ADACTA trial: Tocilizumab more effective than adalimumab in treating RA

Safety results were similar between groups

Data presented today at EULAR 2012, the Annual Congress of the European League Against Rheumatism, demonstrates that tocilizumab monotherapy is more effective than adalimumab monotherapy in the treatment of rheumatoid arthritis (RA) based on change from baseline in DAS28 (-3.3 vs. -1.8, p<0.0001) at week 24. The ADACTA trial, conducted in 325 patients with RA showed that tocilizumab was more effective than adalimumab for DAS28 remission (39.9% vs 10.5%, p<0.0001), low disease activity (51.5% vs. 19.8%, p<0.0001) and ACR20/50/70 responses (65.0%, 47.2%, 32.5% respectively vs. 49.4%, 27.8%, 17.9%, p<0.01). Differences between arms were also noted in favour of tocilizumab from week eight onwards in swollen and tender joint counts, erythrocyte sedimentation rate (ESR, a test that indirectly measures the among of inflammation in the body), and patient global assessment.

"Approximately one third of patients with rheumatoid arthritis receive biologic monotherapy and this is the first head-to-head trial comparing an IL-6 inhibitor to an anti-TNF, two therapies with different modes of action," said Professor Cem Gabay from University Hospitals of Geneva, Switzerland. "This study clearly shows the benefits of tocilizumab over adalimumab on various measures of rheumatoid arthritis disease activity and is the first study of its kind to determine superiority between two approved RA drugs."

The international, multicenter, randomised, double-blind, 24 week study was designed to test for treatment superiority in patients with an RA diagnosis of greater than six months who were methotrexate intolerant or for whom continued treatment with methotrexate was inappropriate. Patients were randomly assigned to two arms for a total of 24 weeks: tocilizumab 8mg/kg IV every four weeks plus placebo or adalimumab 40mg subcutaneously every two weeks plus placebo. The primary endpoint of the study was mean change from baseline in DAS28 at 24 weeks.

The incidence of adverse events (AEs) was similar between groups, with 82.1% of patients having an AE in the tocilizumab arm and 82.7% in the adalimumab arm. Serious AEs and serious infections were also similar between groups (tocilizumab: 11.7%, 3.1%, adalimumab: 9.9%, 3.1%). Changes in transaminase, low-density lipoprotein (LDL) elevations, and neutrophil reductions occurred in both arms, with the proportion of patients with abnormal values higher in the tocilizumab arm. There were two deaths reported in the tocilizumab arm; one from sudden death and one from illicit drug overdose.