GTC Biotherapeutics Inc., a developer of drug therapies derived from animal proteins, has regained U.S. commercialization rights to ATryn, a drug intended to prevent blood clots, from Lundbeck Inc., a wholly owned subsidiary of H. Lundbeck A/S in Denmark. The announcement follows news in June that GTC planned to cut 50 positions, after the company noted it had barely enough funds to last a month.

Lundbeck took on U.S. commercialization rights to ATryn in May 2009, with plans to pay GTC $1 million.

The new agreement calls for a six-month transition period, to ensure ATryn remains available to its users; After six months, Lundbeck will start earning net sales royalty on the drug in two years, GTC noted in a press release today.

Made from proteins in the milk of goats, ATryn is intended to prevent blood clots in hereditary antithrombin deficient, or HD, patients undergoing surgery or childbirth. People with hereditary antithrombin deficiency are at increased risk for venous thromboembolic events, including pulmonary embolism and deep vein thrombosis. Already approved for use in the European Union, ATryn received FDA approval in February 2009.

In March 2009, GTC (Nasdaq: GTCB) closed its contract with LEO Pharma A/S, relating to the commercialization and development of ATryn in Europe, Canada and the Middle East. GTC alleged that LEO is “in breach of its obligations,” and it is pursuing damages as a result.

Last month, amid news the GTC would cut 30 positions at its Framingham headquarters and another 20 at its farm facility, the company announced it had secured a new $7 million convertible debt financing. GTC chairman, president and CEO Geoffrey Cox was also expected to leave the company and be replaced by William Heiden, a GTC board member and former Elixir Pharmaceuticals Inc. president and CEO.