FDA approval of Fayuvi caps decade of effort by one family
The gene therapy for Sanfilippo syndrome, priced near $4 million, stems from research funded by the O'Neill family's viral campaign.
By Talia Bennett ·
The U.S. Food and Drug Administration approved Fayuvi in September, a one-time gene therapy infusion for Sanfilippo syndrome that costs nearly $4 million. The treatment, developed by Ultragenyx, is tied for the second most expensive gene therapy available, according to drug price research firm 46brooklyn.
Sanfilippo syndrome is a rare inherited disorder caused by a faulty gene that prevents the body from breaking down heparin sulfate. The molecule accumulates in cells, causing severe complications including seizures and the loss of speech and mobility. Children with the condition typically do not live past their teens, according to the Cure Sanfilippo Foundation.
The path to approval began in 2013 when Cara O'Neill, a pediatrician in Columbia, South Carolina, learned her daughter Eliza had the disease. Eliza was three years old at the time. Her mother recalled the diagnosis as a sudden wave of dread after a colleague suggested testing for metabolic disorders.
Haiyan Fu, a researcher at Nationwide Children's Hospital in Columbus, Ohio, had been studying the condition in mice since the late 1990s. By 2009, Fu feared she would have to abandon the project due to lack of funding. Families of affected children stepped in to keep the work alive, including the O'Neils, who started the Cure Sanfilippo Foundation.
To fund the first human trial, Glenn O'Neill, Eliza's father, contacted filmmaker Benjamin Von Wong in 2014. The resulting video, titled Saving Eliza, helped the family raise $1 million in a few weeks, breaking a GoFundMe record. The total eventually reached $2 million. Eight patient foundations supported the research until it was ready for clinical testing.
The first human trial began in May 2016. Eliza was the first patient to receive the therapy at age six. She had already lost the ability to speak, which did not return, but she now communicates using picture cards and devices. This summer, she learned to float on a pool noodle.
Ultragenyx acquired the rights to the therapy in 2022 and submitted data to the FDA for review. CEO Emil Kakkis stated that the treatment yields better results in younger children because more brain tissue remains. He noted that patients treated around six months of age have shown strong outcomes. Following the approval announcement, Fu received a call from Cara O'Neill, though Fu described her emotions as mixed, stating it should not have taken this long to reach approval.
