Efficacy and Safety of Thalidomide in Crohn’s Disease Patients with Perianal Fistula and Abscess

Background Medical therapies of parianal Crohn’s disease (CD) are limited. Thalidomide is an effective medical therapy to alleviate disease activity of CD. However, the effects and safety of thalidomide in the treatment of perianal fistula and abscess was not evaluated. Methods This retrospective cohort study was performed at a tertiary referral centre and recruited 73 patients with perianal CD who received thalidomide (50–100 mg) daily for 1 year. Data collected included demographics, medications, and disease behaviour. Clinical assessment of CD was conducted using the Crohn’s Disease Activity Index (CDAI), and perianal lesions were evaluated using the Fistula Drainage Assessment index and Perianal Disease Activity Index (PDAI). At the same time, the occurrence of adverse effects was recorded during treatment. Wilcoxon's signed-rank test and Student’s t-test were used to analyse the data. Results The CDAI score and laboratory indices were significantly lower after thalidomide treatment than at baseline (all P < 0.01). The value of PDAI was significantly lower in patients with symptomatic perianal abscess after thalidomide treatment than at baseline (10 [6.25, 10] versus 2.5 [1, 3.75]; P = 0.05). PDAI was also significantly reduced in all patients treated with thalidomide whether with or without perianal abscess drainage (all P < 0.05). The rates of responsive patients were similar between the thalidomide group and thalidomide combined with azathioprine group (72.73% [8/11] and 84% [21/25], respectively; P = 0.65). In total, 31% (24/77) of patients experienced adverse events, and interventions were required in 15 patients to reduce or eliminate discomfort from adverse events. Four patients discontinued thalidomide due to adverse effects. Side effects (rash, diarrhoea, peripheral neuropathy, somnolence, constipation, and numbness) were mild and mostly transient. Conclusions Thalidomide is effective in inducing clinical remission and response in CD patients with perianal fistula and abscess with or without abscess drainage. Thalidomide in combination with azathioprine is also effective in these patients. Low-dose thalidomide is proven to be effective and safe in treating perianal CD patients.