Ultragenyx gets FDA nod for first Sanfilippo A gene therapy
Patients in the US with Sanfilippo syndrome type A have their first FDA-approved treatment, Ultragenyx Pharma's gene therapy Fayuvi, which will launch with a $3.9 million price tag.
Fayuvi (rebisufligene etisparvovec; formerly UX111) has been cleared as a one-shot treatment for children with the rare and devastating neurodegenerative disease – also known as mucopolysaccharidosis (MPS) IIIA – which leads children to lose cognitive, language, and other developmental abilities over time and cuts their average lifespan to around 15 years.
Previously, treatment of MPS IIIA was limited to managing symptoms and trying to make patients as comfortable as possible.
MPS IIIA is caused by a defect in the SGSH gene, which results in a deficiency of an enzyme (sulfamidase) and leads to the abnormal accumulation of a metabolite (heparan sulfate) in the body and brain. An intravenous infusion of Fayuvi delivers a working copy of the SGSH gene to patient cells, via a viral vector, and prevents that accumulation.
Fayuvi is Ultragenyx's second approved gene therapy after Genglycos (pariglasgene brecaparvovec) for glycogen storage disease type Ia (GSDIa), which was cleared by the FDA in August and has been given a list price of $2.7 million.
The new gene therapy has not had a smooth passage to approval, having been turned down by the FDA last year with a request for more manufacturing data.
Making the case of the Fayuvi list price, which makes it one of the most expensive medicines worldwide, Ultragenyx said that the lifetime cost of caring for a child with MPS IIIA can be as much as $8 million.
In the open-label, single-arm study that supported its approval, patients between the ages of two and five years who were treated with Fayuvi maintained or improved cognitive function compared to an untreated historical control cohort.
"We recognise the profound urgency of making this therapy available to families, and our focus now is on supporting timely access in the US as we work closely with treatment centres and payers to support families on the gene therapy treatment journey," said the company's chief executive, Emil Kakkis.
The company said it hopes to start making Fayuvi available through treatment centres within the next 30 to 60 days. It estimates that there are between 3,000 and 5,000 patients in the developed world affected by MPS IIIA.
Glenn O'Neill, president and co-founder of the Cure Sanfilippo Foundation, and Terri Klein, president and CEO of the National MPS Society, issued a joint statement hailing the approval as "a remarkable scientific achievement [that] is the culmination of decades of advocacy, fundraising, collaboration, and perseverance across the Sanfilippo community along with researchers, clinicians, and industry partners."
Photo by DESIGNECOLOGIST on Unsplash
