Official Batch Release Research Articles

Allergen-specific immunotherapy andevidence: A European regulatoryperspective.

Allergen immunotherapy (AIT) has been performed for 112 years. In this article we summarize regulatory standards and challenges based on scientific evidence on AIT. Most crucial and timely aspects concerning AIT are addressed from the regulatory perspective of the authors as employees of a national competent authority in Europe: (1) product specificity; (2) clinical efficacy; (3) treatment for adults and children (needs for extrapolation); (4) allergen exposure chambers; (5) biomarkers; (6) standardization; (7) real-world evidence; (8) independent official batch release (benefit and challenges); (9) harmonization on the EU level. The Paul-Ehrlich-Institut (PEI), the Federal Institute for Vaccines and Biomedicines, in Langen near Frankfurt/Main in Germany, examines and evaluates the benefits and risks of AIT products within the course of clinical development, marketing authorization, and subsequently throughout their entire life cycle to ensure high-quality, safe, and effective AIT products.

Falsified medicines in parallel trade

The number of falsified medicines on the German market has distinctly increased over the past few years. In particular, stolen pharmaceutical products, aform of falsified medicines, have increasingly been introduced into the legal supply chain via parallel trading. The reasons why parallel trading serves as a gateway for falsified medicines are most likely the complex supply chains and routes of transport. It is hardly possible for national authorities to trace the history of amedicinal product that was bought and sold by several intermediaries in different EU member states. In addition, the heterogeneous outward appearance of imported and relabelled pharmaceutical products facilitates the introduction of illegal products onto the market. Official batch release at the Paul-Ehrlich-Institut offers the possibility of checking some aspects that might provide an indication of a falsified medicine. In some circumstances, this may allow the identification of falsified medicines before they come onto the German market. However, this control is only possible for biomedicinal products that have not received awaiver regarding official batch release. For improved control of parallel trade, better networking among the EU member states would be beneficial. European-wide regulations, e. g., for disclosure of the complete supply chain, would help to minimise the risks of parallel trading and hinder the marketing of falsified medicines.

Development of an in vitro Biochemical Assay System for the Measurement of Residual Toxin Activities in Pertussis Toxin Containing Vaccines

Pertussis (whooping cough) vaccines play an essential role in immunisation programmes worldwide and the histamine sensitisation test (HIST) is currently the official batch-release test for acellular pertussis containing combination vaccines. HIST, being a murine animal test, has large assay variability problems and ethical issues. Therefore, in response to the 3Rs, a biochemical assay system has been developed based on the pertussis toxin (PTx)’s two functional domains: an enzyme active A-protomer and a carbohydrate binding B-oligomer. The clinical relevance of these two biochemical tests in relation to the PTx toxic effects has been demonstrated. In order to assess the practicality of this assay system, an international collaborative study involving 9 countries on method transferability had also been performed and showed that this assay system could be adopted readily in control laboratories and vaccine manufacturing facilities. In this update, we provide further optimised assay conditions for measuring both the residual PTx ADP-ribosyltransferase and carbohydrate binding activities in specific vaccines. In general, appropriate dilution of vaccines would help to increase test sensitivity. Spiking experiments showed carbohydrate binding assay could detect low levels of PTx similar to HIST. Although positive trend with increasing spikes could also be demonstrated in ADP-ribosyltransferase activity assay for some vaccines, the resultant values in a number of spiked vaccines were not statistically significant and this is due to high baseline activity of the unspiked vaccines. Since all the reagents of this biochemical assay system are available worldwide, readily controlled and with good test consistency, both assays could be used for monitoring product consistency. The carbohydrate binding assay could even be considered as a potential alternative to HIST for batch-release of acellular pertussis vaccines. Protocols for this in vitro assay system are supplied as Supplement Documents 1 & 2.

