Sophie Matheron

Dolutegravir in HIV-2–Infected Patients With Resistant Virus to First-line Integrase Inhibitors From the French Named Patient Program

BACKGROUNDnDolutegravir has shown in vitro activity against human immunodeficiency virus type 2 (HIV-2). We report safety and efficacy data of regimens containing dolutegravir (50 mg twice daily) in antiretroviral-experienced, HIV-2-infected patients.nnnMETHODSnHIV-2-infected patients experiencing virological failure to raltegravir received dolutegravir with optimized background antiretroviral combinations within the French Named Patient Program (NPP). Plasma HIV-2 RNA (pVL) was assessed at time of dolutegravir initiation (baseline), month 3, and month 6. Antiretroviral trough plasma concentrations (C12h) were determined using liquid chromatography coupled with tandem mass spectrometry.nnnRESULTSnThirteen HIV-2-infected-patients, with a median duration of 15 years infection and given 16 previous antiretroviral regimens, were included in NPP. Median follow-up was 9 months (min-max, 3-15 months). Median baseline pVL and CD4 cell count were 9544 copies/mL (inter quartile range [IQR], 3096-23 120 copies/mL) and 100 cells/µL (IQR, 77-171 cells/µL), respectively. Available integrase genotypic resistance patterns were Y143C/G/H/R (n = 5), Q148R/K (n = 2), and N155H (n = 4). Optimized background antiretroviral regimens conferring a genotypic sensitivity score ≤2 in 10 patients included nucleoside reverse transcriptase inhibitors associated with darunavir/ritonavir (n = 12), saquinavir/ritonavir (n = 2), and maraviroc (n = 3). At months 3 and 6, pVL was undetectable in 6 of 13 and 4 of 12 patients, respectively, and median CD4 count was 161 (101-188) cells/µL and 167 (135-1353) cells/µL, respectively. Median dolutegravir C12h was 4086 (1756-5717 ng/mL) ng/mL in 9 patients. No serious events were notified except 1 death from progressive multifocal leukoencephalopathy at month 4.nnnCONCLUSIONSnOptimized dolutegravir-containing antiretroviral regimens supported by good plasma exposure provide a substantial initial efficacy rate for salvage therapy in heavily antiretroviral-experienced HIV-2-infected patients with virus harboring resistance to first-generation integrase inhibitors. Larger numbers of patients and longer follow-up are needed to confirm these findings.

New Sensitive One-Step Real-Time Duplex PCR Method for Group A and B HIV-2 RNA Load

ABSTRACT The Agence Nationale de Recherche sur le Sida et les hépatites virales (ANRS) previously developed a widely used method for HIV-1 RNA quantification (Biocentric). Here, we report the development of a new specific and sensitive method for HIV-2 RNA quantification, based on an adaptation of the existing HIV-1 protocol. The new test is based on TaqMan one-step reverse transcription-quantitative PCR (qRT-PCR) targeting two conserved consensus regions of HIV-2 (long terminal repeat [LTR] and gag). Analytic performances were determined in three laboratories. Clinical performances were evaluated on 100 plasma samples from HIV-2-infected patients (groups A, B, and H) by comparison with the assay currently used for the ANRS HIV-2 cohort. The specificity was 100%. Sensitivity was 50 copies/ml (cp/ml) and was optimized to 10 cp/ml. The within-run coefficients of variation in the three laboratories varied from 0.54% to 1.61% at 4 log10 copies/ml and from 7.24% to 14.32% at 2 log10 cp/ml. The between-run coefficients of variation varied from 2.28% to 6.43%. Of the 39 clinical samples below 2 log10 in the current assay, the new test improved the detection or quantification of 17 samples, including eight group B samples. For quantifiable samples, similar loads were obtained with the two assays for group A samples. The median difference between the two assays for group B samples was +0.18 but with greater heterogeneity than for group A. The HIV-2 group H sample had similar results with the two assays. This new assay is highly sensitive and accurately quantifies the most prevalent HIV-2 groups. This test will be useful for monitoring low viral loads in HIV-2-infected patients.

Mutation V111I in HIV-2 reverse transcriptase increases the fitness of the nucleoside analogue resistant K65R and Q151M viruses

