CTRX-101

CTRX-101 is a long-acting monoclonal antibody therapy being developed by CounterX Therapeutics for the prevention and treatment of fentanyl overdose, particularly in high-risk patients with moderate to severe opioid use disorder (OUD). Unlike traditional overdose reversal agents like naloxone, which act as opioid receptor antagonists, CTRX-101 targets the fentanyl molecule itself. By sequestering fentanyl in the systemic circulation, the antibody prevents the drug from entering the central nervous system and causing life-threatening respiratory depression. Administered as a subcutaneous injectable, CTRX-101 is designed to provide sustained protection without precipitating opioid withdrawal. As of late 2024, the drug is in preclinical development with an Investigational New Drug (IND) application anticipated in late 2025.