The US Food and Drug Administration (FDA) has approved a chicken that has been genetically engineered to produce a drug in its eggs.
The drug, Kanuma (sebelipase alfa), is a recombinant human enzyme marketed by Alexion Pharmaceuticals. It replaces a faulty enzyme in people with a rare, inherited condition that prevents the body from breaking down fatty molecules in cells.
Following its approval by the FDA on 8 December, Kanuma joins a small group of ‘farmaceuticals’ on the US market. In 2009, the agencyapproved genetically modified goats that produce an anticoagulant called ATryn (antithrombin) in their milk. And last year, the FDA authorized a drug for treating hereditary angioedema that is produced by transgenic rabbits.
The FDA’s latest decision “shows that the ATryn goats weren’t just a one-off”, says Jay Cormier, a lawyer at Hyman, Phelps and McNamara in Washington DC and a former scientific reviewer for the FDA. “The process can function for more than just one particular unique case.”
The agency moved quickly to consider Kanuma, giving it a priority review, orphan-drug status and a breakthrough-therapy designation. The disease that it is designed to treat, lysosomal acid lipase deficiency, causes fat to accumulate in the liver, spleen and vasculature. A form of the disease that strikes infants is quickly fatal. A second form that affects older patients causes liver enlargement, fibrosis and cirrhosis, as well as cardiovascular disease.
“Before we had this drug, we didn’t have any treatment for the patients that really addressed the underlying biochemical defect in the disorder,” says Barbara Burton, a paediatrician with the Northwestern University Feinberg School of Medicine in Chicago, Illinois. Clinicians could only provide nutrition and supportive care to infants, says Burton, who worked with Alexion to conduct the clinical trials. Older patients are treated with statins—which do not address the fatty build-up in the liver.
A fast-growing salmon has become the first genetically engineered animal to be approved for human consumption in the United States.
The decision, issued by the US Food and Drug Administration (FDA) on November 19, releases the salmon from two decades of regulatory limbo. The move was met with swift opposition from some environmental and food-safety groups.
But for advocates of the technology, the decision comes as a relief after a long and vexing wait. They say that it could spur the development of other genetically engineered animals. “It opens up the possibility of harnessing this technology,” says Alison Van Eenennaam, an animal geneticist at the University of California, Davis. “The regulatory roadblock had really been disincentivizing the world from using it.”
The genetically modified fish, called ‘AquAdvantage' salmon, were engineered by AquaBounty Technologies of Maynard, Massachusetts, to express higher levels of a growth hormone than wild salmon. The fish grow to full size in 18 months rather than 3 years.
Doctors and scientists want drug regulators and research funding agencies to consider medicines that delay ageing-related disease as legitimate drugs. Such treatments have a physiological basis, researchers say, and could extend a person’s healthy years by slowing down the processes that underlie common diseases of ageing — making them worthy of government approval. On 24 June, researchers will meet with regulators from the US Food and Drug Administration (FDA) to make the case for a clinical trial designed to show the validity of the approach.
Current treatments for diseases related to ageing “just exchange one disease for another”, says physician Nir Barzilai of the Albert Einstein College of Medicine in New York. That is because people treated for one age-related disease often go on to die from another relatively soon thereafter. “What we want to show is that if we delay ageing, that’s the best way to delay disease.”
Barzilai and other researchers plan to test that notion in a clinical trial called Targeting Aging with Metformin, or TAME. They will give the drug metformin to thousands of people who already have one or two of three conditions — cancer, heart disease or cognitive impairment — or are at risk of them. People with type 2 diabetes cannot be enrolled because metformin is already used to treat that disease. The participants will then be monitored to see whether the medication forestalls the illnesses they do not already have, as well as diabetes and death.
On 24 June, researchers will try to convince FDA officials that if the trial succeeds, they will have proved that a drug can delay ageing. That would set a precedent that ageing is a disorder that can be treated with medicines, and perhaps spur progress and funding for ageing research.
During a meeting on 27 May at the US National Institute on Aging (NIA) in Bethesda, Maryland, Robert Temple, deputy director for clinical science at the FDA’s Center for Drug Evaluation and Research, indicated that the agency is open to the idea.
