16 research outputs found
Nous fàrmacs per al tractament antiretroviral, una lluita contra la SIDA més eficient
No full textL'avenç del tractament antiretroviral, que aconsegueix suprimir la replicació del virus de la SIDA, ha portat al desenvolupament de la tercera generació dels inhibidors de la proteasa del VIH, que millora l'eficàcia dels fàrmacs que s'havien estat emprant fins ara, reduint-ne, a més, les preses de medicaments que ha de prendre el pacient. El present article revisa les opcions de què es disposen per a la primera etapa del tractament antiretroviral, analitzant-ne els avantatges dels nous fàrmacs i les situacions en les que aquests són preferibles als medicaments anteriors.Los adelantos en el tratamiento antirretroviral, que consigue suprimir la replicación del virus del SIDA, ha llevado al desarrollo de la tercera generación de los inhibidores de la proteasa del VIH, que mejora la eficacia de los fármacos que se venían empleando hasta ahora, reduciendo, además, las tomas de medicamentos que debe tomar el paciente. El presente artículo revisa las opciones disponibles para la primera etapa del tratamiento antirretroviral, analizando las ventajas de los nuevos fármacos y las situaciones en las que éstos son preferibles a los medicamentos anteriores
Clinical impact of HIV-1 resistance against nonnucleoside analogue reverse transcriptase Inhibitors. Impacte clínic de la resistència del VIH-1 als inhibidors de la transcriptassa inversa no anàlegs de nucleòsids
No full textEls 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
El Festival Ravel de Barcelona i el seu ressò crític (1924): estat de la qüestió i indagacions
No full textOrganitzat per l'Associació de Música Da Camera, el Festival Ravel de Barcelona va tenir lloc al Palau de la Música Catalana el 18 de maig del 1924 i va comptar amb la participació del mateix Maurice Ravel (1875-1937). El dia 20, l'Orfeó Català protagonitzà una sessió en honor seu. El present article pren com a punt de partida la recerca que l'autor d'aquestes línies duia a terme en els treballs finals de grau i màster sobre la recepció de la música de Ravel en l'àmbit barceloní. Es proposa resseguir el context històric musical i estètic pròxim a Ravel en l'època, el curs de l'organització d'ambdós concerts i els escrits que van motivar en la crítica musical, amb l'objectiu d'escatir-ne els detalls.Organized by the Da Camera Music Association, the Barcelona Ravel Festival took place at the Palau de la Música on May 18, 1924 and it was attended by Maurice Ravel (1875-1937) himself. On May 20th, the Orfeó Català gave a performance in his honour. This paper is based on the research carried out by the author on this subject in his Bachelor's and Master's dissertations on the reception of Ravel's music in Barcelona. Here we take a look at the historical musical and aesthetic context specifically relating to Ravel at the time, the story of the organization of both concerts, and the music critics' writings to which the concerts gave rise, in order to shed light on the details of these aspects
Clinical impact of HIV-1 resistance against nonnucleoside analogue reverse transcriptase Inhibitors
No full textEls 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. 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 tenofovirNon-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. 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
EPICE-HIV: An Epidemiologic Cost-Effectiveness Model for HIV Treatment
No full textThe goal of this research was to establish a new and innovative framework for cost-effectiveness modeling of HIV-1 treatment, simultaneously considering both clinical and epidemiological outcomes. EPICE-HIV is a multi-paradigm model based on a within-host micro-simulation model for the disease progression of HIV-1 infected individuals and an agent-based sexual contact network (SCN) model for the transmission of HIV-1 infection. It includes HIV-1 viral dynamics, CD4+ T cell infection rates, and pharmacokinetics/pharmacodynamics modeling. Disease progression of HIV-1 infected individuals is driven by the interdependent changes in CD4+ T cell count, changes in plasma HIV-1 RNA, accumulation of resistance mutations and adherence to treatment. The two parts of the model are joined through a per-sexual-act and viral load dependent probability of disease transmission in HIV-discordant couples. Internal validity of the disease progression part of the model is assessed and external validity is demonstrated in comparison to the outcomes observed in the STaR randomized controlled clinical trial. We found that overall adherence to treatment and the resulting pattern of treatment interruptions are key drivers of HIV-1 treatment outcomes. Our model, though largely independent of efficacy data from RCT, was accurate in producing 96-week outcomes, qualitatively and quantitatively comparable to the ones observed in the STaR trial. We demonstrate that multi-paradigm micro-simulation modeling is a promising tool to generate evidence about optimal policy strategies in HIV-1 treatment, including treatment efficacy, HIV-1 transmission, and cost-effectiveness analysis
Effectiveness of a Treatment Switch to Nevirapine plus Tenofovir and Emtricitabine (or Lamivudine) in Adults with HIV-1 Suppressed Viremia
