Bonaventura Clotet

Once-daily dolutegravir versus darunavir plus ritonavir in antiretroviral-naive adults with HIV-1 infection (FLAMINGO): 48 week results from the randomised open-label phase 3b study

BACKGROUNDnDolutegravir has been shown to be non-inferior to an integrase inhibitor and superior to a non-nucleoside reverse transcriptase inhibitor (NNRTI). In FLAMINGO, we compared dolutegravir with darunavir plus ritonavir in individuals naive for antiretroviral therapy.nnnMETHODSnIn this multicentre, open-label, phase 3b, non-inferiority study, HIV-1-infected antiretroviral therapy-naive adults with HIV-1 RNA concentration of 1000 copies per mL or more and no resistance at screening were randomly assigned (1:1) to receive either dolutegravir 50 mg once daily or darunavir 800 mg plus ritonavir 100 mg once daily, with investigator-selected tenofovir-emtricitabine or abacavir-lamivudine. Randomisation was stratified by screening HIV-1 RNA (≤100,000 or >100,000 copies per mL) and nucleoside reverse transcriptase inhibitor (NRTI) selection. The primary endpoint was the proportion of patients with HIV-1 RNA concentration lower than 50 copies per mL (Food and Drug Administration [FDA] snapshot algorithm) at week 48 with a 12% non-inferiority margin. This trial is registered with ClinicalTrials.gov, NCT01449929.nnnFINDINGSnRecruitment began on Oct 31, 2011, and was completed on May 24, 2012, in 64 research centres in nine countries worldwide. Of 595 patients screened, 484 patients were included in the analysis (242 in each group). At week 48, 217 (90%) patients receiving dolutegravir and 200 (83%) patients receiving darunavir plus ritonavir had HIV-1 RNA of less than 50 copies per mL (adjusted difference 7·1%, 95% CI 0·9-13·2), non-inferiority and on pre-specified secondary analysis dolutegravir was superior (p=0·025). Confirmed virological failure occurred in two (<1%) patients in each group; we recorded no treatment-emergent resistance in either group. Discontinuation due to adverse events or stopping criteria was less frequent for dolutegravir (four [2%] patients) than for darunavir plus ritonavir (ten [4%] patients) and contributed to the difference in response rates. The most commonly reported (≥10%) adverse events were diarrhoea (dolutegravir 41 [17%] patients vs darunavir plus ritonavir 70 [29%] patients), nausea (39 [16%] vs 43 [18%]), and headache (37 [15%] vs 24 [10%]). Patients receiving dolutegravir had significantly fewer low-density lipoprotein values of grade 2 or higher (11 [2%] vs 36 [7%]; p=0·0001).nnnINTERPRETATIONnOnce-daily dolutegravir was superior to once-daily darunavir plus ritonavir. Once-daily dolutegravir in combination with fixed-dose NRTIs represents an effective new treatment option for HIV-1-infected, treatment-naive patients.nnnFUNDINGnViiV Healthcare and Shionogi & Co.

Safety and immunogenicity of a modified vaccinia Ankara-based HIV-1 vaccine (MVA-B) in HIV-1-infected patients alone or in combination with a drug to reactivate latent HIV-1

