Mesalamine did not prevent recurrent diverticulitis in phase 3 controlled trials

Gastroenterology. 2014 Oct;147(4):793-802. doi: 10.1053/j.gastro.2014.07.004. Epub 2014 Jul 16.


Background & aims: No therapy has been proven to prevent the recurrence of diverticulitis. Mesalamine has shown efficacy in preventing relapse in inflammatory bowel disease, and there is preliminary evidence that it might be effective for diverticular disease. We investigated the efficacy of mesalamine in preventing recurrence of diverticulitis in 2 identical but separate phase 3, randomized, double-blind, placebo-controlled, multicenter trials (identical confirmatory trials were conducted for regulatory reasons).

Methods: We evaluated the efficacy and safety of multimatrix mesalamine vs placebo in the prevention of recurrent diverticulitis in 590 (PREVENT1) and 592 (PREVENT2) adult patients with ≥1 episodes of acute diverticulitis in the previous 24 months that resolved without surgery. Patients received mesalamine (1.2 g, 2.4 g, or 4.8 g) or placebo once daily for 104 weeks. The primary end point was the proportion of recurrence-free patients at week 104. Diverticulitis recurrence was defined as surgical intervention at any time for diverticular disease or presence of computed tomography scan results demonstrating bowel wall thickening (>5 mm) and/or fat stranding consistent with diverticulitis. For a portion of the study, recurrence also required the presence of abdominal pain and an increase in white blood cells.

Results: Mesalamine did not reduce the rate of diverticulitis recurrence at week 104. Among patients in PREVENT1, 53%-63% did not have disease recurrence, compared with 65% of those given placebo. Among patients in PREVENT2, 59%-69% of patients did not have disease recurrence, compared with 68% of those given placebo. Mesalamine did not reduce time to recurrence, and the proportions of patients requiring surgery were comparable among treatment groups. No new adverse events were identified with mesalamine administration.

Conclusions: Mesalamine was not superior to placebo in preventing recurrent diverticulitis. Mesalamine is not recommended for this indication. ID: NCT00545740 and NCT00545103.

Keywords: Anti-Inflammatory; Clinical Trial; Colon Inflammation; Diverticula.

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Anti-Inflammatory Agents / adverse effects
  • Anti-Inflammatory Agents / therapeutic use*
  • Colectomy
  • Colonic Diseases / diagnosis
  • Colonic Diseases / drug therapy*
  • Colonic Diseases / surgery
  • Diverticulitis / diagnosis
  • Diverticulitis / drug therapy*
  • Diverticulitis / surgery
  • Female
  • Gastrointestinal Agents / adverse effects
  • Gastrointestinal Agents / therapeutic use*
  • Humans
  • Male
  • Mesalamine / therapeutic use*
  • Middle Aged
  • Secondary Prevention
  • Time Factors
  • Treatment Outcome
  • United States


  • Anti-Inflammatory Agents
  • Gastrointestinal Agents
  • Mesalamine

Associated data