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Biotech / Medical : HuMAB companies -- Ignore unavailable to you. Want to Upgrade?

To: scaram(o)uche who wrote (235)	10/4/2001 12:48:22 PM
From: keokalani'nui	Read Replies (1) \| Respond to of 1022

Viragen reports first humanized antibody produced using chicken cells Last Updated: 2001-10-03 16:07:01 EDT (Reuters Health) By Anthony J. Brown, MD WESTPORT, CT (Reuters Health) - Viragen, Inc. announced Wednesday the successful production of the world's first humanized antibody using a chicken cell line. The cell lines were engineered to express GD3, a humanized antibody that is used to treat melanoma and other cancers. The finding provides proof that a functional humanized monoclonal antibody can exist in a chicken cell line. It also suggests that it may be possible to create transgenic chickens that lay eggs containing protein-based drugs. The "proof of principle" study was a collaboration between the Plantation, Florida-based biotechnology company and the Roslin Institute in Scotland, known for its creation of Dolly the sheep. "It has been proposed that chickens should be able to synthesize functional human antibodies, but no one to our knowledge has ever before accomplished this," Dr. Helen Sang, the Roslin Institute's lead scientist on the project, said in a statement. Dr. Joe Conner, a scientist with Viragen who conducted the experiments, explained that "humanizing an antibody requires removing most of the non-human regions of the protein by genetic engineering and replacing them with equivalent human components." Based on an assay provided by Memorial Sloan-Kettering Cancer Center in New York, the antibody produced in chicken cells was functional, Dr. Conner noted. "We wanted to show prospective clients the potential for avian transgenics to be a faster, cheaper means of manufacturing protein-based therapeutic drugs," Douglas Calder, Viragen's Director of Communications, told Reuters Health. "The simplest way to produce monoclonal antibodies is by using bioreactors, but this is very expensive," Calder noted. "An alternative method that is cheaper and faster is mammalian transgenics," he said. "However, it takes years to generate a transgenic herd of animals compared with only months for a transgenic flock of chickens." "The production costs for 1 gram of a protein-based drug using bioreactors is $100. Using mammalian transgenics it is $3 to $5, and for avian transgenics we estimate that it will be 25 to 30 cents," Calder said.