Els inhibidors de la transcriptassa inversa no anàlegs de nucleòsids (ITINAN) s’utilitzen sovint en el tractament antiretroviral (TAR) per la seva eficàcia i simplicitat. La resistència està causada ...per mutacions específiques a posicions de resistència. L’ús clínic dels ITINAN de primera generació (nevirapina i efavirenz) s’ha vist limitat pels efectes adversos, i la baixa barrera en front a la resistència, pel que s’han desenvolupat ITINAN de segona generació (etravirina i rilpivirina), ambdós recentment aprovats.
Rilpivirina mostra també una baixa barrera a la resistència. Al igual que nevirapina o efavirenz, pot perdre l’activitat amb només una o dues mutacions. Hi ha un elevat grau de resistència creuada entre tots els ITINAN, pràcticament complerta entre nevirapina i efavirenz, i més limitada entre els ITINAN de primera i segona generació. Per tant, el coneixement del impacte de les mutacions de resistència seleccionades per ITINAN de primera generació sobre els de segona generació té una importància cabdal.
Els llistats de mutacions de resistència front als ITINAN estan ja ben definits a l’actualitat, permetent el seu anàlisi en mostres clíniques, oferint una oportunitat única per a la investigació del impacte de la resistència del VIH-1 en la resposta al TAR de inici, rescat o simplificació.
En aquesta tesi es discuteix la rellevància de les mutacions de resistència sobre la resposta al tractament, s’identifiquen les mutacions i patrons de mutacions seleccionades en el fracàs virològic (FV) amb determinats ITINAN, i s’analitza el risc de FV posterior a tractaments basats en ITINAN.
El primer capítol avalua la efectivitat de etravirina en el rescat de FV atesos a 4 hospitals de referència de Barcelona. Els tractaments van ser ben tolerats i assolir taxes de supressió virològica superiors a les observades en els seus assaigs clínics de registre, probablement degut a la inclusió de un nombre més elevat de fàrmacs actius als règims. Hem identificat l’associació de recomptes de cèl·lules CD4+ >200 cèls/mm3 i l’ús de raltegravir i darunavir a taxes menors de FV en l’anàlisi multivariant. No hem trobat relació entre interrupció o FV previs a nevirapina o efavirenz, i resposta a etravirina.
El segon capítol analitza el impacte sobre rilpivirina de mutacions de resistència seleccionades en FV als altres ITINAN (nevirapina, efavirenz o etravirina) a 22 centres hospitalaris de España. Es va demostrar resistència a rilpivirina en el 20% de FV a ITINAN, més freqüent en FV a etravirina i nevirapina que a efavirenz. Les mutacions de resistència a rilpivirina més freqüents van ser Y181C, K101E/P, H221Y i E138A/G/K. E138K/M184I, la combinació mes freqüentment seleccionada amb rilpivirina en naives, va estar absent en aquesta població pretractada. L100I i V108I van ser significativament més freqüents en fracassos a efavirenz. Contràriament, Y181C/I, V106A, H221Y i F227L ho van ser amb nevirapina.
Finalment el tercer capítol estima la eficàcia de un règim de simplificació de TAR amb nevirapina, tenofovir i emtricitabina/lamivudina, realitzat a la nostra Unitat a Barcelona. No es van aïllar patrons de mutacions inesperats en els FV. A les 48 setmanes el 90% de malalts tenien una càrrega viral < 50 còpies/mL, el FV va ser infreqüent, i 25 (7.4%) pacients van suspendre el tractament per toxicitat. Els factors associats amb FV a l’anàlisi multivariant van ser drogadicció intravenosa, temps amb càrrega viral indetectable abans de la simplificació, nombre de NRTIs i NNRTIs rebuts, i les interrupcions no programades de tractaments previs amb nevirapina o efavirenz. En base a aquestes dades s’hauria de desaconsellar el reinici del TAR amb nevirapina, tenofovir i emtricitabina/lamivudina en interrupcions no programades del TAR, encara que la càrrega viral sigui indetectable al moment de la suspensió.
Inesperadament, hem trobat una taxa significativament més elevada de FV amb lamivudina que amb emtricitabina amb aquesta combinació, així com una major selecció de M184V. Aquests resultats suggereixen precaució en la substitució de emtricitabina per lamivudina, al menys en règims basats en nevirapina i tenofovir.
Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are popular components of antiretroviral therapy due to their efficacy and simplicity. Resistance is caused only by specific mutations at drug-resistance positions. Despite its proven efficacy, the clinical use of first-generation NNRTIs (nevirapine and efavirenz) has been limited by side effects and low barrier to resistance. To overcome these limitations, a second-generation of NNRTIs has been developed including etravirine and rilpivirine, both recently approved.
Rilpivirine also depicts a low barrier to resistance development. Like nevirapine and efavirenz, complete drug resistance can arise with only one or two resistance-associated mutations (RAMs). In addition, there is a considerable degree of class cross-resistance among all NNRTIs, nearly complete between nevirapine and efavirenz, and more limited from first to second generation NNRTIs. Therefore, the knowledge of RAMs selected by first-generation NNRTIs that have a potential to impact both rilpivirine or etravirine in subsequent treatments is of paramount importance.
Genotypic scores are now fully developed for all these drugs, therefore allowing resistance analyses in clinical samples and offering a unique opportunity to investigate the clinical impact of HIV-1 resistance on treatment response both in initial, salvage or simplification treatment.
In this PhD thesis, we discuss the relevance of RAMs on treatment response; we pinpoint the patterns of RAMs selected at virologic failure (VF) with specific NNRTIs, and the consequent risk of failure to salvage or simplification with NNRTIs.
The first chapter evaluates the effectiveness of etravirine in salvage regimens in VF recruited at four acute-care University hospitals in Barcelona. These regimens were generally well tolerated and achieved rates of virological suppression that exceed those observed in etravirine’s pivotal clinical trials, probably due to the inclusion of a higher number of active drugs in the regimens. We identified baseline CD4+ T cell count >200 cells/mm3 and use of raltegravir and darunavir as factors associated with lower treatment failure rates using a multivariate analysis. We found no relationship between prior interruption or VF with nevirapine or efavirenz and response to etravirine.
The second chapter assesses the RAMs selected in subjects failing NNRTI-based treatments (with nevirapine, efavirenz or etravirine) at 22 clinics in Spain and the potential impact on rilpivirine’s activity. Rilpivirine resistance was recognized in 20% of these patients, more commonly following etravirine or nevirapine failures than efavirenz. The most prevalent rilpivirine RAMs in subjects failing other NNRTIs were Y181C, K101E/P, H221Y and E138A/G/K. E138K/M184I, the most frequently selected combination in initial treatment with rilpivirine, was absent in this treatment-experienced population. L100I and V108I were significantly more frequent in efavirenz failures. Conversely, Y181C/I, V106A, H221Y and F227L were more prevalent in nevirapine ones.
Finally, the third chapter estimates the effectiveness of a nevirapine-based switch regimen in subjects with suppressed viremia, combined with tenofovir and emtricitabine (or lamivudine). The analysis has been done in our clinic in Barcelona. No unexpected RAMs or patterns of RAMs were selected in treatment failures to this regimen. At week 48, nearly 90% of the subjects had HIV-1 RNA <50 copies/mL, VF was uncommon, and 25 (7.4%) subjects discontinued the treatment due to toxicity. Factors independently associated with VF in multivariate analysis were intravenous drug use, time with undetectable viral load before the switch, number of prior NRTIs or NNRTIs, and previous nevirapine or efavirenz unscheduled interruptions. Reinitiation of nevirapine plus tenofovir plus emtricitabine (or lamivudine) should be discouraged in subjects experiencing unplanned treatment interruptions, even with an undetectable plasma viral load at the time of treatment withdrawal.
Unexpectedly, we found a significantly higher rate of VF with lamivudine instead of emtricitabine with this regimen, with a significantly higher selection of M184V as well. Our findings suggest caution against substituting emtricitabine for lamivudine, at least in nevirapine- and tenofovir-based regimens.
