New Resistance Score for Tipranavir

Along with darunavir, tipranavir is one of the twolatest so-called second-generation protease inhibitorsapproved for the treatment of HIV infection.While the magic of darunavir is based on its strongaffinity binding for the HIV protease, the basis for thestrong potency of tipranavir resides in its non-peptidomimeticstructure. In contrast, all other proteaseinhibitors resemble the natural protease substrates.In fact, recent evidences suggest that fosamprenavirand darunavir may share important amino acid positionsfor developing drug resistance (e.g. 50V),which may explain the expected lower response todarunavir after failing fosamprenavir.