GTC Biotherapeutics (fka GTCB)

[DragonBits]

Vinny, is this still a concern? I don't recall reading about it on the board, maybe Dew has it in his read me file? This was an analysis done right after the first rejection.

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That bare-bones 'not enough data' conclusion rather skirts round some of
the underlying issues that transgenic protein producers have to face.

Recombinant proteins produced in animals typically have altered
glycosylation patterns compared with native proteins. This doesn't
necessarily influence their pharmacological properties, of course, but
in the case of Atryn, it clearly did. Compared with the conventional
antithrombin-product, which is extracted from bovine plasma, Atryn's
serum half-life was reduced seven- to tenfold, necessitating infusion of
the protein rather than a one-off injection.

But one of EMEA's principle concerns with Atryn was its potential
immunogenicity. GTC claims that it has not observed adverse
immunogenicity in any of the 200 patients who have received Atryn. It
will be important not only for GTC but also for other animal transgenics
companies to allay the concerns of regulators on this matter. The
problem is that it is pretty difficult for transgenics producers to
produce 'nature-identical' proteins in milk. In cows and sheep and GTC's
bioreactor of choice, the goat, the oligosaccharide decoration on
proteins typically contains N-glycolylneuraminic acid (NGNA), a monomer
virtually absent in native human proteins. Furthermore, the high
concentrations of protein produced in milk--around a gram per liter--
stretches the glycosylation capacity of the mammary gland to its limits.
In fact, only in rabbits and chickens are the oligosaccharides more
human-like (containing N-acetylneuraminic acid).

Thus, if immunogenicity of milk-produced proteins turns out to be a
generic problem, then a whole class of transgenic production methods may
turn out to have a limited future.

http://www.gene.ch/genet/2006/Jun/msg00025.html

As far as my post, I was only repeating what I had read, and I didn't put any legal spin on it.