CHAPTER 7: Addressing Immunogenicity for Implantable Drug-delivery Devices and Long-acting Injectables, Including Pharmacokinetic and Pharmacodynamic Correlations

Implants and long-acting injectables can provide tremendous benefits for effective treatment for a broad range of medical conditions. Benefits include reduced drug peak and trough plasma levels, improved patient drug compliance, and improved patient quality of life. Paramount to the successful development of these products is the demonstration of patient safety, pharmacokinetics, pharmacodynamics, and efficacy. Unwanted immune responses to therapeutic products have posed problems in medicine leading to either minimal effect, cessation of potential therapeutic drug development, or withdrawal of a commercial marketed product. The focus of this chapter deals with immunogenicity to long-acting implantable and injectable products. This includes considerations of the factors that can influence immunogenicity, characterization of the immune response, appropriate testing, risk assessments, and regulatory considerations.