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Cystic Fibrosis Gene Correction Drug Approved by the FDA
tguyton writes "The good news: the FDA just approved the distribution of the first drug to treat the underlying cause of Cystic Fibrosis, called Kalydeco by Vertex Pharmaceuticals. The bad news: this drug will only affect 4% of patients with the disease in the U.S. From the article: '[Affected patients] with the so-called G551D mutation have a defective protein that fails to balance the flow of chloride and water across the cell wall, leading to the buildup of internal mucus. The vast majority of cystic fibrosis patients have a different genetic defect, in which the protein does not reach the cell wall. Vertex is developing another drug to try and address that problem. Study data for that drug is expected later this year.' Hopefully the research involved will be applicable to finding treatments for other genetic diseases."
Further bad news: "...executives said Kalydeco would cost $294,000 for a year's supply, placing it among the most expensive prescription drugs sold in the U.S."
Good lord, we are animals not plants. There is no such thing as a "cell wall" in our cells! Call it what it is: the cell membrane.
Pedantic? Yes, but the definitions are precise and are intended to be used precisely. Journalism like this makes me want to gouge my eyes out; a single high-school biology class teaches cell wall vs. cell membrane!
http://www.forbes.com/2010/02/19/expensive-drugs-cost-business-healthcare-rare-diseases.html
Alexion Pharmaceutical's Soliris, at $409,500 a year, is the world's single most expensive drug. This monoclonal antibody drug treats a rare disorder in which the immune system destroys red blood cells at night. The disorder, paroxysymal nocturnal hemoglobinuria (PNH), hits 8,000 Americans.
Elaprase ($375,000 per year) treats an ultra-rare metabolic disorder called Hunter's syndrome. Just 500 Americans suffer from the disease, which causes infections, breathing problems and brain damage.
Naglazyme from BioMarin Pharmaceuticals treats another rare metabolic disorder and costs $365,000 a year, according to investment bank Robert W. Baird. Viropharma predicts that sales of its Cinryze, a treatment to prevent a dangerous swelling of the face, will increase from $95 million last year to $350 million several years from now. The drug costs an estimated $350,000 a year.
CF is caused by defects in the CFTR protein, an ion channel on the surface of many cells, including the cells that line the respiratory tract. Basically, it creates an osmotic potential by moving chloride and other ions from the cell to the outside, so water flows out of the cell into the mucous in the airways, making it less viscous. I'm an anaesthetist, not a respiratory physician, but as far as I understand, in the F508 mutation (most common ~70%), CFTR doesn't even make it onto the cell membrane. In the G551D mutation, CFTR reaches the cell membrane, but degrades more rapidly than normal. Ivacaftor acts to increase the length of time the faulty protein stays on the surface until it's degraded. Hence why it's of no benefit in the most common mutation.
At least for new policies, the Affordable Care Act (Obamacare) made lifetime maximums illegal.