The number of viral vectors designed for gene therapy applications in the cGMP pipeline is staggering. Similar in scope to the flurry of recombinant protein products of the 1980s and the monoclonal antibodies (MAbs) of the 1990s, viral vector-based products are surging from research labs and universities into contract manufacturing organizations (CMOs), ultimately destined for use in clinical trials. Unlike recombinant proteins and MAbs, both of which sometimes require grams of vialed final product to start Phase I studies, the amount of material required to move a viral vector-based product into clinical trials can be minute in comparison. Of all the viral vectors currently in clinical trials, more than 25% are based on adenovirus…
BioProcessing Journal Posts
As human immunodeficiency virus type-1 (HIV-1) continues to spread around the world, scientists are actively pursuing effective vaccines against the infectious disease that results in AIDS. A number of vaccine designs have been developed, including plasmid DNA constructs encoding HIV proteins. One advantage of DNA vaccination is that after the uptake of the plasmid by the host cells, the encoded antigens are expressed in the native conformation and allow authentic immunological processing of the antigen. Another advantage of DNA vaccines is that they can be repeatedly administered without vector-directed immunity limiting the efficacy of the boost. DNA vaccines alone can induce both humoral and cellular immune responses and provide modest protection against disease progression in the preclinical, nonhuman primate model when challenged with simian immunodeficiency virus (SIV)…
Of the available on-line biomass assays, the radio-frequency (RF) impedance method has a clear advantage for current good manufacturing process (cGMP) because it is an unambiguous reflection of viable cell bio-volume rather than the total number of cells. Although other more approximate methods are available for cells in suspension, RF impedance is practically the only on-line method available for cells in suspension, attached to microcarriers and immobilized cells at high cell densities. Data are presented to show how live cell concentrations are derived from an RF impedance-derived instrument…
The enzyme-linked immunospot (ELISpot) assay is one of the most useful techniques for the immunological monitoring of vaccine trials and has increasing application as a measure of specific T-cell activation. Recently, we developed, optimized, and validated a customized ELISpot kit for the detection of interferon gamma (IFNγ) positive cells. The precision of the ELISpot was good and it varied over the range of the assay values, independent of the stimulus. Here we describe the development of a library of donors with characterized responses to the CEF peptide pool: cytomegalovirus (CMV), Epstein-Barr virus (EBV), and influenza (Flu); pool of 32 peptides which can be used as controls for IFNγ ELISpot and multiple immune monitoring assay validations for use in clinical trials…
The quantitative and qualitative analysis of proteins and their amino acid sequence composition is a critical operation in many research laboratories and operations. Much protein analysis is performed using high-pressure liquid chromatography (HPLC) with ultraviolet (UV) or fluorescence detection. Although these methods are robust and widely used, certain issues limit their utility. For example, some proteins or peptides may have a poor UV response and can be difficult to detect. Direct comparisons of protein levels when quantitated directly by UV can also be problematic due to differences in extinction coefficients of various proteins…
The United States Pharmacopeia (USP) is a not-for-profit nongovernmental organization founded in 1820 that develops public standards for drug substances and products; these standards are enforceable by FDA and have been adopted by many nations around the world. USP General Chapters provide industrial and academic researchers alike with crucial guidance, particularly in areas where there is a regulatory void. A good recent example is the proposed USP general information chapter…
Poliovirus is a small (28-30 nm diameter) non-enveloped RNA virus belonging to the family Picornaviridae. The ability of poliovirus to cross the blood-brain barrier and its natural infectivity of central nervous system (CNS) tissue via the CD155 receptor, found exclusively in primates, has promoted the investigation of an attenuated poliovirus for the treatment of malignant gliomas. However, use of the virus in clinical testing is limited due to low yields obtained from conventional purification methodologies…
Today concentrated efforts are underway to improve the bioactivity of therapeutic proteins with the aim of reducing: (i) the number and concentration of the applied doses of the therapeutic protein, (ii) undesired side effects, and (iii) the cost of a therapy. A very promising strategy is to optimise the glycosylation of these biotherapeutics. A novel expression platform, GlycoExpressâ„¢, has been developed to produce proteins with fully human glycosylation, optimised sialylation, and improved bioactivity…