Objectives To evaluate treatment with the peptide-based agent, Lupuzor, in a double-blind, randomised, placebo-controlled study of patients with systemic lupus erythematosus.

Methods Patients who met ≥4 of the American College of Rheumatology criteria, had a score of ≥6 on the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) and did not have an A score on the British Isles Lupus Assessment Group (BILAG)-2004 scale were eligible. 149 intention-to-treat (ITT) patients were randomly assigned to receive Lupuzor (200 μg) subcutaneously every 4 weeks (n=49; group 1) or every 2 weeks (n=51; group 2) or placebo (n=49; group 3) in addition to standard of care (SOC). A target population (136 ITT patients) consisting of patients having a clinical SLEDAI score ≥6 at week 0 was considered. The clinical SLEDAI score is the SLEDAI-2K score obtained by omitting low complement and increased DNA binding components.

Results In the ITT overall population, 53.1% in group 1 (p=0.048), 45.1% in group 2 (p=0.18) and 36.2% in the placebo group achieved an SLE Responder Index (SRI) response at week 12. In the target population, the results were more impressive: 61.9% in group 1 (p=0.016), 48.0% in group 2 (p=0.18) and 38.6% in the placebo group achieved an SRI response at week 12. An interim analysis including 114 patients from the target population demonstrated an even better efficacy (according to SLEDAI score) in group 1 compared with placebo (67.6% vs 41.5% (p<0.025) at week 12 and 84.2% vs 45.8% (p<0.025) at week 24). The most common adverse event was a mild injection-site erythema.

Conclusions Lupuzor/200 µg given three times at 4-week intervals during 12 weeks in addition to SOC is efficacious and generally well tolerated.