HIV integrase inhibitors in ART-experienced patients

Incidence of cancer and overall risk of mortality in individuals treated with raltegravir-based and non-raltegravir-based combination antiretroviral therapy regimens

Objectives

There are currently few data on the long‐term risk of cancer and death in individuals taking raltegravir (RAL). The aim of this analysis was to evaluate whether there is evidence for an association.

Methods

The EuroSIDA cohort was divided into three groups: those starting RAL‐based combination antiretroviral therapy (cART) on or after 21 December 2007 (RAL); a historical cohort (HIST) of individuals adding a new antiretroviral (ARV) drug (not RAL) to their cART between 1 January 2005 and 20 December 2007, and a concurrent cohort (CONC) of individuals adding a new ARV drug (not RAL) to their cART on or after 21 December 2007. Baseline characteristics were compared using logistic regression. The incidences of newly diagnosed malignancies and death were compared using Poisson regression.

Results

The RAL cohort included 1470 individuals [with 4058 person‐years of follow‐up (PYFU)] compared with 3787 (4472 PYFU) and 4467 (10 691 PYFU) in the HIST and CONC cohorts, respectively. The prevalence of non‐AIDS‐related malignancies prior to baseline tended to be higher in the RAL cohort vs. the HIST cohort [adjusted odds ratio (aOR) 1.31; 95% confidence interval (CI) 0.95–1.80] and vs. the CONC cohort (aOR 1.89; 95% CI 1.37–2.61). In intention‐to‐treat (ITT) analysis (events: RAL, 50; HIST, 45; CONC, 127), the incidence of all new malignancies was 1.11 (95% CI 0.84–1.46) per 100 PYFU in the RAL cohort vs. 1.20 (95% CI 0.90–1.61) and 0.83 (95% CI 0.70–0.99) in the HIST and CONC cohorts, respectively. After adjustment, there was no evidence for a difference in the risk of malignancies [adjusted rate ratio (RR) 0.73; 95% CI 0.47–1.14 for RALvs. HIST; RR 0.95; 95% CI 0.65–1.39 for RALvs. CONC] or mortality (adjusted RR 0.87; 95% CI 0.53–1.43 for RALvs. HIST; RR 1.14; 95% CI 0.76–1.72 for RALvs. CONC).

Conclusions

We found no evidence for an oncogenic risk or poorer survival associated with using RAL compared with control groups.

Substitution of nevirapine or raltegravir for protease inhibitor vs. rosuvastatin treatment for the management of dyslipidaemia in HIV-infected patients on stable antiretroviral therapy (Nevrast study)

OBJECTIVES

An observational, prospective, cohort study was performed to compare efficacy and safety of a switch from ritonavir-boosted protease inhibitor (PI/r) to nevirapine or raltegravir with that of rosuvastatin addition to current antiretroviral therapy in HIV-infected patients with hyperlipidaemia.

METHODS

All HIV-infected patients receiving a stable PI/r-based antiretroviral regimen, with persistently suppressed viremia, naïve to non-nucleoside analogues and to integrase strand transfer inhibitors, with mixed hyperlipidaemia, and who underwent a switch from PI/r to nevirapine (Group A) or raltegravir (Group B) or who started rosuvastatin at 10 mg daily (group C) with unchanged antiretroviral regimen were enrolled into the study.

RESULTS

Overall, 136 patients were enrolled: 43 patients were included in the group A, 46 in the group B, and 47 in the group C. The mean age was 46.6 years, and 108 (79.4%) were males. After 48 weeks of follow-up, a significantly greater reduction in the mean low-density lipoprotein (LDL) cholesterol level was reported in group C (-28.2%) than in group A (-10.2%; p < .001) and B (-12.4%; p = .021), while a significantly greater reduction in the mean concentration of triglycerides was observed in group A (-31.2%) and B (-35.5%) than in group C (-11.9%; p = .034 and p = .004, respectively). The incidence of adverse events was <10% and comparable across the three groups.

CONCLUSION

In HIV-positive subjects receiving a PI/r, the initiation of rosuvastatin treatment after 48 weeks yielded a greater decline in LDL cholesterol, while the switch from PI/r to nevirapine or raltegravir led to a greater decline in triglycerides.