OBJECTIVESnThe safety, immunogenicity, impact on the latent reservoir and rebound of viral load after therapeutic HIV-1 vaccination with recombinant modified vaccinia Ankara-based (MVA-B) HIV-1 vaccine expressing monomeric gp120 and the fused Gag-Pol-Nef polyprotein of clade B with or without a drug to reactivate latent HIV-1 (disulfiram) were assessed.nnnMETHODSnHIV-1-infected patients were randomized to receive three injections of MVA-B (nu200a=u200a20) or placebo (nu200a=u200a10). Twelve patients (eight who received vaccine and four who were given placebo) received a fourth dose of MVA-B followed by 3 months of disulfiram. Combined ART (cART) was discontinued 8 weeks after the last dose of MVA-B. Clinical Trials.gov identifier: NCT01571466.nnnRESULTSnMVA-B was safe and well tolerated. A minor, but significant, increase in the T cell responses targeting vaccine inserts of Gag was observed [a median of 290, 403 and 435 spot-forming-cells/10(6) PBMCs at baseline, after two vaccinations and after three vaccinations, respectively; Pu200a=u200a0.02 and Pu200a=u200a0.04]. After interruption of cART, a modest delay in the rebound of the plasma viral load in participants receiving vaccinexa0but not disulfiram was observed compared with placebo recipients (Pu200a=u200a0.01). The dynamics of the viral load rebound did not change in patients receiving MVA-B/disulfiram. No changes in the proviral reservoir were observed after disulfiram treatment.nnnCONCLUSIONSnMVA-B vaccination was a safe strategy to increase Gag-specific T cell responses in chronically HIV-1-infected individuals, but it did not have a major impact on the latent reservoir or the rebound of plasma viral load after interruption of cART when given alone or in combination with disulfiram.

Determinants of virological failure and antiretroviral drug resistance in Mozambique

OBJECTIVESnThe objective of this study was to inform public health actions to limit first-line ART failure and HIV drug resistance in Mozambique.nnnMETHODSnThis was a cross-sectional study. HIV-1-infected adults on first-line ART for at least 1 year attending routine visits in the Manhiça District Hospital, in a semi-rural area in southern Mozambique with no HIV-1 RNA monitoring available, were evaluated for clinical, socio-demographic, therapeutic, immunological and virological characteristics. Factors associated with HIV-1 RNA ≥1000 copies/mL and HIV drug resistance were determined using multivariate logistic regression.nnnRESULTSnThe study included 334 adults on first-line ART for a median of 3 years, of which 65% (214/332) had suppressed viraemia, 11% (37/332) had low-level viraemia (HIV-1 RNA 150-999 copies/mL) and 24% (81/332) had overt virological failure (HIV-1 RNA ≥1000 copies/mL). HIV drug resistance was detected in 89% of subjects with virological failure, but in none with low-level viraemia. Younger age [ORu200a=u200a0.97 per additional year (95% CIu200a=u200a0.94-1.00), Pu200a=u200a0.039], ART initiation at WHO stage III/IV [ORu200a=u200a2.10 (95% CIu200a=u200a1.23-3.57), Pu200a=u200a0.003] and low ART adherence [ORu200a=u200a2.69 (95% CIu200a=u200a1.39-5.19), Pu200a=u200a0.003] were associated with virological failure. Longer time on ART [ORu200a=u200a1.55 per additional year (95% CIu200a=u200a1.00-2.43), Pu200a=u200a0.052] and illiteracy [ORu200a=u200a0.24 (95% CIu200a=u200a0.07-0.89), Pu200a=u200a0.033] were associated with HIV drug resistance. Compared with HIV-1 RNA, clinicians judgement of ART failure, based on clinical and immunological outcomes, only achieved 29% sensitivity and misdiagnosed 1 out of every 4.5 subjects.nnnCONCLUSIONSnPublic health programmes in Mozambique should focus on early HIV diagnosis, early ART initiation and adherence support. Virological monitoring drastically improves the diagnosis of ART failure, enabling a better use of resources.

Immunologic Insights on the Membrane Proximal External Region: A Major Human Immunodeficiency Virus Type-1 Vaccine Target

