Dolutegravir + Lamivudine vs. Dolutegravir + Tenofovir Disoproxil Fumarate/Emtricitabine: Very-Low-Level HIV-1 Replication through 144 Weeks in the GEMINI-1 and GEMINI-2 Studies.

In GEMINI-1/-2, dolutegravir + lamivudine was non-inferior to dolutegravir + tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) in achieving viral suppression (viral load [VL] < 50 copies/mL) in treatment-naive adults. Abbott's RealTime HIV-1 assay provides quantitative VL (40-10,000,000 copies/mL) and qualitative target detected or target not detected (TND) for VL < 40 copies/mL. This post hoc analysis assessed very-low-level viremia and "blips" through Week 144. Proportions with VL < 40 copies/mL and TND are presented overall and by baseline VL and CD4+ cell count. "Blips" (single VL ≥ 50 to <200 copies/mL with adjacent values < 50 copies/mL) were assessed from Day 1 after VL suppression and from Weeks 48 through to 144. Proportions with TND increased through Week 48 and were similar between groups at all visits (Week 144: dolutegravir + lamivudine, 451/716 [63%]; dolutegravir + TDF/FTC, 465/717 [65%]). By observed analysis, TND rates were similar between groups across baseline subgroups. Through Week 144, proportions with ≥1 "blip" were generally comparable for dolutegravir + lamivudine vs. dolutegravir + TDF/FTC from Day 1 (15% vs. 20%) and from Week 48 (7% vs. 11%). Through 144 weeks, the proportions with TND or "blips" were similar between dolutegravir + lamivudine and the three-drug comparator, reinforcing the efficacy and durability of dolutegravir + lamivudine.

Integrase Inhibitor Resistance Mechanisms and Structural Characteristics in Antiretroviral Therapy-Experienced, Integrase Inhibitor-Naive Adults with HIV-1 Infection Treated with Dolutegravir plus Two Nucleoside Reverse Transcriptase Inhibitors in the DAWNING Study.

At week 48 in the phase IIIb DAWNING study, the integrase strand transfer inhibitor (INSTI) dolutegravir plus 2 nucleoside reverse transcriptase inhibitors demonstrated superiority to ritonavir-boosted lopinavir in achieving virologic suppression in adults with HIV-1 who failed first-line therapy. Here, we report emergent HIV-1 drug resistance and mechanistic underpinnings among dolutegravir-treated adults in DAWNING. Population viral genotyping, phenotyping, and clonal analyses were performed on participants meeting confirmed virologic withdrawal (CVW) criteria on dolutegravir-containing regimens. Dolutegravir binding to and structural changes in HIV-1 integrase-DNA complexes with INSTI resistance-associated substitutions were evaluated. Of participants who received dolutegravir through week 48 plus an additional 110 weeks for this assessment, 6 met CVW criteria with treatment-emergent INSTI resistance-associated substitutions and 1 had R263R/K at baseline but not at CVW. All 7 achieved HIV-1 RNA levels of <400 copies/mL (5 achieved <50 copies/mL) before CVW. Treatment-emergent G118R was detected in 5 participants, occurring with ≥2 other integrase substitutions, including R263R/K, in 3 participants and without other integrase substitutions in 2 participants. G118R or R263K increased the rate of dolutegravir dissociation from integrase-DNA complexes versus wild-type but retained prolonged binding. Overall, among treatment-experienced adults who received dolutegravir in DAWNING, 6 of 314 participants developed treatment-emergent INSTI resistance-associated substitutions, with a change in in vitro dolutegravir resistance of >10-fold and reduced viral replication capacity versus baseline levels. This study demonstrates that the pathway to dolutegravir resistance is a challenging balance between HIV-1 phenotypic change and associated loss of viral fitness. (This study has been registered at ClinicalTrials.gov under identifier NCT02227238.).

Three-year durable efficacy of dolutegravir plus lamivudine in antiretroviral therapy - naive adults with HIV-1 infection.

