Tretten® Approved Under Orphan Drug Program to Treat Rare Blood Disorder

The FDA approved the drug Tretten®, which is produced by Novo Nordisk A/S, Denmark, and is distributed by Novo Nordisk, Inc., USA, to treat congenital factor XIII A-subunit deficiency. Tretten®, or Coagulation Factor XIII A-Subunit (Recombinant), treats the rare disorder through a routine prevention of bleeding in adults and children. The FDA identified this drug as an orphan drug pursuant to its Orphan Drug Designation Program due to Tretten’s treatment of a condition that only affects a limited number of people in the country. After its approval, Karen Midthun, M.D., director of the FDA Center for Biologics Evaluation and Research, commented, “Without treatment, people with this rare condition are at risk for serious and life-threatening bleeding.”

Congenital Factor XIII Disorder

Individuals who do not produce enough factor XIII, a protein within blood that promotes clotting, are diagnosed with congenital factor XIII deficiency. Factor XIII is made of up of a subunit A and a subunit B. According to an article published in the Journal of the American Society of Hematology, entitled “Recombinant Factor XIII, a Safe and Novel Treatment for Congenital Factor XIII” the A-subunit deficiency is the most common form of a congenital factor XIII deficiency. The article also relates that the disease often causes life-threatening bleeds, impaired wound healing, and spontaneous abortions and is often exhibited by its victims early in life through intracranial bleeding. The report from the Hematology journal was published in March of 2012 and focused on a study to of 41 patients. Although the article’s authors argue that more “safe, reliable, and effective therapy for this condition is badly needed,” they also concede that their own data based on the clinical study was limited because of the rarity of the disease. When the article was published, the 41 patients in that study made up seven percent of those diagnosed with the disease worldwide.

Tretten® and FDA Approval

Tretten®  is a recombinant analogue, or laboratory-created, subunit A,which is injected into the patient’s bloodstream. The recombinant analogue Tretten® is grown in yeast cells, transformed into a freeze-dried powder, reconstituted with diluent, and then injected into the patient intravenously. The injection can be performed by a physician or can be self-administered.

The approval of the FDA followed a clinical study of 77 patients diagnosed with congenital factor XIII A-subunit deficiency. Tretten® was administered to the 77 patients on a monthly basis and was found to be effective in preventing bleeding for 90 percent of those individuals. However, some of the patients complained of side effects, including headaches and pain in extremities and at the location of the injection. Tretton® is the first recombinant analogue which has been approved for treatment of the deficiency. In 2011, the FDA approved the use of Corifact, a routine prophylactic and peri-operative management treatment for congenital factor XIII deficiencies.

Orphan Drug Designation Program

Tretton® was given an orphan drug designation by the FDA, which is granted upon special request and after a showing of certain requisites outlined by the FDA (21 CFR 316). Drugs that are designated under the Orphan Drug Act (ODA) are those used to treat rare diseases and those who sponsor drugs designated under the ODA are qualified to receive certain incentives, such as tax credits for certain clinical testing. Rare diseases are considered disorders that affect less than 200,000 people in the United States or that affect more than 200,000 but that are not expected to recover costs of the development of the drug.