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et al. evaluated the response on adalimumab therapy of ten patients (seven CD, three
UC) previously treated with infliximab, nine of whom developed a hypersensitivity
reaction to this medication [ 30 ]. Eight patients responded to adalimumab with
decreased PCDAI in patients with CD and decreased LCAI in patients with
UC. Seven patients were on concomitant corticosteroids at time of adalimumab
initiation, and four patients were able to successfully taper off this medication
within a mean of 5.5 months. A second small retrospective study of 14 pediatric
patients with CD who had an allergic infusion reaction or decreased response to
infliximab despite dose escalation showed less robust response to adalimumab;
however, a majority of patients still responded, with 50% having complete response
and 14% having a partial response; in the subset of patients with perianal disease,
three of five patients maintained fistula closure with this therapy [ 31 ]. The differ-
ences in the outcomes of these studies may be due to variation of adalimumab dos-
ing, which was not controlled, and patient selection, with the former study focusing
only on patients who had an infusion reaction to infliximab rather than including
those with suboptimal response. Subsequent larger population-based cohort studies
have noted initial response to adalimumab in approximately two-thirds of patients
who have failed infliximab therapy [ 32 , 33 ]. RESEAT, a large, multicenter retro-
spective evaluation of the safety and effect of adalimumab therapy, examined the
outcomes of 115 patients with pediatric Crohn’s disease from 12 centers who had
received at least one dose of adalimumab [ 34 ]. Ninety-five percent of this cohort
had previously received infliximab therapy, and most had discontinued therapy due
to secondary loss of response (47%) or infusion reactions/delayed hypersensitivity
(45%). The majority of patients initially received an induction regimen (160/80 mg
or 80/40 mg) followed by 40 mg every other week; 27% of patients required dose
escalation, most commonly to weekly administration. Clinical response, defined by
a decrease in PGA from moderate/severe to mild/inactive or from mild to inactive,
at 3, 6, and 12 months, occurred in 65, 71, and 70% of patients, respectively. Clinical
remission rates (PGA inactive) at similar time points were 32, 43, and 49%, respec-
tively. Overall, steroid exposure decreased over the study time points, and 42% of
the cohort was in steroid-free clinical remission at 12 months, again highlighting the
efficacy of this therapy in pediatric CD.
An initial preliminary prospective observational study by Viola et al. showed a
remarkable response to adalimumab therapy in 23 patients with moderate to severe
pediatric CD, nine of whom had not received previous anti-TNF therapy [ 35 ]. In
this study, patients were administered induction doses of adalimumab at 0 and
2 weeks followed by maintenance therapy injections every other week over the
course of 48 weeks. The percentage of patients in clinical remission increased from
36.3% after two weeks of adalimumab therapy to 65.2% after 48 weeks of treat-
ment. Clinical response rates also improved from 87 to 91% at these same time
points, respectively. The average dosage of corticosteroid, PCDAI, CRP, and ESR
levels significantly decreased throughout the course of the study. Overall response
and remission rates were higher in this prospective cohort, which may be related to
higher dosing regimens, with 65% of the cohort receiving adalimumab mainte-
nance therapy of 80 mg every other week through at least 12 weeks. The IMAgINE
S. Patel and J. Strople