Study APV20002: Safety and Efficacy Results Through Week 684 for Pediatric Participants Living With HIV-1 Treated With Ritonavir-Boosted Fosamprenavir Oral Solution-Based Antiretroviral Therapy.

APV20002 was a multicenter, international, open-label study that began in 2003 investigating the pharmacokinetics, efficacy, and safety of ritonavir-boosted fosamprenavir (FPV/r) oral solution (OS) in combination with nucleoside reverse transcriptase inhibitor-based antiretroviral therapy (ART) in participants living with HIV-1 aged 4 weeks to <2 years with a primary endpoint at Week 48 (48W). Participants in APV20002 could continue in the study post-48W until FPV OS was locally available in their countries. Children were required to discontinue after reaching >39 kg or if FPV OS had no clinical benefit. Fifty-nine participants were enrolled; 5/59 received a single FPV OS visit for pharmacokinetic determinations. Most (38/54; 70%) were antiretroviral-experienced; 39/59 participants had >48 weeks on treatment, 4/39 of whom discontinued after 48 weeks due to an adverse event (AE). At 48W, 88% of participants had HIV-1 RNA <400 copies/mL by Observed analysis; the proportion with HIV-1 RNA <400 copies/mL remained high (84%-100%) through Week 684. The median CD4+ cell count was 1235 cells/mm3 [n=51] at baseline, 1690 cells/mm3 (n=41) at Week 48, and 1280 cells/mm3 (n=21) at Week 180. From baseline to Week 684, 54/59 (92%) participants had ≥1 treatment-emergent AE regardless of causality; 42/59 (71%) had a treatment-emergent grade 2-4 AE, predominantly maximum toxicity: grade 2; 21/59 (36%) and 21/59 (36%) had severe or grade 3/4 AEs. From baseline to Week 684, 14/54 (26%) participants met virologic failure (VF) criteria, 9/14 before 48W. HIV from 1/9 VFs through 48W developed treatment-emergent reduced susceptibility to FPV and 1/9 to lamivudine/emtricitabine. Post-48W, 4/5 participants with VF had phenotype results; all were still susceptible to all study drugs at VF. In conclusion, FPV OS-based ART was efficacious and generally well tolerated in this long-running pediatric study through 684 weeks of treatment, with a safety profile consistent with experience in adults and older children.

Changes over time in creatinine clearance and comparison of emergent adverse events for HIV-positive adults receiving standard doses (300 mg/day) of lamivudine-containing antiretroviral therapy with baseline creatinine clearance of 30-49 vs ≥50 mL/min.

A retrospective analysis of the randomized controlled DART (Development of AntiRetroviral Therapy in Africa; ISRCTN13968779) trial in HIV-1-positive adults initiating antiretroviral therapy with co-formulated zidovudine/lamivudine plus either tenofovir, abacavir, or nevirapine was conducted to evaluate the safety of initiating standard lamivudine dosing in patients with impaired creatinine clearance (CLcr). Safety data collected through 96 weeks were analyzed after stratification by baseline CLcr (estimated using Cockcroft-Gault) of 30-49 mL/min (n = 168) versus ≥50 mL/min (n = 3,132) and treatment regimen. The Grade 3-4 adverse events (AEs) and serious AEs (for hematological, hepatic and gastrointestinal events), maximal toxicities for liver enzymes, serum creatinine and bilirubin and maximum treatment-emergent hematology toxicities were comparable for groups with baseline CLcr 30-49 versus CLcr≥50 mL/min. No new risks or trends were identified from this dataset. Substantial and similar increases in the mean creatinine clearance (>25 mL/min) were observed from baseline though Week 96 among participants who entered the trial with CLcr 30-49 mL/min, while no increase or smaller median changes in creatinine clearance (<7 mL/min) were observed for participants who entered the trial with CLcr ≥50 mL/min. Substantial increases (> 150 cells/ mm3) in mean CD4+ cells counts from baseline to Week 96 were also observed for participants who entered the trial with CLcr 30-49 mL/min and those with baseline CLcr ≥50 mL/min. Though these results are descriptive, they suggest that HIV-positive patients with CLcr of 30-49 mL/min would have similar AE risks in comparison to patients with CLcr ≥50 mL/min when initiating antiretroviral therapy delivering doses of 300 mg of lamivudine daily through 96 weeks of treatment. Overall improvements in CLcr were observed for patients with baseline CLcr 30-49 mL/min.

Similar neurocognitive outcomes after 48 weeks in HIV-1-infected participants randomized to continue tenofovir/emtricitabine + atazanavir/ritonavir or simplify to abacavir/lamivudine + atazanavir.

