Randomized Controlled Trial of Remimazolam Compared with Placebo in Japanese Patients Undergoing Colonoscopy: A Phase III, Investigator-Initiated Trial

Introduction: We conducted an investigator-initiated clinical trial in which remimazolam was used to achieve sedation in patients undergoing colonoscopies. Methods: This multicenter, double-blind, placebo-controlled, phase III investigator-initiated trial included patients who underwent colonoscopy under sedation with remimazolam (initial dose: 3 mg; additional dose: 1 mg) or normal saline (placebo). The primary endpoint of the study was the successful sedation rate during colonoscopy, defined as achieving a Modified Observer's Assessment of Alertness/ Sedation (MOAA/S) score of ≤4 before the procedure, maintaining this score throughout colonoscopy, and requiring no more than five additional drug doses per 15 min. Results: The sedation success rate was 95.0% (38/ 40 patients) in the remimazolam group and 0.0% (0/11 patients) in the placebo group (p < 0.01). The time from the end of procedure to regaining consciousness was 0.0 (interquartile range: 0.0-0.0)min in both groups. The time from the end of the procedure to ambulation was 5.0 (interquartile range: 0.0-10.0) min in the remimazolam group and 0.0 (interquartile range: 0.0-0.0) min in the placebo group (p = 0.02). Serious adverse events were not observed. Conclusion: The use of remimazolam to achieve sedation in Japanese patients undergoing colonoscopy was more effective than placebo.