[Show abstract][Hide abstract] ABSTRACT: Background: BMS-663068 is a prodrug of BMS-626529, an attachment inhibitor that binds directly to HIV-1 gp120, preventing initial viral attachment and entry into the host CD4+ T-cell. AI438011 is a Phase IIb, randomized, active-controlled trial investigating the safety, efficacy and dose–response of BMS-663068 versus atazanavir/ritonavir (ATV/r) in treatment-experienced (TE), HIV-1-positive subjects (sbj).
Methods: Antiretroviral TE sbj (exposure to ≥1 antiretroviral for ≥1 week) with susceptibility to all study drugs (BMS-626529 IC50 <100 nM), were randomized equally to four BMS-663068 arms (400 or 800 mg, BID; 600 or 1200 mg, QD) and a control group (ATV/r 300/100 mg QD) with tenofovir disoproxil fumarate (TDF) + raltegravir (RAL). A subgroup analysis of viral efficacy and immunologic reconstitution is presented.
Results: 251 sbj were treated. Median age was 39 years, 60% were male and 38% white. Median baseline (BL) viral load (VL) was 4.85 log10 c/mL (43% >100,000 c/mL) and median CD4+ T-cell count was 230 cells/mm3 (38% <200 CD4 cells/mm3). Through Week 24, response rates (HIV-1 RNA <50 c/mL) were comparable across all BMS-663068 arms and the ATV/r arm regardless of gender, age and race. Response rates for sbj with BL VL <100,000 c/mL (BMS-663068, 82–96%; ATV/r, 93%) were higher than those for sbj with BL VL ≥100,000 c/mL (BMS-663068, 70–87%; ATV/r, 73%); however, there were no substantial differences in response across the BMS-663068 and ATV/r arms in either subgroup. Response rates for sbj with BL CD4+ cell counts ≥200 cells/mm3 (87–96%) were higher than those for sbj with BL CD4+ cell counts <200 cells/mm3 (62–82%); however no substantial differences in response were seen across the BMS-663068 and ATV/r arms in either subgroup. Mean changes in CD4+ T-cell counts from BL were similar across all arms regardless of gender, age and BL CD4+ T-cell count.
Conclusion: Virologic response rates were similar across the BMS-663068 and ATV/r arms in TE subjects, regardless of BL demographic characteristics (gender, race, age), BL HIV-1 RNA, or BL CD4+ T-cell count. Mean increases in CD4+ T-cell counts across the BMS-663068 arms were consistent with ATV/r, regardless of gender, age and BL CD4+ T-cell count. These results support continued development of BMS-663068.
IDWeek 2014 Meeting of the Infectious Diseases Society of America; 10/2014
[Show abstract][Hide abstract] ABSTRACT: The clinical advancement of HIV-1 attachment inhibitors was hindered initially by poor bioavailability. Attempts to identify improved candidates revealed that solubility and dissolution-rate-limited absorption are barriers to achieving adequate antiviral plasma levels. This was mitigated by forming nanosized drugs or by creating stabilised amorphous drug-polymer composites. In further improving drug potency and mitigating solubility-limited bioavailability, a candidate based on a phosphate ester prodrug was identified that, although having excellent bioavailability, exhibited unacceptable pharmacokinetics. Based on in silico modelling and a site of absorption study it was confirmed that creating an extended release formulation could provide the desired pharmacokinetic profile. The optimised formulation showed good antiviral activity when dosed employing a once or twice a day regimen.
Drug discovery today 04/2014; · 6.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In an 8 day monotherapy study of subjects infected with HIV-1 (subtype B) (NCT01009814), BMS-626529 (an attachment inhibitor that binds to HIV-1 envelope glycoprotein gp120), administered as the prodrug BMS-663068, produced substantial declines in plasma HIV-1 RNA. However, large variability in susceptibility to BMS-626529 was noted and virus with low susceptibility was less likely to be suppressed by BMS-663068 administration. The current analysis sought to investigate the genotypic correlates of susceptibility to BMS-626529.
