Stability of anti-immunotherapeutic antibodies in frozen human serum samples

Background: To generate exhaustive data on the stability of human anti-immunotherapeutic antibodies. Materials & methods: Samples collected from over 100 different subjects at various timepoints were analyzed shortly after serum collection using specific ELISAs and re-analyzed after long-term storage or multiple cycles of freeze-thaw. The general acceptance criteria for incurred sample reanalysis for ligand-binding assays were applied, as well as alternative stricter acceptance criteria promoted by various white papers. Results: Anti-immunotherapeutic antibodies are stable in undiluted serum samples stored at -80 degrees C for at least 3.5 years and 3-12 freeze-thaw cycles. Conclusion: Samples were selected to cover the heterogeneity of the polyclonal human immune response, therefore this stability data can be extended to all anti-vaccine and anti-drug antibodies.