A Cochrane review concludes that drugs blocking tumour necrosis factor-alpha (TNF) are effective in maintaining remission in Crohn’s disease, but there are no comparative studies and data available do not allow adequate assessment of long-term safety.
The authors note that Crohn’s disease may be refractory to conventional treatment with corticosteroids and immunosuppressive drugs, but there is evidence that anti-TNF drugs may be beneficial.
The review’s aim was to assess evidence for the use of these drugs as maintenance therapy.
The researchers carried out a comprehensive literature search for randomised controlled trials of maintenance therapy with any anti-TNF drug in adult patients with Crohn’s disease, where patients either responded to or were in remission after anti-TNF induction, or who were in remission but unable to stop corticosteroids.
Outcome studied was continued remission.
Nine trials were located, involving four different anti-TNF drugs: infliximab (three studies), adalimumab (two studies), certolizumab (one study) and CDP571 (three studies).
Most of the studies could not be combined, but two of those with infliximab and two with CDP571 were suitable for combination.
Adverse event data could not be pooled because of inconsistent recording.
The trial data showed that infliximab was superior to placebo for maintenance of remission induced with infliximab (relative risk 2.50; 95% CI 1.64-3.80); it was also better for maintaining clinical response and fistula healing, and for corticosteroid-sparing.
The difference between doses of 5mg/kg and 10mg/kg was not statistically significant.
Adalimumab was better than placebo in two studies in maintaining remission and clinical response, and for corticosteroid-sparing, in patients who had adalimumab-induced remission.
There was no significant difference between 40mg given weekly or alternate weeks.
One trial showed certolizumab to be superior to placebo in maintaining remission and clinical response in patients with certolizumab-induced remission.
There was no evidence to support the use of CDP571 in Crohn’s disease.
The authors conclude that infliximab, adalimumab, and certolizumab were effective in maintaining remission in Crohn’s disease induced by the same agent.
There was no comparative data to indicate relative efficacy of the three drugs.
The three drugs were generally well tolerated with adverse effects being similar to placebo, but study sizes were generally inadequate to assess serious adverse effects associated with long-term use.