Broadly neutralizing antibodies (bNAbs) targeting conserved regions within the human immunodeficiency virus type-1 (HIV-1) envelope glycoprotein (Env) can be generated by the human immune system and their elicitation by vaccination will be a key point to protect against the wide range of viral diversity. The membrane proximal external region (MPER) is a highly conserved region within the Env gp41 subunit, plays a major role in membrane fusion and is targeted by naturally induced bNAbs. Therefore, the MPER is considered as an attractive vaccine target. However, despite many attempts to design MPER-based immunogens, further study is still needed to understand its structural complexity, its amphiphilic feature, and its limited accessibility by steric hindrance. These particular features compromise the development of MPER-specific neutralizing responses during natural infection and limit the number of bNAbs isolated against this region, as compared with other HIV-1 vulnerability sites, and represent additional hurdles for immunogen development. Nevertheless, the analysis of MPER humoral responses elicited during natural infection as well as the MPER bNAbs isolated to date highlight that the human immune system is capable of generating MPER protective antibodies. Here, we discuss the recent advances describing the immunologic and biochemical features that make the MPER a unique HIV-1 vulnerability site, the different strategies to generate MPER-neutralizing antibodies in immunization protocols and point the importance of extending our knowledge toward new MPER epitopes by the isolation of novel monoclonal antibodies. This will be crucial for the redesign of immunogens able to skip non-neutralizing MPER determinants.

Perfil de resistencias y barrera genética de dolutegravir

The resistance profile of dolutegravir differs significantly from those of earlier integrase inhibitors (INI). Dolutegravir displays in vitro activity against mutant HIV-1 harboring any isolated resistance mutations selected during failures to raltegravir or elvitegravir (Y143C/H/, N155H, Q148H/K/R, E92G/Q, T66A/I/K, T97A, E138A/K, G140A/S). Its activity is only compromised by Q148X mutations combined with other mutations, particularly > 1 mutation. The drug has pharmacokinetic/pharmacodynamic properties (plasmatic t1/2 15.3 h, inhibitory quotient 19, dissociative t1/2 from the IN-DNA complex 71 h) that favor a high genetic barrier to resistance. In vitro the selection of HIV-1 resistance to dolutegravir is extremely difficult to achieve. The mutations eventually selected (R263K, H51Y and E138K) do not confer significant resistance, and induce a fitness cost that prevents HIV-1 from evading drug pressure. Suprisingly, HIV-1 is not able to compensate, leading the virus to a previously unnoticed evolutionary pathway with very low chances of developing resistance to INI or the backbone. No treatment-naïve patients starting dolutegravir therapy (+TDF/FTC o ABC/3TC) have selected resistance in IN or against the backbone. No INI- naïve patients with prior virologic failure selected phenotypic dolutegravir resistance. Only 4 out of 354 patients selected resistance mutations in IN, and rates of selection of mutations in IN or against the backbone were significantly lower than with raltegravir. In multitreated patients with widespread resistance including IN resistance, the high efficacy of dolutegravir was confirmed, irrespective of the previous pattern of IN mutations, provided that Q148X associated with other mutations was absent.The resistance profile of dolutegravir differs significantly from those of earlier integrase inhibitors (INI). Dolutegravir displays in vitro activity against mutant HIV-1 harboring any isolated resistance mutations selected during failures to raltegravir or elvitegravir (Y143C/H/, N155H, Q148H/K/R, E92G/Q, T66A/I/K, T97A, E138A/K, G140A/S). Its activity is only compromised by Q148X mutations combined with other mutations, particularly > 1 mutation. The drug has pharmacokinetic/pharmacodynamic properties (plasmatic t1/2 15.3 h, inhibitory quotient 19, dissociative t1/2 from the IN-DNA complex 71 h) that favor a high genetic barrier to resistance. In vitro the selection of HIV-1 resistance to dolutegravir is extremely difficult to achieve. The mutations eventually selected (R263K, H51Y and E138K) do not confer significant resistance, and induce a fitness cost that prevents HIV-1 from evading drug pressure. Suprisingly, HIV-1 is not able to compensate, leading the virus to a previously unnoticed evolutionary pathway with very low chances of developing resistance to INI or the backbone. No treatment-naive patients starting dolutegravir therapy (+TDF/FTC o ABC/3TC) have selected resistance in IN or against the backbone. No INI- naive patients with prior virologic failure selected phenotypic dolutegravir resistance. Only 4 out of 354 patients selected resistance mutations in IN, and rates of selection of mutations in IN or against the backbone were significantly lower than with raltegravir. In multitreated patients with widespread resistance including IN resistance, the high efficacy of dolutegravir was confirmed, irrespective of the previous pattern of IN mutations, provided that Q148X associated with other mutations was absent.