Human immunodeficiency virus (HIV)-associated neurocognitive disorders can persist in many patients despite achieving viral suppression while on antiretroviral therapy (ART). Neurocognitive function over 48 weeks was evaluated using a Cogstate test battery assessing psychomotor function, attention, learning, and working memory in 293 HIV-1-infected, ART-experienced, and virologically suppressed adults. The ASSURE study randomized participants 1:2 to remain on tenofovir/emtricitabine (TDF/FTC) and ritonavir-boosted atazanavir (ATV/r) or simplify to abacavir/lamivudine + atazanavir (ABC/3TC + ATV). Neurocognitive z-scores were computed using demographically adjusted normative data and were classified as "impaired" (defined as either a z-score ≤ - 2 or having 2 or more standardized individual test z-scores ≤ - 1); while higher scores (equaling better performance) were classified as "normal". By z-scores, 54.7% of participants had impaired neurocognition at baseline and 50.2% at week 48. There were no significant differences (p < 0.05) in the baseline-adjusted performance between treatment groups for any individual test or by z-score. Specific demographic and medical risk factors were evaluated by univariate analysis for impact on neurocognitive performance. Factors with p < 0.10 were evaluated by backwards regression analysis to identify neurocognition-correlated factors after accounting for treatment, assessment, and baseline. Four risk factors at baseline for impaired neurocognition were initially identified: lower CD4 nadir lymphocyte counts, higher Framingham risk scores, and interleukin-6 levels, and a history of psychiatric disorder not otherwise specified, however none were found to moderate the effect of treatment on neurocognition. In this aviremic, treatment-experienced population, baseline-adjusted neurocognitive function remained stable and equivalent over 48 weeks with both TDF/FTC + ATV/r-treated and in the ART-simplified ABC/3TC + ATV treatment groups.

Assessment of drug interaction potential between the HCV direct-acting antiviral agents elbasvir/grazoprevir and the HIV integrase inhibitors raltegravir and dolutegravir.

BACKGROUND: Elbasvir/grazoprevir is a once-daily fixed-dose combination therapy for the treatment of chronic HCV infection, including HCV/HIV coinfection. OBJECTIVES: To evaluate the pharmacokinetic interaction of elbasvir and grazoprevir with raltegravir or dolutegravir. METHODS: Three open-label trials in healthy adult participants were conducted. In the raltegravir trials, participants received a single dose of raltegravir 400 mg, a single dose of elbasvir 50 mg or grazoprevir 200 mg, and raltegravir with either elbasvir or grazoprevir. In the dolutegravir trial, participants received a single dose of dolutegravir 50 mg alone or co-administered with once-daily elbasvir 50 mg and grazoprevir 200 mg. RESULTS: The raltegravir AUC0-∞ geometric mean ratio (GMR) (90% CI) was 1.02 (0.81-1.27) with elbasvir and 1.43 (0.89-2.30) with grazoprevir. Dolutegravir AUC0-∞ GMR (90% CI) was 1.16 (1.00-1.34) with elbasvir and grazoprevir. The elbasvir AUC0-∞ GMR (90% CI) was 0.81 (0.57-1.17) with raltegravir and 0.98 (0.93-1.04) with dolutegravir. The grazoprevir AUC0-24 GMR (90% CI) was 0.89 (0.72-1.09) with raltegravir and 0.81 (0.67-0.97) with dolutegravir. CONCLUSIONS: Elbasvir or grazoprevir co-administered with raltegravir or dolutegravir resulted in no clinically meaningful drug-drug interactions and was generally well tolerated. These results support the assertion that no dose adjustments for elbasvir, grazoprevir, raltegravir or dolutegravir are needed for co-administration in HCV/HIV-coinfected people.

Changes from 2000 to 2009 in the Prevalence of HIV-1 Containing Drug Resistance-Associated Mutations from Antiretroviral Therapy-Naive, HIV-1-Infected Patients in the United States.