ABSTRACT Infection with HIV-2 can ultimately lead to AIDS, although disease progression is much slower than with HIV-1. HIV-2 patients are mostly treated with a combination of nucleoside reverse transcriptase (RT) inhibitors (NRTIs) and protease inhibitors designed for HIV-1. Many studies have described the development of HIV-1 resistance to NRTIs and identified mutations in the polymerase domain of RT. Recent studies have shown that mutations in the connection and RNase H domains of HIV-1 RT may also contribute to resistance. However, only limited information exists regarding the resistance of HIV-2 to NRTIs. In this study, therefore, we analyzed the polymerase, connection, and RNase H domains of RT in HIV-2 patients failing NRTI-containing therapies. Besides the key resistance mutations K65R, Q151M, and M184V, we identified a novel mutation, V111I, in the polymerase domain. This mutation was significantly associated with mutations K65R and Q151M. Sequencing of the connection and RNase H domains of the HIV-2 patients did not reveal any of the mutations that were reported to contribute to NRTI resistance in HIV-1. We show that V111I does not strongly affect drug susceptibility but increases the replication capacity of the K65R and Q151M viruses. Biochemical assays demonstrate that V111I restores the polymerization defects of the K65R and Q151M viruses but negatively affects the fidelity of the HIV-2 RT enzyme. Molecular dynamics simulations were performed to analyze the structural changes mediated by V111I. This showed that V111I changed the flexibility of the 110-to-115 loop region, which may affect deoxynucleoside triphosphate (dNTP) binding and polymerase activity. IMPORTANCE Mutation V111I in the HIV-2 reverse transcriptase enzyme was identified in patients failing therapies containing nucleoside analogues. We show that the V111I change does not strongly affect the sensitivity of HIV-2 to nucleoside analogues but increases the fitness of viruses with drug resistance mutations K65R and Q151M.

Transmitted drug resistance in French HIV-2-infected patients.

We report the first transmitted drug resistance survey study in HIV-2-infected patients living in France. The prevalence of transmitted drug resistance was 5.0% (95% confidence interval, 0.1–9.9) with mutations detected only in protease, not in reverse transcriptase. In this series, 10% of patients displayed X4/dual-mixed viruses. These findings classified the rate of transmitted drug resistance in the HIV-2 French Cohort as low prevalence.

Cenicriviroc, a Novel CCR5 (R5) and CCR2 Antagonist, Shows In Vitro Activity against R5 Tropic HIV-2 Clinical Isolates.

Background Maraviroc activity against HIV-2, a virus naturally resistant to different HIV-1 antiretroviral drugs, has been recently demonstrated. The aim of this study was to assess HIV-2 susceptibility to cenicriviroc, a novel, once-daily, dual CCR5 and CCR2 antagonist that has completed Phase 2b development in HIV-1 infection. Methods Cenicriviroc phenotypic activity has been tested using a PBMC phenotypic susceptibility assay against four R5-, one X4- and one dual-tropic HIV-2 clinical primary isolates. All isolates were obtained by co-cultivation of PHA-activated PBMC from distinct HIV-2-infected CCR5-antagonist-naïve patients included in the French HIV-2 cohort and were previously tested for maraviroc susceptibility using the same protocol. HIV-2 tropism was determined by phenotypic assay using Ghost(3) cell lines. Results Regarding the 4 R5 HIV-2 clinical isolates tested, effective concentration 50% EC50 for cenicriviroc were 0.03, 0.33, 0.45 and 0.98 nM, similar to those observed with maraviroc: 1.13, 0.58, 0.48 and 0.68 nM, respectively. Maximum percentages of inhibition (MPI) of cenicriviroc were 94, 94, 93 and 98%, similar to those observed with maraviroc (93, 90, 82, 100%, respectively). The dual- and X4-tropic HIV-2 strains were resistant to cenicriviroc with EC50 >1000 nM and MPI at 33% and 4%, respectively. Conclusions In this first study assessing HIV-2 susceptibility to cenicriviroc, we observed an in vitro activity against HIV-2 R5-tropic strains similar to that observed with maraviroc. Thus, cenicriviroc may offer a once-daily treatment opportunity in the limited therapeutic arsenal for HIV-2. Clinical studies are warranted.

Impact of gag genetic determinants on virological outcome to boosted lopinavir-containing regimen in HIV-2-infected patients.

Objective:This study investigated the impact on virological outcome of the gag cleavage sites and the protease-coding region mutations in protease inhibitor-naive and protease inhibitor-experienced patients infected with HIV-2 receiving lopinavir (LPV) containing regimen. Methods:Baseline gag and protease-coding region were sequenced in 46 HIV-2 group A-infected patients receiving lopinavir. Virological response was defined as plasma viral load less than 100 copies/ml at month 3. Associations between virological response and frequencies of mutations in gag [matrix/capsid (CA), CA/p2, p2/nucleocapsid (NC), NC/p1, p1/p6gag] and gag–pol (NC/p6pol) cleavage site and protease-coding region, with respect to the HIV-2ROD strain, were tested using Fishers exact test. Results:Virological response occurred in 14 of 17 (82%) protease inhibitor-naive and 17 of 29 (59%) protease inhibitor-experienced patients. Virological failure was associated with higher baseline viral load (median: 6765 versus 1098 copies/ml, Pu200a=u200a0.02). More protease-coding region mutations were observed in protease inhibitor-experienced compared with protease inhibitor-naive patients (median: 8 versus 5, Pu200a=u200a0.003). In protease inhibitor-naive patients, T435A (NC/p6pol), V447M (p1/p6gag), and Y14H (protease-coding region) were associated with virological failure (Pu200a=u200a0.011, Pu200a=u200a0.033, Pu200a=u200a0.022, respectively). T435A and V447M were associated with Y14H (Pu200a=u200a0.018, Pu200a=u200a0.039, respectively). In protease inhibitor-experienced patients, D427E (NC/p1) was associated with virological response (Pu200a=u200a0.014). A430V (NC/p1) and I82F (protease-coding region) were associated with virological failure (Pu200a=u200a0.046, Pu200a=u200a0.050, respectively). Mutations at position 430 were associated with a higher number of mutations in protease-coding region (median: 10 versus 7, Pu200a=u200a0.008). Conclusion:We have demonstrated, for the first time, an association between gag, gag–pol cleavage site and protease-coding region mutations, with distinct profiles between protease inhibitor-naive and protease inhibitor-experienced patients. These mutations might impact the virological outcome of HIV-2-infected patients receiving LPV-containing regimen.

