In a separate development tied to regulatory scrutiny, the FDA again paused Regenxbio’s gene-therapy trial on safety grounds after imaging findings were observed in treated patients. Regenxbio said the enrolled patients did not have symptoms related to the masses, but regulators required additional review before continuation. The second pause underscores the fragility of gene-therapy timelines when regulators detect potential structural changes that require expanded analyses and longitudinal safety confirmation. The company is managing a program that already faced a prior clinical hold earlier in the year. For the broader CAR-T and AAV landscape, the case is likely to keep regulators and sponsors focused on how MRI surveillance findings are translated into clinical decision-making thresholds.