Pre-existing HIV drug resistance can jeopardize first-line antiretroviral therapy (ART) success. Changes in the prevalence of drug resistance-associated mutations (DRMs) were analyzed from HIV-infected, ART-naive, U.S. individuals seeking ART treatment from 2000 to 2009. HIV DRM data from 3,829 ART-naive subjects were analyzed by year of sample collection using International Antiviral Society-United States (IAS-USA) and World Health Organization (WHO) "surveillance" DRM definitions; minor IAS-USA-defined DRMs were excluded. IAS-USA DRM prevalence between 2000 and 2009 was 14%, beginning with 8% in 2000 and 13% in 2009. The greatest incidence was observed in 2007 (17%). Overall, IAS-USA-defined non-nucleoside reverse transcriptase inhibitor (NNRTI) DRMs were 9.5%; nucleoside reverse transcriptase inhibitor (NRTI): 4%, and major protease inhibitor (PI): 3%. The most frequently detected IAS-USA-defined DRMs by class were NNRTI: K103N/S (4%), NRTI: M41L (1.5%), and PI: L90M (1%). Overall, WHO-defined DRM prevalence was 13% (5% in 2000; 13% in 2009). By class, NNRTI prevalence was 6%, NRTI: 6%, and PI: 3.2%. The most frequent WHO-defined DRMs were NRTI: codon T215 (3.0%), NNRTI: K103N/S (4%), and PI: L90 (1%). WHO-defined NNRTI DRMs declined significantly (p = .0412) from 2007 to 2009. The overall prevalence of HIV-1 containing major IAS-USA or WHO-defined DRMs to ≥2 or ≥3 classes was 2% and <1%, respectively. The prevalence of HIV-1 with WHO-defined dual- or triple-class resistance significantly declined (p = .0461) from 2008 (4%) to 2009 (<1%). In this U.S. cohort, the prevalence of HIV-1 DRMs increased from 2000 onward, peaked between 2005 and 2007, and then declined between 2008 and 2009; the detection of WHO-defined dual- or triple-class DRM similarly decreased from 2008 to 2009.

HLA-B*57:01 allele prevalence in HIV-infected North American subjects and the impact of allele testing on the incidence of abacavir-associated hypersensitivity reaction in HLA-B*57:01-negative subjects.

BACKGROUND: The presence of the HLA-B*57:01 allele in HIV-infected subjects is associated with a higher risk of abacavir-associated hypersensitivity reaction (ABC HSR). HLA-B*57:01 allele prevalence varies in different populations, but HLA-B*57:01 testing with immunological confirmation has had a negative predictive value for ABC HSR between 97 and 100%. METHODS: In the ASSURE study (EPZ113734), the HLA-B*57:01 prevalence in virologically suppressed, antiretroviral treatment-experienced, HIV-infected subjects from the United States, including Puerto Rico, was assessed. RESULTS: Three hundred eighty-five subjects were screened; 13 were HLA-B*57:01 positive and 372 were negative. Only HLA-B*57:01-negative, abacavir-naive subjects were eligible to enroll into the ASSURE trial. Eleven of the 13 subjects who possessed the HLA-B*57:01 allele were white, the other 2 were African-American. There was no geographic clustering of HLA-B*57:01-positive subjects, and the incidence correlated roughly with those states with the greatest numbers of subjects screened. Similarly, there was no statistically significant correlation between subjects who possessed or lacked the allele and age, gender, ethnicity or CD4+ T-cell numbers. The incidence of ABC HSR following abacavir initiation was also evaluated. Only 1 of 199 HLA-B*57:01-negative subjects (an African-American male) randomized to receive abacavir-containing treatment developed symptoms consistent with suspected ABC HSR; ABC HSR was not immunologically confirmed. CONCLUSIONS: These findings confirm the utility of HLA-B*57:01 allele testing to reduce the frequency of ABC HSR. The prevalence of HLA-B*57:01 positivity was higher in white than in African-American subjects. In HLA-B*57:01-negative subjects, suspected ABC HSR is very rare, but should lead to discontinuation of abacavir when ABC HSR cannot be definitively excluded from the differential diagnosis. TRIAL REGISTRATION: The ASSURE (EPZ113734) study was registered on ClinicalTrials.gov registration on April 8th 2010 and the registration number is NCT01102972.

Response by gender of HIV-1-infected subjects treated with abacavir/lamivudine plus atazanavir, with or without ritonavir, for 144 weeks.

PURPOSE: The 144-week results of the open-label, multicenter Atazanavir/Ritonavir Induction with Epzicom Study (ARIES) were stratified by gender to compare treatment responses. METHODS: A total of 369 HIV-infected, antiretroviral-naïve subjects receiving once-daily abacavir/lamivudine + atazanavir/ritonavir (ATV/r) whose HIV-1 RNA was <50 copies/mL by week 30 were randomized 1:1 at week 36 to maintain or discontinue ritonavir for 108 subsequent weeks. Between- and within-treatment gender-related efficacy and safety differences were analyzed. RESULTS: Subjects were 85% male; 64% white; and had a mean age of 39 years, baseline median HIV-1 RNA of 114,815 copies/mL, and median CD4+ cell count of 198 cells/mm3. Gender (ATV [n=189]: 29 females/160 males; ATV/r [n=180]: 25 females/155 males) and most other demographics were similar between groups; more females than males were black (65% vs 25%) and fewer females had baseline HIV-1 RNA ≥100,000 copies/mL (41% vs 58%). At week 144, no significant differences between genders were observed in proportion maintaining HIV-1 RNA <50 copies/mL (ATV, 79% vs 77%; ATV/r, 60% vs 75%) or <400 copies/mL (ATV, 83% vs 84%; ATV/r, 68% vs 82%) (intent-to-treat-exposed: time to loss of virologic response analysis); median CD4+ change from baseline (ATV, +365 vs +300 cells/mm3; ATV/r, +344 vs +301 cells/mm3); proportion with treatment-related grade 2-4 adverse events (baseline to week 144: ATV, 41% vs 31%; ATV/r, 36% vs 43%; weeks 36 to 144: ATV, 14% vs 13%; ATV/r, 24% vs 23%); or proportion developing fasting lipid changes. Female and male virologic failure rates (ATV, 0 vs 5; ATV/r, 2 vs 4) and proportions completing the study were similar during the extension phase. Primary withdrawal reasons were loss to follow-up and pregnancy for females and loss to follow-up and other for males. CONCLUSION: Over 144 weeks, no significant gender differences were observed in efficacy, safety, or fasting lipid changes with abacavir/lamivudine +ATV or abacavir/lamivudine +ATV/r.

