An Engineered Human-Antibody Fragment with Fentanyl Pan-Specificity that Reverses Carfentanil-Induced Respiratory...

Area of Science:

• Pharmacology
• Immunology
• Structural Biology

Background:

• The synthetic opioid crisis has caused over 500,000 deaths in the US in the past 20 years.
• Naloxone is the current standard for reversing opioid overdose but has limitations, necessitating new therapeutic strategies.
• Ultrapotent synthetic opioids like carfentanil pose significant challenges due to their unique pharmacological profiles.

Approach:

• Generated a fully human monoclonal antibody using a drug-specific B cell sorting strategy with carfentanil and fentanyl probes.
• Optimized the antibody (C10-S66K) via single-chain variable fragment (scFv) phage display for enhanced specificity and affinity.
• Determined x-ray crystal structures of the antibody bound to carfentanil and fentanyl to elucidate drug:antibody interactions.

Key Points:

• The developed antibody, C10-S66K, exhibits high affinity for carfentanil, fentanyl, and related synthetic opioid analogs.
• C10-S66K demonstrated efficacy in reversing carfentanil-induced respiratory depression in preclinical models.
• Structural analysis revealed critical interactions between the antibody and the bound opioid ligands.

Conclusions:

• Monoclonal antibodies offer a versatile platform for developing targeted countermeasures against synthetic opioid overdose.
• C10-S66K represents a promising therapeutic candidate for treating overdoses caused by potent synthetic opioids, potentially preventing renarcotization.
• Structural insights from drug:antibody complexes can guide the design of next-generation opioid antagonists.