OBJECTIVE: To assess efficacy and safety of dolutegravir (DTG) + lamivudine (3TC) vs. DTG + tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) in treatment-naive adults with HIV-1 in the prespecified 144-week secondary analyses of GEMINI-1 and GEMINI-2. DESIGN: Identical, multicenter, phase III, randomized, non-inferiority studies (double-blind through 96 weeks). METHODS: Participants with HIV-1 RNA ≤500 000 copies/ml and no major viral resistance mutations to nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, or protease inhibitors were randomized 1:1 to once-daily DTG + 3TC or DTG + TDF/FTC. RESULTS: At week 144, DTG + 3TC (N = 716) was noninferior to DTG + TDF/FTC (N = 717) in proportion of participants achieving HIV-1 RNA <50 copies/ml (Snapshot algorithm) in the pooled analysis (82% vs. 84%, respectively; adjusted treatment difference [95% confidence interval (CI)], -1.8% [-5.8, 2.1]), GEMINI-1 (-3.6% [-9.4, 2.1]), and GEMINI-2 (0.0% [-5.3, 5.3]). Twelve DTG + 3TC participants and nine DTG + TDF/FTC participants met protocol-defined confirmed virologic withdrawal (CVW) criteria; none developed treatment-emergent resistance. One DTG + 3TC participant who did not meet CVW criteria developed M184V at week 132 and R263R/K at week 144, conferring a 1.8-fold change in susceptibility to DTG; non-adherence to therapy was reported. Significantly fewer drug-related adverse events occurred with DTG + 3TC vs. DTG + TDF/FTC (20% vs. 27%; relative risk [95% CI], 0.76 [0.63-0.92]). Renal and bone biomarker changes favored DTG + 3TC. CONCLUSIONS: Three-year durable efficacy, long-term tolerability, and high barrier to resistance support first-line use of DTG + 3TC for HIV-1 treatment (see Supplemental Digital Content 1, http://links.lww.com/QAD/C297; video abstract).

Impact of treatment adherence on efficacy of dolutegravir plus lamivudine and dolutegravir plus tenofovir disoproxil fumarate/emtricitabine: pooled analysis of the GEMINI-1 and GEMINI-2 clinical studies.

Background: GEMINI-1 and GEMINI-2 (ClinicalTrials.gov, NCT02831673 and NCT02831764, respectively) are double-blind, multicenter, phase III studies that demonstrated the non-inferiority of once-daily dolutegravir + lamivudine to dolutegravir + tenofovir disoproxil fumarate/emtricitabine in achieving HIV-1 RNA <50 copies/mL at 48, 96, and 144 weeks in treatment-naive adults with HIV-1 infection.Objective: We present a post hoc analysis of the impact of treatment adherence on Week 48 virologic response.Methods: Adherence was estimated using pill counts and categorized as ≥90% vs <90%. Unadjusted treatment differences with exact 95% CIs were derived for the proportion of participants with HIV-1 RNA <50 copies/mL within each adherence category, using Snapshot algorithm and last available on-treatment viral load through Week 48.Results: In each treatment group, 5% of participants had <90% adherence (dolutegravir + lamivudine group, 35/716; dolutegravir + tenofovir disoproxil fumarate/emtricitabine group, 34/717). The proportion of participants with HIV-1 RNA <50 copies/mL (Snapshot) at Week 48 in the <90% adherence group was 69% in the dolutegravir + lamivudine group and 65% in the dolutegravir + tenofovir disoproxil fumarate/emtricitabine group (analysis by last on-treatment viral load: 91% and 85%, respectively). Corresponding proportions in the ≥90% adherence group were 93% and 96% (analysis by last on-treatment viral load: 97% and 99%, respectively).Conclusions: Decreased adherence resulted in lower Week 48 virologic efficacy outcomes that were comparable between treatment groups. These results indicate that the robust antiviral activity and regimen forgiveness of dolutegravir + lamivudine is similar to dolutegravir-containing 3-drug regimens (see graphical abstract).

