Safety of AMD070 When Administered Alone or Boosted With Low-Dose Ritonavir in HIV Uninfected Men

Current therapy for HIV infection primarily uses drugs that inhibit HIV replication via inhibition of viral protease and reverse transcriptase. Many patients either do not tolerate these medications well or develop virologic failure due to incomplete viral suppression and development of antiviral resistance. New drugs target HIV entry into the cell. AMD070 binds to the chemokine receptor CXCR4, inhibiting membrane fusion and viral entry. Animal studies have shown AMD070 to be generally safe and well tolerated. The dose-escalation and drug-drug interaction study will evaluate the safety, tolerability, and pharmacokinetics of single, multiple, and RTV-boosted doses of AMD070 in healthy, HIV uninfected male volunteers. Participants in this study will be assigned to a single- or multiple-dose AMD070 group (Group 1), a single-dose AMD070 group (Group 2), or an RTV-boosted, multiple-dose AMD070 group (Group 3). Some participants in Group 1 will be given AMD070 once on an empty stomach with no food or drink except for water for 2 hours before and 1 hour after receiving the drug. Up to 4 different doses will be tested in subgroups of Group 1 participants. Some participants in Group 1 will be given AMD070 7 times, 12 hours apart, after eating a standardized breakfast 30 minutes before receiving the drug; 3 different doses will be tested in this group. Participants in Group 2 will be given a single dose of AMD070 after eating a standardized meal. Participants in Group 3 will be given a morning dose of AMD070 on Days 1, 3, and 17 after eating a standardized breakfast 30 minutes before receiving the drug, and a morning and evening dose of RTV on Days 3 through 18. Group 3 participants may also be asked to enroll in an additional study group that will receive a single dose of AMD070 on Days 1 and 3 while fasting. All participants will be observed as hospital inpatients. Group 1 and 2 participants will stay in the hospital for 24 hours; Group 3 participants will stay in the hospital for 4 days. All participants will have blood and urine collection throughout their hospital stay. Group 3 participants selected to join in the additional study group will have blood and urine samples collected throughout the 5-day study. These participants will be discharged from the hospital on Day 5 and have a follow-up visit around Day 35. All study participants will also undergo an ophthalmologic evaluation and questionnaire sometime after receiving AMD070.