Intravenous CDP870, a PEGylated Fab' fragment of a humanized antitumour necrosis factor antibody, in patients with moderate-to-severe Crohn's disease: an exploratory study

Background: CDP870 is a PEGylated Fab' fragment of a humanized monoclonal antibody that neutralizes tumour necrosis factor-alpha. Aim: To evaluate the safety and efficacy of a single intravenous dose of CDP870 or placebo over a 12-week period in patients with moderate-to-severe Crohn's disease. Methods: Ninety-two adult patients with Crohn's disease (Crohn's Disease Activity Index: 220-450 points) were randomized to receive CDP870 [1.25 (n = 2), 5 (n =26), 10 (n = 17) or 20 mg/kg (n = 23)] or placebo (n = 24). Crohn's Disease Activity Index scores were determined at weeks 0, 2, 4, 8 and 12. The primary end-point was the percentage of patients achieving clinical response [i.e. a decrease in Crohn's Disease Activity Index score greater than or equal to 100 points or remission (Crohn's Disease Activity Index score: less than or equal to150 points)] at week 4 in the intent-to-treat population. Results: The percentage of patients achieving the primary end-point was comparable across all treatment groups (56.0%, 60.0%, 58.8% and 47.8% for placebo, CDP870 5, 10 and 20 mg/kg, respectively). The remission rate at week 2 was 47.1% with CDP870 10 mg/kg vs. 16.0% for placebo (P = 0.041). All treatments were well-tolerated: adverse events, reported by 43 patients treated with CDP870 and 15 patients treated with placebo, were mainly mild-to-moderate in intensity. There were no infusion reactions. Conclusions: A single intravenous dose of CDP870 was well-tolerated by patients with Crohn's disease. While no statistically significant difference in clinical response rates between CDP870 and placebo was observed, clinical benefit in terms of remission was demonstrated.