In vitro selection experiments, evaluation of clinical samples of subtype B from the monotherapy study and evaluation of intrinsically resistant subtype AE viruses were conducted. Reverse genetics was used to identify key substitutions in envelope clones responsible for reduced susceptibility.
An M426L or S375M change were the major substitutions associated with reductions in susceptibility to BMS-626529 in baseline samples of subtype B viruses from the monotherapy study, with M434I and M475I contributing to a lesser extent. Class resistance in subtype AE viruses was mapped to 375H and 475I substitutions, found in the vast majority of these viruses. Analysis of multiple envelope clones from infected subjects showed higher intrasubject variability in susceptibility to BMS-626529 compared with other classes of entry inhibitors.
These data define key genotypic substitutions in HIV-1 gp120 that could confer phenotypic resistance to BMS-626529.
Journal of Antimicrobial Chemotherapy 10/2013; · 5.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BMS-986001 is a novel HIV nucleoside reverse transcriptase inhibitor (NRTI). To date, little is known about its resistance profile. In order to examine the cross-resistance profile of BMS-986001 to NRTI mutations, a replicating virus system was used to examine specific amino acid mutations known to confer resistance to various NRTIs. In addition, reverse transcriptase genes from 19 clinical isolates with various NRTI mutations were examined in the Monogram PhenoSense® HIV assay. In the site-directed mutagenesis studies, a virus containing a K65R substitution exhibited a 0.4-fold change in EC50 versus wild type, while the majority of viruses with the Q151M constellation (without M184V) exhibited fold changes in EC50 versus wild type of 0.23-0.48-fold. Susceptibility to BMS-986001 was also maintained in an L74V-containing virus (0.7-fold change), while an M184V-only-containing virus induced a 2-3-fold decrease in susceptibility. Increasing numbers of thymidine analog mutation pattern 1 (TAM-1) pathway mutations correlated with decreases in susceptibility to BMS-986001, while viruses with TAM-2 pathway mutations exhibited a 5-8-fold decrease in susceptibility, regardless of the number of TAMs. A 22-fold-decrease in susceptibility to BMS-986001 was observed in a site-directed mutant containing the T69 insertion complex. Common non-NRTI (NNRTI) mutations had little impact on susceptibility to BMS-986001. The results from the site-directed mutants correlated well with the more complicated genotypes found in NRTI-resistant clinical isolates. Data from clinical studies are needed to determine the clinically relevant resistance cut-off values for BMS-986001.
Antimicrobial Agents and Chemotherapy 08/2013; · 4.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE:: To investigate the safety, tolerability, pharmacokinetics, and antiviral activity of BMS-986001 (a nucleoside reverse transcriptase inhibitor) in treatment-experienced, HIV-1-infected subjects not exposed to antiretroviral treatment in the previous 3 months. METHODS:: Thirty-two HIV-1-infected subjects were randomized (3:1) to receive BMS-986001 or placebo once daily for 10 days in this double-blind, placebo-controlled, dose-escalating monotherapy phase IIa study. There were 4 treatment groups (100, 200, 300, and 600 mg, all once daily) of 8 subjects each (BMS-986001, n = 6/placebo n = 2). RESULTS:: BMS-986001 was generally well tolerated, with no discontinuations due to adverse events and no deaths occurring. Adverse events were experienced by 22 of 24 BMS-986001-treated subjects and did not seem to be dose related. The majority were mild and considered unrelated or unlikely to be related to the study drug. The pharmacokinetics of BMS-986001 were dose proportional. Median decrease in plasma HIV-1 RNA from baseline to day 11 was 0.97, 1.15, 1.28, and 1.15 log10 copies/mL for BMS-986001 at 100, 200, 300, and 600 mg, respectively. Plasma area under the curve correlated with the antiviral activity of BMS-986001, indicating that area under the curves produced by 100-600 mg doses were on the upper end of the exposure-response curve. One subject with a single thymidine analog mutation at baseline responded well to BMS-986001. CONCLUSIONS:: Administration of BMS-986001 for 10 days resulted in substantial decreases in plasma HIV-1 RNA levels for all dose groups and was generally well tolerated. These data support continued clinical development of BMS-986001 at a dose of 100 mg, once daily or greater. TRIAL REGISTRATION:: EUDRACT Number 2008-004810-29.
