GTC Biotherapeutics, a company specializing in the development of therapeutics derived from transgenic animals, has reason to be optimistic. Investing 20 years in the business of developing transgenically derived treatments, the company suffered a recent setback in February when European officials denied approval of a transgenically produced drug. However, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency recently reversed the decision– recommending approval of the injectable antithrombin drug produced by transgenic goats.
The drug is ATryn, a recombinant form of antithrombin that has been purified from the milk of genetically altered goats. Antithrombin is a protein in human plasma that has anticoagulant and anti-inflammatory properties. A relatively small percentage of the population is deficient in antithrombin– the disease affecting about one in 3,000 to 5,000 people. The purified protein used for treatment is currently only available from donated human blood. If approved, ATryn will supplement this limited supply, the potential market a modest, but significant, $50 million.
Part of the controversy surrounding the use of antithrombin derived from transgenic animals is the risk of improper separation of proteins harvested from the milk, which could result in human exposure to animal proteins that could result in adverse effects on those receiving the treatment.
A final decision for the therapy should be issued within three months. If approved, the decision could open the door to a more affordable source of protein drugs that are currently unavailable or too expensive to manufacture.
GTC Biotherapeutics is involved in the development, production, and commercialization of therapeutic proteins through transgenic animal technology. In addition to ATryn, GTC has in development a recombinant human alpha-1 antitrypsin, a recombinant human albumin, a CD137 antibody to stimulate the immune system as a potential treatment for solid tumors, and a malaria vaccine.
