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A key concern about IFX is the cost, given both the drug cost and infusion center
cost. However numerous studies have evaluated the financial benefit of IFX when
accounting for reduction of hospitalizations and surgery over 1 year [ 15 – 17 ].
Adhering to IFX maintenance therapy decreases hospital length of stay and lowers
the overall cost of hospitalization versus nonadherence over the first year [ 18 , 19 ].
Mucosal Healing
In addition to clinical response and remission, IFX is also successful at improving
mucosal lesions. Subsets of the initial trials of IFX demonstrated that improvement
of the Crohn’s Disease Endoscopic Index of Severity (CDEIS) correlated with the
improvement in clinical improvement [ 20 ]. An endoscopic sub-study of ACCENT I
found those on schedule IFX had improved musical healing (defined as lack of
mucosal ulceration) compared to a single dose at week 10 (31% vs. 0%, p < 0.01)
and week 54 (50% vs. 7% in episodic group, p < 0.007) [ 21 ]. Similarly, mucosal
healing was a secondary end point of the SONIC trial (defined as lack of mucosal
ulcerations among those who had them at baseline) [ 14 ]. 30% of subjects in the IFX
monotherapy arm and 43.9% in the combination arm achieved mucosal healing.
Fistula Healing
In an early study to determine the effectiveness of IFX for fistula healing, 94 were
subjects randomized to placebo, IFX 5 mg/kg or 10 mg/kg, and fistula response
(reduction by 50% or more in draining fistulas from baseline at two consecutive
visits) was achieved in 68% of those on IFX 5mg/kg, 56% on IFX 10 mg/kg, and
26% on placebo (p < 0.002 and p < 0.02, respectively) [ 22 ]. Subsequently ACCENT
II was designed to specifically evaluate the efficacy and safety of IFX for maintain-
ing fistula closure [ 23 ]. In ACCENT II, subjects received IFX at 5 mg/kg at weeks
0, 2, and 6. Those with a response (reduction of draining fistulas by 50% at week 10
and 14) were randomized to receive scheduled IFX 5 mg/kg or placebo. The median
time to loss of response among responders was 14 weeks in the placebo group and
over 40 weeks in the IFX group (p < 0.001). At week 54, 19% of subjects receiving
placebo had complete absence of draining fistulas compared to 36% of patients
receiving scheduled IFX (p < 0.009). Patients on maintenance IFX in ACCENT II
had significantly less hospitalization, surgeries, and procedures compared to pla-
cebo [ 24 ]. Combination IFX used with seton placement is also successful with com-
plete healing in approximately two thirds of subjects in one single center study [ 25 ].
ACCENT II also had demonstrated improved closure for rectovaginal fistulas.
Among responders, 72% of rectovaginal fistulas were not draining at 14 weeks [ 26 ].
One potential reason more fistulas do not heal is insufficient drug at the site of
the fistula. Local injection of IFX into a fistula tract has been reported in a small
study with success. Eleven patients had multiple IFX injections every four weeks
B. P. Va u g h n