While new therapies for AIDS are clearly needed due to viral resistance and reservoirs of infectious HIV, the widespread use of triple combination therapy presents a clinical challenge to compounds in development, if only for the number of possible permutations and combinations of drugs. However, this also means that the failure of one combination in pivotal trials does not sound the death knell of a new compound.

Thus the failure of Triangle Pharmaceuticals Inc.'s Coactinon emivirine non-nucleoside reverse transcriptase inhibitor (NNRTI) in a triple combination regimen including a protease inhibitor (PI) is not the end of the world for the company. Instead, VIRS believes that Coactinon may be best used as initial HIV therapy in regimens that do not contain a PI.