Dec 19 (Reuters) - The U.S. Food and Drug Administration on Tuesday approved Spark Therapeutics Inc's treatment for a rare form of blindness, marking the first time the agency has approved a gene therapy for an inherited disease.
The approval is expected to raise new questions about how the United States pays for major medical breakthroughs. The company said it would announce a price for the treatment early next year. Analysts expect it to cost around $1 million.
The drug, Luxturna, treats inherited retinal disease caused by defects in a gene known as RPE65, which tells cells to produce an enzyme critical for normal vision. The condition affects between 1,000 and 2,000 people in the United States.
Luxturna works by delivering 150 billion viral vector particles containing a correct copy of the RPE65 gene to retinal cells, restoring their ability to make the needed enzyme. It is designed to be given just once, though it is unclear how long the benefit will ultimately last.
Clinical trials of Luxturna showed that 93 percent of participants experienced some improvement in their functional vision as measured by their ability to navigate obstacles in poor light after a year.
Analysts on average expect the drug to generate annual sales of $478 million, according to Thomson Reuters data.
Gene therapy in general aims to treat disease by manipulating genes at a cellular level. The field is gaining momentum following several high-profile failures in the late 1990s and early 2000s, and the FDA appears eager to smooth the way for further approvals in the field.
"We're at a turning point when it comes to this novel form of therapy, and at the FDA we're focused on establishing the right policy framework to capitalize on this scientific opening." FDA Commissioner Scott Gottlieb said in a statement.
Still, the pitfalls remain legion. Highly anticipated early-stage data for Spark's gene therapy for hemophilia A disappointed analysts and investors when presented at a recent medical conference, though hopes remain high for its hemophilia B therapy, being developed with Pfizer Inc.
Next year the agency plans to issue guidance documents that will provide instructions for companies developing gene therapies for specific diseases, including "more efficient parameters" than currently exist.
Those parameters could include new, accelerated measures, Gottlieb said. The FDA's accelerated approval program allows for earlier approval of drugs that treat serious conditions based on a marker that is expected to lead to a clinical benefit.
RELATED: The 10 most risky foods, according to the FDA
The 10 Most Risky Foods, According to the FDA
The 10 Most Risky Foods, According to the FDA
Sprouts may look harmless, but they can harbor both Salmonella and E. Coli, which have caused outbreaks over the years. There are two main reasons for this. The first is that seeds can become contaminated before sprouting. The second is that they grow in warm and humid climates, which are perfect conditions for bacteria to flourish.
As with sprouts, Salmonella is the most common culprit in tomato-related outbreaks, followed by the norovirus. Tomatoes can become contaminated either through their root systems or small breaks in the tomato skin. Be sure to cook your tomatoes thoroughly before eating, and be careful when ordering them when eating out: 70 percent of reported illnesses were contracted through tomatoes served at restaurants.
Even kids who hate to eat their fruits and veggies aren't immune to food-borne illnesses. A 1994 Salmonella outbreak was traced an ice cream company using the same truck to transport raw unpasteurized eggs as it used to move ice cream mix. Pregnant moms need to take extra care, as well, as the Listeria bacteria can survive on metal surfaces like those used in ice cream shops.
As with ice cream, the dangers in cheese are primarily traceable to two culprits: Salmonella and Listeria. Soft-cheeses are particularly prone to harboring Listeria.
Believe it or not, potatoes themselves are almost never to blame for outbreaks. Instead, people get sick from all the things that potatoes come into contact with between being pulled from the ground and served up on your plate. Salmonella, E. Coli, Shigella and Listeria have all caused outbreaks in the past. Contamination from other ingredients in things like potato salad, as well as from bacteria that live on deli counters, is often to blame.
Not surprisingly, seafood causes many sicknesses. Oysters are the second-most common culprits in seafood-related illnesses. The creatures are sometimes harvested from waters containing the Norovirus, which causes intestinal inflammation. But the more dangerous Vibrio bacteria can cause a host of illnesses, including -- in people whose immune systems are compromised -- fevers, chills, skin legions, and even death.
When it comes to contamination, tuna ranks as the most dangerous seafood for human consumption. Almost all cases of sickness were caused by Scombrotoxin, which is not caused by a bacteria or virus, but rather is the result of tuna decaying, due to not being refrigerated immediately after being caught. Scombroid poisoning can lead to nausea, cramps, and diarrhea, and the toxin can't be eliminated through cooking or canning.
Between them, the top two foods on this list have caused more illnesses than the rest of the list combined. Not surprisingly, Salmonella is the most common culprit in egg-linked outbreaks. Salmonella survives in the intestinal tracks of chickens, and can only be assuredly killed by cooking eggs thoroughly.
Though leafy greens might seem harmless -- and indeed, healthful -- it actually makes sense that they account for so many outbreaks since greens are rarely cooked at temperatures that kill harmful bacteria. Norovirus was responsible for 64 percent of the reported cases, and is often transmitted when handlers have not washed their hands. Salmonella and E. Coli each accounted for 10 percent of the outbreaks as well.