Multicenter longitudinal study of B-lymphocyte depletion in refractory systemic lupus erythematosus: the LESIMAB study

OBJECTIVE: This study aimed to investigate the effectiveness and safety of single and repeated courses of rituximab in patients with refractory lupus. METHODS: LESIMAB is a multicenter, retrospective, longitudinal study of lupus patients who have not responded to standard therapy and have been treated with rituximab. Response rates at six months and at follow-up were defined as efficacy outcomes. Complete response was defined as a SELENA-SLEDAI score ≤ two and a SELENA-SLEDAI Flare Index of zero. Partial response was defined as a reduction in the SELENA-SLEDAI score of ≥four points with no new or worsening of symptoms. Adverse events were collected. RESULTS: Seventy-three (62.9%) of 116 patients achieved a response at six months (complete in 22 and partial in 51). Ninety-seven (77.6%) of 128 patients achieved a response after a mean follow-up of 20.0 ± 15.2 months (complete in 50 and partial in 47). High baseline SLEDAI score, previous treatment with ≥100 mg/day prednisone, and no history of severe hematologic flare were associated with response after the first treatment course. The median time to response was 6.5 months (95% CI, 5.0-8.0). Thirty-seven patients (38.1%) relapsed after the first infusion. The flare was severe in seven cases and mild to moderate in 29 cases. Serious infection rate was 12.6/100 patient-years. A schedule of four weekly doses was associated with more serious infections. Six patients died: two of infection and four of lupus complications. CONCLUSION: Rituximab can be an effective treatment option for patients who have refractory lupus with severe or life-threatening disease with an acceptable tolerance profile.