No full textAjuts: CHAIN, Collaborative HIV and Anti-HIV Drug Resistance Network (Integrated Project no. 223131, funded by the European Commission Framework 7 Program) i Gala contra la Sida Barcelona 2011BACKGROUND: Switching subjects with persistently undetectable HIV-1 viremia under antiretroviral treatment (ART) to once-daily tenofovir/emtricitabine (or lamivudine) + nevirapine is a cost-effective and well-tolerated strategy. However, the effectiveness of this approach has not been established.METHODS:We performed a retrospective study evaluating the rates of treatment failure, virological failure (VF), and variables associated, in all subjects initiating this switch combination in our clinic since 2001. Analyses were performed by a modified intention to treat, where switch due to toxicity equalled failure. The main endpoint was plasma HIV-RNA < 50 copies/mL. RESULTS: 341 patients were treated for a median of 176 (57; 308) weeks. At week 48, 306 (89.7%) subjects had HIV-1 RNA <50 copies/mL, 10 (2.9%) experienced VF, and 25 (7.4%) discontinued the treatment due to toxicity. During the whole follow-up 23 (6.7%) individuals (17 on lamivudine, 6 on emtricitabine; p = 0.034) developed VF and treatment modification due to toxicity occurred in 36 (10.7%). Factors independently associated with VF in a multivariate analysis were: intravenous drug use (HR 1.51; 95%CI 1.12, 2.04), time with undetectable viral load before the switch (HR 0.98; 0.97, 0.99), number of prior NRTIs (HR 1.49; 1.15, 1.93) or NNRTIs (HR 3.22; 1.64, 6.25), and previous NVP (HR 1.54; 1.10, 2.17) or efavirenz (HR 5.76; 1.11, 29.87) unscheduled interruptions. VF was associated with emergence of usual nevirapine mutations (Y181C/I/D, K103N and V106A/I), M184V (n = 16; 12 with lamivudine vs. 4 with emtricitabine, p = 0.04), and K65R (n = 7). CONCLUSIONS: The rates of treatment failure at 48 weeks, or long-term toxicity or VF with this switch regimen are low and no unexpected mutations or patterns of mutations were selected in subjects with treatment failur
EPICE-HIV: An Epidemiologic Cost-Effectiveness Model for HIV Treatment.
No full textThe goal of this research was to establish a new and innovative framework for cost-effectiveness modeling of HIV-1 treatment, simultaneously considering both clinical and epidemiological outcomes. EPICE-HIV is a multi-paradigm model based on a within-host micro-simulation model for the disease progression of HIV-1 infected individuals and an agent-based sexual contact network (SCN) model for the transmission of HIV-1 infection. It includes HIV-1 viral dynamics, CD4+ T cell infection rates, and pharmacokinetics/pharmacodynamics modeling. Disease progression of HIV-1 infected individuals is driven by the interdependent changes in CD4+ T cell count, changes in plasma HIV-1 RNA, accumulation of resistance mutations and adherence to treatment. The two parts of the model are joined through a per-sexual-act and viral load dependent probability of disease transmission in HIV-discordant couples. Internal validity of the disease progression part of the model is assessed and external validity is demonstrated in comparison to the outcomes observed in the STaR randomized controlled clinical trial. We found that overall adherence to treatment and the resulting pattern of treatment interruptions are key drivers of HIV-1 treatment outcomes. Our model, though largely independent of efficacy data from RCT, was accurate in producing 96-week outcomes, qualitatively and quantitatively comparable to the ones observed in the STaR trial. We demonstrate that multi-paradigm micro-simulation modeling is a promising tool to generate evidence about optimal policy strategies in HIV-1 treatment, including treatment efficacy, HIV-1 transmission, and cost-effectiveness analysis
Effectiveness of a Treatment Switch to Nevirapine plus Tenofovir and Emtricitabine (or Lamivudine) in Adults with HIV-1 Suppressed Viremia
No full textBackground
Switching subjects with persistently undetectable HIV-1 viremia under antiretroviral treatment
(ART) to once-daily tenofovir/emtricitabine (or lamivudine) + nevirapine is a cost-effective
and well-tolerated strategy. However, the effectiveness of this approach has not been
established.
Methods
We performed a retrospective study evaluating the rates of treatment failure, virological failure
(VF), and variables associated, in all subjects initiating this switch combination in our
clinic since 2001. Analyses were performed by a modified intention to treat, where switch
due to toxicity equalled failure. The main endpoint was plasma HIV-RNA < 50 copies/mL.
Results
341 patients were treated for a median of 176 (57; 308) weeks. At week 48, 306 (89.7%)
subjects had HIV-1 RNA <50 copies/mL, 10 (2.9%) experienced VF, and 25 (7.4%) discontinued
the treatment due to toxicity. During the whole follow-up 23 (6.7%) individuals (17 on
lamivudine, 6 on emtricitabine; p = 0.034) developed VF and treatment modification due to
toxicity occurred in 36 (10.7%). Factors independently associated with VF in a multivariate
analysis were: intravenous drug use (HR 1.51; 95%CI 1.12, 2.04), time with undetectable
viral load before the switch (HR 0.98; 0.97, 0.99), number of prior NRTIs (HR 1.49; 1.15,
1.93) or NNRTIs (HR 3.22; 1.64, 6.25), and previous NVP (HR 1.54; 1.10, 2.17) or efavirenz
(HR 5.76; 1.11, 29.87) unscheduled interruptions. VF was associated with emergence of
usual nevirapine mutations (Y181C/I/D, K103N and V106A/I), M184V (n = 16; 12 with lamivudine
vs. 4 with emtricitabine, p = 0.04), and K65R (n = 7).Conclusions
The rates of treatment failure at 48 weeks, or long-term toxicity or VF with this switch regimen
are low and no unexpected mutations or patterns of mutations were selected in subjects
with treatment failure
