Overview
- Avlayah, a brain-penetrating enzyme therapy from Denali Therapeutics, received accelerated approval based on sharp drops in a key cerebrospinal fluid biomarker tied to Hunter syndrome.
- The authorization applies to presymptomatic or symptomatic pediatric patients who weigh at least 5 kg and begin treatment before advanced neurologic impairment.
- An open-label phase 1/2 study in 47 boys showed cerebrospinal fluid heparan sulfate fell 91% by week 24, with 93% reaching levels seen in people without the disease.
- Other markers of nerve and body damage normalized over time, while infusion-related reactions were the most common side effects early and declined with longer treatment.
- The global phase 2/3 COMPASS study is comparing Avlayah with standard enzyme therapy to measure clinical outcomes, and the FDA also issued a Rare Pediatric Disease priority review voucher to the sponsor in a field with few new options over two decades.