This is a transcript from a Q&A interview with Emily Shacter, PhD, Consultant, ThinkFDA LLC (former FDA Scientist and Regulator). We will be talking today about the CMC Forum that was published back in 2005. We are revisiting it in the magazine to specifically update our understanding of how to maintain process control; understanding your process. In general, how do you feel the discussions in the four-part paper from 2005 has held up after 10 years? Emily: I think they…
Recombinant therapeutic proteins are commonly produced by cell lines such as Chinese hamster ovary (CHO), human embryonic kidney (HEK) 293, murine myeloma (NS0), and Escherichia coli bacterial cells. Host-cell proteins (HCPs) are indigenous proteins produced by those expression hosts and considered to be process-related impurities generated from the cell culture process (1). HCPs are potentially harmful and immunogenic to patients, and they can compromise the stability of protein drugs (2–4). For those reasons, HCPs must be consistently removed or reduced…
Protein concentrations in bioprocessing are determined by multiplying the measured absorbance of UV light as it passes through a sample by the protein extinction coefficient. Conventional spectrophotometer measurements are based on a fixed pathlength depending on the cuvette used to hold the sample (typically 10 mm). Only a small portion of the UV curve is linear at that pathlength. As a result, conventional spectrophotometers have a limited linear range and are unable to measure a large range of protein concentrations…
Viral safety is required for biologics manufactured to treat human diseases. Although significant improvements in ensuring viral safety have been made over the past few decades, “zero risk” of viral contamination is a myth. Viral contamination risk can be carefully managed by screening raw materials, testing process intermediates, and evaluating how effectively manufacturing processes remove and inactivate viruses. Viral clearance studies verify virus removal or inactivation by a manufacturing process. Although regulatory agencies have expectations for the designs of those…
During the manufacturing of monoclonal antibody (MAb) products, many process reagents are used for cell culture and MAb purification to facilitate and control process performance. Process reagents are considered to be process-related impurities, so demonstration of their clearance is required for the chemistry, manufacturing, and controls (CMC) information submission of an investigational new drug (IND) application (1, 2). These reagents may be classified into two categories: generally recognized as safe (GRAS) reagents and potential safety concern (PSC) reagents (3). GRAS…
Cell-based immunotherapies (iTx) are emerging as a truly transformative therapeutic modality that is both complementary and convergent with existing regenerative medicine approaches, including gene therapy, cell therapy, and tissue engineering (Figure 1). Critically, iTx offer step-change improvements in efficacy compared with current standards of care (1) for a range of clinical indications and unmet therapeutic needs — particularly oncology. The clear efficacy of iTx is in contrast with some previous regenerative medicine approaches, including early mesenchymal stem cell (MSC) therapies…
All recombinant protein biotherapeutics must be tested for the presence of residual host-cell protein (HCP) impurities (1–3). The most common analytical method for doing so is a polyclonal sandwich immunoassay. Polyclonal anti-HCP antibodies are selected to recognize the broadest population of HCPs possible. The immunogen and analytical standard are produced from a blank-run fermentation that mimics the production run but lacks the specific biotherapeutic protein. Because of the large number of impurities present in harvested cell-culture fluid (HCCF) that might…
Glycosylation of proteins, including monoclonal antibodies (MAbs), is recognized as important for the efficacy, immunogenicity, antibody-dependent cell-mediated cytotoxicity (ADCC), and complement-dependent cytotoxicity (CDC) of biotherapeutics (1–6). So research and development of protein candidates is increasingly focused on the effects of glycosylation and how its pathway is affected in the Golgi system of cells involved in biosynthetic processes (7). Such attention on glycosylation has helped advance analytical technologies such as high-pH anion-exchange chromatography (HPAEC) (8); normal-phase chromatography (NP- HPLC), hydrophilic-interaction chromatography…
To date, the majority of recombinant monoclonal antibodies (MAbs) have been produced by mammalian cells. During such production processes, the potential risk of entrained viruses must be critically considered (1). Contamination can arise from animal cell lines or from adventitious viruses introduced during manufacturing. To ensure the viral safety of biotechnology products, companies can take four complementary approaches (2, 3): Using animal-component–free raw materials wherever possible Virus testing of master cell banks Virus testing of unprocessed harvest Performing downscale virus…
Although vaccines and immunotherapies are designed to engage the human immune system in fighting disease, unwanted immunogenicity can be a major problem for protein-based therapeutics. Some patients produce antidrug antibodies (ADAs), which might lead to drug inactivation or adverse effects. Even human and humanized proteins have proven to be surprisingly immunogenic in some cases, suggesting that immune tolerance requires careful consideration in biologic product design. In rushing to deliver new drugs to market, some biotherapeutics developers have overlooked factors that…