Silicone Oil Microdroplets Can Induce Antibody Responses Against Recombinant Murine Growth Hormone in Mice

Abstract

Therapeutic protein products can cause adverse immune responses in patients. The presence of sub-visible particles is a potential contributing factor to the immunogenicity of parenterally-administered therapeutic protein formulations. Silicone oil microdroplets, which derive from silicone oil used as a lubricating coating on barrels of prefilled glass syringes, are often found in formulations. In this study, we investigated the potential of silicone oil microdroplets to act as adjuvants to induce an immune response in mice against a recombinant murine protein. Antibody responses in mice to subcutaneous injections of formulations of recombinant murine growth hormone (rmGH) that contained silicone oil microdroplets were measured and compared to responses to oil-free rmGH formulations. When rmGH formulations containing silicone oil microdroplets were administered once every other week, anti-rmGH antibodies were not detected. In contrast, mice exhibited a small IgG1 response against rmGH when silicone oil-containing rmGH formulations were administered daily, and an anti-rmGH IgM response was observed at later time points. Our findings showed that silicone oil microdroplets can act as an adjuvant to promote a break in immunological tolerance and induce antibody responses against a recombinant self-protein.

Deep Convolutional Neural Network Analysis of Flow Imaging Microscopy Data to Classify Subvisible Particles in Protein Formulations

“…Figure generated with Matplotlib 48 and TikZ. 49 relevance of the classification [39][40][41] but also by the ease of generating data sets for classifier training with FIM images of only protein aggregates or silicone oil microdroplets. However, for many other relevant particle classification tasks, it is difficult to obtain data sets where each image is labeled as a member of a particle class that we would wish to differentiate from other particle classes.…”

Silicone Oil Particles in Prefilled Syringes With Human Monoclonal Antibody, Representative of Real-World Drug Products, Did Not Increase Immunogenicity in In Vivo and In Vitro Model Systems

“…In contrast to our findings, recent reports regarding the safety of SiOP have shown some increased response in cell-or animal-based model immune systems challenged by mAb or recombinant protein added to stress-induced SiOP. [9][10][11]13 In most cases, emulsified silicone oil is spiked into the protein, or in others, stress-induced SiOP is mixed with mAb in buffers that are not representative of those used in commercial therapeutic protein formulations. It is unclear whether any denaturation of the protein caused by these conditions led to aggregates known to be mildly immunogenic, 18,24 consistent with mildly increased responses as compared to their negative or positive controls.…”

“…Pharmaceutical industry along with regulatory agencies are concerned that SiOP has the potential to increase immunogenicity by functioning as an adjuvant or increasing protein aggregation. 4e7 Either of these mechanisms might generate anti-drug antibodies (ADA), [8][9][10][11] and thereby decrease the safety and efficacy of the drug. 6,12 Various recombinant proteins have been shown to adsorb, to different extents, on SiOP from emulsified silicone oil in the absence of surfactant, which is usually included in protein therapeutics to decrease undesirable interfacial and hydrophobic interactions.…”

Overcoming Challenges of Implementing Closed System Transfer Device Clinical In-Use Compatibility Testing for Drug Development of Antibody Drug Conjugates

“…This highlights a critical gap in the device development process and the current drug product particulate testing guidelines. The introduction of silicone oil into the patient has known immunogenicity risks 38 and directly impacts patient safety. It can also impact drug product quality attributes through the formation of soluble and insoluble aggregates.…”