ORBIT Study Shows Rituximab and TNF inhibitor Equivalence Save

The initial choice of biologic is crucial to long-term success. Yet there are few studies evaluating head-to-head differences in some of our most popular therapies.

Researchers from 35 centers in the UK set out to test the hypothesis. This study was done to test the hypothesis that using rituximab would be clinically non-inferior and cheaper compared with TNF inhibitor treatment in biological-treatment naive patients with rheumatoid arthritis. 

Patients with active (DAS28-ESR >3·2) rheumatoid arthritis (RA) were randomized (1:1) to either rituximab or TNF inhibitor.  Patients were given intravenous rituximab 1 g on days 1 and 15, and after 26 weeks or a TNF inhibitor (adalimumab 40 mg every other week or etanercept 50 mg per week) according to patient and rheumatologist choice.

The primary endpoint was 12 months and the prespecified non-inferiority margin was 0·6 DAS28-ESR units.

Patients were given either rituximab (n=144) or TNF inhibitor (n=151) treatment. After 12 months, the change in DAS28-ESR for patients assigned to rituximab was -2·6 (SD 1·4) and TNF inhibitor was -2·4 (SD 1·5). These findings were within the prespecified non-inferiority margin and hence no significant difference between them.

The health-related costs associated with the rituximab strategy were lower than the TNF inhibitor strategy (£9405 vs £11 523 per patient, p<0·0001).

Adverse events (137 vs. 143) and serious serious adverse events ( 37 vs 26) were not significantly different between groups. There was one death in each group. 

Rituximab proved to be equivalent to to initial TNF inhibitor treatment in biologic naive, seropositive RA patients and  with significant cost saving over 12 months.