Systematic review with meta-analysis: prevalence, risk factors and costs of aminosalicylate use in Crohn's disease.

BACKGROUND: Aminosalicylates are the most frequently prescribed drugs for patients with Crohn's disease (CD), yet evidence to support their efficacy as induction or maintenance therapy is controversial. AIMS: To quantify aminosalicylate use in CD clinical trials, identify factors associated with use and estimate direct annual treatment costs of therapy. METHODS: MEDLINE, Embase and CENTRAL were searched to April 2017 for placebo-controlled trials in adults with CD treated with corticosteroids, immunosuppressants or biologics. The proportion of patients co-prescribed aminosalicylates in placebo arms was pooled using a random-effects model. Meta-regression was used to identify factors associated with aminosalicylate use. Annual treatment costs were estimated using the 2016 Ontario Drug Benefit Program. RESULTS: Forty-two induction and 10 maintenance trials were included. The pooled proportion of patients co-prescribed aminosalicylates was 44% [95% CI: 39%-49%] in induction trials and 49% [95% CI: 35%-64%] in maintenance trials. There was substantial to considerable heterogeneity (I2  = 86.0%, 91.8% for induction and maintenance trials, respectively). In multivariable meta-regression, aminosalicylate use has decreased over time in induction trials (OR 0.50 [95% CI: 0.34-0.74] per 10-year increment). While a decline has been seen over time, 35% of CD patients were still using aminosalicylates in contemporary trials from the last 5 years. The estimated annual cost for the lowest price mesalazine (mesalamine) formulation is approximately $32 million for the Canadian CD population. CONCLUSIONS: Over one-third of CD patients entering clinical trials are still co-prescribed aminosalicylates. A definitive trial is needed to inform the conventional practice of using aminosalicylates as CD maintenance therapy.

Systematic review with meta-analysis: endoscopic and histologic placebo rates in induction and maintenance trials of ulcerative colitis.

BACKGROUND: Regulatory requirements for claims of mucosal healing in ulcerative colitis (UC) will require demonstration of both endoscopic and histologic healing. Quantifying these rates is essential for future drug development. AIMS: To meta-analyse endoscopic and histologic placebo response and remission rates in UC randomised controlled trials (RCTs) and identify factors influencing these rates. METHODS: MEDLINE, EMBASE and the Cochrane Library were searched from inception to March 2017 for placebo-controlled trials of pharmacological interventions for UC. Endoscopic and histologic placebo rates were pooled by random effects. Mixed effects univariable and multivariable meta-regression was used to evaluate the influence of patient, intervention and trial-related study-level covariates on these rates. RESULTS: Fifty-six induction (placebo n = 4171) and 8 maintenance trials (placebo n = 1011) were included. Pooled placebo endoscopic remission and response rates for induction trials were 23% [95 confidence interval (CI) 19-28%] and 35% [95% CI 27-42%] respectively, and 20% [95% CI 16-24%] for maintenance of remission. The pooled histologic placebo remission rate was 14% [95% CI 8-22%] for induction trials. High heterogeneity was observed for all outcomes (I2 56.2%-88.3%). On multivariable meta-regression, central endoscopy reading was associated with significantly lower endoscopic placebo remission rates (16% vs 25%; OR = 0.52, [95% CI 0.29-0.92], P = 0.03). On univariable meta-regression, higher histologic placebo remission was associated with concomitant corticosteroids (OR = 1.17 [95% CI 1.08-1.26], P < 0.0001, per 10% increase in corticosteroid use). CONCLUSIONS: Placebo endoscopic and histologic rates range from 14% to 35% in UC RCTs but are highly heterogeneous. Outcome standardisation may reduce heterogeneity and is needed in this field.