FDA Approves Gazyva (Obinutuzumab) for Childhood-Onset Idiopathic Nephrotic Syndrome — "First FDA-Approved Treatment Option... in 70 Years"

FDA Approves Gazyva (Obinutuzumab) for Childhood-Onset Idiopathic Nephrotic Syndrome — "First FDA-Approved Treatment Option... in 70 Years"

On September 25, 2026, the FDA approved obinutuzumab (Gazyva, Genentech) "to reduce the risk of relapse in adult and pediatric patients aged 2 years and older with frequently relapsing or steroid-dependent childhood-onset idiopathic nephrotic syndrome (INS) who are in complete remission." Genentech chief medical officer Levi Garraway called it "the first FDA-approved treatment option for idiopathic nephrotic syndrome in 70 years¹" — steroids have been the mainstay since the 1950s, with relapse rates exceeding 70% and steroid toxicity limiting long-term use.

The approval rests on the phase 3 INShore trial (NCT05627557, n=85, ages 2–25, open-label vs mycophenolate mofetil): "In the phase 3 INShore trial, 95.5% of patients receiving obinutuzumab achieved sustained complete remission at week 52 vs 73.2% of those receiving mycophenolate mofetil (MMF)" (adjusted difference 23.36%, P=.003). Obinutuzumab also "reduced the risk of relapse or death by 75% (HR, 0.25; P = .007)" and cut relapses through week 52 to 4 vs 23 (rate ratio 0.07, P=.002), with lower cumulative steroid exposure.

The trade-off is immunosuppression: grade ≥3 adverse events in 25.0% vs 7.3% with MMF, infusion-related reactions in 36.4%, and label warnings for hepatitis B reactivation and progressive multifocal leukoencephalopathy; live vaccines must be given ≥28 days before treatment. The FDA granted breakthrough therapy designation and priority review; obinutuzumab is also under FDA review for primary membranous nephropathy and SLE, and already approved for lupus nephritis, CLL, and follicular lymphoma.

Why it matters: INS is the most common childhood glomerular disease, and this is the first steroid-sparing, B-cell-targeted approved option — a CD20 antibody repurposed from oncology into pediatric nephrology, with the sustained-remission gap over MMF (22 points) doing the heavy lifting.