FDA Approves Rare Congenital Blood Disease Treatment

(National Institutes of Health)

The U.S. Food and Drug Administration yesterday approved a treatment for congenital factor XIII A-subunit deficiency, a rare blood clotting disorder, made by the pharmaceutical company Novo Nordisk, based in Denmark. Tretten, the medication’s brand name, is an engineered biologic designed to prevent bleeding in adults and children with the disorder.

People with factor XIII A-subunit deficiency, an inherited disorder, do not make a protein called factor XIII that circulates in the blood and is considered important in normal blood coagulation. Those with the disease are thus susceptible to lifelong bleeding, including spontaneous bleeding in the brain.

Factor XIII is made of two subunits, A and B, and those with the deficiency are usually lacking in subunit A. Novo Nordisk cites estimates from 2011 indicating 1,054 people with the disease worldwide, and 108 of those living in the U.S., affecting all ethnic groups and both genders.

Tretten is an engineered analogue of human factor XIII subunit-A produced in yeast cells and purified into a sterile freeze-dried-powder. The powder is then reconstituted into liquid form and injected intravenously. The medication can be administered by a physician or the patient. FDA earlier designated Tretten as an orphan drug.

The FDA approval is based on results of clinical trial that tested the safety and efficacy of Tretten with 41 factor XIII A-subunit deficiency patients in Europe and Canada, compared to a historical control group of persons with the disorder but not receiving the treatments. The findings show the treatments prevented bleeding episodes in 90 percent of the test patients receiving monthly injections of Tretten.

Reported side effects of the Tretten treatments included headache, pain in the extremities, and pain at injection site. None of the individuals in the trial developed abnormal blood clots.

Novo Nordisk says Tretten will be available to U.S. patients early in 2014. The medication is already approved in Canada and Europe, where it is marketed under the brand name NovoThirteen.

Read more:

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• Nimbus, Shire Partner on Rare Genetic Disease Drug Discovery
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• Database Enables Documentation of Rare Genetic Disorders
• Challenge Seeks Discontinued Drugs to Treat Rare Diseases

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