Factors associated with long-term persistence of rituximab in rheumatoid arthritis In clinical practice: RITAR Study

Treatment of rheumatoid arthritis with rituximab (RTX) requires repeated cycles, but there is no well-established retreatment regimen in dose and frequency. The objective was to analyse the persistence of RTX treatment and factors that influence in terms of routine clinical practice.

Rituximab in Rheumatoid Arthritis (RITAR Study) is an observational, retrospective study that analyses the persistence of RTX in a cohort from 2003 to 2015. Persistence was calculated by the Kaplan-Meier analysis; curves were compared with the Log-Rank test. Cox regression was used to quantify the risk of discontinuation and multivariate analyses were conducted to determine the factors associated with the persistence of the treatment.

454 cycles of RTX in 114 patients were included. Median survival was 10.0 years and incidence rate of discontinuation was 7.7 per 100 patients/year. Factors associated with persistence were autoantibody positivity and use of RTX in combination with csDMARDs. Sex, age, number of comorbidities, rheumatoid arthritis evolution, number of complications, basal DAS28, basal HAQ, number of lines of treatment, fixed or on demand retreatment and year of RTX starting were not associated. Multivariable models confirmed the relationship between autoantibody positivity, monotherapy and persistence of RTX.

The persistence of RTX in clinical practice is higher in seropositive patients and in those who are treated with RTX associated with a csDMARD. Dose per cycle and retreatment frequency do not have a decisive role in rituximab persistence.