A randomized, double-blind, placebo-controlled trial evaluated the efficacy of certolizumab pegol maintenance therapy in adults with moderate-to-severe Crohn's disease. Patients received 400 mg of certolizumab pegol subcutaneously at weeks 0, 2, and 4 for induction therapy. Those who responded to induction therapy (defined as a reduction of at least 100 on the Crohn's Disease Activity Index [CDAI] at week 6) were randomly assigned to receive either certolizumab pegol or placebo every 4 weeks through week 24. The primary endpoint was the maintenance of response at week 26, with 62% of patients in the certolizumab group maintaining response compared to 34% in the placebo group (P<0.001). Additionally, 48% of patients in the certolizumab group achieved remission (CDAI ≤150) at week 26, compared to 29% in the placebo group (P<0.001). Certolizumab pegol was effective in patients using or not using glucocorticoids or immunosuppressants, and in those who had or had not previously used infliximab. Serious adverse events occurred in 3% of certolizumab pegol recipients and less than 1% in the placebo group. Antinuclear antibodies developed in 8% of certolizumab pegol recipients, and antibodies against certolizumab pegol developed in 9% of all patients. The study concluded that patients with moderate-to-severe Crohn's disease who had a response to induction therapy with certolizumab pegol were more likely to maintain response and achieve remission at 26 weeks with continued certolizumab pegol treatment than with a switch to placebo. The trial was supported by a research grant from UCB Pharma and a research grant for infrastructure from the German Federal Ministry of Education and Research (BMBF) Competence Network Inflammatory Bowel Disease.A randomized, double-blind, placebo-controlled trial evaluated the efficacy of certolizumab pegol maintenance therapy in adults with moderate-to-severe Crohn's disease. Patients received 400 mg of certolizumab pegol subcutaneously at weeks 0, 2, and 4 for induction therapy. Those who responded to induction therapy (defined as a reduction of at least 100 on the Crohn's Disease Activity Index [CDAI] at week 6) were randomly assigned to receive either certolizumab pegol or placebo every 4 weeks through week 24. The primary endpoint was the maintenance of response at week 26, with 62% of patients in the certolizumab group maintaining response compared to 34% in the placebo group (P<0.001). Additionally, 48% of patients in the certolizumab group achieved remission (CDAI ≤150) at week 26, compared to 29% in the placebo group (P<0.001). Certolizumab pegol was effective in patients using or not using glucocorticoids or immunosuppressants, and in those who had or had not previously used infliximab. Serious adverse events occurred in 3% of certolizumab pegol recipients and less than 1% in the placebo group. Antinuclear antibodies developed in 8% of certolizumab pegol recipients, and antibodies against certolizumab pegol developed in 9% of all patients. The study concluded that patients with moderate-to-severe Crohn's disease who had a response to induction therapy with certolizumab pegol were more likely to maintain response and achieve remission at 26 weeks with continued certolizumab pegol treatment than with a switch to placebo. The trial was supported by a research grant from UCB Pharma and a research grant for infrastructure from the German Federal Ministry of Education and Research (BMBF) Competence Network Inflammatory Bowel Disease.