Antibody Creation on Corn Patented
A small California biotech company said Tuesday that it has exclusive rights to a new patent on a technique for producing therapeutic antibodies from corn and other farm crops. Epicyte Pharmaceutical Inc. of San Diego claimed that the patent gives it a leadership position in an emerging industry, potentially worth millions, with competitors including such agricultural giants as Monsanto Co.
The patent was granted to Scripps Research Institute, where the technology was developed by Epicyte’s founders in 1989. Epicyte said the patent applies to all plants and all antibodies, whether human or animal.
Antibodies are proteins naturally made by white blood cells that defend the body against disease. They can target specific invaders without disturbing other cells.
Drug makers produce antibodies for cancer and other diseases using conventional genetic engineering techniques. Of the 11 antibody-based drugs on the market, none are made in plants.
Most therapeutic antibodies are manufactured in hamster ovary cells, an intricate process that requires sterile factories with fermentation tanks and sophisticated purification equipment.
Ninety antibody-based drugs are in various stages of development at biotechnology companies. That has ignited a search for cost-effective ways to produce large quantities of antibodies, valued because they can target disease while causing few side effects.
Some companies are experimenting with ways to genetically engineer cows so that they produce human proteins in their milk, or to engineer hens so that their eggs contain human antibodies.
Epicyte is among the handful of companies trying to turn agricultural crops into antibody factories, an alternative dubbed “biopharming.” The company estimates that a single acre of genetically engineered corn can produce the same quantity of drugs as a typical multimillion-dollar factory.
The patent issued to Scripps on Tuesday covers DNA sequences called “zip codes.” They are molecular instructions that direct the antibody production process in plants. The patent is the fourth issued to Scripps on the 13-year-old invention by Epicyte founders Andrew Hiatt and Mich Hein.
Previous patents did not cover all DNA sequences, said Debra Robertson, director of intellectual property for Epicyte. That omission enabled competitors to engineer around the patents by writing their own zip codes, she said.
With the issuance of the patent Tuesday, “we believe now everyone will have to come to us” for a license, Robertson said. The patent expires in 2009.
Monsanto said it was studying the patent and had no comment on it. “We have a large patent base that covers many aspects of the production of proteins in plants,” spokesman Gary Barton said.
Epicyte handled the patent application for Scripps, which licensed the technology to Epicyte many years ago, said Thomas Northrup, patent counsel for Scripps. Northrup and Robertson declined to comment on the financial deal between Epicyte and Scripps. Epicyte is privately held.
Epicyte, in partnership with Dow Chemical Co., is developing an antibody to treat the herpes simplex virus. Other corporate partners include Johnson & Johnson’s biotechnology unit, Centocor.
However, analysts said it is too soon to assess the commercial promise of biopharming.
And some worry that transgenic crops could end up in the food chain. Wind might carry pollen from genetically altered plants to neighboring fields, or animals might ingest the crops. The Food and Drug Administration is expected to issue regulations on transgenic crops soon.
What’s more, antibodies produced in plants contain sugars not found on human antibodies, raising the possibility of rejection by the body’s immune system. Robertson said Epicyte’s antibodies haven’t triggered an immune response in animals. “We don’t think the difference [in antibodies produced in plants and humans] is important,” she said.
An answer may emerge soon. Centocor expects to know in three to six months whether plant-made antibodies function as well as conventionally produced antibodies, said Richard McCloskey, Centocor vice president of medical research. He sits on Epicyte’s scientific advisory board. (Centocor also has a research deal with Monsanto.)
The new technologies, including those using farm animals, could trim antibody production costs by 25%, which would benefit patients, McCloskey said. “If you produce a product, what good does it do if the patients can’t afford it and the health-care system won’t pay for it? As a clinician, that is my primary motivation” for looking at new technologies, he said.
