Danese S, Colombel JF, Lukas M, et al. - Comparing etrolizumab (a gut-targeted anti-β7 integrin monoclonal antibody) to infliximab in patients with moderately to severely active ulcerative colitis, no statistical superiority of etrolizumab was found for the primary endpoint but it performed similarly to infliximab from a clinical perspective. This trial is the first phase 3 maintenance study in moderately to severely active ulcerative colitis to employ infliximab as an active comparator.

• A previous phase 2 induction study has demonstrated significant improvement in clinical remission with etrolizumab vs placebo in patients with moderately to severely active ulcerative colitis.

• In this randomised, double-blind, double-dummy, parallel-group, phase 3 study (GARDENIA), 397 eligible adults (age 18–80 years) with moderately to severely active ulcerative colitis and naïve to tumor necrosis factor inhibitors were randomized to etrolizumab (n=199) or infliximab (n=198); 95 (48%) in the etrolizumab group and 103 (52%) in the infliximab group completed the study through week 54.

• Primary endpoint was defined as the proportion of patients with both clinical response at week 10 and clinical remission at week 54; efficacy was examined in a modified intention-to-treat population (all randomized cases who received at least one dose of study drug).

• The primary endpoint was met by 18·6% (37/199 patients) in the etrolizumab group and 19·7% (39/198 patients) in the infliximab group, at week 54 (adjusted treatment difference –0·9% [95% CI –8·7 to 6·8]; p=0·81).

• Between treatment arms, the number of patients with one or more adverse events was similar; ulcerative colitis was the most common adverse event in both groups (55 [28%] patients in the etrolizumab group and 43 [22%] in the infliximab group).

• Serious adverse events occurred in more patients in the etrolizumab group vs the infliximab group (32 [16%] vs 20 [10%]), and one death occurred during follow-up, in the infliximab group because of a pulmonary embolism, which was not considered to be linked with study treatment.