Week 2, November 2024: Reliability: Addressing Aggregation, Impurities, and Stability

This past week, several news features have highlighted challenges that antibody drug products face in the context of reliability and consistency.

In biomedical science, unreliable antibodies have long hindered research, creating costly reproducibility issues and undermining experiments. Researchers like Carl Laflamme have discovered that many commercial antibodies fail to recognize specific proteins, leading to confusion and flawed data. In response, new initiatives, such as YCharOS, aim to validate antibodies and enhance their reliability by rigorously testing specificity and selectivity. Collaborative efforts involving suppliers, researchers, and organizations are pushing for standardization, the adoption of recombinant antibodies, and unique identifiers like RRIDs to improve tracking. While cultural shifts in lab practices remain challenging, the scientific community is hopeful that these efforts will lead to lasting improvements.

In a recent paper, scientists focused on identifying previously undetected microprotein impurities in antibody drugs produced using Chinese hamster ovary (CHO) cells, a common cell line for monoclonal antibody (mAb) and Fc-fusion protein production. By employing ribosome profiling (Ribo-seq), they discovered thousands of novel short open reading frames (sORFs) likely encoding microproteins, which are often overlooked in CHO cell biology and host cell protein (HCP) impurity analysis. Using an extended protein database, they analyzed eight antibody drugs via mass spectrometry (MS), uncovering microprotein impurities that vary with cell growth and culture conditions. Their findings enhance HCP detection accuracy in antibody drugs and expand knowledge of non-canonical translation in CHO cells, providing insights to improve therapeutic protein quality and manufacturing efficiency.

Stability of therapeutic mAbs is a major issue, as aggregation and fragmentation of mAbs is common during various stages of product life cycle due to stress factors like thermal and air/liquid interfacial agitation. These aggregates may reduce mAb efficacy and trigger adverse immune responses, making stability a critical focus throughout the product lifecycle. A recent review provides a broad overview of mAb aggregation, including types, sizes, causes, analytical techniques, and permissible limits, as well as factors influencing aggregation, methods used to study stress-induced aggregation, and strategies to enhance stability, offering valuable insights for improving mAb formulation from manufacturing through patient administration.

To combat this, one study evaluates the effectiveness of surfactants in preventing mAb adsorption on medical surfaces using a novel device and protocol to detect and quantify mAb adsorption directly on medical plastic bags, ELIBAG. The research reveals that surfactant effectiveness depends on the specific antibody, surfactant type, concentration, and surface material. Findings highlight differences in adsorption behavior between model and real medical surfaces and underscore the importance of using actual medical surfaces to better understand and optimize mAb stability in formulations. This research offers insights into enhancing drug product development and ensuring material compatibility in clinical applications.