A case study of development, validation, and acceptance of a non-animal method for assessing human vaccine potency

Hepatitis B vaccine (Engerix B) is a recombinant vaccine containing hepatitis B surface antigen (HBsAg) produced in Saccharomyces cerevisiae. Initially, this vaccine was released using specifications that required an in vivo potency assay in mice. This paper describes the move from the in vivo potency test toward in vitro potency assays: the in vitro Auszyme test (Abbott Laboratories) and the GSK Biologicals in-house test based upon the inhibition enzyme-linked immunosorbent assay (ELISA) principle. The challenges and difficulties during the development and introduction of this in vitro assay are presented from validation studies performed by GSK Biologicals, through regulatory acceptance, to the implementation of the alternative method by the European Directorate for the Quality of Medicines (EDQM) and HealthCare Control Authorities for Official batch release. Based upon our experience introducing an in vitro model for Engerix B potency assay, we offer suggestions to facilitate future introduction of in vitro assays.

An in vitro assay system as a potential replacement for the histamine sensitisation test for acellular pertussis based combination vaccines

The histamine sensitisation test (HIST) for pertussis toxin is currently an official batch release test for acellular pertussis containing combination vaccines in Europe and North America. However, HIST, being a lethal endpoint assay, often leads to repeated tests due to large variations in test performance. Although a more precise HIST test based on measurement of temperature reduction after the histamine challenge is used in Asian countries, this test still uses animals. An in vitro test system based on a combination of enzyme coupled-HPLC and carbohydrate-binding assays with results analysed by a mathematical formula showed a good agreement with the in vivo HIST results based on measurement of temperature reduction after histamine challenge. The new in vitro test system was shown to be a potential alternative to the current in vivo HIST.

Development and Validation of a Detection System for Wild-type Vibrio cholerae in Genetically Modified Cholera Vaccine

Orochol®, a live oral cholera vaccine licensed in Switzerland and in other countries, is based on the genetically modified Vibrio cholerae strain CVD103-HgR. This strain is derived from the wild-type O1 strain Inaba 569B by deletion of a fragment internal to the ctxA gene encoding the A1 subunit of cholera toxin and by replacement of an internal fragment of the hlyA gene with a fragment carrying the mer operon mediating mercury resistance. In this study we describe a polymerase chain reaction (PCR) system for the detection of wild-type Vibrio cholerae and the identification of the vaccine strain for the quality control of production batches. A multiplex PCR system that targets the intactctxA gene of the wild-type strain and simultaneously the integration site of the mer operon in the hlyA gene (hlyA::mer) of the vaccine strain CVD103-HgR was developed. To evaluate the detection limit of the system, vaccine suspensions were artificially contaminated with wild-type V. cholerae 569B cells and tested by PCR. The detection limit of the system was statistically evaluated and found to be at 11625 wild-type cells per vaccine sachet (95% confidence limit). This number is below the infective dose of wild-type Vibrio cholerae. In Switzerland this test is used in combination with other tests in the official batch-release procedure to assure the safety of each batch of the cholera vaccine Orochol®.

Virus Safety of Prothrombin Complex Concentrates and Factor IX Concentrates

Substantial progress in virus safety has been achieved during the past 15 years. Therefore only a few virus transmissions with plasma-derived products have been observed since 1985. Specific steps to eliminate, remove, or inactivate viruses were developed. Although virus safety is of decisive importance, chemical or physical treatment during the manufacturing process need not activate labile coagulation factors that cause the risk of thrombogenicity nor need not create neoantigens that mediate the risk of inhibitor formation. Thus, any new virus elimination procedure has to be evaluated and validated for all safety aspects. A comprehensive framework of regulations and efforts has been set up involving plasma donors, donation centres, manufacturers, regulatory authorities, politicians responsible for legislation, physicians, and patients. Blood and plasma donation centres and pharmaceutic industry follow “Good Manufacturing Practice” and are subject to regular audits and official inspections. Every single donation as well as plasma pools are tested for virus markers. The final products need both a marketing authorization and official batch release; in Germany, supervised by the Paul-Ehrlich-Institute. European integration is the purpose of the European Medicines Evaluation Agency. An alert pharmacovigilance system enables scientifically adequate reactions in any case of a safety problem. The ultimate evidence of product safety is provided by clinical surveillance. By participating in clinical studies, patients themselves are able to contribute significantly to the safety of plasma-derived products. The currently achieved high level of safety should encourage us to take further steps to stabilize this success and to look for further progress, wherever possible.