Serologicals gains patent for 'Mad Cow' prion clearing process
07/01/2004
BY CHRIS ANDERSON
ATLANTA, Ga.—Serologicals Corp. (www.serologicals.com) has been granted a patent on its proprietary purification process that clears infectious prions — thought to be the cause of Mad Cow Disease—from its bovine-based cell culture growth medium, EX-CYTE.
The patent comes six years after research chemists at the company's Kankakee, Ill., fractionation facility first theorized a method to eliminate prions in the medium while simultaneously preserving the properties and integrity of the finished EX-CYTE product.
"That really is the beauty of the process," says Joe Montalto, senior director/fractionation operations for Serologicals. "We had an idea that the prions under high-alkaline conditions would denature under the appropriate time and ph, and as part of that and complementary to that, the lipoproteins in EX-CYTE would not be affected by that exposure."
Prions, also called proteinaceous infective particles, are misfolded proteins that apparently contain no nucleic acid and are known to cause neurological diseases called transmissible spongiform encephalopathies (TSEs). In cows, it is called bovine spongiform encephalopathy (BSE), though more commonly called Mad Cow disease. Its human variant is Creutzfeldt-Jakob disease. In the United Kingdom and Europe, some humans have a variant of BSE that is thought to have originated from the consumption of BSE-contaminated beef.
In the pharmaceutical world of bovine-based products, manufacturers such as Serologicals have stringent controls designed to source the needed bovine materials from cattle populations at very low risk of BSE. These steps include using younger cattle, selecting cattle from geographic areas known to be disease-free, and using beef cattle as opposed to dairy cattle.
According to Serologicals, more than 60 percent of pharmaceuticals on the market have involved the use of bovine-based products at some point in their development or manufacture.
"Although there have been no reported incidents of bovine spongiform encephalopathy (Mad Cow disease) being transmitted to humans by pharmaceuticals, there is a perceived risk," reports David Dodd, president and CEO of Serologicals. "The public, regulatory agencies and our customers deserve to be assured that pharmaceuticals have been developed using the highest quality, purest materials. Our patented process provides that assurance."
How it works
The process works by exposing the lipoproteins in EX-CYTE to a highly alkaline solution (between 10 and 13 pH) for a number of hours. To prove its efficacy, Serologicals commissioned an in vivo study of simian hamsters to prove that materials with prions present at the outset were effectively prion-free after exposure to the alkaline solution. The hamsters were then exposed to either treated or untreated material and monitored over a period of 16 months. At the completion of the study, an audited report showed prion reductions of 5,000-fold as a result of the Serologicals treatment.
The patent for the purification process runs through 2021 and has the potential to become its own source of revenue generation, though Serologicals officials wouldn't specifically comment on plans for its use beyond its current application with EX-CYTE.
"The patent covers a process we have developed over a period of time, and the granting of this patent reflects the uniqueness of our process," says Dennis Harris, Ph.D., vice president research and development, business development and chief scientific officer. "We are not actively seeking to out-license at this time, but will consider any opportunities that present themselves going forward."
For now, Serologicals considers the patented process a value-add to the company's EX-CYTE cell culture growth medium.
"We have always felt that the bovine material we use is safe based upon the level of the safety of the animals," says Montalto. "But this is a something you bring into the process to enhance what we believe is a pre-existing safe product, to give those who use EX-CYTE an added level of confidence."