BioProcessing Journal Posts

As product development proceeds in the field of cellular therapies, adequate product characterization remains a challenge for both IND Sponsors and FDA/CBER. Cellular therapy products are not considered to be well-defined products, and therefore the control and characterization of each stage of the production process helps to ensure product safety and consistency. Product characterization of cellular products includes demonstration of safety, plus determination of identity, purity, potency, and product stability. Development of appropriate specifications for each of these parameters is necessary for lot release, and also provides an important database of knowledge for addressing regulatory issues, such as lot-to-lot consistency and potential issues with product comparability, should the manufacturing process, or other aspects of product development, change over time…

Cell & Gene Therapy Regulatory

Viral safety and viral clearance evaluation are high-profile areas for product safety. Regulators are keenly focused on viral safety and expect high-quality data to support it, particularly for IND and BLA approvals. Familiarity with process and regulatory requirements, as well as expertise in the key areas of viral clearance, are essential for strategic planning and can yield savings in time, effort, and money…

Biologics Production Manufacturing Regulatory

The characterization of a batch cell culture process to produce a monoclonal antibody from a GS-NS0 mouse myeloma cell line is described. Productivity and cellular metabolism were monitored during scale-up to both characterize the process and aid in assessing cell culture stability. During fermentation scale-up studies, it was found that as culture generation number increased, productivity declined. In both flask and bioreactor cultures, declining production started abruptly at approximately generation 60. In this study, we assessed whether the decline in productivity was due to genetic instability of the cell line, which resulted in the generation of a non-producer sub-population, or a shift to a less productive state of cellular metabolism…

Biologics Production

The use of animal products, such as bovine serum, in the manufacture of biologics is a common practice. The United States’ Code of Federal Regulations, part nine (9CFR), dictates mandatory testing for viruses. In the last few years, we have learned that certain viruses undetected in industry standard tests, like the 9CFR assay, can cause significant contamination of bovine products. Last year in Europe, new guidelines from the Committee for Veterinary Medicinal Products (CVMP), and draft guidelines from the Committee for Proprietary Medicinal Products (CPMP), were published to address testing requirements for bovine serum. The use of these European Guidelines for bovine serum testing broadens the ability to detect viral contamination…

Biologics Production Manufacturing

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

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

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

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

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

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