Randomised clinical trial: certolizumab pegol for fistulas in Crohn’s disease - subgroup results from a placebo-controlled study

BACKGROUND: Treatment options for fistulizing Crohn's disease (CD) are limited. AIM: To examine whether fistula closure is maintained at week 26 following treatment with certolizumab pegol. METHODS: Patients with draining fistulas at baseline from PRECiSE 2 (n = 108) received open-label induction with certolizumab pegol 400 mg at weeks 0 (baseline), 2 and 4. Response was defined as ≥100-point decrease from baseline in the Crohn's Disease Activity Index. Nonresponders (50/108) were excluded. At week 6, responders with draining fistulas (N = 58) were randomised to certolizumab pegol 400 mg (n = 28) or placebo (n = 30) every 4 weeks across weeks 8-24. Fistula closure was evaluated throughout the study, with a final assessment at week 26. RESULTS: The majority of patients (55/58) had perianal fistula. At week 26, 36% of patients in the certolizumab pegol group had 100% fistula closure compared with 17% of patients receiving placebo (P = 0.038). Protocol-defined fistula closure (≥50% closure at two consecutive post-baseline visits ≥3 weeks apart) was not statistically significant (P = 0.069) with 54% and 43% of patients treated with certolizumab pegol and placebo achieving this end point, respectively. CONCLUSION: Continuous treatment with certolizumab pegol improves the likelihood of sustained perianal fistula closure compared with placebo.