Battery hens in cage© Best Shot Factory/Rex Shutterstock

Genetically engineered poultry are to be used in the production of a novel treatment for a rare disease in humans, which causes multi-organ damage and premature death.

The US Food and Drug Administration (FDA) has approved Kanuma for patients with Wolman disease, which leaves them unable to produce enzymes and leads to a build-up of fat in tissue cells that causes liver and heart disease.

Patients are usually diagnosed during infancy, with the disease progressing rapidly, often causing death in the first year. A second, milder form can also affect older children and leads to shortened life expectancy.

The two forms affect 27 individuals per million births.

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The drug is derived by inserting a gene in chickens such that they produce a recombinant form of human lysosomal acid lipase – the enzyme that is deficient in humans with Wolman disease – in their egg whites. This is then purified to produce the new drug Kanuma.

Janet Woodcock, director of the Centre for Drug Evaluation and Research, which approved the process, said: “Using this technology, these patients for the first time ever have access to a treatment that may improve their lives and chances of survival.”

The approval was welcomed by manufacturer Alexion Pharma, which described it as a “transformative treatment”.

Clinical trials have been taking place in the Children’s Hospital, Chicago, which found that more than two-thirds of infants who received enzyme replacement therapy survived beyond 12 months. And both children and adults had significant improvements in multiple disease-related liver and lipid abnormalities.

The genetically engineered chicken and their eggs do not enter the human food chain, the FDA added.