[Show abstract][Hide abstract] ABSTRACT: Background: BMS-626529 is a novel small-molecule HIV-1 attachment inhibitor active against both CCR5- and CXCR4-tropic viruses. BMS-626529 functions by preventing gp120 from binding to CD4. A prodrug of this compound, BMS-663068, is currently in clinical development. As a theoretical resistance pathway to BMS-663068 could be the development of a CD4-independent phenotype, we examined the activity of BMS-626529 against CD4-independent viruses and investigated whether resistance to BMS-626529 could be associated with a CD4-independent phenotype. Finally, we evaluated whether cross-resistance exists between BMS-626529 and other HIV-1 entry inhibitors.Methods: Two laboratory-derived envelopes with a CD4-independent phenotype (one CXCR4- and one CCR5-tropic), five envelopes from clinical isolates with pre-existing BMS-626529 resistance and several site-specific mutant BMS-626529-resistant envelopes were examined for their dependence on CD4 for infectivity or susceptibility to BMS-626529. Viruses resistant to other entry inhibitors (enfuvirtide, maraviroc and ibalizumab) were also examined for susceptibility to BMS-626529.Results: Both CD4-independent laboratory isolates retained sensitivity to BMS-626529 in CD4(-) cells, while HIV-1 envelopes from viruses resistant to BMS-626529 exhibited no evidence of a CD4-independent phenotype. BMS-626529 also exhibited inhibitory activity against ibalizumab- and enfuvirtide-resistant envelopes. While there appeared to be some association between maraviroc resistance and reduced susceptibility to BMS-626529, an absolute correlation cannot be presumed since some CCR5-tropic maraviroc-resistant envelopes remained sensitive to BMS-626529.Conclusions: Clinical use of the prodrug BMS-663068 is unlikely to promote resistance via generation of CD4-independent virus. No cross-resistance between BMS-626529 and other HIV entry inhibitors was observed, which could allow for sequential or concurrent use with different classes of entry inhibitors.
Antimicrobial Agents and Chemotherapy 06/2013; · 4.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND:: BMS-663068 is the phosphonooxymethyl prodrug of BMS-626529, a small-molecule attachment inhibitor that targets the HIV-1 envelope glycoprotein gp120 preventing it from binding to CD4+ T-cells. In vitro investigations have demonstrated considerable variation in susceptibility of different HIV-1 isolates to BMS-626529. BMS-663068 monotherapy in HIV-1 infected subjects produced a mean maximum change from baseline of -1.64 log10 copies/mL, but response was variable. METHODS:: In this analysis, baseline and Day 8 samples were analyzed for susceptibility to BMS-626529 and the presence of known HIV-1 attachment inhibitor resistance mutations. In addition, predictors of virologic response (maximal HIV-1 RNA decline ≥1 log10 copies/mL) and resistance selection were investigated. RESULTS:: The only factor associated with reduced virologic response was low baseline susceptibility to BMS-626529. There was no apparent relationship between virologic response and baseline treatment experience, co-receptor tropism, plasma HIV-1 RNA level or CD4+ T-cell count. Examination of all positions with known BMS-626529 resistance mutations based on in vitro selection studies showed that gp120 M426L was the primary substitution most clearly associated with non-response to BMS-663068. There was minimal change in susceptibility to BMS-626529 over the course of the study and no clear evidence of emergence of a known HIV-1 attachment inhibitor resistance mutation in the majority of subjects as measured by standard population-based phenotypic and genotypic approaches. CONCLUSIONS:: Non-response to BMS-663068 was associated with low baseline susceptibility to BMS-626529 and the presence of M426L. In this short-term trial, there was minimal evidence of selection for BMS-626529 high level resistance over 8 days of monotherapy with BMS-663068 by population-based approaches.