In this update, antiretroviral therapy (ART) is recommended for all patients infected by type 1 human immunodeficiency virus (HIV-1). The objective of ART is to achieve an undetectable plasma viral ...load (PVL). Initial ART should comprise 3 drugs, namely, 2 nucleoside reverse transcriptase inhibitors (NRTI), and 1 drug from another family. Four of the recommended regimens, all of which have an integrase strand transfer inhibitor (INSTI) as the third drug, are considered a preferred regimen; a further 6 regimens, which are based on an INSTI, a non-nucleoside reverse transcriptase inhibitor (NNRTI), or a protease inhibitor boosted with cobicistat or ritonavir (PI/COBI, PI/r), are considered alternatives. The reasons and criteria for switching ART are presented both for patients with an undetectable PVL and for patients who experience virological failure, in which case the rescue regimen should include 3 (or at least 2) drugs that are fully active against HIV. The specific criteria for ART in special situations (acute infection, HIV-2 infection, pregnancy) and comorbid conditions (tuberculosis and other opportunistic infections, kidney disease, liver disease, and cancer) are updated.
Highly active antiretroviral therapy (HAART) results in potent and durable suppression of HIV-1 viremia. However, HIV-1 replication resumes if therapy is interrupted. Although it is generally ...believed that active replication has been halted in individuals on HAART, immune activation and inflammation continue at abnormal levels, suggesting continued, low-level viral replication. To assess whether active replication might be driving immune activation in HAART, we examined the impact of treatment intensification with the integrase inhibitor raltegravir on viral complementary DNA and immune activation parameters. In the presence of raltegravir, linear HIV-1 cDNA is prevented from integrating into chromatin and is subsequently converted to episomal cDNAs. Raltegravir intensification of a three-drug suppressive HAART regimen resulted in a specific and transient increase in episomal DNAs in a large percentage of HAART-suppressed subjects. Furthermore, in subjects with these episomal DNAs, immune activation was higher at baseline and was subsequently normalized after raltegravir intensification. These results suggest that, despite suppressive HAART, active replication persists in some infected individuals and drives immune activation. The ability of raltegravir intensification to perturb the reservoir that supports active replication has implications for therapeutic strategies aimed at achieving viral eradication.
Background. It is unknown if tenofovir disoproxil fumarate (TDF), which is often coformulated with the lipid-neutral emtricitabine (FTC), has a lipid-lowering effect. Methods. We performed a ...randomized, crossover, double-blind, placebo-controlled clinical trial on human immunodeficiency virus type 1 (HIV-1)–infected subjects with HIV-1 RNA < 50 copies/mL during ≥6 months on stable darunavir/ritonavir (800/100 mg once daily) or lopinavir/ritonavir (400/100 mg twice daily) monotherapy, fasting total cholesterol (TC) ≥200 mg/dL or low-density lipoprotein cholesterol (LDL-c) ≥130 mg/dL, and no lipid-lowering drugs. In arm 1, TDF/FTC was added for 12 weeks, followed by 12 weeks of placebo (washout) and 12 additional weeks of placebo (placebo period). Subjects in arm 2 added placebo for 12 weeks (placebo period) followed by TDF/FTC for 12 weeks and placebo for 12 additional weeks (washout). The primary endpoint was change in median fasting TC levels. Results. Of 46 subjects enrolled, 56% received darunavir/ritonavir and 44% lopinavir/ritonavir. Exposure to TDF/FTC reduced TC from 234 to 205 mg/dL (P < .001), LDL-c from 155 to 128 mg/dL (P < .001), and high-density lipoprotein cholesterol (HDL-c) from 50.3 to 44.5 mg/dL (P < .001). It also decreased the proportion of subjects with fasting TC ≥200 mg/dL from 86.7% to 56.8% (P = .001), and LDL-c ≥130 mg/dL from 87.8% to 43.9% (P < .001). After 12 weeks, TDF/FTC exposure was associated with lower TC and LDL-c levels than placebo (P = .001 and P = .002, respectively). The TC/HDL-c ratio and triglyceride levels did not change with TDF/FTC exposure. Conclusions. Coformulated TDF/FTC has an intrinsic lipid-lowering effect, likely attributable to TDF. Clinical Trials Registration. NCT01458977.
