Bioavailability of 2 Different Nevirapine Extended Release Formulations Compared to Viramune® in HIV-1 Infected Subjects

Inclusion Criteria: * HIV-1 infected males or females ≥ 18 and ≤ 60 years of age * Body mass index 18.5 to 29.9 kg/m2, inclusive * Signed and dated written informed consent prior to admission to the study in accordance with Good Clinical Practice and local legislation * Treated with a stable Viramune® BID based regimen since at least 12 weeks prior to study entry. If however, the subject's current Viramune® treatment consists of two 200mg tablets once daily (prescribed off label), the subject is allowed to participate if he/she agrees to switch to Viramune® 200mg twice daily, 14 days before the start of Nevirapine Extended Release. * An HIV-1 viral load of ≤ 50 c/mL at screening * Acceptable screening laboratory values that indicate adequate baseline organ function with the following exceptions: * Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≤2.5 times the upper limit of normal (ULN) (DAIDS Grade 1) or * Gamma-glutamyl transferase (GGT) \<2.5 times ULN (DAIDS Grade 1) * Willingness to abstain from alcoholic beverages for 24 hours prior to intensive pharmakokinetic sampling days * Willingness to abstain from ingesting substances which may alter drug plasma levels by interaction with the cytochrome P450 system during the study * Willingness to abstain from grapefruit and grapefruit juice, Seville oranges and juice, and St John's wort or milk thistle starting 14 days prior to administration of study medication until the end of the study, and * Karnofsky performance score ≥70 Exclusion Criteria: * Current treatment with any PI * Participation in another trial with an investigational medicine within two months prior to Day 1 of this study * Serum creatinine levels \>1.5 times ULN at screening * History of acute illness within 60 days prior to Day 1, which would make the subject, in the opinion of the investigator, unsuitable for the trial * History or evidence of severe illness, malignancy or any other conditions which would make the subjects, in the opinion of the investigator, unsuitable for the trial * Any evidence of a clinically relevant concomitant disease, including gastrointestinal, hepatic, renal disorders of clinical relevance * Surgery of the gastrointestinal tract (except appendectomy and herniotomy) * Diseases of the central nervous system (such as epilepsy) or psychiatric disorders or neurological disorders * Chronic or relevant acute infections other than HIV-1 (e.g. hepatitis B virus (HBV), hepatitis C virus (HCV) co infection: A chronic or acute HBV infections is defined as: HBs Ag positive. Chronic or acute HCV infection is defined as: HCV Ab positive and 1 confirmed positive viral load measurement preceding study entry) * Alcohol or substance abuse within 6 months prior to screening or during the study * Inability to comply with protocol requirements * Screening laboratory values \<DAIDS grade 1 * All fertile males or females, and their respective partner(s) not willing to use two forms of effective contraception. A double-barrier method must be used. A double-barrier method is defined as e.g.: 1) a condom with spermicidal jelly or with a foam suppository; 2) a diaphragm with spermicide; or 3) a male condom and a diaphragm * Female of child-bearing potential who: * Has a positive serum pregnancy test at screening, * Is breastfeeding, * Is planning to become pregnant, or * Is not willing to use barrier method protection or require ethinyl estradiol administration * Any AIDS-defining illness that is unresolved, symptomatic, or not stable on treatment for at least 12 weeks before the screening visit * HIV-2 infection