A Two-Way Steady-State Pharmacokinetic Interaction Study of Doravirine (MK-1439) and Dolutegravir.

INTRODUCTION: Doravirine, a non-nucleoside reverse-transcriptase inhibitor in development for the treatment of patients with human immunodeficiency virus-1 infection, has potential to be used concomitantly in antiretroviral therapy with dolutegravir, an integrase strand transfer inhibitor. The pharmacokinetic interactions between these drugs were therefore assessed. METHODS: Oral formulations of doravirine and dolutegravir were dosed both individually and concomitantly once daily in healthy adults. Twelve subjects (six were male), 23-42 years of age, were enrolled and 11 completed this phase I, open-label, three-period, fixed-sequence study per protocol; one subject was discontinued for a positive cotinine test at admission to period 2. In period 1, dolutegravir 50 mg was administered for 7 days. After a 7-day washout, doravirine 200 mg was dosed for 7 days in period 2, followed (without washout) by both doravirine and dolutegravir simultaneously for 7 days in period 3. Plasma samples were taken to determine dolutegravir and doravirine concentrations. RESULTS: The steady-state concentration 24 h post-dose (C24) of dolutegravir was not substantially altered by co-administration of doravirine multiple doses; area under the plasma concentration-time curve from dosing to 24 h post-dose (AUC0-24), maximum concentration (C max), and C24 geometric mean ratios were 1.36, 1.43, and 1.27, respectively. The pharmacokinetics of doravirine was not affected by multiple doses of dolutegravir (geometric mean ratios: 1.00, 0.98, and 1.06 for AUC0-24, C24, and C max, respectively). Both drugs were generally well tolerated. CONCLUSION: The results of this study demonstrate that concomitant administration of doravirine and dolutegravir in healthy subjects causes no clinically significant alteration in the pharmacokinetic and safety profiles of the two drugs, thereby supporting further evaluation of co-administration of these agents for human immunodeficiency virus-1 treatment.

No clinically significant pharmacokinetic interactions between dolutegravir and daclatasvir in healthy adult subjects.

BACKGROUND: Daclatasvir (DCV) is an NS5A replication complex inhibitor recently approved for chronic hepatitis C virus treatment. METHODS: To assess drug interactions between the HIV integrase strand transfer inhibitor dolutegravir (DTG) and DCV, subjects were randomized into 1 of 2 sequences in an open-label, 3-period, crossover study. Subjects received either DTG 50 mg once daily or DCV 60 mg once daily for 5 days in periods 1 and 2 and DTG 50 mg plus DCV 60 mg once daily for 5 days in period 3, with no washout between periods 2 and 3. Between periods 1 and 2, there was a washout period of at least 7 days. RESULTS: The geometric least-squares mean ratios (90 % confidence intervals) of DCV area under the concentration-time curve over a dosing interval (AUC0-τ), maximum observed concentration (Cmax), and concentration at the end of the dosing interval (Cτ) were 0.978 (0.831-1.15), 1.03 (0.843-1.25), and 1.06 (0.876-1.29), respectively, when DCV was administered with DTG compared with DCV alone. Compared with DTG alone, coadministration of DTG with DCV increased DTG AUC0-τ, Cmax, and Cτ by approximately 33, 29, and 45 %, respectively. CONCLUSIONS: DCV plasma exposure was not meaningfully affected by DTG. Coadministration of DTG with DCV resulted in slight increases in DTG AUC0-τ, Cmax, and Cτ. Accumulated safety and tolerability data in humans receiving DTG to date suggests this effect is not considered clinically significant. DTG and DCV can be coadministered without dose adjustment. TRIAL REGISTRATION: Registered on March 6, 2014 with ClinicalTrials.gov; registration number: NCT02082808 and as Study ID: 201102 on the ViiV Clinical Study Registry.