Switch as maintenance to elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate: week 48 results in a clinical cohort

ObjectivesnTo assess, in a clinical cohort, the efficacy of switching current ART in virologically suppressed patients to elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate as a single-tablet regimen (STR) using the PCR signal of the plasma viral load (pVL) assay and determination of plasma drug concentration ( C 24 ).nnnPatients and methodsnThis was an observational single-centre study enrolling antiretroviral-treated patients with pVL <50u2005copies/mL initiating elvitegravir-based STR. PCRneg was defined as an undetected PCR signal.nnnResultsnOne hundred and fifty-one patients were enrolled. At STR baseline, the median time since first ART and time of virological suppression were 5u2005years (IQR 3-9) and 24u2005months (IQR 9-44), respectively. By week (W) 48, 26 (17%) of the patients had discontinued STR due to adverse events. The proportion of patients maintaining pVL <50u2005copies/mL on treatment was 98%, 96%, 93% and 97% at W12, W24, W36 and W48, respectively. Five patients (3.3%) experienced a virological failure and emergence of resistance was observed in two of them with the selection of M184V and N155H mutations. At baseline, W12, W24, W36 and W48, 70%, 57%, 72%, 61% and 74% of the patients with pVL <20u2005copies/mL had a PCRneg, respectively. The median elvitegravir plasma C 24 value was 648u2005ng/mL (IQR 348-989; nu2009 = u2009 237), with 84% of elvitegravir C 24 values >45u2005ng/mL, the protein-adjusted IC 95 .nnnConclusionsnIn this clinical cohort of virologically suppressed patients switching to STR, most subjects had adequate elvitegravir C 24 values with a high proportion maintaining virological suppression with no residual viraemia until W48.

A28 Phylogeographic analysis of HIV-2 ANRS CO5 cohort reveals new trends in HIV-2 epidemic patterns in West Africa

sion alters the mutational profile (frequency and spectra) of integrated proviruses. We will explore how mutation rates of HIV2 can be manipulated through the use of nucleoside analogs and RNRI drugs to explore what effects these compounds have on the HIV-2 mutation profile. Using single-cycle infectivity assays as well as long-term spreading experiments, we will be able to correlate mutagenesis with viral evolution and infectivity data to explore how sensitive these two viruses are to changes in viral mutation. This work will serve to understand how HIV-2 operates at a lower mutation frequency than HIV-1, elucidate the relationship between mutagenesis and infectivity for the two viruses, and provide insights into the contrasting phenotypes observed between the viruses.

HIV-2 Vif Diversity Among Defective and Nondefective Sequences.

To the Editors: In HIV-1, hypermutation introduced by cellular APOBEC3F/3G cytidine deaminase activity generating guanosine to adenosine substitutions might produce stop codons leading to defective viruses. The viral regulation protein “virion infectivity factor” (Vif) is able to counteract APOBEC3F/3G antiretroviral activity, by binding them specifically and directing them for proteasomal degradation. Highly conserved motifs, essential in vitro for viral replication and binding of Vif to APOBEC3F/3G proteins, have been described in lentivirus Vif proteins. In vitro data showed that the APOBEC3F/3G proteins also act as retroviral restriction factor in HIV2. Our group recently described a high level of APOBEC3F/3G editing in HIV-2 with 24% of antiretroviralnaive patients displaying vif proviral hypermutated or truncated sequences. We hypothesized that this high proportion of defective sequences could result from Vif polymorphisms that would be less able to counteract APOBEC3F/3G activity. In HIV-1, it has been described that some Vif allelic variants displayed a decreased anti-APOBEC3F/3G activity. Recently, and for the first time, an in vitro study was performed specifically on HIV-2 Vif protein. This mutational analysis, based on the first 62 amino acids of HIV-2 Vif, identified 13 major determinants of the interaction between Vif and APOBEC3F/3G proteins that are critical for their degradation and distinct from those identified for HIV-1. Analysis of these latter positions in a data set containing both defective and nondefective sequences issued from HIV-2–infected patients would be of interest to support their role in vivo. The aim of this study was to compare HIV-2 Vif genetic diversity among defective and nondefective viruses.