Mesalazine and inflammatory bowel disease - From well-established therapies to progress beyond the state of the art

Inflammatory bowel disease incidence has been constantly rising for the past few decades. Current therapies attempt to mitigate its symptoms since no cure is established. The most commonly prescribed drug for these patients is 5-aminosalicylic acid (5-ASA). Due to the low rate and seriousness of side effects compared to other therapies, 5-ASA is still largely prescribed in many stages of inflammatory bowel disease, including scenarios where evidence suggests low effectiveness. Although commercialized formulations have come a long way in improving pharmacokinetics, it is still necessary to design and develop novel delivery systems capable of increasing effectiveness at different stages of the disease. In particular, micro- and nano-sized particles might be the key to its success in Crohn's disease and in more serious disease stages. This review provides an overview on the clinical significance of 5-ASA formulations, its limitations, challenges, and the most recent micro- and nanoparticle delivery systems being designed for its controlled release. Emergent alternatives for 5-ASA are also discussed, as well as the future prospects for its application in inflammatory bowel disease therapies.

Recent advances in mesalamine colonic delivery systems

Background

Increased attention has been focused on the continuous development and improvement of mesalamine colonic specific delivery systems, for the effective treatment of inflammatory bowel diseases; thus enhancing therapeutic efficacy and reducing potential side effects. Mesalamine is a class IV drug, according to the Biopharmaceutics Classification System, used usually to treat inflammation associated with colon related diseases such as Crohn’s disease and ulcerative colitis.

Main text

An ideal colon targeting system aims to deliver a therapeutic agent, selectively and effectively, to the colon. This system should ideally retain the drug release in the upper GI tract (stomach and small intestine); while trigger the drug release in the colon. Several approaches have been used to fabricate formulations to achieve a colon specific delivery of mesalamine such as; time dependent, pH responsive, enzymatic/microbial responsive and ultrasound mediated approaches. This overview outlines the recent advances in mesalamine-colon delivery approaches for the potential treatment of ulcerative colitis and Crohn’ disease.

Conclusion

A combined pH-time dependent delivery system can improve mesalamine colonic drug delivery via employing carriers capable of retarding mesalamine release in the stomach and delivering it at predetermined time points after entering the intestine. The existence of specific enzymes, produced by various anaerobic bacteria present in the colon advocates the advantage of designing enzyme sensitive systems and combining it with pH-time dependent system to improve mesalamine colonic delivery. The use of ultrasound has shown promises to effectively treat inflammatory bowel diseases.

Budesonide is more effective than mesalamine or placebo in short-term treatment of collagenous colitis

BACKGROUND & AIMS

Studies reporting that budesonide is effective for the treatment of collagenous colitis have been small and differed in efficacy measures. Mesalamine has been proposed as a treatment option for collagenous colitis, although its efficacy has never been investigated in placebo-controlled trials. We performed a phase 3, placebo-controlled, multicenter study to evaluate budesonide and mesalamine as short-term treatments for collagenous colitis.

METHODS

Patients with active collagenous colitis were randomly assigned to groups given pH-modified release oral budesonide capsules (9 mg budesonide once daily, Budenofalk, n = 30), mesalamine granules (3 g mesalamine once daily, Salofalk, n = 25), or placebo for 8 weeks (n = 37) in a double-blind, double-dummy fashion. The study was conducted in 31 centers (hospital clinics and private practices) in Germany, Denmark, Lithuania, Spain, and the United Kingdom. The primary end point was clinical remission at 8 weeks defined as ≤ 3 stools per day. Secondary end points included clinical remission at 8 weeks, according to the Hjortswang-Criteria of disease activity, taking stool consistency into account.

