Let’s try this again, FDA aligns with Regenxbio on path to refile

Regenxbio (NASDAQ: RGNX) announced it has reached an agreement with the U.S. Food and Drug Administration on next steps for resubmitting its Biologics License Application for NAVSUNLI (clemidsogene lanparvovec-sngl), a gene therapy candidate for Mucopolysaccharidosis II, also known as Hunter syndrome.

The FDA, as part of the company’s appeal of a February 2026 Complete Response Letter, confirmed that existing clinical data is sufficient for consideration under the accelerated approval pathway and that no additional patients or studies are required. This includes the FDA’s previously recommended incorporation of an untreated control arm, which will no longer be needed.

The FDA asked Regenxbio to request a Type A meeting to review existing longer-term biomarker and clinical data before resubmitting the BLA. The agency stated it would review the resubmission on an expedited basis, with labeling discussions to begin shortly after resubmission.

Regenxbio expects the Type A meeting to occur in July 2026 and plans to resubmit the BLA in the third quarter of 2026.

MPS II is a rare, X-linked recessive disease affecting approximately 2,000 patients worldwide, with more than 500 births annually. The majority of patients have severe forms of the disease. NAVSUNLI is designed as a one-time gene therapy to deliver the iduronate-2-sulfatase gene to the central nervous system.