A Comprehensive Single-Center Analysis of Subcutaneous Infliximab in the Management of Inflammatory Bowel Disease, Lahore Pakistan

Abstract

Background: Subcutaneous infliximab (SC-IFX) offers a promising alternative to intravenous infliximab (IV-IFX) for managing moderate-to-severe inflammatory bowel disease (IBD), providing pharmacokinetic stability, patient convenience, and improved adherence. Further evidence is needed to validate its clinical efficacy, safety, and pharmacokinetic profile in real-world settings.

Objective: To evaluate the clinical efficacy, safety, and pharmacokinetics of SC-IFX in patients with Crohn’s disease (CD) and ulcerative colitis (UC).

Methods: This single-center, open-label, interventional study enrolled 190 patients with IBD (58 CD, 132 UC) aged 18–75 years with moderate-to-severe disease activity (Crohn’s Disease Activity Index [CDAI] 250–450 or Mayo score 6–12). Participants received SC-IFX with a loading dose of 240 mg at weeks 0 and 2, followed by 120 mg every other week from week 4 onward. Assessments at baseline, week 11, and week 22 included disease activity (CDAI and Mayo scores), inflammatory markers (CRP and fecal calprotectin), hematological parameters, and serum infliximab levels. Adverse events were recorded per CTCAE guidelines. Statistical analyses utilized repeated measures ANOVA and chi-square tests, with significance set at P < 0.05.

Results: Among 190 patients, clinical remission was achieved in 81.3% of CD (CDAI <150) and 84.8% of UC (Mayo ≤2) patients by week 22. Serum infliximab levels rose from

undetectable at baseline to 17.74 ± 0.14 µg/mL at week 11 and stabilized at 11.94 ± 0.11 µg/mL by week 22 (P < 0.001). CRP levels decreased from 35.31 ± 1.24 mg/L to 5.24 ± 0.33 mg/L in CD and from 23.98 ± 0.82 mg/L to 4.18 ± 0.22 mg/L in UC (P < 0.001). Fecal calprotectin levels declined from 470.16 ± 17.32 µg/g to 146.43 ± 2.66 µg/g in CD and from 889.17 ± 11.48 µg/g to 89.42 ± 1.77 µg/g in UC (P < 0.001). Hemoglobin increased significantly in CD and UC patients (P < 0.001), while platelet counts decreased substantially (P < 0.001). Adverse events were mild and primarily injection site reactions, with no serious adverse events reported.

Conclusion: SC-IFX demonstrated significant efficacy, pharmacokinetic stability, and a favorable safety profile in managing moderate-to-severe IBD in this cohort of 190 patients. These findings support its use as a convenient and effective alternative to IV-IFX.