Objectives The aim of this study was to assess the influence of hepatitis B virus or hepatitis C virus co-infection and the extent of liver fibrosis on saquinavir and ritonavir pharmacokinetics in ...HIV-infected subjects without liver function impairment. Methods A cross-sectional, comparative study enrolling HIV-infected adults receiving saquinavir/ritonavir 1000/100 mg twice daily or 1500/100 mg once daily was conducted. Patients with chronic viral hepatitis (HEP+) were grouped as having advanced liver fibrosis (HEP+/FIB+) or not (HEP+/FIB−) based on the FIB-4 index. Saquinavir and ritonavir trough concentrations (Ctrough) in plasma were determined by HPLC. The geometric mean ratio (GMR) was used to compare saquinavir and ritonavir Ctrough between HEP− and HEP+ patients, and the influence of the extent of liver fibrosis on saquinavir and ritonavir pharmacokinetics was explored using analysis of variance. Results One hundred and thirty-eight patients on twice-daily saquinavir/ritonavir (67 HEP−, 71 HEP+) and 36 patients on once-daily saquinavir/ritonavir (12 HEP−, 24 HEP+) were included. Saquinavir Ctrough was comparable between HEP− and HEP+ patients receiving either saquinavir/ritonavir 1000/100 mg twice daily GMR 0.91, 95% confidence interval (CI) 0.60–1.37; P = 0.655 or 1500/100 mg once daily (GMR 0.88, 95% CI 0.39–1.97; P = 0.752). Similarly, ritonavir Ctrough was also comparable between HEP− and HEP+ patients. The extent of liver fibrosis was not significantly related to saquinavir or ritonavir Ctrough in patients receiving either of the two studied doses. Conclusions Saquinavir Ctrough was not increased in HIV-infected patients with chronic viral hepatitis in the absence of liver function impairment. These results confirm that no specific dose modification of saquinavir/ritonavir should be recommended in this setting.
HIV-1 infection increases plasma levels of inflammatory markers. Combination antiretroviral therapy (cART) does not restore inflammatory markers to normal levels. Since intensification of cART with ...raltegravir reduced CD8 T-cell activation in the Discor-Ral and IntegRal studies, we have evaluated the effect of raltegravir intensification on several soluble inflammation markers in these studies.
Longitudinal plasma samples (0-48 weeks) from the IntegRal (n = 67, 22 control and 45 intensified individuals) and the Discor-Ral studies (44 individuals with CD4 T-cell counts<350 cells/µl, 14 control and 30 intensified) were assayed for 25 markers. Mann-Whitney, Wilcoxon, Spearman test and linear mixed models were used for analysis.
At baseline, different inflammatory markers were strongly associated with HCV co-infection, lower CD4 counts and with cART regimens (being higher in PI-treated individuals), but poorly correlated with detection of markers of residual viral replication. Although raltegravir intensification reduced inflammation in individuals with lower CD4 T-cell counts, no effect of intensification was observed on plasma markers of inflammation in a global analysis. An association was found, however, between reductions in immune activation and plasma levels of the coagulation marker D-dimer, which exclusively decreased in intensified patients on protease inhibitor (PI)-based cART regimens (P = 0.040).
The inflammatory profile in treated HIV-infected individuals showed a complex association with HCV co-infection, the levels of CD4 T cells and the cART regimen. Raltegravir intensification specifically reduced D-dimer levels in PI-treated patients, highlighting the link between cART composition and residual viral replication; however, raltegravir had little effect on other inflammatory markers.
Latent HIV-1-infected cells generated early in the infection are responsible for viral persistence, and we hypothesized that addition of maraviroc to triple therapy in patients recently infected with ...HIV-1 could accelerate decay of the viral reservoir.
Patients recently infected (<24 weeks) by chemokine receptor 5 (CCR5)-using HIV-1 were randomized to a raltegravir + tenofovir/emtricitabine regimen (control arm, n = 15) or the same regimen intensified with maraviroc (+MVC arm, n = 15). Plasma viral load, cell-associated HIV-1 DNA (total, integrated, and episomal), and activation/inflammation markers were measured longitudinally.
Plasma viral load decayed in both groups, reaching similar residual levels at week 48. Total cell-associated HIV-1 DNA also decreased in both groups during the first month, although subsequently at a slightly faster rate in the +MVC arm. The transient increase in two long terminal repeat (2-LTR) circles observed in both groups early after initiation of treatment decreased earlier in MVC-treated individuals. Early (week 12) increase of CD4 T-cell counts was higher in the +MVC arm. Conversely, CD8 T-cell counts and CD4 T-cell activation decreased slower in the +MVC arm. Absolute CD4 T-cell and CD8 T-cell counts, immune activation, CD4/CD8 T-cell ratio, and soluble inflammation markers were similar in both arms at the end of the study.
