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"RNA, Viral - metabolism"
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Nucleotide Polymerase Inhibitor Sofosbuvir plus Ribavirin for Hepatitis C
by
Hindes, Robert G
,
Svarovskaia, Evguenia
,
Hyland, Robert H
in
Adult
,
Aged
,
Antibiotics. Antiinfectious agents. Antiparasitic agents
2013
In this small, preliminary study of sofosbuvir, a nucleotide inhibitor of HCV polymerase, treatment with sofosbuvir and ribavirin, without peginterferon, was effective in achieving a sustained virologic response in patients with HCV genotype 1, 2, or 3 infection.
Recent progress in the treatment of chronic hepatitis C virus (HCV) infection — the approval of the first-generation protease inhibitors telaprevir and boceprevir — has benefited many but not all patients with HCV infection. One quarter of patients with HCV genotype 1 infection who have not received previous therapy and 71% of those with no response to previous therapy do not have a sustained virologic response with protease-inhibitor–based regimens.
1
No direct-acting antiviral agents have yet been approved for patients with HCV genotype 2 or 3 infection.
The standard of care for all patients with HCV infection continues to include 24 . . .
Journal Article
Sofosbuvir and ledipasvir fixed-dose combination with and without ribavirin in treatment-naive and previously treated patients with genotype 1 hepatitis C virus infection (LONESTAR): an open-label, randomised, phase 2 trial
by
Hyland, Robert H
,
Symonds, William T
,
Mo, Hongmei
in
Antibiotics. Antiinfectious agents. Antiparasitic agents
,
Antiviral agents
,
Antiviral Agents - administration & dosage
2014
Interferon-based treatment is not suitable for many patients with hepatitis C virus (HCV) infection because of contraindications such as psychiatric illness, and a high burden of adverse events. We assessed the efficacy and safety of an interferon-free regimen—a fixed-dose combination of the nucleotide polymerase inhibitor sofosbuvir (400 mg) and the HCV NS5A inhibitor ledipasvir (90 mg), with and without ribavirin—in patients with genotype-1 hepatitis C infection who were treatment-naive or previously treated with a protease-inhibitor regimen.
For this open-label study, we enrolled 100 adult patients (>18 years) with HCV infection at a centre in the USA between Nov 2, 2012, and Dec 21, 2012. In cohort A, we used a computer-generated sequence to randomly assign (1:1:1; stratified by HCV genotype [1a vs 1b]) 60 non-cirrhotic, treatment-naive patients to receive sofosbuvir plus ledipasvir for 8 weeks (group 1), sofosbuvir plus ledipasvir and ribavirin for 8 weeks (group 2), or sofosbuvir plus ledipasvir for 12 weeks (group 3). In cohort B, we randomly allocated (1:1; stratified by genotype and presence or absence of cirrhosis) 40 patients who previously had virological failure after receiving a protease inhibitor regimen to receive sofosbuvir plus ledipasvir for 12 weeks (group 4) or sofosbuvir plus ledipasvir and ribavirin for 12 weeks (group 5). 22 (55%) of 40 patients in cohort B had compensated cirrhosis. The primary endpoint was sustained virological response 12 weeks after treatment (SVR12), analysed by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01726517.
In cohort A, SVR12 was achieved by 19 (95%) of 20 patients (95% CI 75–100) in group 1, by 21 (100%) of 21 patients (84–100) in group 2, and by 18 (95%) of 19 patients (74–100) in group 3. In cohort B, SVR12 was achieved by 18 (95%) of 19 patients (74–100) in group 4 and by all 21 (100%) of 21 patients (84–100) in group 5. Two patients had viral relapse; one patient was lost to follow-up after achieving sustained virological response 8 weeks after treatment. The most common adverse events were nausea, anaemia, upper respiratory tract infection, and headache. One patient in group five had a serious adverse event of anaemia, thought to be related to ribavirin treatment.
These findings suggest that the fixed-dose combination of sofosbuvir-ledipasvir alone or with ribavirin has the potential to cure most patients with genotype-1 HCV, irrespective of treatment history or the presence of compensated cirrhosis. Further clinical trials are needed to establish the best treatment duration and to further assess the contribution of ribavirin.
Gilead Sciences.
