Microcystalline Cellulose-Free Sodium Phosphate(NaP) Tablets(INKP-102)Require Less Irrigation During Colonoscopy Than Visicol® Tablets

Abstract

Background: Visicol(V)is an FDA approved NaP tablet(tab) purgative;its safety and efficacy has been previously established. V contains 13% microcrystalline cellulose(MCC), a commonly used binder for tablets. MCC may leave residue in the colon requiring irrigation to ensure adequate visualization of the mucosa. This added time for irrigation impacts the efficiency of performing colonoscopy. We compared the irrigation requirements during colonoscopy for INKP-102, a new MCC-free NaP tab formulation, to V (Salix Pharmaceuticals, Inc, Morrisville, NC). Methods: A multicenter, investigator-blinded study compared 2 doses of INKP-102 with 40 tabs of V. Patients (pts) were randomized to 1 of 3 treatment groups (grps): INKP-102 40 (60g) or 32 tabs (48g) or V 40 tabs(60g). Each grp took 20 tabs the evening prior, and the remainder the next morning 3-5 hrs before colonoscopy. Overall colon cleansing was evaluated by physician questionnaire using a 4-point scale based on retained colonic content and need for suctioning. Also, irrigation requirements during colonoscopy were scored from 0 to 3 [0 = none, 1 = <50 mL, 2 = 50-100 mL, 3 = >100 mL]. Results: 704 pts (INKP-102 40 tabs = 233; 32 tabs = 236; V = 235) took ≥1 tab of study med, had a colonoscopy and were evaluated. Colon cleansing was comparable between the 3 grps with ≥95% having excellent/good scores. Less irrigation was required for INKP-102 (both 32 and 40 tabs) compared to V. Significantly fewer pts receiving 40 (21%) and 32 tabs (25%)of INKP-102 required irrigation during colonoscopy compared with pts receiving V (44%) (P < 0.0001 V vs both INKP-102 grps). The distribution of irrigation scores were significantly different from V for the 40 and 32 tab INKP-102 arms (P < 0.0001; P = 0.0003). Mean irrigation scores were significantly lower for pts receiving 40 (0.42 ± 0.91) and 32 tabs (0.47 ± 0.92) INKP-102 compared to V(0.86 ± 1.13) (P < 0.0001 Visicol vs both INKP-102 grps). The distribution of irrigation scores for INKP-102(40 and 32 tabs) remained significantly different from V when the following analyses were performed: females (P = 0.0004; P < 0.0001), males (P = 0.0042; P = 0.0420), pts ≤ 64 yrs (P = 0.0001; P = 0.0021) and pts > 64 yrs (N = 175)in the 40 tab(P = 0.004) but not the 32 tab grp (P = 0.1333). This difference from V compared to INKP-102 32, and 40 tabs respectively, was also observed for the mean irrigation scores for female (P = 0.0018; P = 0.0003), males (P = 0.0002; P = 0.0181), pts ≤ 64(P = 0.0004; P = 0.0003) and pts > 64 (P = 0.0004; P = 0.0277). Conclusions: Significantly less irrigation during colonoscopy is necessary for INKP-102 compared to V. Given the lower requirement for irrigation and established efficacy, INKP-102 may improve colonoscopy efficiency.