A phase II trial of dual protease inhibitor therapy: amprenavir in combination with indinavir, nelfinavir, or saquinavir.

This study evaluated dual protease inhibitor (PI) regimens containing amprenavir (APV) in PI-naive, HIV-1-infected patients over 48 weeks. Patients were randomized to 800-mg APV combined with 800-mg indinavir (IDV), 750-mg nelfinavir (NFV), or 800-mg saquinavir-soft gel capsule (SGV-SGC), all three times daily without nucleoside reverse transcriptase inhibitors, or APV given alone for 3 weeks and then with 150-mg lamivudine (3TC) and 300-mg zidovudine (ZDV), twice daily. Dual PI therapy demonstrated substantial antiviral activity and was generally safe and well tolerated. Eight patients had virologic failure; 5 were receiving dual PI therapy and 3 were in the APV/3TC/ZDV arm. The protease I50V mutation characteristic of APV resistance was not observed, although other key PI mutations were selected in 4 patients failing therapy, 2 of whom had PI resistance at baseline.