Posted 4/2/2009 6:26 PM (GMT 0)
Not sure if this is the answer you want, but the technical answer is...
Remicade = chimeric human and mouse antibody. Antibodies are shaped like a "Y" as you probably already know. Part of the region that binds to TNF, the "arms" of the Y, originates from mouse, and the remainder is of human origin.
Humira = 100% human origin. Basically they started with a human antibody and engineered it to bind TNF with great strength.
One important thing about the above two, which separates them from Cimzia, is how they are made. Both of the above are produced in mammalian cells. Culturing mammalian cells is more difficult and expensive and there is a chance of contamination with viruses, etc. that people are susceptible to. The reason why they culture in mammalian cells is that the mammalian cells will decorate the antibodies they produce with sugars (bacteria do not). This makes them appear more natural to our own bodies, so you are less likely to mount an immune response agaisnt them.
Cimzia = an antibody fragment, fused to a chemical called polyethylene glycol (PEG). Imagine the "Y" shaped antibody again. Cimzia contains only the TNF-binding "arms" without the rest of the protein. In place of the rest of the protein, the "arms" are bound to PEG, a chemical that also is anti-immunogenic, similar to the effect of the sugars decorating humira/remicade antibodies.
Since Cimzia is bound to PEG, and because it is only a fragment and not a full antibody, it can be produced in bacterial culture, which is much less expensive. Then the PEG is added later by a chemical reaction.