Treatment-Emergent Mutations and Resistance in HIV-Infected Children Treated with Fosamprenavir-Containing Antiretroviral Regimens.

Treatment-emergent mutations and drug resistance were analyzed in virus from HIV-infected children meeting virologic failure (VF) criteria over 48 weeks following treatment with unboosted fosamprenavir or fosamprenavir/ritonavir-containing regimens in studies APV20002 and APV29005. Both antiretroviral therapy (ART)-naïve and ART-experienced patients were enrolled. Patients met VF criteria by either failing to suppress HIV-RNA to <400 copies/mL through week 24 or after confirmed viral rebound (≥400 copies/mL) anytime through week 48. Viral isolates were analyzed for treatment-emergent mutations or reduced drug susceptibility. Through week 48, 25/109 (23%) of APV29005 and 9/54 (17%) APV20002 study patients met VF. VF was more common in ART-experienced patients (68% and 78%, respectively). Major or minor treatment-emergent mutations were detected at VF in virus from 3 patients receiving unboosted fosamprenavir-containing regimens and in virus from 10 patients receiving fosamprenavir/ritonavir-containing regimens across the two studies. Major protease inhibitor mutations and the reverse transcriptase mutation M184V were detected at VF in virus from 4 and 5 patients, respectively, across both studies. Reduced drug susceptibility to any drug emerged in virus from 9 patients at VF, although reduced fosamprenavir susceptibility emerged in virus from only 4 patients (2 ART-naïve and 2 ART-experienced). No cross-resistance to the protease inhibitor darunavir was observed. In conclusion, given the high proportion of ART-experienced children (71%) in these two studies, the overall incidence of children meeting VF criteria through 48 weeks was relatively low (21%) and development of fosamprenavir reduced drug susceptibility at VF was uncommon, further supporting the use of fosamprenavir-containing ART regimens in HIV-infected children.

Simplification to abacavir/lamivudine + atazanavir maintains viral suppression and improves bone and renal biomarkers in ASSURE, a randomized, open label, non-inferiority trial.

OBJECTIVE: Simplification of antiretroviral therapy in patients with suppressed viremia may minimize long-term adverse effects. The study's primary objective was to determine whether abacavir/lamivudine + atazanavir (ABC/3TC+ATV) was virologically non-inferior to tenofovir/emtricitabine + atazanavir/ritonavir (TDF/FTC+ATV/r) over 24 weeks in a population of virologically suppressed, HIV-1 infected patients. DESIGN: This open-label, multicenter, non-inferiority study enrolled antiretroviral experienced, HIV-infected adults currently receiving a regimen of TDF/FTC+ATV/r for ≥ 6 months with no history of virologic failure and whose HIV-1 RNA had been ≤ 75 copies/mL on 2 consecutive measurements including screening. Patients were randomized 1 ∶ 2 to continue current treatment or simplify to ABC/3TC+ATV. METHODS: The primary endpoint was the proportion of patients with HIV-RNA<50 copies/mL at Week 24 by the Time to Loss of Virologic Response (TLOVR) algorithm. Secondary endpoints included alternative measures of efficacy, adverse events (AEs), and fasting lipids. Exploratory endpoints included inflammatory, coagulation, bone, and renal biomarkers. RESULTS: After 24 weeks, ABC/3TC+ATV (n = 199) was non-inferior to TDF/FTC+ATV/r (n = 97) by both the primary analysis (87% in both groups) and all secondary efficacy analyses. Rates of grade 2-4 AEs were similar between the two groups (40% vs 37%, respectively), but an excess of hyperbilirubinemia made the rate of grade 3-4 laboratory abnormalities higher in the TDF/FTC+ATV/r group (30%) compared with the ABC/3TC+ATV group (13%). Lipid levels were stable except for HDL cholesterol, which increased significantly in the ABC/3TC+ATV group. Bone and renal biomarkers improved significantly between baseline and Week 24 in patients taking ABC/3TC+ATV, and the difference between groups was significant at Week 24. No significant changes occurred in any inflammatory or coagulation biomarker within or between treatment groups. CONCLUSIONS: After 24 weeks, simplification to ABC/3TC+ATV from TDF/FTC+ATV/r maintained viral suppression was well-tolerated, and led to improvements in bone and renal biomarkers and HDL cholesterol. TRIAL REGISTRATION: ClinicalTrials.gov NCT01102972 GlaxoSmithKline Clinical Study Register #113734.

HIV-1 transmission patterns in antiretroviral therapy-naïve, HIV-infected North Americans based on phylogenetic analysis by population level and ultra-deep DNA sequencing.

