FDA Accepts sBLA for Obinutuzumab in Systemic Lupus Erythematosus Based on Phase 3 ALLEGORY Data

The FDA has accepted Genentech's supplemental Biologics License Application (sBLA) for obinutuzumab (Gazyva) for the treatment of systemic lupus erythematosus (SLE), with a decision expected by December 2026.

The filing is supported by data from the phase 3 ALLEGORY trial, in which obinutuzumab added to standard therapy produced statistically significant and clinically meaningful improvements across the primary endpoint and all key secondary endpoints at 52 weeks compared with placebo.¹ If approved, obinutuzumab would represent the first anti-CD20 therapy indicated for SLE — a population for which B cell–targeted treatment has long been investigated but has historically yielded mixed results.

Obinutuzumab is a humanized, type II anti-CD20 monoclonal antibody engineered with a glycomodified Fc region for enhanced antibody-dependent cellular cytotoxicity. Unlike rituximab, which was evaluated in 2 negative SLE trials (EXPLORER and LUNAR), obinutuzumab's type II design promotes direct B cell death through a distinct mechanism. It is already approved in the US and EU for lupus nephritis based on the REGENCY and NOBILITY studies.¹

ALLEGORY (NCT04963296) was a randomized, double-blind, placebo-controlled, multicenter phase 3 study enrolling approximately 300 adults with SLE on background standard therapy, randomized 1:1 to obinutuzumab or placebo for 52 weeks, followed by an open-label extension period of up to 104 weeks. The primary endpoint was the proportion of patients achieving SLE Responder Index 4 (SRI-4) response at week 52, a composite measure incorporating changes in disease severity, organ-specific activity, and physician global assessment. Full ALLEGORY data were published in the New England Journal of Medicine in March 2026 and simultaneously presented at the 15th European Lupus Meeting, SLEuro 2026.¹,²

In the primary analysis, 76.7% of patients treated with obinutuzumab achieved SRI-4 response at week 52, compared with 53.5% in the placebo group (adjusted difference 23.1%; 95% CI, 12.5–33.6; P <.001).¹ Obinutuzumab was superior to placebo across all five prespecified key secondary endpoints. BICLA response at week 52 was achieved by 62.0% of obinutuzumab-treated patients versus 40.1% with placebo (adjusted difference 21.9%; 95% CI, 10.8–32.9; P <.001). Sustained SRI-4 response from week 40 to 52 was observed in 72.0% versus 46.4% (adjusted difference 25.4%; 95% CI, 14.6–36.2; P <.001), and SRI-6 response at week 52 was achieved in 68.9% versus 38.9% (adjusted difference 30.0%; 95% CI, 19.8–40.7; P <.001).²

The flare reduction data carry particular clinical weight for rheumatologists, given the role of recurrent flares in driving cumulative organ damage in SLE. Patients receiving obinutuzumab were significantly less likely to experience a flare through week 52 as defined by the BILAG index (HR, 0.58; 95% CI, 0.40–0.82; P = .002); median time to first flare could not be estimated in the obinutuzumab group versus 52.3 weeks in the placebo group.² Sustained glucocorticoid reduction to ≤7.5 mg/day from week 40 to 52 was achieved by 80.0% of obinutuzumab-treated patients versus 54.1% with placebo (adjusted difference 30.2%; 95% CI, 15.3–45.1; P <.001) — a clinically meaningful endpoint given the long-term morbidity associated with chronic steroid use in SLE.²

Among additional secondary endpoints, 35.1% of patients in the obinutuzumab arm achieved DORIS remission at week 52 versus 13.8% with placebo (adjusted difference 21.2%; 95% CI, 11.8–30.5), and Lupus Low Disease Activity State (LLDAS) at week 52 was reached by 57.6% versus 25.0% (adjusted difference 32.6%; 95% CI, 22.3–43.0).² Safety was consistent with obinutuzumab's established profile; no new safety signals were identified. Known risks — including infusion-related reactions, serious infections, neutropenia, hepatitis B reactivation, and progressive multifocal leukoencephalopathy — are outlined in the prescribing information and carry boxed warnings.¹

Genentech has also submitted ALLEGORY data to the European Medicines Agency. The sBLA filing joins 3 other positive phase 3 programs for obinutuzumab in immune-mediated diseases: REGENCY in lupus nephritis, INShore in idiopathic nephrotic syndrome, and MAJESTY in primary membranous nephropathy.¹

References

1. Genentech. FDA accepts application for Genentech's Gazyva for the treatment of the most common form of lupus. Business Wire. April 21, 2026. https://www.businesswire.com/news/home/20260420770652/en/CORRECTING-and-REPLACING-FDA-Accepts-Application-for-Genentechs-Gazyva-for-the-Treatment-of-the-Most-Common-Form-of-Lupus

2. Genentech. New England Journal of Medicine publishes phase III ALLEGORY data showing Genentech's Gazyva significantly reduces disease activity in the most common form of lupus. Business Wire. March 6, 2026. https://www.businesswire.com/news/home/20260306732863/en/New-England-Journal-of-Medicine-Publishes-Phase-III-ALLEGORY-Data-Showing-Genentechs-Gazyva-Significantly-Reduces-Disease-Activity-in-the-Most-Common-Form-of-Lupus