FDA Grants Obinutuzumab Priority Review as Primary Membranous Nephropathy’s Potential First Therapy

The US Food and Drug Administration (FDA) has granted priority review to Genentech's supplemental Biologics License Application (sBLA) for obinutuzumab (Gazyva) to treat primary membranous nephropathy (pMN). An FDA decision is expected by November 2026, and if approved, obinutuzumab would become the first FDA-approved therapy for the chronic autoimmune kidney disease.

According to a July 14, 2026, press release, the FDA's decision was supported by results from the phase 3 MAJESTY trial, in which 36.9% of adults receiving obinutuzumab achieved complete remission (CR) at 104 weeks compared with 5.7% of those treated with tacrolimus (adjusted difference, 31.1%; 95% confidence interval [CI], 18.2-44.0; P <.001).

"This priority review represents an important step for patients living with primary membranous nephropathy, a chronic disease with no FDA-approved treatments," said Levi Garraway, MD, PhD, chief medical officer and head of Global Product Development, in a statement. "By targeting tissue-resident B cells, Gazyva addresses an underlying cause of pMN and has the potential to help more patients achieve complete remission, a necessary step to maintaining kidney function."

Primary membranous nephropathy is a chronic autoimmune disease in which autoantibodies damage the kidney's glomeruli, leading to nephrotic syndrome, progressive kidney dysfunction, and, in some patients, kidney failure. Up to 30% of patients progress to kidney failure within 10 years without effective treatment, underscoring the importance of achieving durable remission.¹

Obinutuzumab Builds on Expanding Kidney Disease Portfolio

Obinutuzumab is a glycoengineered type II anti-CD20 monoclonal antibody designed to deplete B cells and target a key driver of antibody-mediated autoimmune disease. The therapy is currently approved for chronic lymphocytic leukemia, follicular lymphoma, and active lupus nephritis.

The pMN priority review follows additional regulatory momentum for obinutuzumab in kidney disease. Earlier this year, the FDA granted Breakthrough Therapy Designation for pMN, and in May 2026 accepted a separate application for priority review in idiopathic nephrotic syndrome following positive results from the phase 3 INShore trial.

Data from MAJESTY were presented as a late-breaking oral presentation at the 63rd European Renal Association 2026 Congress and were simultaneously published in the New England Journal of Medicine.¹

MAJESTY Evaluated Obinutuzumab Against Tacrolimus

MAJESTY was the first global phase 3 randomized, open-label, multicenter trial conducted in adults with primary membranous nephropathy.

Investigators enrolled 142 adults, randomly assigning participants in a 1:1 ratio to receive obinutuzumab or tacrolimus. The primary endpoint was complete remission at week 104, defined as a urinary protein-to-creatinine ratio ≤ 0.3 with stable estimated glomerular filtration rate (eGFR).

Key secondary endpoints included complete or partial remission at week 104, complete remission at week 76, sustained eGFR decline of at least 30%, duration of complete remission, and change from baseline in Patient-Reported Outcomes Measurement Information System (PROMIS) Fatigue T scores.

MAJESTY Results Supported FDA Priority Review

At week 104, obinutuzumab demonstrated a significantly higher complete remission rate than tacrolimus, with 36.9% of treated patients achieving complete remission compared with 5.7% of those receiving tacrolimus (adjusted difference, 31.1%; 95% CI, 18.2-44.0; P <.001).

Obinutuzumab also significantly improved complete or partial remission at week 104 and complete remission at week 76. However, the prespecified analysis of sustained eGFR decline did not reach statistical significance, precluding formal testing of subsequent endpoints in the hierarchical testing sequence.

Grade 3 or higher adverse events occurred in 22% of patients treated with obinutuzumab and 19% of those receiving tacrolimus, while serious adverse events were reported in 17% and 14% of patients, respectively. Investigators reported no new safety signals, with the safety profile remaining consistent with previous experience with obinutuzumab.¹

Per the release, the findings position obinutuzumab as the first therapy to demonstrate superiority over tacrolimus in a global phase 3 trial in pMN, supporting the FDA's priority review decision.

References

1. Genentech. FDA grants priority review to Genentech's Gazyva for adults with primary membranous nephropathy. July 14, 2026.

2. Fervenza FC, et al. Obinutuzumab versus tacrolimus in primary membranous nephropathy. N Engl J Med. 2026.