F1-CRM

F1-CRM is an anti-fentanyl conjugate vaccine designed to treat opioid use disorder (OUD) and prevent fatal fentanyl overdose. The vaccine consists of a fentanyl-based small molecule hapten (F1) covalently conjugated to the immunogenic carrier protein CRM197 (diphtheria toxin cross-reactive material). Its mechanism of action involves stimulating the immune system to produce high-affinity, fentanyl-specific polyclonal antibodies that remain in the systemic circulation. These antibodies act as a "peripheral sink," sequestering fentanyl molecules and preventing them from crossing the blood-brain barrier. By reducing the distribution of fentanyl to the central nervous system, the vaccine attenuates the drug's reinforcing effects and protects against life-threatening respiratory depression and bradycardia. F1-CRM is typically formulated with adjuvants, such as aluminum hydroxide and the synthetic TLR7/8 agonist INI-4001, to enhance its immunogenicity and clinical efficacy. The vaccine is being developed by researchers at the University of Washington and Inimmune Corporation.

Other names

fentanyl-CRM197 conjugate vaccinefentanyl-CRM-197 conjugate vaccinefentanyl-CRM 197 conjugate vaccineanti-fentanyl vaccineFEN-CRM