Brief Report: Virologic Response by Baseline Viral Load With Dolutegravir Plus Lamivudine vs Dolutegravir Plus Tenofovir Disoproxil Fumarate/Emtricitabine: Pooled Analysis.

BACKGROUND: To investigate antiviral potency of the 2-drug regimen (2DR) dolutegravir plus lamivudine vs the 3-drug regimen (3DR) dolutegravir plus tenofovir disoproxil fumarate/emtricitabine, we performed a post-hoc analysis assessing antiviral response rates in the phase III GEMINI-1 and GEMINI-2 studies by baseline viral load (VL). SETTING: One hundred ninety-two centers in 21 countries. METHODS: Treatment-naive HIV-1-infected participants with screening VL ≤500,000 copies/mL were randomized 1:1 to once-daily dolutegravir plus lamivudine or dolutegravir plus tenofovir disoproxil fumarate/emtricitabine. Median change from baseline was determined for log10-transformed VL in the overall study population and the subpopulation with baseline VL >100,000 copies/mL. Proportion of participants achieving plasma VL <50 copies/mL (Snapshot algorithm) or <40 copies/mL (Abbott RealTime HIV-1 assay) and target not detected was assessed through week 48 by baseline VL. Time to viral suppression was determined (nonparametric Kaplan-Meier method). RESULTS: For 293 participants with baseline VL >100,000 copies/mL, median change from baseline at week 4 was -3.38 and -3.40 log10 copies/mL in the 2DR and 3DR groups, respectively; reduction was sustained throughout 48 weeks. Time to VL <50 copies/mL was longer in participants with baseline VL >100,000 copies/mL than the overall study population (57 [week 8] vs 29 days [week 4]) and similar between the 2DR and 3DR groups. Proportion of participants with VL <50 or <40 copies/mL and target not detected was similar between groups, irrespective of baseline VL, at all tested visits throughout 48 weeks. CONCLUSION: Dolutegravir plus lamivudine demonstrates high antiviral potency in treatment-naive HIV-1-infected individuals across baseline VL strata.

Durable Efficacy of Dolutegravir Plus Lamivudine in Antiretroviral Treatment-Naive Adults With HIV-1 Infection: 96-Week Results From the GEMINI-1 and GEMINI-2 Randomized Clinical Trials.

BACKGROUND: The 2-drug regimen dolutegravir + lamivudine was noninferior to dolutegravir + tenofovir disoproxil fumarate/emtricitabine in achieving HIV-1 RNA <50 copies/mL in treatment-naive adults in the 48-week primary analysis of the GEMINI trials. We present results from the prespecified 96-week secondary analyses. SETTING: One hundred eighty-seven centers in 21 countries. METHODS: GEMINI-1 and GEMINI-2 are identical, double-blind phase III studies. Participants with screening HIV-1 RNA ≤500,000 copies/mL were randomized 1:1 to once-daily dolutegravir + lamivudine or dolutegravir + tenofovir disoproxil fumarate/emtricitabine. RESULTS: At week 96, dolutegravir + lamivudine (N = 716) was noninferior to dolutegravir + tenofovir disoproxil fumarate/emtricitabine (N = 717) in achieving HIV-1 RNA <50 copies/mL (Snapshot algorithm; -10% noninferiority margin) in the pooled analysis (proportion of responders, 86.0% vs 89.5%, respectively; adjusted treatment difference [95% CI], -3.4% [-6.7 to 0.0007]), GEMINI-1 (-4.9% [-9.8 to 0.03]), and GEMINI-2 (-1.8% [-6.4 to 2.7]). Proportions of participants in the HIV-1 RNA ≥50 copies/mL Snapshot category were largely unchanged from week 48 to 96. Eleven participants taking dolutegravir + lamivudine and 7 taking dolutegravir + tenofovir disoproxil fumarate/emtricitabine met confirmed virologic withdrawal criteria through week 96; none had treatment-emergent resistance mutations. Dolutegravir + lamivudine had a lower rate of drug-related adverse events than dolutegravir + tenofovir disoproxil fumarate/emtricitabine (19.6% vs 25.0%; relative risk ratio, 0.78; 95% CI: 0.64 to 0.95). Renal and bone biomarker changes favored dolutegravir + lamivudine. CONCLUSIONS: Consistent with 48-week data, dolutegravir + lamivudine demonstrated long-term, noninferior efficacy vs dolutegravir + tenofovir disoproxil fumarate/emtricitabine without increased risk of treatment-emergent resistance, supporting its use in treatment-naive HIV-1-infected individuals.

