Optimization of an anti-fentanyl monoclonal antibody to improve stability

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Presentation Time: 09:15 AM - 09:30 AM
Abstract ID: 5953 - B

Presenting Author:
Brooke Hoppe , Research Scientist II at Univ. of Washington

Abstract:

Fentanyl and other synthetic opioids continue to be the primary contributors to overdose deaths despite widespread availability of FDA-approved reversal agents, highlighting the need for novel complementary therapeutics to address this epidemic. Monoclonal antibodies (mAbs) targeting fentanyl and related analogues have been shown to be promising candidates to help treat opioid overdose in preclinical models. Maintaining formulation stability is critical to the clinical utility of these immunotherapeutics. Previously, the structure of a lead anti-fentanyl mAb in complex with fentanyl was solved through X-ray crystallography, identifying a residue near the binding site that was liable to oxidation. Using a structure-guided approach, the identified amino acid residue was mutated to residues that were expected to have reduced oxidative liability. Stability of the resulting mAbs was quantified using differential scanning fluorimetry, and affinity of the mAbs for fentanyl was assessed via biolayer interferometry (BLI) and competitive enzyme-linked immunosorbent assays (ELISA). Replacing the oxidation-liable residue improved antibody stability as evidenced by an increase in Fab melting temperature. One specific mutation resulted in a 40-fold increase in affinity measured against a fentanyl hapten by BLI, and a 4-fold increase in affinity for free fentanyl by competitive ELISA. Future studies will seek to validate the improved mAb affinity in vivo relative to the parent mAb.