Downstream Validation

Conditional/Inducible Gene-Expression Mouse Models Using Advanced Gene Editing

Transgenic mouse models have been an essential part of biomedical research for many decades. They have provided valuable insights in developmental biology, gene regulation, and our understanding of the genetic basis of human disease. And they play a critical role in drug discovery and development. Traditional methods to generate these mouse models entailed a milieu of disadvantages: e.g., low efficiency, high incidence of undesirable recombination outcomes, randomly and multiply inserted genes of interest, ectopic expression, gene silencing, and insertional mutations…

Residual Host-Cell DNA in Biopharmaceutical Products: 96-Well Plate-Based Extraction and Real-Time PCR Assay for Quantitative Measurement

Regulatory guidelines that cover the development of biopharmaceutical products require testing of host-cell deoxyribonucleic acid (DNA) impurities. Real-time polymerase chain reaction (PCR) has become a popular technology for DNA quantitation and monitoring of process impurities associated with biomanufacturing. One critical challenge associated with host-cell DNA impurity testing is that recombinant proteins (e.g., monoclonal antibodies, MAbs) and their corresponding buffer components often interfere with DNA quantitation in real-time PCR reactions (1, 2). Some sample types do not require a full extraction…

A Statistical Approach to Assess and Justify Potential Product Specifications

As stated in ICH Q6B, specifications are critical quality standards that are both proposed and justified by drug product manufacturers. Xiaoyu et al. provide information on several statistically based strategies to establish specification acceptance criteria (SAC) (1). Here we address an alternative approach to relate proposed SAC for quantitative data to relevant lot history. In particular, proposed SAC can be derived in part by using calculated limits for which the lower bound of an approximate 95% confidence interval for the…

Examining Single-Use Harvest Clarification Options: A Case Study Comparing Depth-Filter Turbidities and Recoveries

Steadily increasing demand for biopharmaceutical drugs has led the industry to examine its manufacturing scales while pressuring research and development groups to produce high-yielding clones and processes. Improved media, feed supplements, bioreactor designs, and control of process parameters have helped biomanufacturers achieve multifold increases in volumetric productivity from production bioreactors. However, cell culture processes are significantly affected by their bioreactor’s ability to support cells at higher densities and sustain cultures at lower viabilities. With the implementation of a number of…

CMC Forum: Evolution of Biopharmaceutical Control Strategy Through Continued Process Verification

As defined in the ICH Q10 guideline, a control strategy is “a planned set of controls, derived from current product and process understanding, that assures process performance and product quality” (1). Every biopharmaceutical manufacturing process has an associated control strategy. FDA’s 2011 guidance for process validation (2) describes process validation activities in three stages (Figure 1). A primary goal of stage 1 is to establish a strategy for process control that ensures a commercial process consistently produces acceptable quality products.…

Response to the Publication of USP ‹1207›

The BioPhorum Operation Group’s (BPOG’s) Container Closure Integrity Testing (CCIT) workstream would like to congratulate the United States Pharmacopeia’s committee for its latest revision to USP chapter <1207> Package Integrity Evaluation: Sterile Products. Generally, we believe it provides a comprehensive overview of the available methods for container–closure testing and outlines many important elements for consideration in establishing a successful CCIT strategy. We first responded to the USP <1207> draft when it was released for comment in 2014. And from our…

HCP Antigens and Antibodies from Different CHO Cell Lines

Cell lines derived from Chinese hamster ovary (CHO) cells are widely used in therapeutic protein production because they can perform human-compatible posttranslational modifications, they are easy to use for manufacturing, and they do not propagate most human pathogenic viruses (1, 2). Expressed therapeutic proteins are secreted into CHO culture supernatant along with impurities originating from the host cells themselves. Such host cell proteins (HCPs) are important contaminants for monitoring because they directly affect drug quality, safety, and efficacy. HCPs are…

Using Technology to Overcome Bioprocessing Complexity: Advanced Concentration and Analytical Technologies Accelerate Development and Manufacture of mAbs, Vaccines, and Biosimilars

Unlike chemically synthesized drugs, whose structure is known and reproducible, biological drugs are derived from living cells and are sensitive, complex mixtures requiring cutting-edge biological technologies for their production. The growing importance of biosimilars in recent years is reflected in a corresponding rise in market value. The value of the global biologic therapeutic drug market reached approximately US$230 billion in 2014 and, according to BCC Research, will increase to nearly $390 billion by the end of 2019. This corresponds to…

Clearance of Persistent Small-Molecule Impurities: Alternative Strategies

Small-molecule impurities that bind to and copurify with protein biopharmaceuticals traditionally have been removed using bind-and-elute (BE) chromatography. However, that approach may be undesirable for a number of reasons. For instance, it may present a facility-fit challenge or provide a lower process yield than what is acceptable. A common scenario in which BE chromatography may be undesirable is in removal of unreacted conjugation reagents. Bioconjugates represent an important and growing class of pharmaceuticals that include PEGylated proteins, vaccines, and antibody–drug…

Best Practices for Critical Sterile Filter Operation: A Case Study

A number of regulatory guidelines recommend preuse integrity testing of critical sterilizing liquid filters for aseptic processing (1–3). Before sterilization, a preuse test will confirm that a filter is installed properly and was not damaged during shipment or handling. Performing a preuse test after sterilization detects damage that may have occurred during the sterilization cycle. Testing after sterilization limits risk, so it is a practice applied based on risk assessment. Because it is perceived to reduce business loss risk, preuse…