The FDA pushed back its approval decision for Beren Therapeutics’ adrabetadex, extending the review after the company submitted major updates and clarifications. The decision date was originally set for Aug. 17 following acceptance of adrabetadex for priority review in Niemann-Pick disease type C. Beren’s reply to FDA information requests was categorized as a major amendment, prompting the regulator to extend the timeline to Nov. 17 for additional review. The case continues a long development history for cyclodextrin-based therapy that dates back to delayed disease onset findings in mouse models. The filing relies on evidence presented using an external control arm approach after earlier late-stage trial failure, a strategy that has faced scrutiny in other gene and therapy approvals. For rare-disease biotech, the key operational takeaway is how amendment classification can re-set the regulatory clock even after priority designation. Beren now faces the same central evaluation question: whether the updated package sufficiently de-risks the external control comparisons that have tripped up regulators in the past year.