FDA reverses course on Regenxbio’s childhood gene therapy after rejection
The FDA will reconsider Navsunli, a gene therapy for Hunter syndrome. The agency now views existing data as sufficient for an accelerated filing. Regenxbio expects to resubmit the application in the third quarter of 2026.
What changed
The FDA now deems the current data sufficient to support an accelerated filing.
Live updates
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FDA accepts Regenxbio data for Hunter syndrome therapy resubmission
confidence 100%The FDA will reconsider Navsunli, a gene therapy for Hunter syndrome. The agency now views existing data as sufficient for an accelerated filing. Regenxbio expects to resubmit the application in the third quarter of 2026.
What's confirmed:
- The FDA will reconsider the approval of Navsunli, also known as RGX-121.
- Regenxbio plans to resubmit its application in the third quarter.
- The therapy targets Hunter syndrome.
Still unconfirmed:
- The FDA's pivot follows a similar reversal regarding uniQure's Huntington's disease gene therapy.
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FDA Reverses Rejection of Regenxbio Hunter Syndrome Gene Therapy
confidence 100%The FDA will reconsider Navsunli, a one-time gene therapy for Hunter syndrome also known as MPS II. The agency reversed its previous demand for an untreated control arm and now backs an accelerated approval path. Regenxbio plans to resubmit its BLA in Q3 2026.
What's confirmed:
- The FDA reversed its rejection of Regenxbio's gene therapy for Hunter syndrome.
- Navsunli is a one-time gene therapy for Mucopolysaccharidosis II, also known as Hunter syndrome.
- The FDA dropped the requirement for an untreated control arm or placebo.
- Regenxbio expects to resubmit the BLA in Q3 2026.
- This is the third rare disease drug reversal by the FDA in two months.
- The FDA confirmed that no additional studies are required.