Factors that contribute to the transmission of human immunodeficiency virus type 1 (HIV-1), especially drug-resistant HIV-1 variants remain a significant public health concern. In-depth phylogenetic analyses of viral sequences obtained in the screening phase from antiretroviral-naïve HIV-infected patients seeking enrollment in EPZ108859, a large open-label study in the USA, Canada and Puerto Rico (ClinicalTrials.gov NCT00440947) were examined for insights into the roles of drug resistance and epidemiological factors that could impact disease dissemination. Viral transmission clusters (VTCs) were initially predicted from a phylogenetic analysis of population level HIV-1 pol sequences obtained from 690 antiretroviral-naïve subjects in 2007. Subsequently, the predicted VTCs were tested for robustness by ultra deep sequencing (UDS) using pyrosequencing technology and further phylogenetic analyses. The demographic characteristics of clustered and non-clustered subjects were then compared. From 690 subjects, 69 were assigned to 1 of 30 VTCs, each containing 2 to 5 subjects. Race composition of VTCs were significantly more likely to be white (72% vs. 60%; p = 0.04). VTCs had fewer reverse transcriptase and major PI resistance mutations (9% vs. 24%; p = 0.002) than non-clustered sequences. Both men-who-have-sex-with-men (MSM) (68% vs. 48%; p = 0.001) and Canadians (29% vs. 14%; p = 0.03) were significantly more frequent in VTCs than non-clustered sequences. Of the 515 subjects who initiated antiretroviral therapy, 33 experienced confirmed virologic failure through 144 weeks while only 3/33 were from VTCs. Fewer VTCs subjects (as compared to those with non-clustering virus) had HIV-1 with resistance-associated mutations or experienced virologic failure during the course of the study. Our analysis shows specific geographical and drug resistance trends that correlate well with transmission clusters defined by HIV sequences of similarity. Furthermore, our study demonstrates the utility of molecular and epidemiological analysis of VTCs for identifying population-specific risks associated with HIV-1 transmission and developing effective local healthcare strategies.

Pharmacokinetics, safety and antiviral activity of fosamprenavir/ritonavir-containing regimens in HIV-infected children aged 4 weeks to 2 years-48-week study data.

BACKGROUND: Pharmacokinetics, safety and antiviral activity of fosamprenavir (FPV) with ritonavir (RTV) twice daily were evaluated in HIV-1-infected infants and children 4 weeks to <2 years over 48 weeks. METHODS: Results from intensive pharmacokinetic sampling of subjects enrolled in single dose visits was used to determine individualized dosing for the first 6-10 subjects in each of 2 cohorts (4 weeks to <6 months, 6 months to <2 years); steady state pharmacokinetic data were then used to select the dosage regimen for the remaining subjects recruited to the cohort. Intensive pharmacokinetic sampling was performed at week 2 or 8; predose samples were collected every 4-12 weeks thereafter. Safety and plasma HIV-1 RNA were monitored every 4-12 weeks. RESULTS: Fifty-nine subjects received study medication. FPV 45 mg/kg boosted with RTV 7 to 10 mg/kg BID achieved average plasma amprenavir area under curve(0-τ) values 26% to 28% lower and Cmax similar to historical adult data for FPV/RTV 700/100 mg BID; amprenavir Cτ values were lower in the subjects <6 months of age. At week 48, 35 of 54 (65%) subjects had achieved plasma HIV-1 RNA <400 copies/mL and 33 of 54 (61%) had plasma HIV-1 RNA values <50 copies/mL. The most common adverse events were diarrhea, upper respiratory tract infection, gastroenteritis and otitis media. CONCLUSIONS: Final FPV/RTV dosing regimens achieved plasma amprenavir exposures comparable with those from regimens approved in adults, with the exception of trough exposures in the <6-month-old infants. The FPV/RTV regimens led to viral suppression in 61% of patients and were generally well tolerated.

Pharmacokinetics and 48-week safety and antiviral activity of fosamprenavir-containing regimens in HIV-infected 2- to 18-year-old children.

