The future of protein particle characterization and understanding its potential to diminish the immunogenicity of biopharmaceuticals: a shared perspective.

Biopharmaceuticals represent an important and growing class of medicines. Immunogenic responses to biopharmaceuticals in patients can sometimes result in reduced safety and efficacy. Although multiple factors are known to influence immunogenicity, our understanding of the complex underlying mechanisms remains imperfect. In particular, the potential impact of protein aggregates (particulates) on immunogenicity is currently not well understood. This commentary discusses emerging technologies for particle assessment, what is known about the link between particulates and product safety and efficacy, and current regulatory guidances and perspectives. We consider approaches that in the future may permit specific particle attributes to be correlated with relative immunogenic risk, including the value of data derived from clinical and postmarketing surveillance. Finally, we identify some key remaining questions, which, when answered, may guide future strategies for decreasing the immunogenicity of biopharmaceuticals.