Efficacy and Safety of Obinutuzumab in Active Systemic Lupus Erythematosus
In the phase 3 ALLEGORY trial, the type II anti-CD20 antibody obinutuzumab was superior to placebo for active systemic lupus erythematosus without proliferative or membranous lupus nephritis, meeting its primary SRI-4 endpoint and all key secondary endpoints.
Background
Obinutuzumab is a glycoengineered type II anti-CD20 monoclonal antibody that induces potent B-cell depletion and is already approved for active lupus nephritis. Its efficacy and safety in patients with active systemic lupus erythematosus (SLE) without proliferative or membranous lupus nephritis had not been established.
Study design
ALLEGORY was a phase 3, multicenter, double-blind, placebo-controlled trial enrolling adults with active SLE on standard therapy who did not have proliferative or membranous lupus nephritis. A total of 303 patients were randomized 1:1 to obinutuzumab 1000 mg or placebo on day 1 and at weeks 2, 24, and 26. The primary endpoint at week 52 was an SLE Responder Index 4 (SRI-4) response.
Key findings
At week 52, an SRI-4 response occurred in 76.7% of obinutuzumab-treated patients versus 53.5% with placebo (adjusted difference 23.1 percentage points; 95% CI 12.5 to 33.6; P<0.001). Obinutuzumab was superior for all key secondary endpoints, including BILAG-based composite lupus assessment response, sustained glucocorticoid reduction, sustained SRI-4 and SRI-6 responses, and time to first BILAG flare. Adverse events occurred in 88.7% versus 81.5% and serious adverse events in 15.9% versus 11.9%; one obinutuzumab and three placebo patients died during the double-blind period.
Clinical implications
These results extend the benefit of obinutuzumab beyond lupus nephritis to active SLE more broadly, with consistent improvements across disease-activity measures and a glucocorticoid-sparing effect, supporting B-cell depletion with a type II anti-CD20 antibody as an effective option in this population.
Category
Research
Source
New England Journal of Medicine
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