BACKGROUND: Pharmacokinetics, safety and antiviral activity of twice-daily fosamprenavir with or without ritonavir were evaluated in 2- to 18-year-old protease inhibitor-naïve and -experienced HIV-1-infected children. METHODS: Serial pharmacokinetic samples were collected at week 2 and predose samples every 4-12 weeks. Safety and plasma HIV-1 RNA were monitored every 4-12 weeks. RESULTS: Twenty protease inhibitor-naïve 2- to <6-year-old subjects received antiretroviral treatment including unboosted fosamprenavir twice-daily, whereas 89 protease inhibitor-naïve and -experienced 2- to 18-year-old subjects received fosamprenavir/ritonavir-containing therapy twice-daily. Median fosamprenavir exposure was 891 days (range 15-1805 days), with 88% exposed >48 weeks. Twice-daily doses of fosamprenavir/ritonavir 23/3 mg/kg in 2- to <6-year olds, 18/3 mg/kg in ≥6-year olds and 700/100 mg in adolescents achieved plasma amprenavir exposures comparable with or higher than 700/100 mg twice-daily in adults while fosamprenavir 30 mg/kg twice-daily in 2- to <6-year olds led to exposures higher than 1400 mg twice-daily in adults. The proportion of subjects with HIV-1 RNA <400 copies/mL at week 48 was 60% for fosamprenavir and 53-74% for fosamprenavir/ritonavir (intent-to-treat [exposed], snapshot analysis). Median increases in absolute and relative (percentage) CD4 counts from baseline to week 48 occurred in both the fosamprenavir (340 cells/mm; 8%) and fosamprenavir/ritonavir group (190 cells/mm; 8%). The most common adverse events were vomiting, cough, and diarrhea; 18 subjects experienced serious adverse events, including 9 with suspected abacavir hypersensitivity. CONCLUSIONS: Fosamprenavir regimens administered to HIV-1-infected children aged 2-18 years were generally well-tolerated and provided sustained antiviral activity over 48 weeks, with plasma amprenavir exposures comparable with or higher than adults.

Inflammatory biomarker changes and their correlation with Framingham cardiovascular risk and lipid changes in antiretroviral-naive HIV-infected patients treated for 144 weeks with abacavir/lamivudine/atazanavir with or without ritonavir in ARIES.

Propensity for developing coronary heart disease (CHD) is linked with Framingham-defined cardiovascular risk factors and elevated inflammatory biomarkers. Cardiovascular risk and inflammatory biomarkers were evaluated in ARIES, a Phase IIIb/IV clinical trial in which 515 antiretroviral-naive HIV-infected subjects initially received abacavir/lamivudine + atazanavir/ritonavir for 36 weeks. Subjects who were virologically suppressed by week 30 were randomized 1:1 at week 36 to either maintain or discontinue ritonavir for an additional 108 weeks. Framingham 10-year CHD risk scores (FRS) and risk category of <6% or ≥6%, lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), interleukin-6 (IL-6), and high-sensitivity C-reactive protein (hsCRP) were assessed at baseline, week 84, and week 144. Biomarkers were stratified by FRS category. When ritonavir-boosted/nonboosted treatment groups were combined, median hsCRP did not change significantly between baseline (1.6 mg/liter) and week 144 (1.4 mg/liter) in subjects with FRS <6% (p=0.535) or with FRS ≥6% (1.9 mg/liter vs. 2.0 mg/liter, respectively; p=0.102). Median IL-6 was similar for subjects with FRS <6% (p=0.267) at baseline (1.6 pg/ml) and week 144 (1.4 pg/ml) and for FRS ≥6% (2.0 pg/ml vs. 2.2 pg/ml, respectively; p=0.099). Median Lp-PLA(2) decreased significantly (p<0.001) between baseline (197 nmol/min/ml) and week 144 (168 nmol/min/ml) in subjects with FRS <6% and with FRS ≥6% (238 nmol/min/ml vs. 175 nmol/min/ml, respectively; p<0.001). In conclusion, in antiretroviral-naive subjects treated with abacavir-based therapy for 144 weeks, median inflammatory biomarker levels for hsCRP and IL-6 generally remained stable with no significant difference between baseline and week 144 for subjects with either FRS <6% or FRS ≥6%. Lp-PLA(2) median values declined significantly over 144 weeks for subjects in either FRS stratum.

ARIES 144 week results: durable virologic suppression in HIV-infected patients simplified to unboosted atazanavir/abacavir/lamivudine.

BACKGROUND: The open-label study ARIES (ClinicalTrials.gov NCT00440947) utilized a ritonavir (/r)-boosted protease inhibitor treatment simplification strategy. Antiretroviral-naïve subjects received abacavir/lamivudine (ABC/3TC) + atazanavir/ ritonavir (ATV/r) from baseline through randomization at week 36, then maintained or discontinued ritonavir for an additional 108 weeks. Non-inferiority of the unboosted regimen was demonstrated at week 84. In this optional extension phase, virologic suppression and adverse events were assessed through week 144. METHODS: Patients were randomized at week 36 if they had confirmed HIV RNA <50 copies/mL by week 30 and no previous virologic failure (VF; defined as failure to achieve HIV RNA <400 copies/mL or confirmed rebound after achieving HIV RNA ≥400 copies/mL). Three hundred sixty-nine subjects who completed 84 weeks in ARIES participated in the extension phase and maintained their randomized regimen for an additional 60 weeks post randomization. RESULTS: At week 144, 146/189 (77%) versus 132/180 (73%) subjects in the unboosted ATV and ATV/r groups, respectively, maintained HIV RNA <50 copies/mL. Post randomization (weeks 36-144), treatment-related grade 2-4 adverse events were more common in the ATV/r-treated (23%) compared to the ATV-treated (13%) group; the most frequently reported was increased serum bilirubin (6% of ATV-treated subjects vs 14 % of ATV/r-treated subjects). During the extension phase, 3% (11/369) of subjects met protocol-defined VF (5 ATV-treated and 6 ATV/ r-treated subjects); one ATV/r-treated subject had treatment-emergent major viral resistance-associated mutations. The median change in fasting triglycerides from baseline to week 144 was significantly different (P=.001) in the ATV-treated (-8.5 mg/dL) compared to the ATV/r-treated (28.5 mg/dL) groups. CONCLUSIONS: These long-term study results demonstrate that ATV in combination with ABC/3TC is a potent, well-tolerated regimen in patients who have achieved initial suppression on a ritonavir-boosted regimen.