Journal Article
Dolutegravir versus raltegravir in antiretroviral-experienced, integrase-inhibitor-naive adults with HIV: week 48 results from the randomised, double-blind, non-inferiority SAILING study
2013
Dolutegravir (GSK1349572), a once-daily HIV integrase inhibitor, has shown potent antiviral response and a favourable safety profile. We evaluated safety, efficacy, and emergent resistance in antiretroviral-experienced, integrase-inhibitor-naive adults with HIV-1 with at least two-class drug resistance.
ING111762 (SAILING) is a 48 week, phase 3, randomised, double-blind, active-controlled, non-inferiority study that began in October, 2010. Eligible patients had two consecutive plasma HIV-1 RNA assessments of 400 copies per mL or higher (unless >1000 copies per mL at screening), resistance to two or more classes of antiretroviral drugs, and had one to two fully active drugs for background therapy. Participants were randomly assigned (1:1) to once-daily dolutegravir 50 mg or twice-daily raltegravir 400 mg, with investigator-selected background therapy. Matching placebo was given, and study sites were masked to treatment assignment. The primary endpoint was the proportion of patients with plasma HIV-1 RNA less than 50 copies per mL at week 48, evaluated in all participants randomly assigned to treatment groups who received at least one dose of study drug, excluding participants at one site with violations of good clinical practice. Non-inferiority was prespecified with a 12% margin; if non-inferiority was established, then superiority would be tested per a prespecified sequential testing procedure. A key prespecified secondary endpoint was the proportion of patients with treatment-emergent integrase-inhibitor resistance. The trial is registered at ClinicalTrials.gov, NCT01231516.
Analysis included 715 patients (354 dolutegravir; 361 raltegravir). At week 48, 251 (71%) patients on dolutegravir had HIV-1 RNA less than 50 copies per mL versus 230 (64%) patients on raltegravir (adjusted difference 7·4%, 95% CI 0·7 to 14·2); superiority of dolutegravir versus raltegravir was then concluded (p=0·03). Significantly fewer patients had virological failure with treatment-emergent integrase-inhibitor resistance on dolutegravir (four vs 17 patients; adjusted difference −3·7%, 95% CI −6·1 to −1·2; p=0·003). Adverse event frequencies were similar across groups; the most commonly reported events for dolutegravir versus raltegravir were diarrhoea (71 [20%] vs 64 [18%] patients), upper respiratory tract infection (38 [11%] vs 29 [8%]), and headache (33 [9%] vs 31 [9%]). Safety events leading to discontinuation were infrequent in both groups (nine [3%] dolutegravir, 14 [4%] raltegravir).
Once-daily dolutegravir, in combination with up to two other antiretroviral drugs, is well tolerated with greater virological effect compared with twice-daily raltegravir in this treatment-experienced patient group.
ViiV Healthcare.
Journal Article
Routine versus clinically driven laboratory monitoring of HIV antiretroviral therapy in Africa (DART): a randomised non-inferiority trial
by
Kagina, G
,
Gilks, C F
,
Barungi, G
in
Acquired immune deficiency syndrome
,
Adenine - analogs & derivatives
,
Adenine - therapeutic use
2010
HIV antiretroviral therapy (ART) is often managed without routine laboratory monitoring in Africa; however, the effect of this approach is unknown. This trial investigated whether routine toxicity and efficacy monitoring of HIV-infected patients receiving ART had an important long-term effect on clinical outcomes in Africa.
In this open, non-inferiority trial in three centres in Uganda and one in Zimbabwe, 3321 symptomatic, ART-naive, HIV-infected adults with CD4 counts less than 200 cells per μL starting ART were randomly assigned to laboratory and clinical monitoring (LCM; n=1659) or clinically driven monitoring (CDM; n=1662) by a computer-generated list. Haematology, biochemistry, and CD4-cell counts were done every 12 weeks. In the LCM group, results were available to clinicians; in the CDM group, results (apart from CD4-cell count) could be requested if clinically indicated and grade 4 toxicities were available. Participants switched to second-line ART after new or recurrent WHO stage 4 events in both groups, or CD4 count less than 100 cells per μL (LCM only). Co-primary endpoints were new WHO stage 4 HIV events or death, and serious adverse events. Non-inferiority was defined as the upper 95% confidence limit for the hazard ratio (HR) for new WHO stage 4 events or death being no greater than 1·18. Analyses were by intention to treat. This study is registered, number ISRCTN13968779.
