Replies to post #3646 on GTC Biotherapeutics (fka GTCB)

[Tuff-Stuff]

ty Dew for all ur updates!

[gym gravity]

Dew, what about complement fixation?

I was at a wedding this weekend with my ex-roommate from graduate school who just accepted a position at Sloan Kettering. He is setting up a lab that will look at the mix of activating and inhibitory signals that occurs when NK cells encounter targets. I asked him a little about Vectibix and Erbitux and his second thought was that there might be differences in compement activation. He's such a basic science guy that he has no mind for drugs though, so he hadn't heard of this story. I'm on the road so I haven't had time to look up more than this tutorial:

http://microvet.arizona.edu/Courses/MIC419/Tutorials/complement.html

something about fucose deficient antibodies ADCC:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&l...

[DewDiligence]

ImClone clearly believes in ADCC. Check out this
excerpt from one of IMCL’s ASCO 2007 PR’s:

http://biz.yahoo.com/bw/070605/20070605006223.html?.v=1

>>
Like its marketed product ERBITUX® (cetuximab), the monoclonal antibodies in the ImClone pipeline are all type 1 immunoglobulin G (IgG1) antibodies. In vitro, IgG1 antibodies elicit antibody-dependent cellular cytotoxicity (ADCC), which can kill cancer cells and may contribute to their overall therapeutic effects.
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As previously noted (#msg-19999027), AMGN’s Vectibix, which targets the same receptor as Erbitux, does not have ADCC functionality. It also doesn’t seem to work as well as Erbitux, and that’s probably not a coincidence.