Addition of maraviroc in early integrase inhibitor-based treatment of HIV-1 infection results in faster reduction of 2-LTR newly infected cells and recovery of CD4 T-cell counts, and a modest reduction in total reservoir size after 48 weeks of treatment. Paradoxically, CCR5 blockade also induced a slower decrease in plasma viremia and immune activation.
In order to design strategies for eradication of HIV-1 from infected individuals, detailed insight into the HIV-1 reservoirs that persist in patients on suppressive antiretroviral therapy (ART) is ...required. In this regard, most studies have focused on integrated (proviral) HIV-1 DNA forms in cells circulating in blood. However, the majority of proviral DNA is replication-defective and archival, and as such, has limited ability to reveal the dynamics of the viral population that persists in patients on suppressive ART. In contrast, extrachromosomal (episomal) viral DNA is labile and as a consequence is a better surrogate for recent infection events and is able to inform on the extent to which residual replication contributes to viral reservoir maintenance. To gain insight into the diversity and compartmentalization of HIV-1 under suppressive ART, we extensively analyzed longitudinal peripheral blood mononuclear cells (PBMC) samples by deep sequencing of episomal and integrated HIV-1 DNA from patients undergoing raltegravir intensification. Reverse-transcriptase genes selectively amplified from episomal and proviral HIV-1 DNA were analyzed by deep sequencing 0, 2, 4, 12, 24 and 48 weeks after raltegravir intensification. We used maximum likelihood phylogenies and statistical tests (AMOVA and Slatkin-Maddison (SM)) in order to determine molecular compartmentalization. We observed low molecular variance (mean variability ≤0.042). Although phylogenies showed that both DNA forms were intermingled within the phylogenetic tree, we found a statistically significant compartmentalization between episomal and proviral DNA samples (P<10(-6) AMOVA test; P = 0.001 SM test), suggesting that they belong to different viral populations. In addition, longitudinal analysis of episomal and proviral DNA by phylogeny and AMOVA showed signs of non-chronological temporal compartmentalization (all comparisons P<10(-6)) suggesting that episomal and proviral DNA forms originated from different anatomical compartments. Collectively, this suggests the presence of a chronic viral reservoir in which there is stochastic release of infectious virus and in which there are limited rounds of de novo infection. This could be explained by the existence of different reservoirs with unique pharmacological accessibility properties, which will require strategies that improve drug penetration/retention within these reservoirs in order to minimise maintenance of the viral reservoir by de novo infection.
Residual viraemia is a major obstacle to HIV-1 eradication in subjects receiving HAART. The intensification with raltegravir could impact latent reservoirs and might lead to a reduction of plasma ...HIV-1 viraemia (viral load VL), complementary DNA intermediates and immune activation.
This was a prospective, open-label, randomized study comprising 69 individuals on suppressive HAART randomly assigned 2:1 to add raltegravir during 48 weeks.
Total and integrated HIV-1 DNA, and ultrasensitive VL remained stable despite intensification. There was a significant increase in episomal HIV DNA at weeks 2-4 in the raltegravir group returning to baseline levels at week 48. Median CD4(+) T-cell counts increased 124 and 80 cells/µl in the intensified and control groups after 48 weeks (P=0.005 and P=0.027, respectively), without significant differences between groups. No major changes were observed in activation of CD4(+) T-cells. Conversely, raltegravir intensification significantly reduced activation of CD8(+) T-cells at week 48 (HLA-DR(+)CD38(+), P=0.005), especially in the memory compartment (CD38(+) of CD8(+)CD45RO(+), P<0.0001). Linear mix models also depicted a larger decrease in CD8(+) T-cell activation in the intensification group (P=0.036 and P=0.010, respectively). Raltegravir intensification was not associated to any particular adverse event.
Intensification of HAART with raltegravir during 48 weeks was safe and associated with a significant decrease in CD8(+) T-cell activation, and a transient increase of episomal HIV-1 DNA. However, raltegravir did not significantly contribute to changes in CD4(+) T-cell counts, ultrasensitive VL, and total and integrated HIV-1 DNA. These findings suggest that raltegravir impacts residual HIV-1 replication and support new strategies to impair HIV-1 persistence. ClinicalTrials.gov identifier: NCT00554398.
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