SP1093V is a new compound which appears to inhibit the activity of HIVs reverse transcriptase enzyme in two ways. The compound appears to block the activity of RT in the same way as other nucleoside analogues, but also blocks the activity of ribonucleose H. This means that HIV must develop resistance to the drug at two different sites, and changes in the activity of ribonuclease H caused by resistance to SP1093V have been observed to cause a reduction in HIV replication.

Test tube studies suggest that this drug is active against NNRTI- resistant virus, and against virus with some of the common mutations associated with AZT. Resistance to SP1093V is slow to emerge.

It is being developed in Canada by researchers at McGill University, Montreal. No human studies have been conducted yet.

Reference

Parniak M et al. Favourable antiviral resistance properties of SP1093V, an inhibitor of the ribonucleose activity of HIV-1 reverse transcriptase. Fourth International Workshop on HIV Drug Resistance and Treatment Strategies, Sitges, abstract O2, 2000.