Objectives of the study were to evaluate the efficacy and safety of two different doses of tipranavir (TPV) in combination with ritonavir (TPV/r) compared with a standard dual PI combination of saquinavir (SQV) and ritonavir (RTV) and to evaluate the dose response of two different doses of TPV in combination with RTV for efficacy and safety.

Inclusion Criteria:

• Clinical failure while on the current PI-containing regimen of indinavir, nelfinavir, or amprenavir
• In the investigator's opinion, adherence to the present PI-containing regimen
• Exposure of >=6 months to the current PI therapy
• Stable PI-containing regimen, i.e., receiving the current two reverse transcriptase inhibitors (RTIs) for at least 2 months prior to study entry
• HIV-1 RNA >=1000 copies/mL (assayed using the Amplicor polymerase chain reaction (PCR) method at the initial screening visit)
• No limit in CD4+ cell count at the initial screening
• At least two new nucleoside reverse transcriptase inhibitor (NRTI) options available
• Age >=18 years
• Acceptable screening laboratory test values that indicated adequate baseline organ function at the time of screening. Acceptable laboratory test values consisted of the following: severity <=Grade 1 (ACTG Grading Scale). Stable Grade 2 abnormalities were permitted if the values had been demonstrated and documented for at least >=2 months. All laboratory values >Grade 2 were subject to approval by the P&U Clinical Program Leader or designated personnel and subsequently by the BI designated personnel
• Acceptable medical history, physical examination, ECG, and chest radiograph prior to entry into the treatment phase of the study
• Use of a barrier contraceptive method of birth control for at least 30 days prior to study drug administration, during the study, and 30 days after study completion
• Ability to swallow numerous tablets and capsules without difficulty
• Ability to understand and provide informed consent. Minors had to have approval of a parent or legal guardian

Exclusion Criteria:

• Treatment with more than one PI-containing regimen
• Clinically significant active or acute (onset within the month previous to study entry) medical problems, including the following: opportunistic infections, e.g., active cryptococcosis, Pneumocystis carinii pneumonia, herpes zoster, histoplasmosis, or cytomegalovirus; nonopportunistic diseases, including but not limited to the following: progressive multifocal leukoencephalopathy, lymphoma, or malignancy requiring systemic therapy
• Prior exposure (>7 days) to tipranavir, saquinavir, or ritonavir
• History of clinically significant nervous system or muscle diseases, seizure disorder, or psychiatric disorder that might impair adherence to the protocol
• Taking of any known P450 3A enzyme-inducing drugs within 30 days of study entry and including the following: rifabutin, rifampin, carbamazepine, dexamethasone, phenobarbital, phenytoin, sulfadimidine, sulfinpyrazone, or troleandomycin
• Hypersensitivity to tipranavir, saquinavir, or ritonavir
• Use of interferons, interleukins, HIV vaccines, or any active immunizations within 30 days of study entry
• Taking of any investigational medication with the exception of adefovir dipivoxil (Preveon™) within 30 days of study entry
• Pregnancy or lactation (serum β-human chorionic gonadotrophin test had to have been negative within 14 days of study entry)
• Evidence of substance abuse, which in the investigator's opinion could affect adherence to the protocol
• In the investigator's judgment, inability to comply with the protocol requirements for reasons other than those specified