Dolutegravir(DTG, S/GSK1349572) combined with other ARTs is superior to RAL- or EFV-based regimens for treatment of HIV-1 infection: a meta-analysis of randomized controlled trials

Background

The first-generation integrase inhibitors (INIs) raltegravir (RAL) and elvitegravir (EVG) have shown efficacy against HIV infection, but they have the limitations of once-more daily dosing and extensive cross-resistance. Dolutegravir (DTG, S/GSK1349572), a second-generation drug that overcomes such shortcomings, is under spotlight. The purpose of this study is to review the evidence for DTG use in clinical settings, including its efficacy and safety.

Methods

PubMed, EMbase, Ovid, Web of Science, Science Direct, and related websites were screened from establishment until July 2013, and scientific meeting proceedings were manually searched. Two reviewers independently screened 118 citations repeatedly to identify randomized controlled trials comparing the efficacy and safety of DTG-based regimen with those of RAL- or elvitegravir-based regimens. Using the selected studies with comparable outcome measures and indications, we performed a meta-analysis based on modified intention-to-treat (mITT), on-treatment (OT), and as-treated (AT) virological outcome data. Independent data extraction and quality assessment were conducted.

Results

Four unique studies were included with the use of DTG in antiretroviral therapy-naive patients. In therapy-naive patients, DTG combined with abacavir/lamivudine (ABC/3TC) or tenofovir/emtricitabine (TDF/FTC) resulted in a significantly better virological outcome with a mITT relative risk (RR)of 1.07 (95 % confidence interval (95 % CI 1.03–1.12). Evidence further supported use of DTG had a better virological suppression in the 50 mg once daily group (mITT RR 1.07; 95 % CI 1.03–1.12) as well as in the sub-analysis in dolutegravir/efavirenz(DTG/EFV) and dolutegravir/raltegravir (DTG/RAL) groups (RR 1.09, 95 % CI 1.03–1.15; RR 1.06, 95 % CI 0.98–1.15, respectively). In the matter of safety of DTG-based regimen, the risk of any event was RR 0.98 (95 % CI 0.94–1.01), the risk of serious adverse events (AEs) was RR 0.84 (95 % CI 0.62–1.15), and the risk of drug-related serious AEs was RR 0.33 (95 % CI 0.13–0.79).

Conclusion

In general, DTG 50 mg given once daily combined with an active background drug is a better choice in terms of both efficacy and safety.

Usefulness of Integrase resistance testing in proviral HIV-1 DNA in patients with Raltegravir prior failure

Background

In our study, we have hypothesized that proviral DNA may show the history of mutations that emerged at previous failures to a Raltegravir containing regimen, in patients who are currently undetectable and candidates to simplification to a Dolutegravir containing regimen, in order to decide on once a day or twice a day dosing.

Methods

We have performed a pilot, observational, retrospective, non interventional study, including 7 patients infected by HIV-1, all with a history of previous failure to a RAL containing regimen, that were successfully salvaged and had reached viral suppression. A genotypic viral Integrase region study was available for each patient at the moment of RAL failure. After an average (IQR) time of 48 months (29–53) Integrase resistance mutations in proviral DNA were studied.

Results

All the patients were infected by HIV-1 B subtypes, with a mean age of 55 (range 43 to 56), originating from Spain, and 4 were women. Median viral load (log) and CD4 count at the moment of the study on proviral DNA was of 1.3 log cp/ml (range 0–1.47) and 765.5 cells/μL (range; 436.75–1023.75). The median time (IQR) between previous failure to RAL and the study on proviral DNA was 48 (29–53) months. At Raltegravir failure, N155H was detected in four patients, and other secondary mutations were detected in five patients (71.4 %). In proviral DNA, N155H was detected by population sequencing in three patients (42.8 %), and UDS demonstrated a 9.77 % relative abundance of N155H in the remaining patient. Sanger sequencing correctly identified all the secondary mutations.

Conclusion

This is a pilot study that demonstrates the possibility of properly identifying N155H and some secondary mutations 29–53 months after failure.

