The United States Federal Drug Administration (FDA) has approved a new gene therapy treatment for a rare blood clotting disease called Hemophilia B. The drug Hemgenix costs US$ 3.5mn (Rs 28.52 Crore).
Until now, the world’s costliest drug was Zolgensma – a drug for gene therapy used to treat children below two years diagnosed with ultra-rare genetic disease Spinal Muscular Atrophy (SMA) Type 1.
However, with the US FDA approving the one-time gene therapy drug Hemgenix on November 22, 2022, it has now become the world’s heftiest-priced drug! The approval was granted to CSL Behring LLC, a global rare disease biotech company.
The gene therapy drug is known to treat a rare genetic blood disorder called haemophilia B (Congenital Factor IX deficiency), which causes reduced clotting of the blood leading to excessive and uncontrollable bleeding.
Taken intravenously, the US FDA in its approval letter says that the one-time drug HEMGENIX is an ‘adeno-associated virus vector-based gene therapy indicated for the treatment of adults with Hemophilia B.
The US FDA website note says the drug can be used for Hemophilia B adult patients under the following conditions:
- Those who currently use Factor IX prophylaxis therapy or
- Have current or historical life-threatening haemorrhage, or
- Have repeated, serious spontaneous bleeding episodes.
The US FDA approved this drug after two successful clinical studies. “The safety and effectiveness of Hemgenix were evaluated in two studies of 57 adult men 18 to 75 years of age with severe or moderately severe Hemophilia B,” the US FDA notes on its website publication.
Science Alert writes in this article that “Hemophilia B tends to be more common in men than women, and while an exact number is hard to come by, estimates suggest nearly 8,000 men in the US currently suffer from the lifelong disease.”
It is also observed by Science Alert that the exorbitantly high cost of US$ 3.5mn (Rs 28.52 Crore) for Hemgenix is actually “reasonable” if the existing lifetime costs of Hemophilia B are taken into account.
“Today, researchers estimate the adult lifetime cost for every patient with moderate to severe haemophilia B is around US$21 to $23 million. Treatment costs in the UK are cheaper than in the US or elsewhere in Europe, but still add up to tens of millions of dollars per patient over their lifetime” says the article.
