Low-dose rituximab protocol in rheumatoid arthritis—outcome and economic impact

Abstract

Abstract Objectives A significant proportion of RA patients, particularly those associated with poor prognostic factors, fail on conventional DMARDs (cDMARDs). Although rituximab (RTX) has been effective in these patients, the cost of therapy makes it unaffordable, particularly in poor and developing countries. Numerous, albeit small, studies using lower doses have shown contradictory results. We aimed to analyse the effectiveness of a low-dose RTX protocol based on clinical outcomes in RA patients. Methods Seropositive RA patients with moderate to high disease activity (DAS28-ESR > 3.2) despite combination cDMARDs, treated with RTX, were included in retrospective analysis. All patients were treated according to a predefined protocol, using 500 mg RTX with ongoing cDMARDs at baseline and repeat dosing at 6 weeks or beyond, on lack of moderate to good EULAR response. The B cell count was assessed at baseline, 2 and 24 weeks. Results At 12 weeks, 93% of 166 patients [mean (s.d.) age, 51.5 (11.96) years, 25 men and 141 women, with a disease duration of 10.4 (6.29) years] achieved moderate to good EULAR response. At 24 weeks, 90.8% of patients achieved moderate to good EULAR response, 19.8% achieved low disease activity and 29.5% achieved remission, with a mean change in DAS28-ESR from baseline of 2.9 (1.3). RTX failure and relapse were seen in 5.4% and 3.6%, respectively. The response was maintained for 12.3 (7.2) months with a mean RTX dose 521.1 (100.8) mg. Adverse events were seen in 9.6%. When compared with the standard dosing regimen with the originator molecule, a cost reduction of 90% was achieved. Conclusion A low-dose RTX regimen achieved reasonably good clinical outcomes at the end of 6 months, with a significantly lower cost.