Background Rituximab is the only currently available B-cell depleting agent, licensed for use in treatment of rheumatoid arthritis (RA).The optimal therapeutic strategy that would give an answer to the question when is the best moment to repeat a course of rituximab, has not yet been clearly defined. In addition to strictly controlled randomized studies, registers show the effectiveness of different therapeutic strategies applied in daily clinical practice.
Objectives To assess the efficacy of rituximab in RA when administered every six months in comparison to a longer period between two courses, according to data from the Serbian registry of RA patients (NARASS).
Methods 161 RA patients, treated with rituximab are followed to date in NARRAS. Forty of them (33 women and 7 men, mean age 52 years), who received at least three courses of the drug were selected and analyzed. They were divided into two subgroups: subgroup I (SG1) - 26 (65%) patients who received rituximab every six months, and subgroup II (SG2) - 14 (35%) patients with a time period of seven months or more between two courses. Disease activity score (DAS28) was assessed before each course and six months after the third course of rituximab, and compared between two subgroups of patients. The analysis of variance (ANOVA) and Student’s T-test were used for statistical analyses of data.
Results Mean disease duration before diagnosis of RA in two subgroups of patients did not differ significantly (SG1: SG2=12.6: 17.5 months, p=0.85), as well as disease duration from diagnosis to beginning of treatment with rituximab (SG1: SG2 =133.1: 123.6 months, p=0.71). The mean time period between two courses of rituximab for patients in SG1 was 6.2 months and for patients in SG2 8.9 months. Analyzing the data for the whole group of 40 patients we have noticed a statistically significant decrease in disease activity six months after the third course of rituximab, compared to the period before treatment (DAS28 index decreased from 5.87 to 4.47, p<0.001). The effectiveness of rituximab on disease activity was better in SG1 compared to SG2 - mean DAS28 decreased significantly (p=0.002) from 6.30 (before treatment) to 4.31 (six months after the third course) in SG1, and from 5.12 to 4.80 in SG2 (p=0.057).
Conclusions The efficacy of rituximab is better when patients are retreated regularly at six-month intervals, compared to patients who receive the drug with a longer time period between the courses
Disclosure of Interest None Declared