Karmiris K, Paintaud G, Noman M et al. Gastroenterology 2009;137:1628–40.
This was an observational study evaluating the effects of adalimumab in Crohn’s disease patients who had previously failed on infliximab. Of 156 patients who received adalimumab maintenance therapy, 65.4% had to step up to adalimumab 40 mg/week during the follow-up period (median 20.4 weeks) and 38.5% eventually stopped adalimumab therapy – mainly due to loss of response. Significantly lower adalimumab trough serum levels were measured during the follow-up period in those who discontinued therapy compared with patients who remained on adalimumab, although on multivariate analysis, no predictors for short-term clinical response were detected, including trough serum levels.
For infliximab users, beyond 1 year there is a dropout rate of approximately 10% per year, either secondary to loss of response or due to adverse events. Data from the GAIN (Gauging Adalimumab Efficacy in Infliximab Nonresponders) study showed that adalimumab can be effective in the short-term in prior infliximab users who withdrew therapy [1].