The efficacy and tolerability of AST-120 (spherical carbon adsorbent) in active pouchitis

Although a majority of patients with pouchitis respond favorably to antibiotic therapy, many relapse frequently, and nonabsorbable and non-antibiotic-based agents are desirable for reducing bacterial resistance and the systemic adverse effects associated with long-term antibiotic exposure. AST-120 (a spherical carbon adsorbent) comprises highly adsorptive, porous carbon microspheres with the ability to adsorb small-molecular-weight toxins, inflammatory mediators,and harmful bile acids. The aim of this pilot trial was to evaluate the efficacy and tolerability of AST-120 in the treatment of active pouchitis.

Eligible patients were recruited from two subspecialty pouchitis clinics. Inclusion criteria were(i) ileal pouch-anal anastomosis performed for ulcerative colitis; (ii) active pouchitis with Pouchitis Disease Activity Index (PDAI) scores > or =7; and (iii) discontinuation of antibiotic therapy for at least 2 weeks. Exclusion criteria included Crohn's disease of the pouch, isolated cuffitis, pouch strictures, abscess, and sinuses. All eligible patients received AST-120 in 2-g sachets (oral) open label, thrice a day for 4 weeks. The primary efficacy end point was remission as defined by a PDAI score of < 7 points; the main secondary end point was clinical response, defined by a reduction of the PDAI score of > or =3 points.

Nineteen of 20 patients completed the trial. Eleven patients (55.0 % ) had a clinical response to the therapy and 10 patients (50.0 % ) entered remission. Median reduction in the PDAI symptom, endoscopy, and histology subscores, and PDAI total scores after 4 weeks were -2( P = 0.002), -2 ( P = 0.003), 0 ( P = 0.32), and -4 ( P = 0.001) points, respectively. The agent was well tolerated; one patient experienced transient mild elevation of alkaline phosphatase of uncertain significance and one patient experienced an upper respiratory infection after taking one dose of AST-120 and was excluded from the fi nal analysis for the calculation of pre- and post-trial PDAI scores.

AST-120 seems to be effective and well tolerated in treating patients with active pouchitis.A randomized, placebo-controlled trial is warranted for assessing the long-term efficacy and safety of AST-120 in the disease.