BioProcessing Journal

Assuring Viral Safety in Products Produced in Milk from Transgenic Animals: What Can Be Learned from Ascites-Derived Products

Various systems are used for production of biopharmaceuticals, including bacteria, yeast, mouse ascites, and animal cell culture. Each production system has its own set of risk factors for infection by viruses and their potential transmission in the final product. Viral contamination in products can arise from the animals themselves, from environmental sources, from the starting cells, or from materials introduced during the production and purification procedures. Methods have been developed for the prevention and control of these risks. The strategy used to minimize the risk of viral contamination combines several levels of viral safety…

Biologics Production Risk Analysis and Management

contaminant control purification safety viral contamination

Adenovirus Type 5 (Ad5) Chromatographic Purification Process at the 20 L Scale

Recombinant adenovirus are attractive as vectors for gene therapy because: they exhibit wide tissue tropism and high transduction efficiency; adenovirus cultures can reach high specific titers (10^10 VP/mL), and; their use in the treatment of cancer and other serious diseases is valuable. A primary mode of adenovirus purification continues to be CsCl density gradient centrifugation…

Viral Vectors

adenoviral vectors adenovirus adenovirus serotype 5 chromatography purification transduction

Methods for Detection and Evaluation of Replication Competent Adenovirus (RCA)

In the past, researchers developing gene therapy applications used replication-defective human Adenovirus 5 (Ad5) as a vector for delivering DNA sequences, almost exclusively. Ad5 vectors are typically rendered replication defective by the deletion of E1a gene sequences. A complementing cell line containing the E1a gene makes it possible to produce Ad5 vectors in large scale. Of the various cell lines that have been constructed for the purpose of high-titer Ad5 production, HEK293 cells and PER.C6 cells are the most widely used…

Biologics Production Viral Vectors

adenoviral vectors adenovirus serotype 5 replication replication-competent

Production Criteria in the Development of a K562-Based Vaccine Platform

The K562 cell line is a human myelogenous leukemic cell which has been used by several groups, including ours, as a vehicle for cell-based vaccines and immuno-gene therapies. The attractiveness of K562 cells is the ease with which they can be cultured, plus the fact that they express very low levels of MHC proteins. Low MHC expression facilitates the use of these cells in patients with different MHC backgrounds, and it may improve the in vivo survival of the cells by delaying immune rejection. Based largely on these properties, we have been developing the K562 cell line as a universal platform for expressing cytokines, tumor antigens, and other immuno-modulating proteins…

Biologics Production

cryopreservation ELISA immunotherapy mammalian cell culture protein expression vaccines

Chemical Cell Lysis for Large-Scale Adenoviral Vector Production

Production of non-enveloped viruses generally requires a cell lysis procedure to liberate mature particles trapped within their host cells. The standard bench-scale practice of using freeze/thaw cycles is simple and effective, but heat transfer limitations restrict the technique to relatively small applications. Here we show that a ten-minute treatment with a dilute mixture of polysorbate-80 and tri-butyl phosphate effectively liberates adenovirus from host cells…

Biologics Production Viral Vectors

adenoviral vectors adenovirus cell lysis scale-up

FDA Perspectives on the Use of the Adenovirus Reference Material

As development proceeds for adenoviral vectors in gene transfer clinical trials, it becomes increasingly important that these products demonstrate a good safety profile, and thereby build confidence in those who must make decisions about risk/benefit ratios, dose escalation, and efficacy. Currently, safety and efficacy are based predominantly upon the analysis of data generated by non-standardized methods, resulting in inconsistent values being reported for virus titer and particle counts…

Risk Analysis and Management Viral Reference Materials

adenovirus FDA infectious titer particle concentration safety

A Statistical Analysis of Adenovirus Reference Material Assay Results

The Adenovirus Reference Material (ARM) was developed under the guidance of the Adenovirus Reference Material Working Group (ARMWG) and the U.S. Food and Drug Administration (FDA), and was made possible through the donation of services and supplies by a large number of laboratories and institutions from the United States, Canada, France, The Netherlands, Germany, and the United Kingdom. The purpose of the ARM is to provide a reference material for use in validating assays and internal standards for adenoviral particle concentration and infectious titer. The NIH Recombinant DNA Advisory Committee recommended the development of such a reference-testing agent in their report issued January 2002. The ARM consists of purified wild type 5 Adenovirus as described by ATCC’s catalog number VR-5…

Viral Reference Materials

adenovirus adenovirus serotype 5 analysis infectious titer particle concentration

Animal Viral Vaccine Manufacturing

This paper reviews the manufacturing of veterinary viral vaccines and discusses the industry regulatory frameworks in both the European Union and the United States, the world’s two largest regulatory markets. We also address specific technical and regulatory issues associated with viral vaccine inactivation. Finally, we present two case histories for conventional viral vaccines: Foot and Mouth Disease Virus (FMDV) and Marek’s Disease, which are both long-established conventional vaccines, but nevertheless of great interest…

Manufacturing Regulatory

vaccines veterinary viral vaccines

Risk Management Tools for the Management of Critical Raw Materials

Risk management deals with planning for, and reacting to, hazard or loss. The regulatory authorities are focusing on the issues associated with establishing alternative sources of raw materials, especially as they are noticing a number of related quality problems in biopharmaceutical manufacturing. Supply chain management for critical raw materials used in biopharmaceutical manufacturing is an appropriate subject for risk management. This paper analyzes five important areas in risk management as it applies to the supply chain for critical raw materials…

Risk Analysis and Management

quality raw materials supply chain management

A Contaminant in the Adenovirus Reference Material

The Adenovirus Reference Material (ARM) is a purified and well-characterized wild type adenovirus (Ad5) now available to researchers worldwide. Due to the need for a common reference material, the ARM was produced with the purpose of validating assay methods and internal standards for use in developing recombinant adenovirus for gene therapy. Analysis of ARM by RP-HPLC, however, detected the presence of a contaminant peak with a distinctive A240 local wavelength maximum. The contaminant was found in all of the vials, with some variability in amount between vials. It appears that the contaminant is not associated with the virus and it is unlikely that it will interfere with the use of the ARM as a reference material. The source of the contaminant was probably a leachate or plasticizer from the tubing or containers used during the final processing step…

Viral Reference Materials

adenovirus serotype 5 contaminant control standards

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