Pragmatic targets for moderate/severe SLE and their implications for clinical care and trial design: sustained DORIS or LLDAS for at least 6 months is sufficient while their attainment for at least 24 months ensures high specificity for damage-free progression

Abstract

Objectives: Treatment targets in systemic lupus erythematosus (SLE) have been validated in unselected-in terms of severity-cohorts, which limits their generalisability. We assessed remission (Definition of Remission in SLE (DORIS)) and Lupus Low Disease Activity State (LLDAS) in a historical cohort of 348 patients with active moderate-to-severe disease and median follow-up of 5 years.

Methods: Active SLE was defined as Physician Global Assessment ≥1.5 and/or SLE Disease Activity Index 2000 ≥6, requiring therapy intensification. DORIS/LLDAS, organ damage, flares and adverse events were monitored. Shared frailty survival, generalised linear models and K-means clustering were applied.

Results: Sustained DORIS and LLDAS for ≥6 months occurred in 41.1% and 80.4%, respectively, and resulted in reduced damage accrual (HR: 0.58; 95% CI 0.36 to 0.93 and 0.61; 0.43 to 0.86) and severe flares (HR: 0.14; 0.08 to 0.27 and 0.19; 0.13 to 0.27). LLDAS without DORIS was also protective (HR: 0.65; 0.43 to 0.98 for damage, 0.49; 0.36 to 0.67 for flares). Models fitting increasing duration of targets showed that DORIS ≥50% and LLDAS ≥60% of time, or alternatively, ≥24 and ≥36 months, achieved optimal balance between feasibility (20.2-41.7%) and specificity (73.3-86.1%) for damage-free outcome. These targets were linked to reduced serious adverse events (risk ratio (RR): 0.56-0.71), hospitalisation (RR: 0.70) and mortality (RR: 0.06-0.13). Patients with predominant arthritis and mucocutaneous disease experienced reduced DORIS/LLDAS, compared with counterparts with major organ involvement. Conventional drugs were more frequently used in the former group, whereas potent immunosuppressive/biological agents in the latter.

Conclusions: In moderate-to-severe SLE, sustained DORIS/LLDAS for at least 6 months is sufficient, while attainment for at least 24 months ensures higher specificity for damage-free progression, thus facilitating treat-to-target strategies and clinical trials. Arthritis and skin disease represent unmet therapeutic needs that could benefit from novel biologics.

Keywords: Lupus Erythematosus, Systemic; Outcome Assessment, Health Care; Therapeutics.