Two participants assigned to CDM and three to LCM were excluded from analyses. 5-year survival was 87% (95% CI 85–88) in the CDM group and 90% (88–91) in the LCM group, and 122 (7%) and 112 (7%) participants, respectively, were lost to follow-up over median 4·9 years' follow-up. 459 (28%) participants receiving CDM versus 356 (21%) LCM had a new WHO stage 4 event or died (6·94 [95% CI 6·33–7·60]
vs 5·24 [4·72–5·81] per 100 person-years; absolute difference 1·70 per 100 person-years [0·87–2·54]; HR 1·31 [1·14–1·51]; p=0·0001). Differences in disease progression occurred from the third year on ART, whereas higher rates of switch to second-line treatment occurred in LCM from the second year. 283 (17%) participants receiving CDM versus 260 (16%) LCM had a new serious adverse event (HR 1·12 [0·94–1·32]; p=0·19), with anaemia the most common (76
vs 61 cases).
ART can be delivered safely without routine laboratory monitoring for toxic effects, but differences in disease progression suggest a role for monitoring of CD4-cell count from the second year of ART to guide the switch to second-line treatment.
UK Medical Research Council, the UK Department for International Development, the Rockefeller Foundation, GlaxoSmithKline, Gilead Sciences, Boehringer-Ingelheim, and Abbott Laboratories.
Journal Article
Recruitment of RED-SMU1 Complex by Influenza A Virus RNA Polymerase to Control Viral mRNA Splicing
by
Chiang, Chiayn
,
Munier, Sandie
,
Jacob, Yves
in
Active Transport, Cell Nucleus
,
Alternative Splicing
,
Biology and Life Sciences
2014
Influenza A viruses are major pathogens in humans and in animals, whose genome consists of eight single-stranded RNA segments of negative polarity. Viral mRNAs are synthesized by the viral RNA-dependent RNA polymerase in the nucleus of infected cells, in close association with the cellular transcriptional machinery. Two proteins essential for viral multiplication, the exportin NS2/NEP and the ion channel protein M2, are produced by splicing of the NS1 and M1 mRNAs, respectively. Here we identify two human spliceosomal factors, RED and SMU1, that control the expression of NS2/NEP and are required for efficient viral multiplication. We provide several lines of evidence that in infected cells, the hetero-trimeric viral polymerase recruits a complex formed by RED and SMU1 through interaction with its PB2 and PB1 subunits. We demonstrate that the splicing of the NS1 viral mRNA is specifically affected in cells depleted of RED or SMU1, leading to a decreased production of the spliced mRNA species NS2, and to a reduced NS2/NS1 protein ratio. In agreement with the exportin function of NS2, these defects impair the transport of newly synthesized viral ribonucleoproteins from the nucleus to the cytoplasm, and strongly reduce the production of infectious influenza virions. Overall, our results unravel a new mechanism of viral subversion of the cellular splicing machinery, by establishing that the human splicing factors RED and SMU1 act jointly as key regulators of influenza virus gene expression. In addition, our data point to a central role of the viral RNA polymerase in coupling transcription and alternative splicing of the viral mRNAs.
Journal Article
Molecular point-of-care testing for respiratory viruses versus routine clinical care in adults with acute respiratory illness presenting to secondary care: a pragmatic randomised controlled trial protocol (ResPOC)
by
Malachira, Ahalya K.
,
Clark, Tristan W.
,
Brendish, Nathan J.
in
Accuracy
,
Acute Disease
,
Adenoviruses
2017
Background
Respiratory viruses are associated with a huge socio-economic burden and are responsible for a large proportion of acute respiratory illness in hospitalised adults. Laboratory PCR is accurate but takes at least 24 h to generate a result to clinicians and antigen-based point-of-care tests (POCT) lack sensitivity. Rapid molecular platforms, such as the FilmArray Respiratory Panel, have equivalent diagnostic accuracy to laboratory PCR and can generate a result in 1 h making them deployable as POCT. Molecular point-of-care testing for respiratory viruses in hospital has the potential to improve the detection rate of respiratory viruses, improve the use of influenza antivirals and reduce unnecessary antibiotic use, but high quality randomised trials with clinically relevant endpoints are needed.
Methods
The ResPOC study is a pragmatic randomised controlled trial of molecular point-of-care testing for respiratory viruses in adults with acute respiratory illness presenting to a large teaching hospital in the United Kingdom. Eligible participants are adults presenting with acute respiratory illness to the emergency department or the acute medicine unit. Participants are allocated 1:1 by internet-based randomisation service to either the intervention of a nose and throat swab analysed immediately on the FilmArray Respiratory Panel as a POCT or receive routine clinical care. The primary outcome is the proportion of patients treated with antibiotics. Secondary outcomes include turnaround time, virus detection, neuraminidase inhibitor use, length of hospital stay and side room use. Analysis of the primary outcome will be by intention-to-treat and all enrolled participants will be included in safety analysis.