[Show abstract][Hide abstract] ABSTRACT: Background: HIV-1 attachment inhibitors are a new class of viral entry inhibitors which target viral gp120 preventing attachment of virus to its host cell receptor CD4. This class presents major challenges for development based upon low solubility and short half-lives. For progression into clinical studies, requirements include reliable and reproducible absorption from a tolerable and convenient oral dosing regimen. Methods: A series of highly soluble prodrugs were designed to overcome the poor absorption caused by the low solubility of the active compounds. A regional absorption study was conducted to assess the uptake of active throughout the gastro-intestinal tract following oral prodrug delivery. An extended-release (ER) strategy was subsequently devised to optimise tolerability, decrease peak to trough ratios and reduce frequency of dosing. In silico absorption modelling was used to verify feasibility and drive in vitro testing leading to dosage form development and selection. The performance of the ER dosage form was verified in vivo prior to use in clinical studies. Results: Phosphonooxymethyl prodrugs with aqueous solubilities in excess of 250 mg/mL were synthesised and shown to be readily converted to parent compound via alkaline phosphatase in vitro. Results of regional absorption studies for the selected compound, BMS-663068, confirmed the rapid absorption but short half-life of active following oral administration of prodrug. Delivery to specific regions throughout the GI tract showed absorption of active to be subject to regional variation with an extent of colonic absorption of approximately 40% of intestinal absorption. Incorporation of this data into an in silico model guided development of an ER tablet which releases prodrug over 24 hours and achieves the required exposure, pharmacokinetics and reproducibility in vivo. Conclusions: The novel approach of combining prodrug synthesis and ER formulation has enabled clinical evaluation of a promising new class of therapeutic entity into Phase 2b studies.
Journal of the International AIDS Society 11/2012; 15(6):18266. · 3.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background. BMS-663068 is a prodrug of the small-molecule inhibitor BMS-626529, which inhibits human immunodeficiency virus type 1 (HIV-1) infection by binding to gp120 and interfering with the attachment of virus to CD4+ T-cells. Methods. Fifty HIV-1-infected subjects were randomized to 1 of 5 regimen groups (600 mg BMS-663068 plus 100 mg ritonavir every 12 hours [Q12H], 1200 mg BMS-663068 plus 100 mg ritonavir every bedtime, 1200 mg BMS-663068 plus 100 mg ritonavir Q12H, 1200 mg BMS-663068 Q12H plus 100 mg ritonavir every morning, or 1200 mg BMS-663068 Q12H) for 8 days in this open-label, multiple-dose, parallel study. The study assessed the pharmacodynamics, pharmacokinetics, and safety of BMS-663068. Results. The maximum median decrease in plasma HIV-1 RNA load from baseline ranged from 1.21 to 1.73 log(10) copies/mL. Plasma concentrations of BMS-626529 were not associated with an antiviral response, while low baseline inhibitory concentrations and the minimum and average steady-state BMS-626529 plasma concentrations, when adjusted by the baseline protein binding-adjusted 90% inhibitory concentration (inhibitory quotient), were linked with antiviral response. BMS-663068 was generally well tolerated. Conclusions. Administration of BMS-663068 for 8 days with or without ritonavir resulted in substantial declines in plasma HIV-1 RNA levels and was generally well tolerated. Longer-term clinical trials of BMS-663068 as part of combination antiretroviral therapy are warranted. Clinical Trials Registration. NCT01009814.