Decreased plasma phospholipid concentrations and increased acid sphingomyelinase activity are accurate biomarkers for community-acquired pneumonia.

BACKGROUND: There continues to be a great need for better biomarkers and host-directed treatment targets for community-acquired pneumonia (CAP). Alterations in phospholipid metabolism may constitute a source of small molecule biomarkers for acute infections including CAP. Evidence from animal models of pulmonary infections and sepsis suggests that inhibiting acid sphingomyelinase (which releases ceramides from sphingomyelins) may reduce end-organ damage. METHODS: We measured concentrations of 105 phospholipids, 40 acylcarnitines, and 4 ceramides, as well as acid sphingomyelinase activity, in plasma from patients with CAP (n = 29, sampled on admission and 4 subsequent time points), chronic obstructive pulmonary disease exacerbation with infection (COPD, n = 13) as a clinically important disease control, and 33 age- and sex-matched controls. RESULTS: Phospholipid concentrations were greatly decreased in CAP and normalized along clinical improvement. Greatest changes were seen in phosphatidylcholines, followed by lysophosphatidylcholines, sphingomyelins and ceramides (three of which were upregulated), and were least in acylcarnitines. Changes in COPD were less pronounced, but also differed qualitatively, e.g. by increases in selected sphingomyelins. We identified highly accurate biomarkers for CAP (AUC ≤ 0.97) and COPD (AUC ≤ 0.93) vs. Controls, and moderately accurate biomarkers for CAP vs. COPD (AUC ≤ 0.83), all of which were phospholipids. Phosphatidylcholines, lysophosphatidylcholines, and sphingomyelins were also markedly decreased in S. aureus-infected human A549 and differentiated THP1 cells. Correlations with C-reactive protein and procalcitonin were predominantly negative but only of mild-to-moderate extent, suggesting that these markers reflect more than merely inflammation. Consistent with the increased ceramide concentrations, increased acid sphingomyelinase activity accurately distinguished CAP (fold change = 2.8, AUC = 0.94) and COPD (1.75, 0.88) from Controls and normalized with clinical resolution. CONCLUSIONS: The results underscore the high potential of plasma phospholipids as biomarkers for CAP, begin to reveal differences in lipid dysregulation between CAP and infection-associated COPD exacerbation, and suggest that the decreases in plasma concentrations are at least partially determined by changes in host target cells. Furthermore, they provide validation in clinical blood samples of acid sphingomyelinase as a potential treatment target to improve clinical outcome of CAP.

Dolutegravir versus ritonavir-boosted lopinavir both with dual nucleoside reverse transcriptase inhibitor therapy in adults with HIV-1 infection in whom first-line therapy has failed (DAWNING): an open-label, non-inferiority, phase 3b trial.