RESULTS

A greater percentage of patients in the budesonide group were in clinical remission at week 8 than the placebo group (intention-to-treat analysis, 80.0% vs 59.5%; P = .072; per-protocol analysis, 84.8% vs 60.6%; P = .046). Based on the Hjortswang-Criteria, 80.0% of patients given budesonide achieved clinical remission compared with 37.8% of patients given placebo (P = .0006); 44.0% of patients given mesalamine achieved clinical remission, but budesonide was superior to mesalamine (P = .0035). Budesonide significantly improved stool consistency and mucosal histology, and alleviated abdominal pain. The rate of adverse events did not differ among groups.

CONCLUSIONS

Oral budesonide (9 mg once daily) is effective and safe for short-term treatment of collagenous colitis. Short-term treatment with oral mesalamine (3 g once daily) appears to be ineffective. ClinicalTrials.gov number, NCT00450086.

Mesalamine in the treatment and maintenance of remission of ulcerative colitis

Ulcerative colitis (UC) is a chronic disease of the GI tract that is characterized by mucosal inflammation in the colon. Mesalamine (mesalazine) is a 5-aminosalicylic acid compound that is the first-line treatment for patients with mild-to-moderate UC. There are multiple formulations of mesalamine available, primarily differentiated by their means of delivering active mesalamine to the colon. Mesalamine has been demonstrated in randomized controlled trials to induce both clinical response and remission, and maintain clinical remission, in these patients. It has few serious adverse effects and is generally well tolerated by patients. The main areas of uncertainty with use of mesalamine in patients with UC center on the optimal dose for induction of response, how to maintain patient adherence and the role of mesalamine in cancer chemoprophylaxis. Generic forms of mesalamine have yet to be approved by regulatory bodies in the USA.

Once-daily versus multiple-daily mesalamine for patients with ulcerative colitis: a meta-analysis

OBJECTIVE

To systematically review the efficacy and safety of once-daily (OD) mesalamine for the treatment of ulcerative colitis (UC) compared with multiple-daily (MD) mesalamine.

METHODS

Electronic databases up to July 2011 were searched for related studies evaluating the efficacy of OD vs MD for treatment of UC. Only randomized controlled trials (RCTs) were considered eligible. Remission rates or relapse rates were analyzed using intention-to-treat (ITT) and per-protocol (PP) analysis. Pooled relative risk (RR) and 95% confidence interval (CI) were calculated. Publication bias was assessed with a funnel plot.

RESULTS

Overall 10 RCTs including 9 full-text manuscripts and one abstract met the inclusion criteria. OD dosing of mesalamine was shown to be as effective as MD dosing for the maintenance of clinical remission in patients with quiescent UC (RR = 1.00, 95% CI 0.89-1.12) by ITT analysis. For active UC, a mild but significant benefit was achieved by OD dosing compared with MD dosing (RR = 0.80, 95% CI 0.64-0.99). Total adverse events were similar using OD and MD mesalamine in quiescent UC (RR = 1.06, 95% CI 0.93-1.20). Compliance with OD was slightly better than with MD (RR = 0.92, 95% CI 0.82-1.03).

CONCLUSIONS

OD mesalamine is as effective and has a comparable safety profile as MD regimens for the maintenance treatment of UC, and is even more effective for inducing remission in active UC.

Drug development in inflammatory bowel disease: the role of the FDA

All medicinal compounds sold in the United States for inflammatory bowel disease (IBD) are regulated by the Food and Drug Administration (FDA) via a number of regulations dating back to 1906. The primary contemporary role of the FDA is in the assessment of safety and efficacy, and subsequent marketing, of medications based on preclinical and clinical trial data provided by sponsors. This includes pharmacokinetic, toxicology and clinical studies, and postapproval safety monitoring. Mesalamine formulations, budesonide, and biologic therapies have all been assessed for efficacy and safety in IBD by the FDA via large randomized controlled trials (RCTs). There has been considerable evolution in the endpoints used by the FDA to approve medications for IBD, and the mechanisms through which newer agents have been approved. This review examines the methods of drug approval by the FDA, the bench-marks used to approve drugs for IBD, and recent controversies in the FDA's role in drug approval in general.