Objective: Intravenously administered infliximab, a monoclonal antibody directed against tumor necrosis factor-alpha, has been proven to be efficacious in the treatment of fistulas in patients with Crohn's disease. It has recently been suggested that local injections of infliximab might be beneficial as well. The aim of this study was to assess whether infliximab could play an effective role in the local treatment of perianal fistulas in Crohn's disease.
Material and methods: Local infliximab injections were administered to 11 patients suffering from Crohn's disease complicated by perianal disease. Eligible subjects included Crohn's disease patients with single or multiple draining fistulas, regardless of status of luminal disease at baseline. Patients, however, were excluded from the study if they had perianal or rectal complications, such as abscesses or proctitis or if they had previously been treated with infliximab. Twenty-milligram doses of infliximab were injected along the fistula tract and around both orifices at baseline and then every 4 weeks for up to 16 weeks or until complete cessation of drainage. No further doses were administered to patients who did not respond after three injections. Efficacy was measured in terms of response (a reduction in fistula drainage of 50% or more) and remission (complete cessation of fistula drainage for at least 4 weeks). Time to loss of response and health-related quality of life were also evaluated.
Results: Overall, 8/11 patients (72.7%) responded to the therapy and 4/11 (36.4%) reached remission, whereas 3/11 patients (27.2%) showed no response. Response or remission was very much dependent on the location of the fistulas, and time to loss of response was generally longer for patients who reached remission compared to patients in response. Changes in health-related quality of life, as assessed by the Inflammatory Bowel Disease Questionnaire (IBDQ), also reflected response or remission, with more marked improvements associated with remission. After a mean 10.5 months' follow-up (range 7-18 months), 6/11 patients (54.5%) are in response and 4/11 patients (36.4%) are in remission. No adverse events have been observed in this cohort of patients.
Conclusions: Local injections of infliximab along the fistula tract seem to be an effective and safe treatment of perianal fistulas in Crohn's disease. However, further controlled clinical investigations are warranted.