GTC Biotherapeutics Inc. raised $10.4 million by selling about 7.7 million shares of common stock to fund development for ATryn, its product for antithrombin deficiency.

Shares are priced at $1.35 each. SG Cowen & Co. LLC in New York acted as placement agent for the offering.

Net proceeds will be used "to continue our clinical and regulatory strategy, primarily around ATryn, our recombinant form of human antithrombin under review for approval now with the [European Medicines Evaluation Agency]," said Thomas Newberry, vice president of corporate communications for the Framingham, Mass.-based company. Pending approval, GTC plans to launch the product later this year.

The company also plans to file an investigational new drug application for a U.S. study, Newberry said. "This will be one more trial on top of the European data we already have, and we'll seek [FDA] approval in a year's time or so," he said.

Funds will be used to move forward the U.S. clinical trial, as well as producing more of the company's product for a larger market study in late 2005 and early 2006, he added.

Newberry said GTC expects to report $22 million in cash for the end of 2004.

"This adds $10 million to that," he told BioWorld Today. "We're expecting to burn $20 million or $25 million in 2005."

That burn will include funding a hereditary deficiency study in the U.S. for ATryn. An additional $5 million could be used for ATryn production to support a large market study, he said. "One of our objectives here is to be sure we can maintain the momentum of the program in development," he said.

The company's burn rate depends on partnership options for marketing and expanding ATryn. Newberry said GTC anticipates an opinion on the product in April and hopes to receive full approval by mid-year.

"We're in partnership discussions, and our main objective is to gain a broader base of support for development [of ATryn] for larger indications," he said, though "we're not sure what those indications might be at this time."

ATryn is a plasma protein with anticoagulant and anti-inflammatory uses, produced using the company's transgenic technology. The drug also is being developed to treat hereditary antithrombin deficiency, a genetic defect that causes the overdevelopment of blood clots. Patients with antithrombin deficiency can manage their conditions with blood-thinners, but run the risk of excessive bleeding during surgery or childbirth.

"We also are developing plans for larger indications," Newberry said, adding that ATryn also could be used to treat severe burns, smoke inhalation in the lungs, sepsis, hemorrhage resistance and coronary bypass surgery.

"These are conditions in which the body acquires antithrombin deficiency, as opposed to having a genetic condition," he said. "The larger market indications are people who have normal levels of antithrombin, but because of consumption or trauma, they need antithrombin replacement therapy."

Products in GTC's pipeline are "dominated by recombinant forms of human blood protein," Newberry said. The company also is developing a recombinant human albumin, used as a stabilizer in biological drug formulations. Another blood protein, an alpha 1 antitrypsin, could be used as a replacement therapy associated with emphysema.

The company also is developing a malaria vaccine, having filed a patent on the technology, and receives funding for it through the National Institute of Allergy and Infectious Diseases. It also continues work on a preclinical antibody, CD137, to stimulate the immune system as a possible treatment for solid tumors.

Products are developed by obtaining and purifying proteins found in the milk of transgenic animals.

"We take advantage of the mammary glands, which are very good at producing very complex proteins," Newberry said. Proteins are linked to milk-promoting genes, inserted into the embryos of goats or cows and then recovered for purification when the animal begins lactating.

Transgenic technology has worked well when dealing with complex proteins that are difficult for a bioreactor to express, he said. "Another reason is for dealing with large production volumes. Transgenic production requires much lower capital investment than you'd need with bioreactor organisms."

If it receives European approval later this year, Newberry said, ATryn would be the first transgenic protein to win marketing approval.

In addition to GTC's own product pipeline, the company also has formed partnerships to license its technology to other companies. One program, with Cambridge, Mass.-based Merrimack Pharmaceuticals Inc., features the development of MM-093, a recombinant protein, for rheumatoid arthritis and multiple sclerosis. That product is in Phase I trials. An unnamed product, in development with Centocor Inc., of Malvern, Pa., is in the preclinical stage, Newberry said.

Last year, GTC raised $15 million by selling 6.4 million shares of its common stock at $2.34 per share. (See BioWorld Today, March 17, 2004.)

For the quarter ending Oct. 3, GTC posted a net loss of $7.2 million. Before Monday's offering, there were about 38.8 outstanding shares.

GTC's stock (NASDAQ: GTCB) dropped 9 cents Monday to close at $1.47.