Dataset Information

Evidence for Reduced Drug Susceptibility without Emergence of Major Protease Mutations following Protease Inhibitor Monotherapy Failure in the SARA Trial.

ABSTRACT:

Background

Major protease mutations are rarely observed following failure with protease inhibitors (PI), and other viral determinants of failure to PI are poorly understood. We therefore characterized Gag-Protease phenotypic susceptibility in subtype A and D viruses circulating in East Africa following viral rebound on PIs.

Methods

Samples from baseline and treatment failure in patients enrolled in the second line LPV/r trial SARA underwent phenotypic susceptibility testing. Data were expressed as fold-change in susceptibility relative to a LPV-susceptible reference strain.

Results

We cloned 48 Gag-Protease containing sequences from seven individuals and performed drug resistance phenotyping from pre-PI and treatment failure timepoints in seven patients. For the six patients where major protease inhibitor resistance mutations did not emerge, mean fold-change EC50 to LPV was 4.07 fold (95% CI, 2.08-6.07) at the pre-PI timepoint. Following viral failure the mean fold-change in EC50 to LPV was 4.25 fold (95% CI, 1.39-7.11, p = 0.91). All viruses remained susceptible to DRV. In our assay system, the major PI resistance mutation I84V, which emerged in one individual, conferred a 10.5-fold reduction in LPV susceptibility. One of the six patients exhibited a significant reduction in susceptibility between pre-PI and failure timepoints (from 4.7 fold to 9.6 fold) in the absence of known major mutations in protease, but associated with changes in Gag: V7I, G49D, R69Q, A120D, Q127K, N375S and I462S. Phylogenetic analysis provided evidence of the emergence of genetically distinct viruses at the time of treatment failure, indicating ongoing viral evolution in Gag-protease under PI pressure.

Conclusions

Here we observe in one patient the development of significantly reduced susceptibility conferred by changes in Gag which may have contributed to treatment failure on a protease inhibitor containing regimen. Further phenotype-genotype studies are required to elucidate genetic determinants of protease inhibitor failure in those who fail without traditional resistance mutations whilst PI use is being scaled up globally.

SUBMITTER: Sutherland KA

PROVIDER: S-EPMC4575205 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

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Publications

Evidence for Reduced Drug Susceptibility without Emergence of Major Protease Mutations following Protease Inhibitor Monotherapy Failure in the SARA Trial.

Sutherland Katherine A KA Parry Chris M CM McCormick Adele A Kapaata Anne A Lyagoba Fred F Kaleebu Pontiano P Gilks Charles F CF Goodall Ruth R Spyer Moira M Kityo Cissy C Pillay Deenan D Gupta Ravindra K RK

PloS one 20150918 9

<h4>Background</h4>Major protease mutations are rarely observed following failure with protease inhibitors (PI), and other viral determinants of failure to PI are poorly understood. We therefore characterized Gag-Protease phenotypic susceptibility in subtype A and D viruses circulating in East Africa following viral rebound on PIs.<h4>Methods</h4>Samples from baseline and treatment failure in patients enrolled in the second line LPV/r trial SARA underwent phenotypic susceptibility testing. Data ...[more]

PMID: 26382239

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Project description:IntroductionA worsening heart failure event (WHFE) is defined as progressively escalating heart failure signs/symptoms requiring intravenous diuretic treatment or hospitalization. No studies have compared the burden of chronic heart failure with reduced ejection fraction (HFrEF) following a WHFE versus stable disease to inform healthcare decision makers.MethodsA retrospective study using the IBM® MarketScan® Commercial Database included patients younger than 65 years of age with HFrEF (one inpatient or two outpatient claims of systolic HF or one outpatient claim of systolic HF plus one outpatient claim of any HF). The first claim for HFrEF during 2016 was the index date. Patients were followed for the first 12 months after the index date (the worsening assessment period) to identify a WHFE, and for an additional 12 months or until the end of continuous enrollment (the post-worsening assessment period). Mean per patient per month (PPPM) health care resource use (HCRU) and costs were compared between patients following a WHFE and stable patients during the two periods using generalized linear models adjusting for patient characteristics.ResultsOf 16,646 patients with chronic HFrEF, 26.8% developed a WHFE. Adjusted all-cause hospitalizations (0.16 vs. 0.02 PPPM, P < 0.0001), outpatient visits (3.54 vs. 2.73 PPPM, P < 0.0001), and emergency department visits (0.25 vs. 0.06 PPPM, P < 0.0001) were higher in patients following a WHFE than stable patients during the worsening assessment period. Similar differences in HCRU were observed between the two cohorts during the post-worsening assessment period. Mean total adjusted cost of care PPPM was $8657 in patients with HFrEF following a WHFE versus $2195 in stable patients during the worsening assessment period, and $6809 versus $2849, respectively, during the post-worsening assessment period.ConclusionHCRU and costs were significantly greater in patients with chronic HFrEF following a WHFE compared to those who remained stable, suggesting an unmet need to improve clinical and economic outcomes among these patients.

Dataset Information

Evidence for Reduced Drug Susceptibility without Emergence of Major Protease Mutations following Protease Inhibitor Monotherapy Failure in the SARA Trial.

Background

Methods

Results

Conclusions

Publications

Evidence for Reduced Drug Susceptibility without Emergence of Major Protease Mutations following Protease Inhibitor Monotherapy Failure in the SARA Trial.

Similar Datasets

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