Stability of Anti-Drug Antibodies Against Antibody Therapeutics

Biotherapeutics have the potential to elicit unwanted immune responses that can lead to the production of anti-drug antibodies (ADA). It is critical that ADA responses are detected, characterized, and monitored to understand the safety and efficacy of a drug. ADA samples must remain stable in long- and short-term storage conditions to ensure reliable analysis. Whereas the stability of anti-vaccine antibodies has been well-studied, there are few reports examining the stability of anti-therapeutic antibodies using clinical samples. In this study, ADA samples from four clinical trials of antibody therapeutics were found to be stable after long-term storage (1-10 years) at -80°C and short-term storage (24 h to two weeks) at 4°C, 22°C, and 37°C. In addition, samples were stable after 16 freeze/thaw cycles. The results demonstrate the stability of ADA in clinical samples under various conditions. Consequently, the results observed herein suggest that the routine assessment of ADA sample stability may not be warranted.