WTAS: FDA Approves Drug to Treat Neurologic Manifestations of Hunter Syndrome

The U.S. Food and Drug Administration approved Avlayah (tividenofusp alfa-eknm) to treat certain individuals with Hunter syndrome (Mucopolysaccharidosis type II or MPS II).

"Today is a milestone day for children and their families battling Hunter syndrome," said FDA Commissioner Marty Makary, M.D., M.P.H. "The FDA is capable of doing two things: one, exercising regulatory flexibility; and two, complying with our obligation under the law to approve drugs based on 'substantial evidence' of effectiveness. We will continue to do everything we can to accelerate treatments for rare diseases."

“Avlayah is the first product approved to address neurologic complications of Hunter Syndrome, a very rare and often severe X-linked disorder in children, almost exclusively males,” said Acting CDER Director Dr. Tracy Beth Hoeg, M.D., Ph.D. “This accelerated approval was based on a surrogate endpoint: reduction of cerebrospinal fluid heparan sulfate, which the review team determined was reasonably likely to predict Avlayah’s clinical benefit. Heparan sulfate is one of the glycosaminoglycans that accumulates in the body in this disorder and is linked to the organ damage that occurs in early childhood. The drug’s application holder, Denali Therapeutics, is now conducting a randomized clinical trial that is more than 95% enrolled to evaluate the clinical benefit of this product. In the meantime, families with young children with Hunter Syndrome will have access to a product that may favorably alter the course of the disease at the crucial time in life when there is the greatest potential for benefit.”

Hunter syndrome is a rare inherited lysosomal disorder in which sugar molecules called glycosaminoglycans build up within the cells' lysosomes. This substrate accumulation affects physical and mental development by causing abnormalities in the skeleton, heart, respiratory system, brain, and other organs.

Headlines
Doctors & Scientists
Advocates & Organizations
 

Headlines:

• Reuters: US FDA approves Denali's genetic disorder therapy for children
• Fierce Pharma: FDA approves Denali's Hunter syndrome drug, handing rare disease community a win
• STAT: FDA approves Denali Therapeutics drug for Hunter syndrome
• BioSpace: Denali Delivers 'Welcome Positive' for Rare Disease Space With FDA's Hunter Syndrome Nod
• San Francisco Business Times: Some 13 years and $2 billion later, Denali Therapeutics wins first drug approval
• Medpage Today: FDA Signals Regulatory Flexibility With Accelerated Approval of Rare Disease Drug
• Neurology Live: FDA Grants Accelerated Approval to Tividenofusp Alfa for Neurologic Hunter Syndrome
• Contemporary Pediatrics: FDA approves Avlayah for Hunter syndrome
• FirstWord Pharma: Denali's enzyme-replacement therapy wins US nod for Hunter syndrome
• Pharmacy Times: FDA Approves Tividenofusp alfa-eknm, Targeting Neurologic Manifestations of Hunter Syndrome
• MedCity News: FDA Approval for Denali Therapeutics Blazes a New Trail for Brain-Penetrating Drugs
• BioPharma Dive: FDA clears Denali drug in 'clear step' for rare disease biotechs
• PharmaExec.com: FDA Approves Avlayah for Treatment of Hunter Syndrome

Doctors & Scientists:

• University of North Carolina at Chapel Hill's Director of the Muenzer MPS Research and Treatment Center and Distinguished Professor in Pediatric Genetics, Joseph Muenzer, M.D., Ph.D., via press release: "The FDA approval of AVLAYAH represents a breakthrough advance as the first therapeutic innovation for the Hunter syndrome community in nearly 20 years...The neurologic manifestations of Hunter syndrome, which affect nearly all patients, have been one of the most challenging and persistent medical needs for the community and a central focus of many years of scientific research. As the first FDA-approved, brain-penetrant medicine for Hunter syndrome, AVLAYAH will substantially change how we treat patients and has the potential to become a new standard of care."
• Denali Therapeutics' Chief Medical Officer and Head of Development, Peter Chin, M.D., via press release: "Today's accelerated approval of AVLAYAH is an important advancement for the Hunter syndrome community as the first and only enzyme replacement therapy designed to reach the central nervous system and periphery that is now FDA-approved to treat neurologic manifestations for individuals living with this disease."
• Houman David Hemmati, MD, PhD, Board Certified Ophthalmologist & research scientist, via X: "Hunter Syndrome is a rare, devastating, and previously untreatable condition that impacts all of the senses and all of the organ systems of the body by allowing toxins to accumulate in cells. Today, with the @US_FDA approval of a new treatment, there's hope for patients & families. I applaud the researchers who did the tireless work as well as @DrMakaryFDA & team for applying scientific rigor in the review process."
• Rachid Akiki, MD, MBA, via X: "Rare disease approvals matter most when they change the window of action. FDA approval of Avlayah for neurologic manifestations of Hunter syndrome is notable because it targets patients early, before advanced neurologic decline. That is the real lesson: in rare disease, speed is not a talking point. It is part of the treatment strategy. For families and teams working in this space, timing may be everything."

Advocates & Organizations:

• National MPS Society President and CEO, Terri Klein, via press release: "This accelerated approval for MPS II based on a biomarker as a surrogate endpoint is an extraordinary day for the MPS and rare disease community. It represents both recognition that time matters profoundly for families affected by these devastating disorders and the potential to accelerate drug development more broadly across MPS and other rare diseases...This approval affirms that when strong science and advocacy come together, meaningful change, continued progress and hope are possible for individuals living with MPS and other rare diseases who are waiting for treatments."
• Project Alive's Executive Director and parent of child with Hunter syndrome, Kristin McKay, via press release: "For families living with Hunter syndrome, progress has often felt incremental while the disease itself continues to move relentlessly forward. For many, disease progression includes cognitive impacts that can add emotional weight to an already challenging diagnosis...Families have been waiting for new options that reach the brain, so the availability of this new therapeutic approach brings renewed optimism and hope for our community."
• Megan Selser, mother of a two-year old son with MPS, via STAT: "Generations of Hunter Syndrome and MPS families have fought for this exact moment..."
• Lauren Holder, hunter syndrome advocate, via X: "I am so happy to see this win for the #HunterSyndrome #raredisease community!! Congrats, guys! #saverare"
• Sara Mitchell, mother to a son with hunter syndrome, via X: "Thank God...this new drug by Denali will be the new standard of care for Hunter Syndrome. It crosses the blood brain barrier which we NEED. Absolutely overjoyed. The FDA came through- it was a well designed trial w conclusive data. Plus I know some kids crushing it..."
• Denali Therapeutics' CEO and Co-Founder, Ryan Watts, Ph.D. via press release: "This approval reflects the determination and partnership of the MPS community, as well as the FDA's collaborative engagement to incorporate biomarker evidence to help accelerate the development of urgently needed treatments."
• John Maraganore, founding CEO of Alnylam Pharmaceuticals, via X: "Wonderful news for patients! @US_FDA @DrMakaryFDA. Importantly, this is the first approval of a trans-bbb shuttle-enabled therapy, with important implications for neurodegenerative and neurological disease treatment with biotherapeutics and oligonucleotides!"
• Stifel analyst, Paul Matteis, via BioPharma Dive: "[A] clear step in the right direction for rare disease sponsors..."