The Journal of Infectious Diseases 08/2012; 206(7):1002-11. · 5.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BMS-663068 is the phosphonooxymethyl prodrug of BMS-626529, a novel small-molecule attachment inhibitor that targets HIV-1 gp120 and prevents its binding to CD4(+) T cells. The activity of BMS-626529 is virus dependent, due to heterogeneity within gp120. In order to better understand the anti-HIV-1 spectrum of BMS-626529 against HIV-1, in vitro activities against a wide variety of laboratory strains and clinical isolates were determined. BMS-626529 had half-maximal effective concentration (EC(50)) values of <10 nM against the vast majority of viral isolates; however, susceptibility varied by >6 log(10), with half-maximal effective concentration values in the low pM range against the most susceptible viruses. The in vitro antiviral activity of BMS-626529 was generally not associated with either tropism or subtype, with few exceptions. Measurement of the binding affinity of BMS-626529 for purified gp120 suggests that a contributory factor to its inhibitory potency may be a relatively long dissociative half-life. Finally, in two-drug combination studies, BMS-626529 demonstrated additive or synergistic interactions with antiretroviral drugs of different mechanistic classes. These results suggest that BMS-626529 should be active against the majority of HIV-1 viruses and support the continued clinical development of the compound.
Antimicrobial Agents and Chemotherapy 04/2012; 56(7):3498-507. · 4.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: Administered as monotherapy for 8 days, BMS-663068, the prodrug of the attachment inhibitor BMS-626529, demonstrated significant reductions in plasma HIV-1 RNA. Although baseline IC50>100 nM to BMS 626529 correlated with a poor virologic response, BMS-663068 did not appear to select for BMS-626529 resistance on population sequencing or phenotyping. Methods: Genotypic population analyses of baseline samples from non-responders identified amino acid changes that could potentially encode for reduced susceptibility to BMS-626529. Reverse genetics of functional envelope clones confirmed changes responsible for this in phenotypic assays. Additional genotypic, phenotypic and reverse genetic assays were performed on samples from responders to probe the context dependence of the identified substitutions. Results: The gp120 M426L substitution was the major change associated with reduced virologic response (present in 5 of 6 non-responders) and high BMS-626529 IC50 (present in virus from 6 of 7 subjects with IC50>100 nM). The remaining non-responder virus sample contained a S375M substitution that encoded reduced susceptibility. However, the M426L substitution was also identified in two responders, one with reduced susceptibility (IC50 6300 nM) and another with low IC50 (38 nM). A series of functional clones from 4 samples (including 2 responders with resistance mutations on population genotyping) were analyzed for susceptibility to BMS-626529. Variability of susceptibility of clones (37-246 fold) was higher than variability observed with other entry inhibitors (enfuvirtide, 6-9 fold; maraviroc, 3-9 fold). In the responder subject with M246L, all functional clones contained M426L and susceptibility varied by 246-fold, suggesting that susceptibility is highly context dependent. One of the responders contained viruses of either tropism. Clones of R5- or X4-tropic viruses from this individual exhibited the same variable range of susceptibility to BMS-626529. Conclusions: gp120 substitutions M426L and S375M were found to be strongly, albeit not exclusively, associated with low susceptibility to BMS-626529 and a lack of virologic response to its prodrug, BMS-663068. Functional clones derived from single individuals exhibited 2-3 log10 variability in susceptibility to the agent, regardless of tropism, suggesting that susceptibility can be highly context-dependent.
