Activity of Elvitegravir, a Once-Daily Integrase Inhibitor, against Resistant HIV Type 1: Results of a Phase 2, Randomized, Controlled, Dose-Ranging Clinical Trial
Div of Infectious Diseases and Geographic Medicine, Stanford University, 300 Pasteur Dr, Rm S-156 GrantBldg, Stanford, CA 94305, USA. The Journal of Infectious Diseases
(Impact Factor: 6).
02/2010; 201(6):814-22. DOI: 10.1086/650698
This phase 2, randomized, active-controlled, 48-week study assessed the noninferiority of the human immunodeficiency virus (HIV) integrase inhibitor elvitegravir to comparator ritonavir-boosted protease inhibitor (CPI/r) in treatment-experienced subjects.
Subjects had HIV RNA levels 1000 copies/mL and 1 protease resistance mutation. Subjects received nucleoside or nucleotide reverse-transcriptase inhibitors (NRTIs) with or without T-20 and either CPI/r or once-daily elvitegravir at a dose of 20 mg, 50 mg, or 125 mg (blinded to dose) with ritonavir. After week 8, the independent data monitoring committee stopped the elvitegravir 20 mg arm and allowed subjects in the elvitegravir 50 mg and 125 mg arms to add protease inhibitors. The primary end point was the time-weighted average change from baseline in HIV RNA level through week 24 (DAVG(24)).
A total of 278 subjects with a median of 11 protease and 3 thymidine analog mutations were randomized and treated. One-half of subjects received NRTIs without expected antiviral activity. Compared with the DAVG(24) for the CPI/r arm (-1.19 log(10) copies/mL), the elvitegravir 50 mg arm was noninferior (-1.44 log(10) copies/mL), and the elvitegravir 125 mg arm was superior (-1.66 log(10) copies/mL; P = .021). Efficacy was impacted by activity of background agents. There was no relationship between elvitegravir dosage and adverse events.
Elvitegravir was well-tolerated and produced rapid virologic suppression that was durable with active background therapy. Trial registration. ClinicalTrials.gov identifier number: NCT00298350.
Available from: Nele Brusselaers
- "In the GS-183-105 dose ranging study, elvitegravir plus optimized background regimen was compared with ritonavir boosted PI plus optimized background regimen (n = 63) in predominantly high PI experienced patients . In the 50 mg qd arm (n = 75) elvitegravir was non-inferior while in the 125 mg arm (n = 73) elvitegravir was superior at reaching successful virological outcomes after 24 weeks (mITT time-weighted average change in log10 HIV-1 RNA (DAVG) treatment difference: −0.42, 95% CI −0.77 to −0.06, p = 0.021). "
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ABSTRACT: Optimal regimen choice of antiretroviral therapy is essential to achieve long-term clinical success. Integrase inhibitors have swiftly been adopted as part of current antiretroviral regimens. The purpose of this study was to review the evidence for integrase inhibitor use in clinical settings.
MEDLINE and Web-of-Science were screened from April 2006 until November 2012, as were hand-searched scientific meeting proceedings. Multiple reviewers independently screened 1323 citations in duplicate to identify randomized controlled trials, nonrandomized controlled trials and cohort studies on integrase inhibitor use in clinical practice. Independent, duplicate data extraction and quality assessment were conducted.
48 unique studies were included on the use of integrase inhibitors in antiretroviral therapy-naive patients and treatment-experienced patients with either virological failure or switching to integrase inhibitors while virologically suppressed. On the selected studies with comparable outcome measures and indication (n = 16), a meta-analysis was performed based on modified intention-to-treat (mITT), on-treatment (OT) and as-treated (AT) virological outcome data. In therapy-naive patients, favorable odds ratios (OR) for integrase inhibitor-based regimens were observed, (mITT OR 0.71, 95% CI 0.59-0.86). However, integrase inhibitors combined with protease inhibitors only did not result in a significant better virological outcome. Evidence further supported integrase inhibitor use following virological failure (mITT OR 0.27; 95% CI 0.11-0.66), but switching to integrase inhibitors from a high genetic barrier drug during successful treatment was not supported (mITT OR 1.43; 95% CI 0.89-2.31). Integrase inhibitor-based regimens result in similar immunological responses compared to other regimens. A low genetic barrier to drug-resistance development was observed for raltegravir and elvitegravir, but not for dolutegravir.
