Abstract Background Crohn’s disease (CD)-related complex perianal fistula (cPAF) is difficult to treat, and iv-anti–tumor necrosis factor (TNF) remains the standard medical option. Recent switch studies suggest that sc-Infliximab (IFX) is not inferior to iv-IFX for luminal CD. In this study, we compared iv-IFX and sc-IFX in treatment-naïve patients with cPAF. Methods In two centres, patients with cPAF who received either sc- or iv-IFX according to preference were retrospectively evaluated. iv-IFX was reimbursed, whereas the sc formulation was provided through early-access program. After adjustment for clinical parameters, patients receiving sc-IFX were matched 1:1 to those receiving iv-IFX (n:22 each). Sc-IFX was administered as iv-IFX at weeks 0-2, followed by sc-IFX 120mg/2w from w6; iv-IFX as 5 mg/kg at w0-2-6, then 5 mg/kg/8w thereafter. Dose escalation for inadequate clinical response was permitted up to 10–15 mg/kg/4w in the iv cohort and up to 240mg/w in the sc cohort. IFX trough levels were monitored, and dose escalation was undertaken with assessing clinical activity and /or when levels were 10 µg/mL; high levels did not prompt de-escalation unless radiological remission of cPAF or treatment-related adverse events occurred. Results Among the 44 patients, 59% were male, with a mean age of 45.5±15.5 years. Baseline perianal drainage, SES-CD, CDAI, CRP, and the use of immunomodulators or antibiotics were comparable between the groups (Table1a). Sc and iv groups had similar IFX persistence rates with longer follow-up in iv-IFX. Clinical remission defined as the absence of perianal drainage for 3 months, did not differ between sc- and iv-IFX at 6 and 12 months (Table2). Endoscopic SES-CD scores and radiologic remission at 12 months were comparable between groups (Table2). At month 6, median IFX trough levels were higher in the sc cohort than in the iv cohort (27.1vs 2.3 µg/mL, p 0.001), and this difference persisted at month 12, despite a greater need for dose escalation in the IV group during follow-up (SC 47.6% -IV 90.9%, p:0.002). This may be related to the lower incidence of anti-drug antibodies in the sc cohort (0%- 35.3% p:0.004). Rates of new surgery, steroid requirement, and adverse events did not differ between the groups (p:0.61, 0.15, and 0.65, respectively). Conclusion In the difficult-to-treat setting of cPAF, sc-IFX provided clinical and radiologic remission rates similar to iv-IFX, while yielding higher trough drug levels, less need for dose escalation, and lower anti-drug antibody formation. The additional advantages of SC administration compared to IV infusions further support SC IFX as a preferable treatment option in cPAF Conflict of interest: Akpınar, Atilla: Non-financial support: Celltrion (medicines) Bakkaloglu, Oguz Kagan: Non-financial support: Celltrion (medicines) Unal, Nalan Gulsen: Non-financial support: Celltrion (medicines) Baytar, Sena: No conflict of interest Kati, Okan: Non-financial support: Celltrion (medicines) Eskazan, Tugçe: Non-financial support: Celltrion (medicines) Erzin, Yusuf Ziya: Non-financial support: Celltrion (medicines) Hatemi, Ali Ibrahim: Non-financial support: Celltrion (medicines) Çelik, Aykut Ferhat: Non-financial support: Celltrion (medicines)
Akpınar et al. (Thu,) studied this question.