Long-term data on viral resistance to HIV protease inhibitors may have surprised investors last week, but it wasn't unexpected, now that PIs have been used for long enough to begin generating such data. And it's exactly what doctors need in order to optimize their treatment regimens.

What made things tough for Agouron Pharmaceuticals Inc. (AGPH, San Diego, Calif.), whose Viracept was the topic of much discussion, was that negative data from a poorly designed study came out first, followed two days later by positive data from better-designed trials. In fact, the overall message from the week was supportive of the early addition of Viracept to treatment combinations.