Discussion
Multiple novel molecular POCT platforms for infections including respiratory viruses have been developed and licensed in the last few years and many more are in development but the evidence base for clinical benefit above standard practice is minimal. This randomised controlled trial aims to close this evidence gap by generating high quality evidence for the clinical impact of molecular POCT for respiratory viruses in secondary care and to act as an exemplar for future studies of molecular POCT for infections. This study has the potential to change practice and improve patient care for patients presenting to hospital with acute respiratory illness.
Trial registration
This study was registered with ISRCTN, number
ISRCTN90211642
, on 14th January 2015.
Journal Article
Comprehensive Pharmacokinetic, Pharmacodynamic and Pharmacogenetic Evaluation of Once-Daily Efavirenz 400 and 600 mg in Treatment-Naïve HIV-Infected Patients at 96 Weeks: Results of the ENCORE1 Study
2016
Background
ENCORE1 demonstrated non-inferiority of daily efavirenz 400 mg (EFV400) versus 600 mg (EFV600) to 96 weeks in treatment-naïve, HIV-infected adults but concerns regarding lower EFV400 concentrations remained. Therefore, relationships between EFV pharmacokinetics (PK) and key genetic polymorphisms with 96-week efficacy and safety were investigated.
Methods
Relationships between EFV PK parameters and single nucleotide polymorphisms (SNP;
CYP2B6,
CYP2A6
,
CYP3A4
,
NR1I3
,
NR1I2
,
ABCB1
) with plasma HIV-RNA (pVL) <200 copies/mL and EFV discontinuation and adverse events at 96 weeks were explored. Receiver operating characteristic curve analysis evaluated the predictability of mid-dose interval (C
12
) cutoffs and 96-week pVL.
Results
A total of 606 patients (32 % female; 37 % African, 33 % Asian;
n
=
311 EFV400,
n
=
295 EFV600) were included. EFV PK parameters, including C
12
, were not associated with pVL <200 copies/mL at 96 weeks (odds ratio [OR] 5.25, 95 % confidence interval [CI] 0.41–67.90,
p
=
0.204). Lower risk of CNS-related adverse events was associated with
CYP2B6
983TC/CC (OR 0.35, 95 % CI 0.15–0.81,
p
=
0.015) and higher risk was associated with
CYP2B6
15582CT/TT and
ABCB1
3435TT (OR 1.46, 95 % CI 1.02–2.09,
p
=
0.040; OR 2.31, 95 % CI 1.33–4.02,
p
=
0.003, respectively). Discontinuation due to adverse events (clinician decision) was independently associated with dose (OR 2.54, 95 % CI 1.19–5.43,
p
=
0.016). C
12
between 0.47 and 0.76 mg/L provided sensitivity/specificity >90 % (100 %/92.3 to 98.9 %/92.3 %) for achieving pVL <200 copies/mL at 96 weeks.
Conclusions
A higher rate of EFV-related adverse events and discontinuations due to these events for EFV600 were not driven by polymorphisms assessed. Although a single threshold concentration associated with HIV suppression may be clinically useful, it was not viable for ENCORE1. Implementation of EFV400 would improve toxicity management whilst still maintaining good efficacy.
Journal Article
Structure of replicating SARS-CoV-2 polymerase
2020
The new coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) uses an RNA-dependent RNA polymerase (RdRp) for the replication of its genome and the transcription of its genes
1
–
3
. Here we present a cryo-electron microscopy structure of the SARS-CoV-2 RdRp in an active form that mimics the replicating enzyme. The structure comprises the viral proteins non-structural protein 12 (nsp12), nsp8 and nsp7, and more than two turns of RNA template–product duplex. The active-site cleft of nsp12 binds to the first turn of RNA and mediates RdRp activity with conserved residues. Two copies of nsp8 bind to opposite sides of the cleft and position the second turn of RNA. Long helical extensions in nsp8 protrude along exiting RNA, forming positively charged ‘sliding poles’. These sliding poles can account for the known processivity of RdRp that is required for replicating the long genome of coronaviruses
3
. Our results enable a detailed analysis of the inhibitory mechanisms that underlie the antiviral activity of substances such as remdesivir, a drug for the treatment of coronavirus disease 2019 (COVID-19)
4
.
