Phil, there's more to the efficacy story of DMP-266 than "4 to 5 log" reduction in viral particles.
Merck presented information on use of DMP 266 with Crixivan vs. use of Crix alone. Viral load was reduced 4.1 log with the combo, counting "below detection" as a VL of zero.
The viral load assay used was only sensitive to 400 viral particles per ml. Reporting VL as "zero" obviously skewed the results, because VL was somewhere between 0 and 400, the lower limit of the assay. So Merck also presented the data assigning a viral load of 200 to the "undetectables". In this presentation, the combo (Crix and DMP-266) reduced vl by 2.4 log.
A new protease inhibitor, VRTX-478, is in Phase III conducted by Glaxo (GLX 141W). And double protease inhibitor trials are being run for Crixivan, Invirase, and Norvir (each paired with Viracept).
Glaxo is also advancing with an RTI, 1592. PNU has approval for its NNRTI, Rescriptor. Not to mention GILD's NNRTI and PMPA, though this is GILD's thread.
So where is that bottom line? uhh, oh yeah, right here: the combo therapies are effective, more and better combinations are on the way, and people are not getting "AIDS-defining" opportunistic infections at the rate they used to. |
