Bowel preparation quality of NER1006 versus oral trisulfate solution as assessed by colonoscopists at site: a post hoc analysis from a randomized controlled trial

Authors: Michael Epstein, Pradeep Bekal; Richard Ng Kwet Shing

Background: Effective colonoscopy requires successful bowel cleansing. Inadequate bowel cleansing may decrease diagnostic sensitivity, necessitate repeat procedures and potentially delay appropriate treatment. The increasing frequency of the incidence of colorectal cancer arising in the ascending colon necessitates effective cleansing of this area; additionally these cancers are often associated with poorer prognoses. NER1006 is the first 1L polyethylene glycol (PEG)-based bowel preparation, a patented combination optimized for effective bowel cleansing. The NOCT study (a multicenter randomized Phase 3 clinical trial investigating bowel cleansing efficacy of NER1006 vs trisulfate solution) reported bowel preparation quality assessed by central readers.1 This post hoc analysis shows the cleansing assessment by site colonoscopists, who typically guide clinical decision making; hence this study may be more relevant for clinical practice than previous studies.

Methods: In the NOCT study 621 patients (males and females, aged 18–85) were randomly assigned in a 1:1 ratio to receive either NER1006 or trisulfate solution, each administered as an overnight split-dose. Data from the 523 patients who underwent a colonoscopy and had a site colonoscopist assessment were used in this analysis. Colonoscopists were blinded to the preparation administered. Cleansing was assessed according to the Harefield Cleansing Scale2; segmental scores 3 and 4 were judged as high quality cleansing.

Results: As Table 1 shows, the bowel preparation quality of NER1006 when assessed by site colonoscopists did not show a statistically significant difference to trisulfate for the overall colon (93.1% vs 93.9%, P=0.681; 95% CI: -5.1–3.3%) or ascending colon (80.3 vs 73.9%, P=0.079; 95% CI: -0.7–13.6%). There was, however, a numerical advantage in favor of NER1006 on the proportion of patients achieving high-quality cleansing success in the right colon.

Conclusions: For both preparations, site colonoscopist findings demonstrated similar very high rates of cleansing success for the overall colon (>93%) and high rates of high-quality cleansing of the ascending colon (>73%), however, statistical significance was not met in either comparison. The rates of cleansing success in the ascending colon reported by the site colonoscopists are notably higher than those previously reported by central readers.

  1. DeMicco M et al. United European Gastroenterol J 2016; 4(5S): A1–156. OP375