Potential and prognostic factor for belimumab-free remission in patients with systemic lupus erythematosus: a single-center retrospective analysis

Belimumab is an effective and safe treatment option for systemic lupus erythematosus (SLE). However, data on treatment cessation are lacking. Thus, we investigated belimumab-free remission in SLE patients. SLE patients receiving belimumab in our institute (May 1, 2013-May 31, 2019) were retrospectively identified using electronic health records. Eligibility criteria included receiving belimumab for > 180 days and discontinuation for any reason. BILAG category A or B in at least one organ system indicated a disease flare. Follow-up monitoring during post-treatment at week 52 identified relapse-free and relapse patients. Thirty-one patients received belimumab, and 8 patients were included. Of the 8 patients, 4 relapsed within 52 weeks. At belimumab discontinuation, relapse-free patients achieved lower SELENA-SLEDAI (1 [IQR, 0-2] vs. 7 [IQR, 5.5-8] (p = 0.03)), received significantly less steroid (prednisolone equivalent, 3.0 mg/day [IQR, 2.8-3.2] vs. 9.5 mg/day [IQR, 7.3-13.3],p = 0.02) than relapse patients, and significantly more relapse-free patients achieved SELENA-SLEDAI less than 4 and received prednisolone less than 5 mg/day than relapse patients. Furthermore, on discontinuation day, relapse-free patients tended to have higher C3 (91.0 mg/dL [IQR, 78.8-102.3] vs. 56.0 mg/dL [IQR, 39.8-73.0],p = 0.15) and C4 levels (22.0 mg/dL [IQR, 19.00-26.00] vs. 11.0 mg/dL [IQR, 6.00-16.00],p = 0.08) and less anti-dsDNA antibody (5.2 IU/mL [IQR, 3.8-7.8] vs. 48.0 IU/mL [IQR, 11.5-137.3],p = 0.08) than relapse patients. Belimumab discontinuation can be considered for patients who achieved good responses. Normalization of complement, anti-dsDNA antibody, SELENA-SLEDAI less than 4, and steroid dosage less than 5 mg/day might be prognostic markers for belimumab-free remission.