August 16, 2002

Transgenic Cows Offer Life-Saving Medicines Sooner

"If this application is approved it will greatly increase the likelihood of effective treatments being available sooner, some of them life-saving, for some rare but very severe diseases. The application is about more than experimental and basic science. It is also about the reality of production of medicines that are in short supply".

This statement to the ERMA hearing on AgResearch's application to genetically modify cows to produce therapeutic proteins, was made by John Forman, Executive Director of NZORD, the NZ Organisation for Rare Disorders.

Mr Forman cited one example of a medicinal protein extracted from the milk of a transgenic rabbit, saving the lives of children who would otherwise have died at less than one year of age from a fatal infantile disease, Pompe disease, a Lysosomal storage disorder. A very limited number of patients with juvenile and adult forms of the disease are also receiving treatments of the rabbit-sourced protein, in extended trials over the past three years.

"The proof of principle established in this clinical trial has led to the need to scale up production of Alpha-Glucosidase for wider trials and treatment of Pompe disease", Mr Forman told the ERMA hearing panel, "but there is a world wide shortage of production capacity for these complex proteins," he said. "Genzyme, the Biotech company, is stretched to capacity with existing production plus this new protein, in its large scale cell-line fermentation vats. Two additional fermenters for Pompe medicine alone, will cost Genzyme about NZ$10Million each. The delays are leading to high levels of anxiety and frustration among the patient group, including New Zealanders affected by Pompe and similar diseases."

Meanwhile other Lysosomal disorders have the potential for trials and treatment to begin as soon as their particular proteins can be produced in sufficient quantity, but the knowledge of the disease, and technical ability to treat, is well ahead of current production capacity. Several of these diseases are now waiting in a queue for commercial development of the protein.

"That is one very good reason we need this transgenic cows development project to proceed," said Mr Forman. "Production of these proteins through transgenic cows offers the possibility of highly functional proteins that will be good medicines, available in good quantity, and at lower cost than current production methods".

Mr Forman also told the hearing that the alternative production by cell-line fermentation, itself a genetic modification process, poses environmental stresses with the disposal of large quantities of disinfected cell-culture waste after each batch, and cannot always produce proteins of the required complexity, facts noted by the Royal Commission on Genetic Modification.

"It is important for many of the Lysosomal diseases, and potentially many other groups of rare disorders, that experimentation on new ways of producing these proteins is permitted", said Mr Forman. "The rabbits demonstrated the possibility, but while they might breed like rabbits, unfortunately they do not milk like cows".

Scientists and patient groups see the enormous potential of the cows' mammary gland to solve supply and cost problems, while producing well targeted and effective medicinal proteins for many diseases, and AgResearch's expertise in cow biology could make them a leader in the transgenic cow herds that are now being established in several countries.

END

© Scoop Media