In first-line therapy, integrase inhibitors are superior to other regimens. Integrase inhibitor use after virological failure is supported as well by the meta-analysis. Careful use is however warranted when replacing a high genetic barrier drug in treatment-experienced patients switching successful treatment.
Available from: ncbi.nlm.nih.gov
- "Fewer new agents are being developed for treating HIV, and some of them (e.g., rilpivirine) are aimed specifically at first-line therapy of treatment-naïve patients . Two new integrase inhibitors, elvitegravir and dolutegravir, may play a role in treatment of drug-resistant HIV [68, 69]; however, elvitegravir demonstrates significant cross-resistance with raltegravir and is therefore unlikely to be effective for patients who have failed a raltegravir-based regimen . Given the paucity of new antiretroviral drugs in the pipeline, the agents that are currently available will need to continue to control HIV replication for many years. "
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ABSTRACT: In the early years of the highly active antiretroviral therapy (HAART) era, HIV with resistance to two or more agents in different antiretroviral classes posed a significant clinical challenge. Multidrug-resistant (MDR) HIV was an important cause of treatment failure, morbidity, and mortality. Treatment options at the time were limited; multiple drug regimens with or without enfuvirtide were used with some success but proved to be difficult to sustain for reasons of tolerability, toxicity, and cost. Starting in 2006, data began to emerge supporting the use of new drugs from the original antiretroviral classes (tipranavir, darunavir, and etravirine) and drugs from new classes (raltegravir and maraviroc) for the treatment of MDR HIV. Their availability has enabled patients with MDR HIV to achieve full and durable viral suppression with more compact and cost-effective regimens including at least two and often three fully active agents. The emergence of drug-resistant HIV is expected to continue to become less frequent in the future, driven by improvements in the convenience, tolerability, efficacy, and durability of first-line HAART regimens. To continue this trend, the optimal rollout of HAART in both rich and resource-limited settings will require careful planning and strategic use of antiretroviral drugs and monitoring technologies.
Available from: Mark Holodniy
- "Ten EVG-treated patients that were enrolled in Gilead 183-0105 , a dose-ranging phase 2-study that explored the use of ritonavir-boosted EVG in the absence of PIs with optimized RTI background in heavily treatment-experienced patients, were studied. A convenience sample of patients was selected from this study based on the following criteria: 1) received 125 mg/day of EVG; 2) had cryopreserved plasma from multiple time points; 3) had virologic failure on their EVG-containing regimen, and 4) had evidence of evolving EVG resistance (mixtures) based on preliminary population-based genotypes. "
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ABSTRACT: Failure of antiretroviral regimens containing elvitegravir (EVG) and raltegravir (RAL) can result in the appearance of integrase inhibitor (INI) drug-resistance mutations (DRMs). While several INI DRMs have been identified, the evolution of EVG DRMs and the linkage of these DRMs with protease inhibitor (PI) and reverse transcriptase inhibitor (RTI) DRMs have not been studied at the clonal level. We examined the development of INI DRMs in 10 patients failing EVG-containing regimens over time, and the linkage of INI DRMs with PI and RTI DRMs in these patients plus 6 RAL-treated patients. A one-step RT-nested PCR protocol was used to generate a 2.7 kB amplicon that included the PR, RT, and IN coding region, and standard cloning and sequencing techniques were used to determine DRMs in 1,277 clones (mean 21 clones per time point). Results showed all patients had multiple PI, NRTI, and/or NNRTI DRMs at baseline, but no primary INI DRM. EVG-treated patients developed from 2 to 6 strains with different primary INI DRMs as early as 2 weeks after initiation of treatment, predominantly as single mutations. The prevalence of these strains fluctuated and new strains, and/or strains with new combinations of INI DRMs, developed over time. Final failure samples (weeks 14 to 48) typically showed a dominant strain with multiple mutations or N155H alone. Single N155H or multiple mutations were also observed in RAL-treated patients at virologic failure. All patient strains showed evidence of INI DRM co-located with single or multiple PI and/or RTI DRMs on the same viral strand. Our study shows that EVG treatment can select for a number of distinct INI-resistant strains whose prevalence fluctuates over time. Continued appearance of new INI DRMs after initial INI failure suggests a potent, highly dynamic selection of INI resistant strains that is unaffected by co-location with PI and RTI DRMs.
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