John,
Just to clarify things here too, my concern is the _market's_ perception of Viracept's half-life. If I'm not mistaken, the market's current perception goes something like this:
1. There are already a bunch of PI's on the market, with a promising new one VX-478 coming down the pike (with some disagreement about just how long the pike is, but anyhow less than 3/4 years).
2. When you become resistant to one PI, you tend to become resistant to others.
3. There are umpteen other AIDS drugs/vaccines somewhere on the horizon.
4. Because of 1-3 above, Viracept is a 4-5 year drug, not a 10 or 15 year drug.
Now I don't personally agree with this logic. My view is that the success of triple-therapy has raised the bar considerably for other drugs, and quick trials and short-cuts will become ever less possible.
For example, see the article in the April 25, 1997 issue of _Science_, entitled "AIDS Trials Ethics Questioned." This article criticizes monotherapies as one arm of a trial, and states that "... potent combination therapies [have] dramatically changed the ground rules for AIDS drug testing."
The resistance argument might actually end up benefitting Viracept, particularly if the preliminary AGPH studies on the best order to take PI's holds up. These studies support using Viracept first, and only moving on to other PI's if resistance develops.
Now remember that misperception by the market is a GOOD THING, because we can only make considerable money when we are right and the market is initially wrong, and then sees the light.
Peter (still very much long AGPH and SEPR). |
