Randomized, Double-Blind, Placebo-Controlled Trial, Followed by Single-Arm Treatment of PRO 140

PRO 140, in combination with other antiretroviral agents, is indicated for treatment experienced adult HIV-1 patients infected with CCR5-tropic virus. These patients must demonstrate evidence of HIV-1 replication despite ongoing antiretroviral therapy and have documented genotypic or phenotypic resistance to at least one ART drug within three drug classes (or within two or more drug classes with limited treatment option). The options may be limited as a result of drug antiviral class cross-resistance, documented treatment intolerance, documented objective assessments such as renal or hepatic insufficiency (e.g. high creatinine at baseline, limiting treatment options due to potential for toxicity), past adverse reactions such as hypersensitivity reactions or neuropsychiatric issues that could limit use of currently approved drugs. Study population includes treatment-experienced HIV-infected patients with CCR5-tropic virus who demonstrates evidence of HIV-1 replication despite ongoing antiretroviral therapy with documented genotypic or phenotypic resistance to ART drugs within three drug classes (or within two drug classes with limited treatment option). Enrollment will be stratified to have HIV-1 virus resistant to ART drugs within three drug classes or within two drug classes with limited treatment option. The primary objective is to assess the efficacy, clinical safety and tolerability parameters of PRO 140 compared to placebo in reducing HIV-1 viral load during the 1-week double-blind treatment period. The secondary objectives of the trial are to assess the efficacy, clinical safety and tolerability parameters of PRO 140 in combination with Optimized Background Therapy during the 24-week single-arm, open-label treatment period.