A small study from three centers in the Netherlands shows that there is no good rationale for increasing the standard 2 x 1000 mg infusion dose of rituximab to reduce progression of structural damage over one year in patients with active rheumatoid arthritis (RA), and a lower dose may even prevent progression adequately.
Boumans M, Teng O, Thurlings R, et al., Progression of structural damage is not related to rituximab serum levels in rheumatoid arthritis patients.Rheumatology (2013) 52:1462-1466
A small study from three centers in the Netherlands shows that there is no good rationale for increasing the standard 2 x 1000 mg infusion dose of rituximab to reduce progression of structural damage over one year in patients with active rheumatoid arthritis (RA).
The researchers find no relationship between radiographic progression of structural damage and serum rituximab levels at 4, 12, or 16 weeks after starting treatment. Certainly using a higher dose to try to reduce progression is not warranted, and it may even be possible to reduce the dose to 2 x 500 mg at 24 weeks with equal efficacy, they suggest.
The study drew patients from three independent prospective cohorts: the Academic Medical Center/University of Amsterdam (AMC), Leiden University Medical Center (LUMC), and the University Medical Centre, Utrecht (UMCU).
The 62 patients, mostly women ages 51 to 58 with active RA (mean DAS28 6.0-6.6), started the same dose of rituximab (2 x 1000 mg infusions) on days 1 and 15 at each center. Patients were monitored by DAS28 and Sharp–van der Heijde scoring (SHS) of hand and foot radiographs. Some were retreated with the same dose at around 6 months (all patients at two of the centers but at the third center only "on demand," for those who showed DAS scores of at least 53.2 at 6 months).
Patients were judged to be “progressors” or “nonprogressors” based on changes in SHS from baseline after 1 year, using three different definitions of progression (an increase in SHS of ≥1 point, ≥3 points, or ≥5 points).
Pooled data show no differences at any time point in serum rituximab levels among progressors and non-progressors (even at the differing cut-off points), and no correlation between the change in SHS after 1 year and serum rituximab levels at different time points.
Although the cohorts followed different re-treatment regimens for a year (fixed vs on demand re-treatment, and no re-retreatment for some patients), the researchers also find no trend towards any difference in the progression of structural damage between the retreated (n = 45) and non-retreated (n=17) groups.