FDA just approved the world's most expensive drug that costs $3.5 million

The U.S. Food and Drug Administration (FDA) recently approved a new drug Hemgenix, to be used in patients with hemophilia B, a blood clotting disorder. Since the condition is rare, it will be used only in a small group of patients worldwide. Yet, the drug is making headlines due to its hefty price tag, Science Alert reported.

Hemophilia B is a genetic condition affecting males more than females in which the patient's body does not produce sufficient protein levels called Factor IX (Roman numeral). The protein is a clotting factor required to stop bleeding in the event of an injury or during surgery or other medical procedures.

Since Hemophilia patients lack enough clotting factor, so they are at risk of complications of prolonged bleeding that can also affect joints, internal organs, and the brain, an FDA document said. Treatment for such individuals constitutes intravenous infusions of clotting Factor IX to prevent bleeding episodes, which must be conducted over the patient's lifetime.

How can Hemgenix help Hemophilia patients?

Developed by Pennysylvania-based pharmaceutical company CSL Behring, Hemgenix is a one-time gene therapy product given through an intravenous infusion. The infusion consists of viral vectors that carry a copy of the gene for producing Factor IX protein, which is then expressed in the patient's liver to increase the clotting factor levels in the body.

The effectiveness of the intervention has been evaluated in two studies that involved 57 adult men affected with moderate to severe Hemophilia B. One of the studies, which included 54 patients, demonstrated increased levels of Factor IX activity and a reduction in annualized bleeding rate in these patients.

The intervention is expected to cost patients $3.5 million per dose, which might still be relatively cheaper than the $23 million hemophilia B patients shell out for infusions over their lifetime, Science Alert said in its report.

Why is Hemgenix so expensive?

Estimates suggest that there are around 8,000 patients of Hemophilia B in the U.S. This is rather a tiny number compared to the number of patients of other ailments, such as cardiovascular diseases or cancer, that pharmaceutical companies trial drugs for.

The development of treatment options for conditions such as Hemophilia B, therefore, gets neglected by pharma companies since it does not make economic sense to spend billions on developing a drug that only a few people will use.

The FDA calls such treatments "orphan drugs" and provides incentives to conduct and accelerate their development. When treatment is deemed successful, the drug developer gets exclusive rights to sell the drug, often at high prices.

Before Hemgenix, a similar gene therapy intervention for another rare condition called spinal muscular atrophy held the tag of the most expensive drug and was developed using similar mechanisms.

Even as the most expensive drug in the world, insurance companies might include Hemgenix in their plans since it offers considerable cost savings for hemophilia patients. While the prices might be higher in the U.S., countries that use price controls on the drugs might see a substantial reduction in the cost per dose when approved in those markets.