Background  Thalidomide has been shown to be an effective treatment in Crohn's disease.

Aim  To assess the efficacy and tolerability of thalidomide in refractory Crohn's disease patients.

Methods  Twenty-five patients were treated. Retrospective ‘estimated’ Crohn's Disease Activity Indices were assessed at baseline and at the end of follow-up. Clinical response was defined as symptomatic improvement and a reduction in the ‘estimated’ Crohn's Disease Activity Index of >100 points, ≥50% reduction in draining fistulas or clinical improvement in perianal ulcers. Clinical remission was defined as symptom resolution and an ‘estimated’ Crohn's Disease Activity Index <150, complete fistula closure or complete ulcer healing.

Results  Six of eight patients treated for luminal disease responded to thalidomide at a median follow-up of 12 months (three clinical responses, three clinical remissions). The median reduction in ‘estimated’ Crohn's Disease Activity Index was 212 points (P = 0.005). Nine of 11 patients with active fistulizing disease responded to thalidomide (six responses; three remissions). The four patients treated for both luminal and fistulizing disease had fistula response. Three of them had a response in luminal disease activity. One of two patients with ulcerating perianal disease responded. Twelve patients discontinued treatment because of adverse effects (three sedation; two abdominal pain; one leucopoenia; six neuropathy).

Conclusion  Thalidomide is an effective short- to medium-term treatment in selected patients with refractory luminal and fistulizing Crohn's disease. Its long-term use is limited by toxicity.