FDA approves gene therapy for hemophilia

The Food and Drug Administration on Tuesday approved a gene therapy for hemophilia — the latest in a series of decisions to advance pricey, personalized treatments that bring new hope to patients, along with cost concerns to the health system.

Why it matters: With a list price of $3.5 million, Hemgenix from CSL Behring LLC will become the most expensive therapy in the world.

• As Axios' Caitlin Owens reported in September, while the expected number of patients who'll receive such treatments is relatively low, employers, insurers, and public payers like state Medicaid programs may absorb large costs all at once.
• The Institute for Clinical and Economic Review this month suggested the highest price that should be charged for the treatment is about $2.9 million.

Details: Hemgenix is used to treat Hemophilia B, an inherited disorder affecting about one in 40,000 people that stems from missing or insufficient levels of a protein that's required to produce clots to stop bleeding.

• The treatment is given as a single dose by IV and contains a viral vector carrying a gene for the clotting factor.
• Its effectiveness was established based on decreases in the annualized bleeding rate of subjects in two studies.

• “Gene therapy for hemophilia has been on the horizon for more than two decades," said Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, adding Tuesday's decision "represents important progress in the development of innovative therapies for those experiencing a high burden of disease associated with this form of hemophilia.”

Catch up quick: The FDA recently approved two other multi-million-dollar gene therapies: Bluebird bio's Zynteglo for a blood disorder called beta-thalassemia and Skysona for a rare neurological disorder called cerebral adrenoleukodystrophy.