2a-2b

[mirceani]

Which are the differences between Interferon Alpha 2A (Pegasys) and Interferon Alpha 2B (Pegintron)
Are they essentially the same product, same formula, different name or two different products (drugs)

Thank you

[desrt]

The 'Peg' part of Pegasys is a branched polyethylene glycol molecule which makes it larger than the PegIntron molecule. It has a longer half-life (5-6 days) as opposed to PegIntron (4-5 days). When Pegasys first came out five years ago, everyone was predicting it was going to be the greatest thing since sliced bread and was going to knock PegIntron out of the market. Trouble is, they've always given about the same results. So you'd think, if the Peg part of Pegasys is better, there must be something about IFN Alpha 2b in PegIntron that's better than IFN Alpha 2a. Turns out, a small Argentine study a couple years ago seems to show that 'Alpha 2b has some properties that are more effective during the earlier part of tx. There seems to be  a very small % of people who get better results from Pegasys' longer exposure and a few who seem to get better results from PegIntron's early biochem' properties.
Since I've never heard of anyone being able to predict who'll get better results with which product, flip a coin.

[mirceani]

Thank you, great information
The flipped coin in my case looks like this:

2002 - 8 wks on Pegintron - less than 1 log drop, dr stopped it
2007 - after week 8 on Pegasys, undetected already.

Trying to figure out why this happened, and of course if drs had any way to predict it. Also trying to figure out the future outcome in my case, based on  the info available (this forum and its people are the BEST)