P324 Comparative short and long-term efficacy of infliximab and adalimumab in patients with ulcerative colitis refractory to corticosteroids: a retrospective study
N. Yoshimura*, M. Sako, M. Takazoe
Tokyo Yamate Medical Centre, Department of Internal Medicine, Tokyo, Japan
Currently, anti-tumour necrosis factor (anti-TNF) biologics, infliximab (IFX) and adalimumab (ADA), are administered to induce and maintain clinical remission in patients with steroid-refractory ulcerative colitis (UC), although the subsequent loss of response to biologics during maintenance therapy remains a challenging clinical issue. This study was to evaluate the short- and long-term efficacy of IFX and ADA in patients with moderately to severely active UC and are anti-TNF naïve, as well as those with prior exposure to an anti-TNF.
In a single-centre retrospective setting, 111 consecutive patients with moderately to severely active UC refractory to corticosteroids were included. In total, 76 patients were treated with IFX; 64 naïve to an anti-TNF and 12 had switched from another anti-TNF, the remaining 35 patients were treated with ADA; 21 naïve, and 14 had switched. At week 8, clinical response rates were compared amongst the 4 groups. Clinical response was defined as Rachmilewitz’s clinical activity index (CAI) ≤ 4. The subsequent loss of response was defined as CAI ≥ 7. Patients with remission had received maintenance IFX (5 mg/kg) every 8 weeks or ADA (40mg) at 2 weeks intervals. All patients were followed for 52 weeks. The cumulative remission maintenance rates were compared by the Kaplan–Meier estimator graphs.
At week 8, 59 of 76 patients (77.6%) in the IFX group had responded; 50 of 64 in the naïve sub-group (78.1%) and 9 of 12 in the switched sub-group (75.0%). In the ADA group, 24 of 35 patients (68.6%) had responded; 15 of 21 in the naïve sub-group (71.4%) and 9 of 14 in the switched sub-group (64.3%). There was no significant difference amongst the 4 groups. Further, after 52 weeks, 65% in the IFX-naïve group had maintained remission vs 85.7% in the IFX switched, 69.2% in the ADA naïve, and 37.5% in the ADA switched (ADA switched vs ADA naïve and IFX group, p < 0.05). The fraction of patients in the IFX-naïve group with the loss of response was 25.0% vs 14.3% in the IFX switched, 30.8% in the ADA naïve, and 62.5% in the ADA switched (ADA switched vs ADA naïve and IFX group, p < 0.05). The Kaplan–Meier survival analysis showed significantly highest loss of response in the ADA switched sub-group (p < 0.05).
In this retrospective study, with respect to the initial clinical response rate in patients with steroid-refractory UC receiving anti-TNF therapy, there was no significant difference between IFX and ADA, regardless of prior exposure to an anti-TNF. However, the long-term remission maintenance rate was significantly lower in the ADA sub-group with prior exposure to an anti-TNF as compared with the other 3 sub-groups, but this finding is limited by the small sample size of the patients with prior exposure to an anti-TNF.