Denali Therapeutics Faces Regulatory Setback as FDA Extends Drug Review Timeline

Regulatory Delay Follows Data Submission

Biotechnology firm Denali Therapeutics has encountered a significant regulatory hurdle. The U.S. Food and Drug Administration has postponed its decision on the company’s Hunter syndrome treatment, tividenofusp alfa, extending the review period by three months. Investors who anticipated a January approval must now endure an additional waiting period until April 5, 2026.

The FDA’s extended timeline stems from Denali’s submission of updated clinical pharmacology information, which regulators classified as a “Major Amendment.” Company officials emphasize that this delay does not reflect concerns about the drug’s safety profile, effectiveness, or biomarker data. Rather, the extension provides regulators additional time to evaluate the newly provided information.