Journal of the International AIDS Society 01/2012; 15(6):18270. · 3.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Attachment inhibitors (AI) are a novel class of HIV-1 antivirals, with little information available on clinical resistance. BMS-488043 is an orally bioavailable AI that binds to gp120 of HIV-1 and abrogates its binding to CD4(+) lymphocytes. A clinical proof-of-concept study of the AI BMS-488043, administered as monotherapy for 8 days, demonstrated significant viral load reductions. In order to examine the effects of AI monotherapy on HIV-1 sensitivity, phenotypic sensitivity assessment of baseline and postdosing (day 8) samples was performed. These analyses revealed that four subjects had emergent phenotypic resistance (a 50% effective concentration [EC(50)] >10-fold greater than the baseline value) and four had high baseline EC(50)s (>200 nM). Population sequencing and sequence determination of cloned envelope genes uncovered five gp120 mutations at four loci (V68A, L116I, S375I/N, and M426L) associated with BMS-488043 resistance. Substitution at the 375 locus, located near the CD4 binding pocket, was the most common (maintained in 5/8 subjects at day 8). The five substitutions were evaluated for their effects on AI sensitivity through reverse genetics in functional envelopes, confirming their role in decreasing sensitivity to the drug. Additional analyses revealed that these substitutions did not alter sensitivity to other HIV-1 entry inhibitors. Thus, our studies demonstrate that although the majority of the subjects' viruses maintained sensitivity to BMS-488043, substitutions can be selected that decrease HIV-1 susceptibility to the AI. Most importantly, the substitutions described here are not associated with resistance to other approved antiretrovirals, and therefore, attachment inhibitors could complement the current arsenal of anti-HIV agents.
Antimicrobial Agents and Chemotherapy 11/2010; 55(2):729-37. · 4.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BMS-488043 is a novel and unique oral small-molecule inhibitor of the attachment of human immunodeficiency virus type 1 (HIV-1) to CD4(+) lymphocytes. The antiviral activity, pharmacokinetics, viral susceptibility, and safety of BMS-488043 were evaluated in an 8-day monotherapy trial. Thirty HIV-1-infected study subjects were randomly assigned to sequential, safety-guided dose panels of 800 and 1,800 mg BMS-488043 or a matched placebo in a 4:1 ratio, and the drug was administered every 12 h with a high-fat meal for 7 days and on the morning of day 8. Dose-related, albeit less-than-dose-proportional, increases in plasma BMS-488043 concentrations were observed. Mean plasma HIV-1 RNA decreases from the baseline for the BMS-488043 800- and 1,800-mg dose groups on day 8 were 0.72 and 0.96 log(10) copies/ml, respectively, compared with 0.02 log(10) copies/ml for the placebo group. A lower baseline BMS-488043 50% effective concentration (EC(50)) in the active-treatment groups was predictive of a greater antiviral response. Although absolute drug exposure was not associated with an antiviral response, the trough concentration (C(trough)), adjusted by the baseline EC(50) (C(trough)/EC(50)), was associated with antiviral activity. During dosing, four subjects experienced >10-fold reductions in viral susceptibility to BMS-488043, providing further support of the direct antiviral mechanism of BMS-488043. BMS-488043 was generally safe and well tolerated. These results suggest that further development of this novel class of oral HIV-1 attachment inhibitors is warranted.
Antimicrobial Agents and Chemotherapy 11/2010; 55(2):722-8. · 4.57 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hepatitis B virus (HBV) DNA and alanine aminotransferase (ALT) levels predict future complications in chronic hepatitis B (CHB) patients. To determine when to initiate antiviral therapy, treatment guidelines recommend monitoring of HBV DNA and ALT levels at least annually. This study aimed to assess adherence to treatment guideline-recommended monitoring of CHB patients not receiving antiviral treatment and to identify predictors of laboratory monitoring and subsequent initiation of antiviral therapy.
This retrospective cohort study used data from a large US health care claims database over a 5-year period (January 1, 2003 to December 31, 2007). The study population included patients 18-65 years of age with at least two paid medical claims with an ICD-9 code for CHB, at least one positive hepatitis B surface antigen test, and at least 12 months of continuous health plan enrollment after initial diagnosis. Descriptive statistics assessed the proportion of patients with claims for ALT and/or HBV DNA monitoring. Multivariate logistic regression models were used to determine predictors of monitoring and subsequent antiviral therapy.
