Safety and efficacy of anifrolumab therapy in systemic lupus erythematosus in real-world clinical practice: LOOPS registry

To determine the safety and efficacy of anifrolumab in patients with systemic lupus erythematosus (SLE) classified based on the Lupus Low Disease Activity State (LLDAS) in real-world clinical practice. This retrospective observational study involved SLE patients who started anifrolumab therapy. The primary end point was the retention rate over 26 weeks after initiating anifrolumab therapy; 45 patients followed up for 12 weeks or longer were analysed in the following groups to determine the safety and efficacy up to week 12 after treatment initiation: (i) non-LLDAS achievement group and (ii) minor flare group. Safety and efficacy were compared between the minor flare group and the standard of care (SoC) group (treated by adding glucocorticoids [GCs] or immunosuppressants) after adjustment with inverse probability of treatment weighting using propensity score (PS-IPTW). The retention rate of anifrolumab was 89.7% at week 26.The LLDAS achievement rates at week 12 were 42.9% and 66.7% in the non-LLDAS achievement and minor flare groups, respectively. In both groups, GC doses and SELENA-SLEDAI score significantly decreased. When the anifrolumab group with minor flare was compared with the SoC group or the GC dose increase group, the GC dose and SLEDAI score were significantly lower in the anifrolumab group than in either of the other groups; there was no significant difference in LLDAS achievement. At week 26 after initiating anifrolumab therapy, ∼90% of patients remained on therapy. Anifrolumab might lower disease activity without initiating GCs and reduce GC doses, especially in patients who experience minor flares after LLDAS achievement.