Factors associated with virological success with raltegravir-containing regimens and prevalence of raltegravir-resistance-associated mutations at failure in the ARCA database

Raltegravir (RAL) is the only licensed human immunodeficiency virus (HIV) integrase inhibitor. The factors associated with the virological response to RAL-containing regimens and the prevalence of integrase mutations associated with RAL failure deserve further investigation. From the Antiretroviral Resistance Cohort Analysis database, we selected triple-class-experienced subjects failing their current treatment with complete treatment history available. Selection criteria included HIV-RNA, CD4 count and HIV genotype within 3 months of RAL initiation. Factors associated with 24-week response were analysed; genotypic sensitivity scores (GSS) and weighted-GSS were evaluated. Virological response was achieved in 74.3% of 105 subjects. Mutations associated with RAL failure were detected in 12/24 subjects with an integrase genotype, with the prevalence of Q148H + G140S. Each extra unit of GSS (p 0.05, OR 2.62; 95% CI 1.00-6.87). was found to be a associated with response. Weighted-GSS had borderline statistical significance (p 0.063, OR 2.04; 95% CI 0.96-4.33) When stratifying for different cut-offs (<1 as reference, 1-1.49, ≥1.5), a borderline significant increase in the probability of response appeared for GSS ≥1.5 (p 0.053, OR 4.00; 95% CI 0.98-16.25). GSS ≥1 showed the highest sensitivity, 82.6%. Receiver operating characteristic curves depicted the widest area under the curve (0.663, p 0.054) of GSS ≥1. Unresponsiveness to RAL-containing regimens among triple-class-experienced subjects was low. The activity of the background regimen was strongly associated with response. Although few integrase genotypes were available at failure, half of these were without integrase resistance mutations. The substantial rate of RAL failure in the absence of known RAL-resistance mutations may be associated with adherence issues and this issue warrants further analysis in longer observations.

HIV-1 integrase resistance among antiretroviral treatment naive and experienced patients from Northwestern Poland

Background

HIV integrase inhibitor use is limited by low genetic barrier to resistance and possible cross-resistance among representatives of this class of antiretrovirals. The aim of this study was to analyse integrase sequence variability among antiretroviral treatment naive and experienced patients with no prior integrase inhibitor (InI) exposure and investigate development of the InI drug resistance mutations following the virologic failure of the raltegravir containing regimen.

Methods

Sequencing of HIV-1 integrase region from plasma samples of 80 integrase treatment naive patients and serial samples from 12 patients with observed virologic failure on raltegravir containing treatment whenever plasma vireamia exceeded >50 copies/ml was performed. Drug resistance mutations were called with Stanford DB database and grouped into major and minor variants. For subtyping bootstrapped phylogenetic analysis was used; Bayesian Monte Carlo Marcov Chain (MCMC) model was implemented to infer on the phylogenetic relationships between the serial sequences from patients failing on raltegravir.

Results

Majority of the integrase region sequences were classified as subtype B; the remaining ones being subtype D, C, G, as well as CRF01_AE , CRF02_AG and CRF13_cpx recombinants. No major integrase drug resistance mutations have been observed in InI-treatment naive patients. In 30 (38.5%) cases polymorphic variation with predominance of the E157Q mutation was observed. This mutation was more common among subtype B (26 cases, 54.2%) than non-B sequences (5 cases, 16.7%), p=0.00099, OR: 5.91 (95% CI:1.77-22.63)]. Other variants included L68V, L74IL, T97A, E138D, V151I, R263K. Among 12 (26.1%) raltegravir treated patients treatment failure was observed; major InI drug resistance mutations (G140S, Q148H and N155H, V151I, E92EQ, V151I, G163R) were noted in four of these cases (8.3% of the total InI-treated patients). Time to the development of drug resistance ranged from 2.6 to 16.3 months with mean increase of HIV viral load of 4.34 (95% CI:1.86-6.84) log HIV-RNA copies/ml at the time of emergence of the major mutations. Baseline polymorphisms, including E157Q were not associated with the virologic failure on raltegravir.

Conclusions

In InI treatment naive patients polymorphic integrase sequence variation was common, with no major resistance mutants. In the treatment failing patients selection of drug resistance occurred rapidly and followed the typical drug resistance pathways. Preexisting integrase polymorphisms were not associated with the treatment failure.