Efficacy and safety of a ready-to-drink bowel preparation for colonoscopy: a randomized, controlled, non-inferiority trial

Background: We performed a randomized, controlled, assessor-blinded, multicenter, non-inferiority (NI) study to compare the safety and efficacy of a ready-to-drink formulation of sodium picosulfate, magnesium oxide, and citric acid (SPMC oral solution) with a powder formulation (P/MC powder) for oral solution. Methods: Eligible participants (adults undergoing elective colonoscopy) were randomized 1:1 to split-dose SPMC oral solution or P/MC powder. The primary efficacy endpoint assessed overall colon-cleansing quality with the Aronchick Scale (AS), and the key secondary efficacy endpoint rated quality of right colon cleansing with the Boston Bowel Preparation Scale (BBPS). Assessments were performed by a treatment-blinded endoscopist. Tolerability was assessed using the Mayo Clinic Bowel Prep Tolerability Questionnaire. Safety assessments included adverse events and laboratory evaluations. Results: The study included 901 participants: 448 for SPMC oral solution; 453 for P/MC powder. SPMC oral solution demonstrated non-inferiority to P/MC powder {87.7% (393/448) responders versus 81.5% (369/453) responders [difference (95% confidence interval): 6.3% (1.8, 10.9)]}. The key secondary efficacy objective assessing the right colon was also met. According to the prespecified hierarchical testing, after meeting the primary and key secondary objectives, SPMC oral solution was tested for superiority to P/MC powder for the primary endpoint (p = 0.0067). SPMC oral solution was well tolerated. Most common adverse events were nausea (3.1% versus 2.9%), headache (2.7% versus 3.1%), hypermagnesemia (2.0% versus 5.1%), and vomiting (1.3% versus 0.7%) for SPMC oral solution and P/MC powder, respectively. Conclusions: Ready-to-drink SPMC oral solution showed superior efficacy of overall colon cleansing compared with P/MC powder, with similar safety and tolerability. [ClinicalTrials.gov identifier: NCT03017235.]