15/10/2025
The International MPS Network (IMPSN) would like to share an important update from Denali Therapeutics regarding the review of their investigational therapy for Hunter syndrome (MPS II).
On October 13, 2025, Denali announced that the U.S. Food and Drug Administration (FDA) has extended its review timeline for the Biologics License Application (BLA) seeking accelerated approval of tividenofusp alfa (DNL310).
🔹 New FDA target decision date: April 5, 2026 (previously January 5, 2026)
🔹 The extension follows Denali’s submission of additional clinical pharmacology information as part of the standard review process.
🔹 This update is not related to efficacy, safety, or biomarkers, and no new data were requested by the FDA.
We know this news brings disappointment and frustration for many families who have been waiting and hoping for new treatment options. The IMPSN shares in that sentiment and recognizes how deeply these delays can affect those living with MPS II and their loved ones.
At the same time, we remain hopeful. Denali continues to work closely with the FDA and has reaffirmed its commitment to advancing tividenofusp alfa responsibly and as quickly as possible.
The IMPSN will continue to advocate, communicate, and stand alongside every family as this process continues. Your resilience, unity, and strength continue to inspire all of us.
📄 Read Denali’s full announcement: https://investors.denalitherapeutics.com/news-releases/news-release-details/denali-therapeutics-announces-fda-review-extension-bla