Evaluation of Intravenous CS-1103 Safety and Effects After Fentanyl and Naloxone Challenge in Healthy Adults Aged 18 to 55

What this Trial Is About

Researchers are evaluating the safety, tolerability, pharmacokinetics, and effects of CS-1103 given by intravenous infusion in healthy adults aged 18 to 55 years. The study involves a clinically relevant dose of fentanyl followed by naloxone blockade to better understand how CS-1103 interacts in this setting. This Phase 2 trial aims to collect important data on how the drug behaves in the body and its safety profile under these conditions. Participants are randomly assigned to one of two groups one group receives naloxone followed by fentanyl and then a placebo saline, while the other group receives naloxone followed by fentanyl and then CS-1103 1,000 mg by intravenous infusion. The study uses a parallel design and is quadruple-blinded, meaning participants, caregivers, investigators, and outcome assessors do not know group assignments. During the study, participants are monitored closely for adverse events through physical exams, vital signs, ECGs, and laboratory tests over 3 days plus follow-up on day 10. Blood and urine samples are collected to measure drug concentrations and fentanyl excretion over 48 hours. The research team also evaluates effects on heart rhythm and naloxone levels. The total study participation lasts through primary outcome assessment by month 7, with full study completion by month 10.

A Phase 2 Safety, Tolerability, PK, and Efficacy Study of CS-1103 Following Fentanyl Challenge With Naloxone Blockade