An antidote for acute cocaine toxicity

Area of Science:

• Immunopharmacology
• Toxicology
• Drug Abuse Treatment

Background:

• Immunopharmacotherapy has evolved to treat substance abuse, including passive immunization with monoclonal antibodies.
• Previous research focused on active vaccines for cocaine abuse, with limited success in clinical trials.
• Murine antibodies showed potential in reversing cocaine overdose in animal models, prompting the development of humanized versions.

Purpose of the Study:

• To develop and evaluate a human monoclonal antibody (mAb) with improved affinity and efficacy for neutralizing cocaine.
• To assess the therapeutic potential of this new mAb in preventing and reversing cocaine overdose, even after toxicity onset.

Main Methods:

• Engineered a humanized mAb (GNCgzk) with enhanced cocaine binding affinity (K(d) = 0.18 nM).
• Tested F(ab')₂ and Fab formats of GNCgzk in a mouse model of cocaine overdose.
• Administered antibodies after the appearance of acute behavioral signs of cocaine toxicity.

Main Results:

• Human mAb GNCgzk demonstrated a 10-fold improvement in cocaine binding affinity compared to previous murine antibodies.
• Administration of GNCgzk formats, even post-toxicity onset, nearly completely prevented lethality in a cocaine overdose mouse model.
• Minimal antibody doses were sufficient to counteract lethal levels of circulating cocaine.

Conclusions:

• Passive immunization with engineered anti-cocaine monoclonal antibodies is a viable and effective strategy for treating cocaine overdose.
• Human mAb GNCgzk represents a significant advancement in developing a clinical antidote for cocaine toxicity.
• This approach offers a novel therapeutic avenue for managing acute cocaine poisoning.