Comparison of the efficacy of HAART: single, dual or triple-class antiretroviral therapy

Current antiretroviral therapy guidelines [1] recommend the combination of at least two nucleoside retrotranscriptase inhibitors (NRTI) plus at least one protease inhibitor (PI) and/or at least one nonnucleoside retrotranscriptase inhibitor (NNRTI) for the treatment of HIV infection. Different specific drugs are chosen to comply with this general scheme considering the stage of the disease, the occurrence of AIDS-defining events, plasma viral load and patient’s immune status, prior pharmacologic history, likeliness to adhere to treatment, as well as drug interactions, adverse events and comorbidity.

Impact of intensification with raltegravir on HIV-1-infected individuals receiving monotherapy with boosted PIs

Abstract Background Monotherapy with ritonavir-boosted PIs (PI/r) has been used to simplify treatment of HIV-1-infected patients. In previous studies raltegravir intensification evidenced ongoing viral replication and reduced T cell activation, preferentially in subjects receiving PI-based triple ART. However, data about low-level viral replication and its consequences in patients receiving PI/r monotherapy are scarce. Methods We evaluated the impact of 24u2009weeks of intensification with raltegravir on markers of viral persistence, cellular immune activation and inflammation biomarkers in 33 patients receiving maintenance PI/r monotherapy with darunavir or lopinavir boosted with ritonavir. ClinicalTrials.gov identifier: NCT01480713. Results The addition of raltegravir to PI/r monotherapy resulted in a transient increase in 2-LTR (long-terminal repeat) circles in a significant proportion of participants, along with decreases in CD8+ T cell activation levels and a temporary increase in the expression of the exhaustion marker CTLA-4 in peripheral T lymphocytes. Intensification with raltegravir also reduced the number of samples with intermediate levels of residual viraemia (10–60 HIV-1 RNA copies/mL) compared with samples taken during PI/r monotherapy. However, there were no changes in cell-associated HIV-1 DNA in peripheral CD4+ T cells or soluble inflammatory biomarkers (CD14, IP-10, IL-6, C-reactive protein and D-dimer). Conclusions Intensification of PI/r monotherapy with raltegravir revealed persistent low-level viral replication and reduced residual viraemia in some patients during long-term PI/r monotherapy. The concomitant change in T cell phenotype suggests an association between active viral production and T cell activation. These results contribute to understanding the lower efficacy rates of PI/r monotherapies compared with triple therapies in clinical trials.

Variable endothelial cell function restoration after initiation of two antiretroviral regimens in HIV-infected individuals

BackgroundnThe effect of ART on endothelial cell function is incompletely characterized.nnnMethodsnWe performed a 24 week prospective, case-control and comparative pilot study of ART-naive HIV-infected patients who started a darunavir- or rilpivirine-based regimen, matched with non-HIV-infected volunteers, to compare changes at week 24 from baseline in levels of circulating endothelial cells (CECs), endothelial progenitor cells (EPCs) and circulating angiogenic cells, as well as changes in immune-activation markers.nnnResultsnThe study population comprised 24 HIV-infected patients and 24 non-infected volunteers. Both HIV groups completely suppressed viraemia. HIV-infected patients had higher levels of activation markers than the control group in CD8 T cells at baseline; these decreased after 24 weeks of treatment, but without reaching the levels of the control group. No statistical differences in immune activation were seen between the darunavir and rilpivirine groups. Levels of CECs were higher and levels of EPCs and circulating angiogenic cells were lower in HIV-infected patients than in the control group, although these parameters were similar between the darunavir group and the control group, but not the rilpivirine group, at week 24. An unfavourable association was observed between rilpivirine, age and increased number of CECs.nnnConclusionsnRestoration of circulating levels of EPCs and CECs in darunavir-treated patients was greater than in those treated with rilpivirine, suggesting ongoing endothelial repair mechanisms.

