Host-cell proteins (HCPs) are bioprocess-related impurities that may be present in intermediate or final biopharmaceutical products such as recombinant monoclonal antibodies (MAbs). Although the potential clinical and genetic effects of HCPs are largely unknown, studies have shown that HCPs may cause immune responses and adverse reactions in patients when present at sufficient high levels (1,2,3). Consequently, US Food and Drug Administration (FDA) and European Commission regulations require that the level of HCP in a bioproduct be quantitatively measured during manufacturing…
QA/QC
How QbD and the FDA Process Validation Guidance Affect Product Development and Operations, Part 2
Earlier this year, the FDA issued its long-awaited process validation guidance document, which had been several years in development. It is well written and effectively articulates what many progressive companies have been thinking and doing for years. But many people in the industry are asking questions. Part 1 of this article described the history of process validation before the FDA’s quality by design (QbD) initiative and discussed QbD in general. It also described the new process validation…
Analysis and Immunogenic Potential of Aggregates and Particles
The conclusion of this CMC Forum continued to focus on the latest developments in detection and characterization of protein aggregates (1). Afternoon sessions detailed the most recent experiments probing the role of protein aggregates in immunogenicity, with discussions on the best models to use and initial results. Topics included potential thresholds for immunogenicity, linking laboratory and clinical data, and predicting and testing potential immunogenicity of products throughout a development lifecycle. Afternoon Sessions Amy Rosenberg (Division…
Analysis and Immunogenic Potential of Aggregates and Particles
The number of biotherapeutics on the market has rapidly increased during the past several years. Such proteins commonly exhibit a concentration-dependent propensity for self-association, which often leads to the formation of aggregates that range in size from nanometers (oligomers) to microns (subvisible and visible particles). Publications two years ago focused attention on the potential immunogenicity of active-ingredient aggregates ((1,2,3,4). The authors discussed lack of specificity of compendial measurements and inability of other current methods to address potential effects…
Imaged Capillary Isoelectric Focusing for Charge-Variant Analysis of Biopharmaceuticals
Analyzing charge variants of therapeutic proteins is critical for characterizing and monitoring quality attributes of antibodies. Charge variants include deamidation, formation of N-terminal pyroglutamate, aggregation, isomerization, sialylated glycans, antibody fragmentation, and glycation at the lysine residues. In some cases, such changes affect binding, biological activity, patient safety, and shelf life. The biopharmaceutical industry relies on tools such as ion-exchange chromatography (IEC), isoelectric-focusing gel electrophoresis (IEF), and capillary equivalents such as capillary isoelectric focusing (CIEF) and imaged CIEF (iCIEF)…
Limited Analytical Technologies Are Inhibiting Industry Growth
Progress in the development of bioprocessing-related assays and analytical instrumentation has not kept up with industry demands. The industry wants analytical technologies (especially for single use) to help improve productivity, optimize and monitor processes, provide real-time product quality control, and characterize biosimilars. These trends are reflected in our recent survey data. Over 30% of biopharmaceutical manufacturers and contract manufacturing organizations (CMOs) have expressed demands for improved assays and analytical equipment (1). BioPlan Associates’ eighth annual survey of biopharmaceutical…
Implementation of the ASTM Standard for Manufacturing Systems Verification
In 2007, ASTM International (ASTM), formerly known as the American Society for Testing and Materials, published its “E2500-07” international industry consensus standard for conducting a risk-based design and qualification of good manufacturing practice (GMP) manufacturing systems (1). This guide incorporates risk- and science-based practices to focus on critical aspects affecting equipment systems throughout their design–qualification–operation lifecycle. Presentations at recent PDA and ISPE annual meetings indicate that the bioprocess industry is embracing E2500 to improve system designs and reduce costly validations.…
Comparing H1N1 Virus Quantification with a Unique Flow Cytometer and Quantitative PCR
A novel influenza A (H1N1) virus was discovered in Mexico in early 2009 (1). Infections from this strain led to declaration of a pandemic midyear, with about 61 million patients and 13,000 deaths reported by the US Centers for Disease Control (2). Although the pandemic officially ended in August 2010 (3), vaccines are still in demand to protect people against the H1N1 strain that is now expected to circulate seasonally for years to come. To best respond to…
Distinctions Between Analytical and Bioanalytical Test Methods
Analytical methods used for characterization, release, and stability testing of biotechnological/biological products are often automatically referred to as “bioanalytical” methods by some in the field. Many times the term is used to distinguish between test methods applied to small-molecule chemical products and those for macromolecular, biologically based products. It seems sensible enough: We use analytical methods to test chemical pharmaceutical products, so aren’t test methods used for biopharmaceutical products therefore bioanalytical methods? Any way, who cares whether the term is…
Protein Conjugates
Methods and Materials Thanks to vendors large and small — such as Invitrogen (www.invitrogen.com), ProteoChem (www.proteochem.com), Sigma Aldrich (www.sigmaaldrich.com), Soltec Ventures (www.soltecventures.com), and Thermo Scientific Pierce (www.piercenet.com) — bioconjugation chemistry is a field of many options. For example, amine coupling of lysine amino-acid residues typically involves amine-reactive succinimidyl esters. Sulfhydryl coupling of cysteine residues uses a sulfhydryl-reactive maleimide. Photochemically initiated free-radical reactions offer broader reactivity. Most processes couple small molecules to proteins or proteins to one another (e.g., antibodies…