Phase 2 Safety and Efficacy Study of Bevirimat Functional Monotherapy in HIV Treatment-Experienced Patients for 2 Weeks*

Bevirimat (PA103001-04) represents a new class of antivirals that blocks HIV replication by disrupting virus maturation; specifically, by inhibiting a late step in the Gag processing cascade. Short term (7-10 days) functional monotherapy studies (conducted in patients with detectable viral loads on a failing regimen)help in determining the potency of the drug, and enable dose finding. This is a two part (A and B)randomized, placebo-controlled, double-blind, multiple-dose, dose-escalation study in HIV treatment-experienced patients on a failing regimen (harboring resistance mutations to at least one member of the NRTI, NNRTI or PI classes. The antiretroviral activity, safety, and pharmacokinetics of up to 5 different dose levels of bevirimat will be compared to placebo when added to a failing approved antiretroviral regimen. The study is conducted in two parts: A and B. In Part A following 14 days of daily dosing patients commenced a new optimized ART regimen in addition to their randomized treatment. In Part Part B dosing with the randomized treatment ends after the initial 14 days of daily dosing.

Inclusion criteria

• Male or female. Females of child-bearing potential, must have a documented negative pregnancy test and be willing to utilize double-barrier contraception through-out the study period.
• Have HIV-1-infection.
• Have a screening plasma HIV-1 RNA value, measured by the Roche Amplicor assay, of 2,000 - 250,000 copies/ml (inclusive).
• Have documented evidence of genotypic resistance in their medical records (at screening) or have resistance at screening by genotype to any major mutation from the IAS-USA list of resistance drug mutations, defined as: NRTI resistance: M41L, K65R, D67N, K70R, K70E, L74V, Y115F, M184V, M184V/I, L210W, T215Y/F, K219Q/E; NNRTI resistance: L100I, K103N, V106M, V106A/M, V108I, Y181C, Y181C/I, Y188L, Y188C/L/H, G190S/A, G190A, P225H; Major PI resistance: D30N, V32I, L33F, M46I/L, I47V/A, G48V, I50L, I50V, I54M/L, L76V, V82A/F/T, V82A/F/T/S, V82L/T, I84V, N88S, L90M
• Be receiving an antiretroviral therapy regimen containing at least 3 drugs (regimens containing ritonavir must not exceed a total daily dose of 400 mg) which has been unchanged for at least 8 weeks prior to initial screening.
• Be able to receive an optimized background regimen.
• Be free from any acute infection or serious medical illness within 14 days prior to study entry.
• Be informed of the nature of the study and provide written informed consent.
• Be willing to comply with the meal requirements described in the protocol.

Exclusion criteria

• Current opportunistic infection characteristic of AIDS
• Patients unable or unwilling to comply with the dosing schedule and protocol evaluations.
• Patients with malabsorption syndromes affecting drug absorption.
• Patients with systolic blood pressure < 90 mmHg or > 140 mmHg or diastolic blood pressure < 60 mmHg or > 90 mmHg measured in a semi-recumbent position after at least 10 minutes of rest at the screening or qualification visit.
• A history of seizures (excluding pediatric febrile seizures), migraines, cluster and/or chronic headaches, cerebrovascular accident (CVA) or transient ischemic attacks (TIA).
• Patients with abnormal Hemoglobin (< 10.0 g/dL for men and < 9.0 g/dL for women), Neutrophil count (< 1000/mm3), Platelet count (< 100,000/mm3), AST or ALT > 2.5 times the upper limit of normal (patients with a positive HBV surface antigen or HCV antibody test at screening must have AST and ALT no more than 1.5 times the upper limit of normal)
• Patients who have received radiation therapy or cytotoxic chemotherapeutic agents, immunomodulating agents, HIV immunotherapeutic vaccine, an investigational drug or product, or participation in a drug study within 4 weeks prior to the first dose of study drug.
• A history of alcoholism or drug addiction within the past 1 year (unless enrolled in a treatment program and approved by the sponsor). Recent use of any recreational drugs (except marijuana).
• A history of difficulty donating blood or inadequate venous access.
• The donation of blood or plasma within 30 days prior to receiving study medication.

Note: patients with a CD4 count <100 cells/mm3 will be considered for enrollment following discussion and agreement between the Investigator and the Sponsor.