Tenofovir (TDF)-selected or abacavir (ABC)-selected low-frequency HIV type 1 subpopulations during failure with persistent viremia as detected by ultradeep pyrosequencing.

Detection of drug resistance is critical for determining antiretroviral treatment options. Ultradeep pyrosequencing (UDPS; 454 Life Sciences) is capable of detecting virus variant subpopulations with much greater sensitivity than population sequencing, which typically has a detection limit around 20%. UDPS of the HIV-1 reverse transcriptase (RT) (amino acids 56-120) was performed to detect the key mutations K65R and L74V associated with tenofovir and abacavir use. Plasma specimens from subjects with persistent rebound viremia following suppression on tenofovir (n = 8) or abacavir (n = 9)-based therapy were studied. Samples from a subject treated with zidovudine/lamivudine/efavirenz with a similar loss of virologic response served as a control. HIV-1 plasma RNA was ≥3.68 log(10) copies/ml at all time points sequenced. The median number of UDPS sequences analyzed/time point was 33,246. Among the eight tenofovir-treated subjects, three showed high-frequency (>20%) RT K65R at the time of failure, whereas one showed low-frequency (<20%) L74V; no low-frequency K65R was detected in these subjects. Among the nine abacavir-treated subjects, three showed low-frequency K65R; no L74V was detected in these patients. No K65R or L74V was detected in the samples from the control subject. At failure, other RT mutations were detected, including low-frequency NNRTI-resistant species detected at ≥1 time point in nine subjects; the key NNRTI mutation K103N, however, was always observed at >20% frequency. Although UDPS is useful in the detection of low-frequency subpopulations with transmitted resistance in antiviral-naive patients, it may have less utility in treatment-experienced patients with persistent viremia on therapy.

Similar efficacy and tolerability of atazanavir compared with atazanavir/ritonavir, each with abacavir/lamivudine after initial suppression with abacavir/lamivudine plus ritonavir-boosted atazanavir in HIV-infected patients.

BACKGROUND: Treatment simplification strategies involving induction with a ritonavir (RTV)-boosted (/r) protease inhibitor regimen followed by simplification (without RTV) are appealing because they may offer sustained virologic suppression while minimizing potential long-term adverse effects associated with RTV. METHODS: This open-label, randomized, noninferiority study enrolled 515 antiretroviral therapy-naive patients to receive abacavir/lamivudine plus atazanavir/RTV (ATV/r) followed by randomization at week 36 (N = 419) to maintain or discontinue RTV for an additional 48 weeks. Eligibility for randomization required confirmed HIV RNA level below 50 copies/ml and no virologic failure. Protocol-defined virologic failure after week 36 was confirmed rebound of HIV RNA level at least 400 copies/ml. The primary endpoint was the proportion of patients with HIV RNA level below 50 copies/ml at week 84 (time to loss of virologic response). This study is registered with ClinicalTrials.gov number NCT00440947. RESULTS: At week 84, noninferiority of ATV to ATV/r (95% confidence interval around the treatment difference -1.75 to 12.48%) was demonstrated with 181 of 210 (86%) patients in the ATV group and 169 of 209 (81%) in the ATV/r group maintaining HIV RNA level below 50 copies/ml. During the randomized phase (weeks 36-84), 10 versus 14% of patients in the ATV and ATV/r arms, respectively, experienced a drug-related grades 2-4 adverse event with hyperbilirubinemia being the most frequently reported (4 versus 10%). The overall rate of protocol-defined virologic failure was 2%; no patient had virus that developed a major protease inhibitor mutation. CONCLUSION: ATV in combination with abacavir/lamivudine is a potent and well tolerated regimen in patients who have achieved initial suppression on an induction regimen and represents a viable treatment simplification strategy.