Authors: Michael Epstein, Lucy Clayton, Richard Ng Kwet Shing
Introduction. Successful bowel cleansing is required for effective colonoscopy. Polyethylene glycol (PEG) –based bowel preparations are widely used for this, despite many still requiring high fluid volume intake. To avoid that inconvenience, the phase 2 study OPT1 assessed the clinical proof of concept of NER1006, a novel 1L PEG-based bowel preparation, versus standard 2L PEG + ascorbate (Control). Here we report the total fluid intake versus the achieved colon cleansing quality for NER1006 and the Control.
Methods. The OPT study had two parts and analysed five different low volume PEGs vs the control. This post hoc analysis assessed NER1006 vs the control in Part 2 of the study. Treatment-blinded colonoscopists assessed the bowel cleansing quality using the Harefield Cleansing Scale (HCS). For each patient, observed segmental cleansing scores of 0-4 for each of the 5 segments, adding to a total of max 20, and the total fluid volume intake (= preparation volume + required additional fluid volume + voluntary ad libitum clear fluid volume) were calculated.
Results. Sixty patients underwent screening colonoscopy. They were either 40 to 70 years old with a known personal or familial risk of contracting CRC, or 55 to 70 years old. Thirty patients per group had their bowels prepared with overnight split dosing regimens of either NER1006 or the Control. Patient baseline characteristics and required fluid volumes are indicated in Tables 1 and 2. Results from each patient are shown in Figure 1. Among patients taking NER1006, 29/30 (97%) achieved cumulative segmental scores of HCS 15 or higher which is in the high-quality domain of the HCS. This happened seemingly independent of their total fluid volume intake beyond the total required minimum of 2L. The control showed larger cleansing variability. At an average of 3004 ± 718 mL (SD) for the NER1006 group the total fluid volume intake was significantly lower than for the control group (3667 ± 530 mL; P<0.001). Half of the patients (15/30) taking NER1006 chose to drink under 3L in total but still achieved a very high level of cleansing.
Discussion. Bowel preparation with overnight split dosing regimen of NER1006 can achieve a clinically useful bowel cleansing with a low total volume intake, even if some patients voluntarily preferred to drink more than 3L in total. NER1006 achieved its cleansing success mostly at the high quality level and at a significantly lower total fluid intake than standard 2L PEG + ascorbate.