Predictors of rituximab response identified in patients with SLE
medwireNews: A real-world study of patients with systemic lupus erythematosus (SLE) suggests that those with more active disease and minimal previous immunosuppressive treatment are most likely to benefit from single-course treatment with rituximab.
For patients receiving rituximab maintenance therapy, active articular disease at treatment initiation may increase the risk for flares, report Federico Alberici (University of Milano ‐ ASST Santi Paolo e Carlo, Italy) and colleagues in Arthritis & Rheumatology.
Alberici and team found that by 6 months after first administration of rituximab, 45% of 147 patients with SLE achieved a complete response to treatment, defined as a physician’s assessment score of 0 or 1, a reduction in European Consensus Lupus Activity Measurement (ECLAM) score of at least 50%, and a decrease in immunomodulating therapy of at least 25% from baseline.
In addition, 28% achieved a partial response, and 27% experienced treatment failure.
After adjustment for other immunosuppressive drugs and prednisolone dose, the researchers found that each 0.1 g/L increase in baseline C4 level was associated with a significant 1.76-fold increased likelihood for treatment failure.
In addition, patients who were receiving more than four immunosuppressive agents at baseline were 7.77 times more likely to experience rituximab failure than those receiving none, which taken together “would suggest that the ideal candidates for [rituximab] may be those with more active disease and without a clear refractory course,” Alberici and co-authors remark.
In order to prevent relapse, 80 (54%) patients received rituximab maintenance therapy over a median of 24.5 months. During this time, 85 relapses occurred in 52 patients, to give a relapse rate of 53 per 100 patient–years. The most common sites for relapse were the joints (66%) and skin (40%).
Just over a third (35%) of patients on maintenance therapy never flared and were classed as “sustained responders.” In multivariate analysis comparing the sustained responders with those who had at least one flare during follow-up, the researchers found that presence of active articular disease at the time of the first rituximab administration was associated with a significant 3.55 times increased risk for flares.
At the time of the last rituximab course, 84% of the patients who received maintenance therapy were in remission. After this time, relapse-free survival was similar between the patients who received a single rituximab course and those who received maintenance, at 16 and 17 months, respectively.
However, the authors advise caution when interpreting this data because the comparison was between two heterogeneous groups, with patients in the maintenance cohort having more severe disease.
Alberici et al conclude: “Our cohort of 147 patients treated with [rituximab] is one of the largest published so far and the overall positive response further supports the role of this drug in SLE management.”
They add that a rituximab maintenance regimen “might be considered for patients with severe disease-related complications, for whom waiting for the relapse in order to treat on demand may be risky, and when first-line immunosuppressive options are exhausted.”
By Laura Cowen
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