Federal panel will weigh in on GTC's blood-clotting drug

GTC Biotherapeutics uses milk from genetically altered goats to make Atryn. (Wiqan Ang for the Boston Globe/File 2007)

A federal advisory panel is scheduled to consider tomorrow whether to recommend US approval for a Framingham company's drug that is made with the help of genetically altered goats. GTC Biotherapeutics Inc.'s goats are engineered to produce a key therapeutic protein in their milk, which is used to manufacture Atryn, a treatment for blood-clotting complications in some surgery patients.

European regulators approved Atryn in 2006, making it the first therapy approved anywhere using the goat-based process, called transgenic production. The Food and Drug Administration, which normally follows recommendations of its advisory panels, is expected to make a final decision by Feb. 7.