Background and aims: Adalimumab has been shown to be efficacious and well-tolerated in Western patients with Crohn's disease. These 2 randomized, double-blind clinical trials evaluated adalimumab efficacy and safety in Japanese patients with moderate to severe Crohn's disease.
Methods: 90 patients enrolled in the induction trial and were randomized to receive adalimumab 160/80 mg, adalimumab 80/40 mg or placebo at Weeks 0/2. At Week 4, patients who achieved a decrease in CDAI ≥ 70 points versus Baseline entered the maintenance trial and were randomized to adalimumab 40 mg every other week or placebo for 52 weeks. All other patients received 4 more weeks of blinded adalimumab before entering the open-label portion of the maintenance trial. At/after Week 4 of the maintenance trial, blinded patients who flared/failed to respond entered the open-label portion. Open-label maintenance patients received adalimumab 40 mg every other week with the option of 80 mg every other week for flare/non-response.
Results: Clinical remission rates at Week 4 in the induction trial were 33.3%, 17.6% and 13.0% in the adalimumab 160/80 mg, adalimumab 80/40 mg and placebo groups, respectively. Maintenance remission rates were 38.1% for adalimumab and 9.1% for placebo at Week 52. Anti-TNF naïve patients achieved greater efficacy than anti-TNF exposed patients. Patients randomized to adalimumab achieved greater quality of life improvement versus placebo. There were no clinically relevant differences in safety between adalimumab and placebo.
Conclusions: Adalimumab is effective and well-tolerated for inducing and maintaining clinical remission in Japanese patients with moderate to severe Crohn's disease. NCT00445939; NCT00445432.