Double-blind, Randomized, Dose Optimization Trial of Three Doses of Tipranavir Boosted With Low Dose Ritonavir (TPV/RTV) in Multiple Antiretroviral Drug-experienced Subjects

Inclusion criteria:

* Signed informed consent prior to trial participation.

* Human immunodeficiency virus 1 (HIV-1) infected males or females \> 18 years of age.

* At least 3 months experience taking Nucleoside reverse transcriptase inhibitors (NRTIs), Non-nucleoside reverse transcriptase inhibitor (NNRTIs), and Protease inhibitors (PIs).

* Current PI-based Antiretroviral (ARV) medication regimen for at least 3 months prior to randomization, and at least 3 months experience taking at least one other PI-based regimen.

* HIV-1 viral load ≥1000 copies/mL at screening.

* Genotypic resistance report indicating one or more primary PI resistance mutation(s), including 30N, 46I/L, 48V, 50V, 82A/F/T, 84V or 90M.

* Availability of 2 or more non-PI ARV medications by genotypic resistance testing, i.e. 2 drugs tested as "no evidence of resistance" or "possible resistance".

* Acceptable screening laboratory values that indicate adequate baseline organ function.

* Laboratory values are considered to be acceptable if severity is no higher than Grade 3 Gamma glutamyl transferase (GGT), Grade 2 cholesterol or triglycerides, and no higher than Grade 1 for all other tests based on the "Division of Acquired Immune Deficiency Syndrome" of National Institute of Health, USA - DAIDS - Grading Scale. All laboratory values outside these limits are subject to approval by Boehringer Ingelheim (BI).

* Further inclusion criteria apply.

Exclusion criteria:

* ARV medication naïve.

* Only one or no available ARV medications as determined by genotypic resistance testing.

* Female subjects who:

* have a positive serum pregnancy test at screening or during the study;

* are breast feeding;

* are planning to become pregnant;

* are not willing to use two methods of contraception to include at least one barrier method (e.g. latex condom plus spermicidal jelly/foam).

* Any active opportunistic infection within 60 days before study entry.

* Active Hepatitis B (HCB) or Hepatitis C (HCV) disease defined as HBsAg positive or HCV RNA positive with Aspartate aminotransferase (AST)/Alanine aminotransferase (ALT) \> Grade 1.

* Prior tipranavir use.

* Use of investigational medications within 30 days before study entry or during the trial.Some expanded access drugs may be acceptable; must be approved by BI. Tenofovir, investigational at time of preparation of this protocol, is acceptable.

* Use of concomitant drugs which may significantly reduce plasma levels of the study medications.

* Further exclusion criteria apply.