A cryo-electron microscopy structure of the RNA-dependent RNA polymerase of SARS-CoV-2 sheds light on coronavirus replication and enables the analysis of the inhibitory mechanisms of candidate antiviral drugs.
Journal Article
Risk Factor Analyses for Immune Reconstitution Inflammatory Syndrome in a Randomized Study of Early vs. Deferred ART during an Opportunistic Infection
by
Andersen, Janet
,
Grant, Philip M.
,
Eron, Joseph
in
Acquired immune deficiency syndrome
,
Adult
,
AIDS
2010
Immune reconstitution inflammatory syndrome (IRIS) is reported widely in patients initiating antiretroviral therapy (ART). However, few studies are prospective, and no study has evaluated the impact of the timing of ART when allocated randomly during an acute opportunistic infection (OI).
A5164 randomized 282 subjects with AIDS-related OIs (tuberculosis excluded), to early or deferred ART. IRIS was identified prospectively using pre-defined criteria. We evaluated associations between IRIS and baseline variables in subjects with follow-up on ART using Wilcoxon and Fisher's exact tests, logistic regression, and Cox models with time-varying covariates. Twenty of 262 (7.6%) subjects developed IRIS after a median of 33 days on ART. Subjects with fungal infections (other than pneumocystis) developed IRIS somewhat more frequently (OR = 2.7; 95% CI: 1.02, 7.2; p-value = 0.06 (using Fisher's exact test)). In Cox models, lower baseline and higher on-treatment CD4+ T-cell counts and percentage were associated with IRIS. Additionally, higher baseline and lower on-treatment HIV RNA levels were associated with IRIS. Corticosteroids during OI management and the timing of ART were not associated with the development of IRIS.
In patients with advanced immunosuppression and non-tuberculous OIs, the presence of a fungal infection, lower CD4+ T-cell counts and higher HIV RNA levels at baseline, and higher CD4+ T-cell counts and lower HIV RNA levels on treatment are associated with IRIS. Early initiation of ART does not increase the incidence of IRIS, and concern about IRIS should not prompt deferral of ART.
ClinicalTrials.gov NCT00055120.
Journal Article
Superiority of Directly Administered Antiretroviral Therapy over Self-Administered Therapy among HIV-Infected Drug Users: A Prospective, Randomized, Controlled Trial
by
Altice, Frederick L.
,
Springer, Sandra A.
,
Maru, Duncan Smith-Rohrberg
in
Adult
,
AIDS
,
Antibiotics. Antiinfectious agents. Antiparasitic agents
2007
Background. Directly administered antiretroviral therapy (DAART) is one approach to improve treatment adherence among human immunodeficiency virus (HIV)—infected drug users. Methods. In this randomized, controlled trial (ClinicalTrials.gov identifier, NCT00367172), the biological outcomes of a 6-month community intervention of DAART were compared with those of self-administered therapy among HIV-infected drug users. Patients randomized to receive DAART received supervised therapy 5 days per week from workers in a mobile health care van. The primary outcome, using an intention-to-treat approach, was the proportion of patients achieving either a reduction in HIV-1 RNA level of ⩾1.0 log10 copies/mL or an HIV-1 RNA level ⩽400 copies/mL at 6 months. Secondary outcomes included the mean change from baseline in HIV-1 RNA level and CD4+ T lymphocyte count. Results. of the 141 patients who met the entry criteria, 88 were randomized to receive DAART, and 53 were randomized to receive self-administered therapy; 74 (84%) of 88 of the patients randomized to receive DAART accepted the intervention. of the 74 patients who initiated DAART, 51 (69%) completed the full 6-month intervention. At the end of 6 months, a significantly greater proportion of the DAART group achieved the primary outcome (70.5% vs. 54.7; P = .02). Additionally, compared with patients receiving self-administered therapy, patients receiving DAART demonstrated a significantly greater mean reduction in HIV-1 RNA level (-1.16 log10 copies/mL vs. -0.29 log10 copies/mL; P = .03) and mean increase in CD4+ T lymphocyte count (+58.8 cells/μL vs. -24.0 cells/μL; P = .002). Conclusions. This randomized, controlled trial was, to our knowledge, the first to demonstrate the effectiveness of DAART at improving 6-month virologic outcomes among drug users. These results suggest that DAART should be more widely available in HIV treatment programs that target drug users who have poor adherence to treatment.
Journal Article