Safety and efficacy of remimazolam in high risk colonoscopy: A randomized trial

Background: Procedural sedation of ASA III/IV patients has increased risk. Remimazolam (an ultra-short-acting benzodiazepine) has proven safe and efficient for outpatient colonoscopy sedation. Methods: A double-blind, randomized, multi-center, parallel group trial was performed, comparing remimazolam to placebo with an additional open-label arm for midazolam in procedural sedation of 79 ASA III/IV patients undergoing colonoscopy. This was the third of 3 Phase III trials for remimazolam in the procedural sedation program. The primary end point was the safety of remimazolam. Results: Of 79 patients randomized at 3 US sites, 77 underwent sedation and colonoscopy (31 received remimazolam, 16 placebo and 30 midazolam). Incidence and frequency of treatment emergent adverse events (TEAEs) were comparable in all three treatment arms, and independent of ASA status. One TEAE leading to discontinuation and one serious TEAE were reported; both in the open label midazolam arm. The efficacy endpoint was achieved for remimazolam, placebo, and midazolam in 87.1%, 0%, and 13.3% of patients (p<0.00001 for remimazolam versus placebo and versus midazolam, respectively). Conclusions: Remimazolam is safe and efficient in procedural sedation of high risk ASA patients undergoing colonoscopy, showing a safety profile comparable to that in low risk ASA.