P323. The effectiveness of adalimumab maintenance treatment for Crohn's disease and related prognostic factors: a Japanese single-center study
H. Tanaka, M. Miyakawa, M. Nasuno, S. Motoya, A. Imamura, Sapporo Kosei General Hospital, IBD Center, Sapporo, Japan
Adalimumab has been established as a useful treatment option for patients diagnosed with Crohn's disease (CD) in Japan. However, very few studies have reported on Japanese patients with CD receiving adalimumab maintenance treatment for more than 52 weeks. Here, we evaluated the effectiveness of adalimumab maintenance treatment in Japanese patients with CD and related prognostic factors.
We investigated all patients who were treated with adalimumab for luminal CD between October 2010 and March 2013 at the IBD Center, Sapporo Kosei General Hospital. The effectiveness of adalimumab maintenance treatment was evaluated using the sustained treatment success rates, which were estimated using the Kaplan–Meier method. Sustained treatment success was defined as a lack of treatment failure. Treatment failure was defined as follows: (1) discontinuation of adalimumab due to loss of response or side effects; 2) the need for dose escalation due to loss of response; (3) the need for surgery for CD; or (4) the need for hospitalization for CD. Prognostic factors related to the sustained treatment success rates were evaluated using the log-rank test.
A total of 88 patients were included for this retrospective study. Of these, 39 were female, with a mean age of 30.9 years and a mean disease duration of 9.0 years. The mean C-reactive protein level was 2.1 mg/dl. Sixty-one patients had ileocolitis, 15 had ileitis, and 12 had colitis. Furthermore, 29 patients had stricturing disease, 7 had intra-abdominal fistulas, and 43 had perianal disease. Eighteen patients were smokers. Concomitant treatment with azathioprine or 6-mercaptopurine, 5-aminosalicylic acid, elemental diet therapy, and prednisolone was administered in 43, 76, 46, and 13 patients, respectively. Before initiating adalimumab therapy, 35 patients had at least 1 surgery, and 48 patients were naïve to infliximab, while 40 had prior infliximab use. The 1- and 2-year sustained treatment success rates were 58% and 45%, respectively. Colitis type, disease duration of more than 2 years, prior infliximab use, stricturing disease, intra-abdominal fistulas, and concomitant treatment with prednisolone were significant predictors of treatment failure. The 2-year sustained treatment success rates in patients who were naïve to infliximab (71%) and had the disease duration of less than 2 years (76%) were higher compared with other prognostic factors.
Treatment failure was experienced by 55% of Japanese patients with CD receiving adalimumab maintenance treatment over a 2-year period. The effectiveness of adalimumab maintenance treatment is expected to improve by selecting infliximab-naïve patients with CD and by initiating adalimumab therapy as soon as possible from the diagnosis.