BACKGROUND: Doubts exist regarding optimal second-line treatment options for HIV-1-infected patients in resource-limited settings. We assessed safety and efficacy of dolutegravir compared with ritonavir-boosted lopinavir, plus two nucleoside reverse transcriptase inhibitors (NRTIs) in adults in whom previous first-line antiretroviral therapy with a non-nucleoside reverse transcriptase inhibitor (NNRTI) plus two NRTIs has failed. METHODS: DAWNING is a phase 3b, open-label, parallel-group, non-inferiority, active-controlled trial done at 58 sites in 13 countries. Eligible adults were aged at least 18 years and, during at least 6 months of treatment with a first-line treatment containing an NNRTI and two NRTIs, had virological failure (confirmed HIV-1 RNA ≥400 copies per mL). Participants were randomly assigned by a central randomisation system to receive oral dolutegravir (50 mg once daily) or ritonavir-boosted lopinavir (800 mg lopinavir plus 200 mg ritonavir once daily or 400 mg plus 100 mg twice daily), plus two investigator-selected NRTIs (at least one fully active based on resistance testing at screening). The primary outcome was the proportion of participants achieving viral suppression (defined as plasma HIV-1 RNA <50 copies per mL) at week 48 using the snapshot algorithm and a non-inferiority margin of -12%. The primary analysis was done in an intention-to-treat-exposed (ITT-E) population of participants who received at least one dose of study medication, according to original group assignment. Safety was analysed in all participants who received at least one dose of study drug, according to which drug was received. The study was registered at ClinicalTrials.gov, number NCT02227238, and viiv-studyregister.com, number 200304. FINDINGS: Between Dec 11, 2014, and June 27, 2016, 968 adults were screened and 627 were randomly assigned to the dolutegravir group (n=312) or the ritonavir-boosted lopinavir group (n=315). Three patients in the ritonavir-boosted lopinavir group did not receive study medication and so 624 were included in the ITT-E population. At week 48, 261 (84%) of 312 participants in the dolutegravir group achieved viral suppression compared with 219 (70%) of 312 in the ritonavir-boosted lopinavir group (adjusted difference 13·8%; 95% CI 7·3-20·3). Non-inferiority was achieved on the basis of the 95% CI of the adjusted treatment difference having a lower bound greater than -12% (prespecified non-inferiority margin). Because the lower bound of the 95% CI is greater than zero (7·3%), superiority of dolutegravir was also concluded (p<0·0001). The safety profile for dolutegravir was favourable compared with that of ritonavir-boosted lopinavir. More grade 2-4 drug-related adverse events occurred with ritonavir-boosted lopinavir than dolutegravir (44 [14%] of 310 with ritonavir-boosted lopinavir vs 11 [4%] of 314 with dolutegravir), mainly driven by gastrointestinal disorders. INTERPRETATION: When administered with two NRTIs, dolutegravir was superior to ritonavir-boosted lopinavir at 48 weeks and can be considered a suitable option for second-line treatment. FUNDING: ViiV Healthcare.

Dolutegravir plus lamivudine versus dolutegravir plus tenofovir disoproxil fumarate and emtricitabine in antiretroviral-naive adults with HIV-1 infection (GEMINI-1 and GEMINI-2): week 48 results from two multicentre, double-blind, randomised, non-inferiority, phase 3 trials.