The study included 1,168 CHB patients, with a mean follow-up of 728 days (median = 696 days). The proportion monitored at least every 12 months was 53.3% for ALT, 39.0% for HBV DNA, and 35.1% for both. Significant predictors of monitoring were a higher Deyo-Charlson Comorbidity Index (DCCI) score for ALT (OR 1.90, p < 0.001), male gender for HBV DNA (OR 1.49, p < 0.01), and a higher DCCI score (OR 1.10, p < 0.05) and male gender (1.46, p < 0.01) for both. Significant predictors of subsequent initiation of antiviral treatment were HBV DNA monitoring (OR 2.08, p < 0.001), a higher DCCI score (OR 1.24, p < 0.001), and male gender (OR 1.53, p < 0.01).
Laboratory monitoring of CHB patients not receiving antiviral treatment is below guideline recommendations, suggesting that initiation of antiviral therapy may also be delayed, leaving patients at risk for disease progression.
Journal of General Internal Medicine 10/2010; 26(3):239-44. · 3.28 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Antiretroviral-naive HIV-1-infected volunteers received zidovudine/lamivudine plus either lopinavir/ritonavir (n=104) or efavirenz (n=51). Lopinavir/ritonavir-treated subjects demonstrating 3 consecutive monthly HIV-1 RNA levels <50 copies/mL started lopinavir/ritonavir monotherapy. In previous-failure=failure analysis, 48% (lopinavir/ritonavir) and 61% (efavirenz) maintained HIV-1 RNA at <50 copies/mL through week 96, (P= .17; 95% confidence interval [CI] for the difference, -29% to 4%); in noncompletion=failure analysis, 60% (lopinavir/ritonavir) and 63% (efavirenz) maintained HIV-1 RNA at <50 copies/mL at week 96 (P= .73; 95% CI for the difference, -19% to 13%). Significant sparing of peripheral lipoatrophy was noted in the lopinavir/ritonavir simplification strategy. This study has provided important information for future studies using treatment simplified to lopinavir/ritonavir monotherapy.
The Journal of Infectious Diseases 08/2008; 198(2):234-40. · 5.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A total of 71 HIV-negative healthy adults were randomized to 1 of 6 regimens to receive lopinavir/ritonavir tablets 400/100 mg twice daily (bid) or 800/200 mg once daily (qd) or atazanavir 300 mg + ritonavir 100 mg qd from study days 1 to 15 with a moderate-fat meal. One hour before breakfast, either omeprazole 40 mg qd was administered on study days 11 through 15, or a single dose of ranitidine 150 mg was administered on study day 11. Lopinavir, atazanavir, and ritonavir pharmacokinetics were determined on study days 10, 11, and 15 and compared using point estimates and 90% confidence intervals (CIs). The point estimates for lopinavir Cmax and AUCtau were in the range of 0.92 to 1.08, with 90% CI contained within the range of 0.80 to 1.25 after coadministration of omeprazole or ranitidine. The point estimates for atazanavir Cmax and AUCtau were decreased by 48% to 62% with the upper bound of the 90% CI <or=0.55 after coadministration of omeprazole or ranitidine. The results indicated that lopinavir bioavailability was not affected by the coadministration of omeprazole or ranitidine. In contrast, atazanavir bioavailability was decreased by 48% to 62% when coadministered with ritonavir and either omeprazole or ranitidine.
The Journal of Clinical Pharmacology 06/2008; 48(5):553-62. · 2.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Residual viremia can be detected in most HIV-1-infected patients on antiretroviral therapy despite suppression of plasma RNA to <50 copies per ml, but the source and duration of this viremia is currently unknown. Therefore, we analyzed longitudinal plasma samples from 40 patients enrolled in the Abbott M97-720 trial at baseline (pretherapy) and weeks 60 to 384 by using an HIV-1 RNA assay with single-copy sensitivity. All patients were on therapy (lopinavir/ritonavir, stavudine, and lamivudine) with plasma HIV RNA <50 copies per ml by week 96 of the study and thereafter. Single-copy assay results revealed that 77% of the patient samples had detectable low-level viremia (>/=1 copy per ml), and all patients had at least one sample with detectable viremia. A nonlinear mixed effects model revealed a biphasic decline in plasma RNA levels occurring over weeks 60 to 384: an initial phase of decay with a half-life of 39 weeks and a subsequent phase with no perceptible decay. The level of pretherapy viremia extrapolated for each phase of decay was significantly correlated with total baseline viremia for each patient (R(2) = 0.27, P = 0.001 and R(2) = 0.19, P < 0.005, respectively), supporting a biological link between the extent of overall baseline viral infection and the infection of long-lived reservoirs. These data suggest that low-level persistent viremia appears to arise from at least two cell compartments, one in which viral production decays over time and a second in which viral production remains stable for at least 7 years.
