Experience With the Use of Rituximab for the Treatment of Rheumatoid Arthritis in a Tertiary Hospital in Spain: RITAR Study

Long-term drug effectiveness and survival for reference rituximab in rheumatoid arthritis patients in an ordinary outpatient clinic

To explore the long-term drug effectiveness and survival of reference rituximab (ref-RTX)-treated rheumatoid arthritis (RA) patients in an ordinary outpatient clinic. Second, we explored baseline predictors of drug effectiveness and survival, and third, we clarified reasons for stopping treatment. RA patients treated with ref-RTX between 2006 and 2020 in Norway were examined and monitored using recommended measures for disease activity and patient-reported outcomes (PROs). Drug effectiveness was assessed with random intercept linear mixed models; drug survival was assessed with Kaplan-Meier survival analysis. Reasons for discontinuation were ascertained. Baseline predictors of drug effectiveness and survival were estimated. Among 246 RA patients, at baseline, 17.1% were biologic disease-modifying anti-rheumatic drugs (bDMARDs) naïve, and 51.6% were currently using conventional synthetic DMARDs (csDMARDs). During the five-year follow-up, all disease activity and PRO measures improved significantly (p < 0.01), with more substantial changes noted in the second year. Drug survival was 83% after one year and declined to 34% after five years. The two most frequently reported reasons for discontinuation were the doctor's decision (36.2%) and lack or loss of effectiveness (19.2%). No significant difference was found between naïve and previous users of bDMARDs or between concomitant and nonconcomitant users of csDMARDs when analysing drug effectiveness and survival. Our real-life data show that ref-RTX-treated RA patients had satisfactory treatment responses; drug survival declined linearly over time. There was no significant difference between naïve and previous users of bDMARDs or between concomitant and nonconcomitant users of csDMARDs, both for drug effectiveness and survival.

Factors Determining Retreatment Time Interval of Rituximab in Korean Patients With Rheumatoid Arthritis

Unlike other biologic agents for rheumatoid arthritis (RA) that are administered at regular intervals even without flare, rituximab can be administered according to the timing of retreatment determined by the physician. Recently, there has been a tendency to prefer on-demand administration for disease flares rather than regular retreatment. We aimed to investigate the retreatment patterns of rituximab in patients with RA and to identify factors associated with extension of the time interval between retreatment courses. This study included RA patients on rituximab treatment who were enrolled in the Korean Rheumatology Biologics registry (KOBIO) or treated at Ajou University Hospital. Previous or current concomitant conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs), corticosteroids, number of previous biologic agents, withdrawal, and time intervals of rituximab retreatment were collected. In case of treatment failure, the reasons such as lack of efficacy, adverse events, and others, were also identified. A total of 82 patients were enrolled. The mean follow-up period from the first cycle of rituximab was 46.1 months, and the mean interval between the retreatment courses was 16.3 months. The persistent rates of rituximab after 5 years was 72.4%. Concomitant use of at least two csDMARDs (β = 4.672; 95% CI: 0.089-9.255, p = 0.046) and concomitant use of corticosteroids (β = 7.602; 95% CI: 0.924-14.28, p = 0.026) were independent factors for extending the time interval between the retreatment courses. In conclusion, RA patients treated with rituximab in Korea show high persistence rates. Concomitant use of two or more csDMARDs and concomitant use of corticosteroids with rituximab are associating factors of extending the retreatment time interval. These findings should be considered when selecting rituximab as a treatment for patients with RA.

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

BACKGROUND AND OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Cost-effectiveness analysis of treatment sequences containing tofacitinib for the treatment of rheumatoid arthritis in Spain

Objective

To assess the cost-effectiveness of tofacitinib-containing treatment sequences versus sequences containing only standard biological therapies in patients with moderate-to-severe rheumatoid arthritis (RA) after the failure of conventional synthetic disease-modifying antirheumatic drugs (csDMARD-IR population) and in patients previously treated with methotrexate (MTX) who show an inadequate response to second-line therapy with any tumour necrosis factor inhibitor (TNFi-IR population).

Methods

A patient-level microsimulation model estimated, from the perspective of the Spanish Public NHS, lifetime costs and quality-adjusted life years (QALY) for treatment sequences starting with tofacitinib (5 mg twice daily) followed by biological therapies versus sequences of biological treatments only. Concomitant treatment with MTX was considered. Model’s parameters comprised demographic and clinical inputs (initial Health Assessment Questionnaire [HAQ] score and clinical response to short- and long-term treatment). Efficacy was measured by means of HAQ score changes using mixed treatment comparisons and data from long-term extension (LTE) trials. Serious adverse events (SAEs) data were derived from the literature. Total cost estimation (€, 2018) included drug acquisition, parenteral administration, disease progression and SAE management.

Results

In the csDMARD-IR population, sequences starting with tofacitinib proved dominant options (more QALYs and lower costs) versus the corresponding sequences without tofacitinib. In the TNFi-IR population, first-line treatment with tofacitinib+MTX followed by scAbatacept+MTX➔rituximab+MTX➔certolizumab+MTX proved dominant versus scTocilizumab+MTX➔scAbatacept+MTX➔rituximab+MTX➔certolizumab+MTX; and tofacitinib+MTX➔scTocilizumab+MTX➔scAbatacept+MTX➔rituximab+MTX versus scTocilizumab+MTX➔scAbatacept+MTX➔rituximab+MTX➔certolizumab+MTX was less effective but remained a cost-saving option.

Conclusions

Inclusion of tofacitinib seems a dominant strategy in moderate-to-severe RA patients after csDMARDs failure. Tofacitinib, as initial third-line therapy, proved a cost-saving strategy (€− 337,489/QALY foregone) in moderate-to-severe TNFi-IR RA patients.

Key points • Therapeutical approach in rheumatoid arthritis (RA) consisted in sequences of several therapies during patient lifetime. • Treatment sequences initiating with tofacitinib followed by biological drugs provided higher health effects in csDMARDs-IR population, compared with sequences containing only biological drugs. • In both csDMARD-IR and TNFi-IR RA populations, initiating treatment with tofacitinib was associated to lower treatment costs for the Spanish National Health System.