Regenxbio said the FDA will reconsider its Hunter syndrome gene therapy after the agency previously rejected the application. Regenxbio’s update follows another apparent policy reversal after leadership changes at the FDA and comes as regulators revisit which evidence packages can support accelerated approval in ultra-rare settings. The company said FDA staff acknowledged its existing Navsunli clinical data is sufficient for review under the accelerated approval pathway and that Regenxbio would not need to run an additional placebo-controlled-style expansion. The next steps include a Type A meeting expected in July to review longer-term biomarker and clinical data before resubmission. The shift echoes a broader pattern of “reversion” on prior agency positions in rare disease development, and it may materially alter timelines for other applicants whose submissions depended on external control strategies or specific comparator designs. For biotech investors, the move reduces execution risk while still leaving operational sequencing—meeting outcomes and resubmission timing—squarely on the critical path.