Proceedings of the National Academy of Sciences 04/2008; 105(10):3879-84. · 9.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To analyze the extent of improved adherence preceding a clinic visit ("white coat compliance") in a clinical trial and its potential impact on the utility of therapeutic drug monitoring (TDM).
In this randomized, open-label trial, 190 antiretroviral-naïve, HIV-1-infected subjects received lopinavir/ritonavir capsules, once or twice daily, with tenofovir DF and emtricitabine (both once daily) for 96 weeks. Lopinavir/ritonavir compliance was assessed using MEMS.
178 subjects (107 once daily, 71 twice daily) had plasma samples collected for lopinavir concentration resulting in 768 visits with pharmacokinetic (PK) assessment. The results were not used to provide feedback or recommend dose changes. For 239 (31%) of these visits, drug intake was perfect 1-3 days before PK sampling, whereas compliance during the remainder of the inter-PK visit period was < or = 95%. This phenomenon was noted in 66% of subjects, more frequently among twice-daily than once-daily subjects (85% vs. 54%; p < .0001), and may have led to determination of "therapeutic" drug levels despite overall adherence < or = 95%. The opposite phenomenon (>95% compliance reported during the inter-PK visit period, yet a dose missed the day before PK sampling) was observed for 1% of PK visits and clustered in 5% of subjects.
In a substantial portion of visits and a majority of subjects, a white coat compliance pattern was observed. Drug concentration results obtained at these visits could deliver unreliable estimates of long-term drug exposure.
HIV Clinical Trials 01/2008; 9(4):238-46. · 2.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We assessed the safety and efficacy and evaluated the adherence to lopinavir/ritonavir (LPV/r) dosed QD or BID in antiretroviral-naive, HIV-1-infected subjects through 96 weeks of treatment. A randomized, open-label, multicenter comparative study was conducted. A total of 190 antiretroviral-naive subjects with plasma HIV-1 RNA above 1000 copies/ml and any CD4(+) T cell count were enrolled. Subjects were randomized (3:2) to LPV/r 800/200 mg QD (n = 115) or 400/100 mg BID (n = 75). Subjects received TDF 300 mg and FTC 200 mg QD. Adherence to LPV/r through 96 weeks was measured using MEMS((R)) monitors. Median baseline VL and CD4(+) T cell count were 4.8 log(10) copies/ml and 216 cells/mm(3), respectively. Prior to week 96, 37% (QD) and 39% (BID) of subjects discontinued, primarily due either to adverse events (17% QD, 9% BID) or to loss to follow-up or nonadherence (12% QD, 17% BID). The proportion of subjects with VL <50 copies/ml [57% QD, 53% BID; p = 0.582 (ITT NC = F)], change in CD4 count (244 cells/mm(3) QD, 264 cells/mm(3) BID; p = 0.513), and evolution of resistance did not differ between groups through 96 weeks. Diarrhea (17% QD, 5% BID, p = 0.014) was the most common moderate or severe, study drug-related adverse event. Adherence to LPV/r was higher for the QD group than the BID group and declined over time in both groups. Time to loss of virologic response was significantly associated with adherence to LPV/r in both groups. LPV/r QD resulted in virologic response similar to LPV/r BID through 96 weeks in antiretroviral-naive subjects. Adherence was significantly higher in the QD group.
AIDS Research and Human Retroviruses 01/2008; 23(12):1505-14. · 2.71 Impact Factor