BACKGROUND: Effective two-drug regimens could decrease long-term drug exposure and toxicity with HIV-1 antiretroviral therapy (ART). We therefore aimed to evaluate the efficacy and safety of a two-drug regimen compared with a three-drug regimen for the treatment of HIV-1 infection in ART-naive adults. METHODS: We conducted two identically designed, multicentre, double-blind, randomised, non-inferiority, phase 3 trials: GEMINI-1 and GEMINI-2. Both studies were done at 192 centres in 21 countries. We included participants (≥18 years) with HIV-1 infection and a screening HIV-1 RNA of 500 000 copies per mL or less, and who were naive to ART. We randomly assigned participants (1:1) to receive a once-daily two-drug regimen of dolutegravir (50 mg) plus lamivudine (300 mg) or a once-daily three-drug regimen of dolutegravir (50 mg) plus tenofovir disoproxil fumarate (300 mg) and emtricitabine (200 mg). Both drug regimens were administered orally. We masked participants and investigators to treatment assignment: dolutegravir was administered as single-entity tablets (similar to its commercial formulation, except with a different film colour), and lamivudine tablets and tenofovir disoproxil fumarate and emtricitabine tablets were over-encapsulated to visually match each other. Primary endpoint was the proportion of participants with HIV-1 RNA of less than 50 copies per mL at week 48 in the intention-to-treat-exposed population, using the Snapshot algorithm and a non-inferiority margin of -10%. Safety analyses were done on the safety population. GEMINI-1 and GEMINI-2 are registered with ClinicalTrials.gov, numbers NCT02831673 and NCT02831764, respectively. FINDINGS: Between July 18, 2016, and March 31, 2017, 1441 participants across both studies were randomly assigned to receive either the two-drug regimen (n=719) or three-drug regimen (n=722). At week 48 in the GEMINI-1 intention-to-treat-exposed population, 320 (90%) of 356 participants receiving the two-drug regimen and 332 (93%) of 358 receiving the three-drug regimen achieved plasma HIV-1 RNA of less than 50 copies per mL (adjusted treatment difference -2·6%, 95% CI -6·7 to 1·5); in GEMINI-2, 335 (93%) of 360 in the two-drug regimen and 337 (94%) of 359 in the three-drug regimen achieved HIV-1 RNA of less than 50 copies per mL (adjusted treatment difference -0·7%, 95% CI -4·3 to 2·9), showing non-inferiority at a -10% margin in both studies (pooled analysis: 655 [91%] of 716 in the two-drug regimen vs 669 [93%] of 717 in the three-drug regimen; adjusted treatment difference -1·7%, 95% CI -4·4 to 1·1). Numerically, more drug-related adverse events occurred with the three-drug regimen than with the two-drug regimen (169 [24%] of 717 vs 126 [18%] of 716); few participants discontinued because of adverse events (16 [2%] in the three-drug regimen and 15 [2%] in the two-drug regimen). Two deaths were reported in the two-drug regimen group of GEMINI-2, but neither was considered to be related to the study medication. INTERPRETATION: The non-inferior efficacy and similar tolerability profile of dolutegravir plus lamivudine to a guideline-recommended three-drug regimen at 48 weeks in ART-naive adults supports its use as initial therapy for patients with HIV-1 infection. FUNDING: ViiV Healthcare.

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.

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.

Long-term safety study of fosamprenavir-containing regimens in HIV-1-infected patients.

BACKGROUND: Safety and efficacy of the protease inhibitor fosamprenavir (FPV) ± ritonavir (r) was evaluated in 3 pivotal 48-week phase III studies. A follow-on study provides long-term data on FPV-based regimens. METHODS: International, multicenter, uncontrolled open-label study APV30005 provided FPV as part of combination therapy to HIV-1-infected patients aged ≥13 years who had participated in previous FPV and amprenavir studies. Regimens included FPV/r 1400/200 mg once daily, FPV/r 700/100 mg twice daily, or FPV 1400 mg twice daily. Safety and efficacy were evaluated every 12 weeks, including incidence and frequency of adverse events and laboratory abnormalities, plasma HIV-1 RNA levels, CD4+ cell counts, and frequency of HIV disease progression. Because this was a nonrandomized, observational study, no significance testing was performed. RESULTS: Overall, 753 patients were enrolled. The most common reasons for premature discontinuation were lost to follow-up (88 [12%]) and insufficient viral load response (69 [9%]). The majority of patients had ≯192 weeks exposure to FPV, with 53 patients exposed for more than 8 years. Drug-related grade 2-4 adverse events were reported for 250 patients (33%), with the majority reported in the first 48 weeks of the study. Most commonly reported grade 3/4 laboratory parameters were increased lipase, triglycerides, and elevated liver enzymes. The observed proportions of patients with plasma HIV-1 RNA levels <50 copies/mL remained ≯70% from week 48 onwards. CONCLUSIONS: Extended treatment of up to 8 years with FPV-containing regimens revealed no new safety concerns and was associated with sustained antiviral responses.

