are challenged intraperitoneally with FUdR and 2h later they are administered [125I]IUdR intravenously (instead of 125I-labeled HSA). Mice are sacrificed 24 h after challenge and both popliteal lymph nodes are removed and counted in a gamma counter. 

The typical test (illustrated in Figure 15.7) is performed using mice, normally female CBA mice 6-10 weeks of age. Female BALB/c and ICR mice have also been used. After animal receipt, they are typically acclimated to standard laboratory husbandry conditions for 7-10 days. The usual protocol will consist of at least two groups (vehicle control and test article treated) of five mice each. They are treated on the dorsal surface of both ears with 25 pi (on each ear) of test article solution for three consecutive days. Twenty-four to forty-eight hours after the last test article exposure, the animals are given a bolus (0.25 ml) dose of [3H]thymidine (20 pCi with a specific activity of 5.0-7.0 Ci/mmol) in phosphate buffered saline via a tail vein. Five hours after the injection, the animals are euthanized by C02 asphyxiation and the auricular lymph nodes removed. 

The absence of observed activity may represent either a true or false negative effect. If an assay is valid for the particular test article and fails to indicate activity, it is an appropriate indicator of future events (Green, 1997). However, if the assay is insensitive or incapable of response, the test represents a form of bias, albeit unconscious. Many biological products demonstrate a specificity of response that limits the utility of commonly employed safety studies. Specificity for many biologies arises from both their physicochemical properties and their similarity to endogenous substances that are regulated in a carefully controlled manner. To... 

Specificity. Negative test articles in FETAX vs. negative compounds in mammalian studies (%). 

Characterization of the vector batch used in non-clinical safety studies is also performed in compliance with GLPs. Care should be taken to ensure that adequate and appropriate processes are used to produce the batch(es) required, and the production process should be similar to that proposed for production of the vector for human clinical trials, or at least performed in such a way that adequate documentation of the production methods is available for comparative purposes. The GLP regulations state that the identity, purity, and composition of the vector batch (test article) used in a safety study must be known and documented. In addition, the stability of the vector preparation in the specific container used for the study must also be known prior to initiation of the study or acquired concomitantly with the study itself. These test article characterization experiments require that the researcher produce additional amounts of vector identical to the material used in... 

The identification is performed by comparing the infrared absorption spectrum of the test article with that the reference standard according to General Test <197M>. The monograph contains a specific instruction not to dry the test specimen. 

The specification is that the test article contains not more than 0.1% of benzoylformic acid, 1.0% of benzoic acid, 0.05% of benzaldehyde, and 0.01% of acetophenone. 

Test specimens such as those mentioned above are often used to verify the quality of the first article through the production line and then to periodically test articles for conformance. This type of testing procedure detects discrepancies affecting the entire lot of parts, but it cannot evaluate factors that affect individual joints or specific areas within a particular joint. 

Obviously some of these specific assumptions could be questioned, and the associated costs might be very different for different products or within different companies. At the time, however, these were reasonable assumptions for the two products being compared, and these specific assumptions allowed calculation of the amount, time, and cost associated with manufacture of the test articles. 

Figure 9.4 Mean T cell count after one course of treatment. Peripheral blood was collected from individuals administered test article (circles) or placebo (squares) on a weekly basis and stained for the presence of CD4 (a) or CD8 (b) lymphocytes using specific antibodies conjugated to fluorochromes. Samples were then analyzed on the flow cytometer to determine mean relative counts of each subpopulation of cells. The solid bar indicates the dosing interval.

Endpoint assays such as proliferation or cytotoxicity assays are routinely used for functional assessments. For these assessments, primary cells, transformed cells, or cells transfected with the target receptor are exposed to range of concentrations of the test article. Proliferation or cytoxicity is then measured using a variety of methods such as crystal violet vital dye staining, MTT/MTS incorporation, or a luminescence readout like ATP lite. In addition, assays that analyze phosphorylation of specific transcription factors, or release of specific cytokines and chemokines, are also common. Figure 9.5 illustrates the measure of functional consequences of receptor-test article interaction by quantifying cytokine release. Cells from the species under evaluation were cultured in the presence of serial dilutions of the test article or control reagents, and supernatants harvested for determination of cytokine levels by ELISA (i.e.,... 

We have reviewed information from 161 typical cross-reactivity studies conducted by PAI-CRL.3 These studies were selected from more than approximately 800 studies conducted between 1990 and 2006. The information is presented as percentages of total, but it is important to note that the percentages may exceed 100% as not all the studies had identical study design. For example, several studies included more than one test article, but the calculations were based on a per study basis. The specific data are proprietary, and only generalities are presented in the summary tables. The types and forms of the test articles and their epitopes are listed in Table 10.3, and the frequency of unexpected cross-reactivity is listed in Table 10.4. 

This review is intended to provide helpful information regarding potential monoclonal antibody IgG test article (non-CDR-mediated) binding to specific tissues, cell types or other tissue elements, and subcellular locations following exogenous intravenous administration in animal model test systems. Particulars specific to other routes of administration were reviewed by Lobo et al. [1]. 

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