CounterX Therapeutics' Anti-Fentanyl Antibody CTRX-101 Reverses Overdose in Preclinical Study
Key Insights
CounterX Therapeutics (search) published preclinical data in The Journal of Pharmacology and Experimental Therapeutics showing CTRX-101 (search) rapidly reverses fentanyl-induced respiratory depression (search).
The monoclonal antibody works by binding to fentanyl and sequestering it in the bloodstream, preventing lethal effects on the brain and respiratory system.
CTRX-101 (search) is being developed as a long-acting subcutaneous injection for preventing fentanyl overdose (search) in high-risk patients with opioid use disorder (search).
CounterX Therapeutics (search) announced the publication of preclinical data demonstrating that its proprietary anti-fentanyl monoclonal antibody, CTRX-101 (search), can rapidly reverse life-threatening respiratory depression (search) caused by fentanyl overdose (search). The peer-reviewed study, published in The Journal of Pharmacology and Experimental Therapeutics, represents a significant milestone in developing novel therapeutics to combat the opioid crisis.
Novel Mechanism of Action
Unlike existing overdose reversal therapies that rely on opioid receptor blockade, CTRX-101 (search) employs a fundamentally different approach. "CTRX-101 binds to fentanyl, sequesters it in the bloodstream, and prevents its lethal effects on the brain and respiratory system," explained Dr. Marco Pravetoni, Founder and Chief Scientific Officer at CounterX Therapeutics (search) and Professor of Psychiatry and Behavioral Sciences at the University of Washington School of Medicine.
The translational preclinical model demonstrated that administration of CTRX-101 (search) effectively restores normal breathing following fentanyl overdose (search), providing strong evidence for its potential clinical utility.
Addressing a Critical Public Health Crisis
The development of CTRX-101 (search) addresses an urgent medical need. Fentanyl overdose (search) has become the leading cause of death for Americans aged 18-45, resulting in approximately 50,000 deaths and more than 700,000 emergency department visits each year. The therapy is being developed specifically for the prevention and treatment of fentanyl overdose in patients with moderate to severe opioid use disorder (search).
Clinical Development Pathway
CTRX-101 (search) is designed as a long-acting subcutaneous injectable product that is not an opioid or controlled substance. Preclinical studies have shown the antibody was well-tolerated with no serious adverse events when used in combination with other medications for opioid use disorder (search). Importantly, it is not expected to cause opioid withdrawal and may be safe when used alongside other treatments.
"We believe CTRX-101 (search) has the potential to provide a differentiated pre-exposure prophylaxis treatment for fentanyl and complement current standards of care in opioid use disorders," said Dr. Shawn Iadonato, Chief Executive Officer at CounterX Therapeutics (search).
Platform Technology and Future Applications
The study represents a key milestone in translating products developed with CounterX Therapeutics (search)' CounterXL™ Platform from preclinical models to potential human application. The publication builds on previous preclinical studies of CTRX-101 (search) that have demonstrated efficacy, selectivity, and safety for the prevention and treatment of acute fentanyl overdose (search).
Beyond CTRX-101 (search), CounterX Therapeutics (search) is developing a broader pipeline of antibody therapies designed to reduce overdose risk and provide pathways to recovery. The company is also advancing vaccine technology aimed at preventing addiction relapse by blocking the euphoric effects of opioids.