brecanavir and HIV-Infections

Brecanavir (BCV) is a novel, potent protease inhibitor in development for the treatment of human immunodeficiency virus (HIV-1) infection with low nM in vitro 50% inhibitory concentrations (IC50s) against many multiprotease inhibitor resistant viruses. This study was a double-blind, randomized, placebo-controlled repeat-dose escalation to evaluate the safety, tolerability, and pharmacokinetics of BCV, with or without ritonavir (RTV), in 68 healthy subjects. Seven sequential cohorts (n=10) received BCV (50 to 600 mg) in combination with 100 mg RTV (every 12 h [q12h] or q24h) or alone at 800 mg q12h for 15 days. BCV alone or in combination with RTV was well tolerated, with no serious adverse events reported. The most common drug-related adverse event was headache. BCV was readily absorbed with median time to maximum concentration of drug in serum values ranging from 2.5 to 5.0 h postdose following single- and repeat-dose administration of BCV alone and BCV with RTV 100 mg. Geometric mean BCV accumulation ratios ranged from 1.4 to 1.56 following BCV-RTV q24h regimens and from 1.84 to 4.93 following BCV q12h regimens. BCV steady state was generally achieved by day 13 in all groups. All day 15 BCV-RTV trough concentration values in q12h regimens reached or surpassed the estimated protein-binding corrected in vitro IC50 target BCV concentration of 28 ng/ml for highly resistant isolates. The pharmacokinetic and safety profile of BCV-RTV supports continued investigation in HIV-1-infected subjects.

Topics: Adult; Area Under Curve; Benzodioxoles; Carbamates; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Combinations; Female; HIV Infections; HIV Protease Inhibitors; HIV-1; Humans; Male; Middle Aged; Ritonavir; Safety

Brecanavir, a novel protease inhibitor (PI), has sub-nM in vitro antiviral activity against multi-PI-resistant HIV-1 and in vitro is >100-fold more potent than previously marketed PIs and approx. 10-fold more potent than the recently marketed PI, darunavir.. HPR10006 is an open label, single-arm, descriptive 48 week study, with 8 and 24 week interim analyses. Thirty-one HIV-1-infected patients were enrolled and received brecanavir/ritonavir 300 mg/100 mg twice daily, with two nucleoside reverse transcriptase inhibitors, based on history and genotype.. At baseline, 25/31 had PI-sensitive virus and 6/31 had PI-resistant virus (median of two primary PI and five secondary PI mutations). Median baseline HIV-1 RNA was 5.0 and 4.2 log(10) copies/mL, respectively. Four patients discontinued prior to Week 24. At Week 24, 77% (24/31) had HIV-1 RNA <50 copies/mL regardless of screening genotype, including 5/6 patients with PI-resistant virus (6/6 had HIV-1 RNA <400 copies/mL). Brecanavir/ritonavir was well tolerated with no serious adverse events or clinically concerning changes in laboratory parameters. Of 31 patients, 10 (32%) experienced drug-related Grade 2-4 adverse events [most frequent events were fatigue (13%), dyspepsia (10%) and nausea (10%)]. Baseline isolate brecanavir IC(50) values for all patients ranged from 0.1 to 0.2 nM. Median plasma trough concentration at Week 4 was 150 ng/mL. Correcting the IC(50) (0.2 nM) value for protein binding (6-fold increase in vitro with 50% human serum) gives a corrected inhibitory quotient of 180.. Brecanavir/ritonavir was well tolerated and showed potent antiviral activity in HIV-1-infected patients harbouring both PI-sensitive and PI-resistant virus, following 24 weeks of dosing.

Topics: Adult; Amino Acid Substitution; Anti-HIV Agents; Benzodioxoles; Carbamates; CD4 Lymphocyte Count; Drug Resistance, Viral; Drug Therapy, Combination; Female; HIV Infections; HIV Protease; HIV Protease Inhibitors; HIV-1; Humans; Male; Middle Aged; Reverse Transcriptase Inhibitors; Ritonavir; RNA, Viral; Treatment Outcome