A survey of antibiotic resistance in Streptococcus pneumoniae and Haemophilus influenzae in Turkey, 2004 2005.

OBJECTIVES: To determine the prevalence of antimicrobial resistance among Streptococcus pneumoniae and Haemophilus influenzae isolated in Turkey as part of Survey Of Antibiotic Resistance, a surveillance programme in the Africa and Middle East region examining the antimicrobial susceptibility of key bacterial pathogens involved in community-acquired respiratory tract infections (CARTIs). METHODS: Susceptibility was evaluated against a range of antimicrobial agents using disc diffusion and Etest methods. RESULTS: Six centres in five cities collected 301 S. pneumoniae and 379 H. influenzae isolates between October 2004 and November 2005. Among S. pneumoniae, the prevalence of isolates with intermediate susceptibility (MICs 0.12-1 mg/L) and resistance to penicillin (MICs >or=2 mg/L) was 24.6% and 7.6%, respectively; there was a wide variation between cities (2.4% to 36.9% intermediate and 0% to 23.8% resistant phenotypes). Macrolide-azalide resistance rates exceeded those of penicillin resistance in all cities. Overall, 5.0% of isolates were co-resistant to penicillin and erythromycin and 10.0% were multidrug-resistant (joint resistance to erythromycin, co-trimoxazole and tetracycline). Agents tested to which over 90% of countrywide S. pneumoniae isolates remained susceptible were amoxicillin/clavulanate (98.7%), chloramphenicol (94.7%) and cefprozil (90.6%). Overall, the percentage of H. influenzae isolates producing beta-lactamase was 5.5%, differing widely across the country with the highest prevalence of beta-lactamase production detected in Trabzon (14.0%) and no beta-lactamase-positive isolates found in Izmir. H. influenzae had the highest per cent susceptibility to amoxicillin/clavulanate (99.5%) and ofloxacin (99.2%) while >20% were resistant to co-trimoxazole. CONCLUSIONS: Prevalence of penicillin and macrolide-azalide resistance among S. pneumoniae appears to be on the increase in Turkey while overall beta-lactamase production in H. influenzae remains relatively low. To adequately monitor the spread of drug-resistant phenotypes among these two important CARTI pathogens, ongoing collection of resistance surveillance data is required-where possible locally as resistance patterns can vary substantially between cities and institutions.

Novel inhibitors of bacterial cytokinesis identified by a cell-based antibiotic screening assay.

The continuous emergence of antibiotic resistance demands that novel classes of antibiotics continue to be developed. The division machinery of bacteria is an attractive target because it comprises seven or more essential proteins that are conserved almost throughout the bacteria but are absent from humans. We describe the development of a cell-based assay for inhibitors of cell division and its use to isolate a new inhibitor of FtsZ protein, a key player in the division machinery. Biochemical, cytological, and genetic data are presented that demonstrate that FtsZ is the specific target for the compound. We also describe the effects of more potent analogues of the original hit compound that act on important pathogens, again at the level of cell division. The assay and the compounds have the potential to provide novel antibiotics with no pool of pre-existing resistance. They have provided new insight into cytokinesis in bacteria and offer important reagents for further studies of the cell division machinery.

Characterization of the parB-like yyaA gene of Bacillus subtilis.

We have characterized the yyaA gene of Bacillus subtilis, located near the origin of chromosome replication (oriC). Its protein product is similar to the Spo0J protein, which belongs to the ParB family of chromosome- and plasmid-partitioning proteins. Insertional inactivation of the yyaA gene had no apparent effect on chromosome organization and partitioning during vegetative growth or sporulation. Subcellular localization of YyaA by immunofluorescence microscopy indicated that it colocalizes with the nucleoid, and gel retardation studies confirmed that YyaA binds relatively nonspecifically to DNA. Overexpression of yyaA caused a sporulation defect characterized by the formation of multiple septa within the cell. This phenotype indicates that YyaA may have a regulatory role at the onset of sporulation.