Withdrawing inactive NRTIs in HIV-1 subjects with suppressed viraemia: a randomized trial

BACKGROUNDnExtensively pretreated subjects with virological failure (VF) may receive salvage regimens containing NRTIs with only residual or no activity. Once virological suppression is achieved, their contribution remains elusive.nnnMETHODSnThis was a multicentre, randomized, prospective study. Subjects with at least one prior VF, HIV-1 RNA <50 copies/mL for ≥6 months and receiving a regimen with at least two active drugs (one of them a boosted PI) were randomized 1:1 to stop (experimental arm) or maintain (control arm) NRTIs. EudraCT: 2012-000198-21.nnnRESULTSnNinety subjects were randomized (experimental, nu200a=u200a45; and control, nu200a=u200a45). The mean age was 50 years, 80% were male, the mean CD4+ cell count was 542 cells/mm(3) and the median number of prior VFs was 3. Seventy-four subjects (82%) harboured the mutation M184V/I and the median number of thymidine-associated mutations was 3 (IQR: 0-4). In the experimental arm, thirty-two (71%) subjects removed one NRTI and 13 (29%) subjects removed two. Twenty-two of 45 (49%) discontinued tenofovir disoproxil fumarate. Forty-one of 45 (91.1%, experimental arm) and 44 of 45 (97.8%, control arm) had HIV-1 RNA <50 copies/mL at 48 weeks (difference: -6.7%; 95% CI: -17.4, 4.1). In a post-hoc analysis allowing NRTI reintroduction, efficacy rates were 95.6% and 97.8%, respectively (difference: -2.2%; 95% CI: -7.2, 2.7). Rates of discontinuation at 48 weeks were 2% in both arms. One subject developed a late VF with resistance selection.nnnCONCLUSIONSnIn patients receiving a successful multidrug salvage regimen with at least two active drugs (one a boosted PI), the withdrawal of inactive NRTIs was safe, rates of VF were low and drug resistance was uncommon at 48 weeks in this small study. This strategy could potentially prevent long-term toxicities, reduce the number of drugs and reduce costs if non-inferiority was met in a fully powered trial.

Unexpected synergistic HIV neutralization by a triple microbicide produced in rice endosperm

Significance Our paper provides an approach for the durable deployment of anti-HIV agents in the developing world. We developed a transgenic rice line expressing three microbicidal proteins (the HIV-neutralizing antibody 2G12 and the lectins griffithsin and cyanovirin-N). Simultaneous expression in the same plant allows the crude seed extract to be used directly as a topical microbicide cocktail, avoiding the costs of multiple downstream processes. This groundbreaking strategy is realistically the only way that microbicidal cocktails can be manufactured at a cost low enough for the developing world, where HIV prophylaxis is most in demand. The transmission of HIV can be prevented by the application of neutralizing monoclonal antibodies and lectins. Traditional recombinant protein manufacturing platforms lack sufficient capacity and are too expensive for developing countries, which suffer the greatest disease burden. Plants offer an inexpensive and scalable alternative manufacturing platform that can produce multiple components in a single plant, which is important because multiple components are required to avoid the rapid emergence of HIV-1 strains resistant to single microbicides. Furthermore, crude extracts can be used directly for prophylaxis to avoid the massive costs of downstream processing and purification. We investigated whether rice could simultaneously produce three functional HIV-neutralizing proteins (the monoclonal antibody 2G12, and the lectins griffithsin and cyanovirin-N). Preliminary in vitro tests showed that the cocktail of three proteins bound to gp120 and achieved HIV-1 neutralization. Remarkably, when we mixed the components with crude extracts of wild-type rice endosperm, we observed enhanced binding to gp120 in vitro and synergistic neutralization when all three components were present. Extracts of transgenic plants expressing all three proteins also showed enhanced in vitro binding to gp120 and synergistic HIV-1 neutralization. Fractionation of the rice extracts suggested that the enhanced gp120 binding was dependent on rice proteins, primarily the globulin fraction. Therefore, the production of HIV-1 microbicides in rice may not only reduce costs compared to traditional platforms but may also provide functional benefits in terms of microbicidal potency.