Lumicitabine, an orally administered nucleoside analog, in infants hospitalized with respiratory syncytial virus (RSV) infection: Safety, efficacy, and pharmacokinetic results

Respiratory syncytial virus (RSV) infection is the leading cause of infant hospitalizations and mortality. Lumicitabine, an oral nucleoside analog was studied for the treatment of RSV. The phase 1b and phase 2b studies reported here assessed the safety, pharmacokinetics, and pharmacodynamics of lumicitabine in infants/neonates hospitalized with RSV. In the phase 1b study, infants (≥1 to ≤12 months) and neonates (<28 days) received a single-ascending or multiple-ascending doses (single loading dose [LD] then 9 maintenance doses [MD] of lumicitabine, or placebo [3:1]). In the phase 2b study, infants/children (28 days to ≤36 months old) received lumicitabine 40/20 mg/kg, 60/40 mg/kg LD/MD twice-daily or placebo (1:1:1) for 5 days. Safety, pharmacokinetics, and efficacy parameters were assessed over 28 days. Lumicitabine was associated with a dose-related increase in the incidence and severity of reversible neutropenia. Plasma levels of ALS-008112, the active nucleoside analog, were dose-proportional with comparable mean exposure levels at the highest doses in both studies. There were no significant differences between the lumicitabine groups and placebo in reducing viral load, time to viral non-detectability, and symptom resolution. No emergent resistance-associated substitutions were observed at the RSV L-gene positions of interest. In summary, lumicitabine was associated with a dose-related increase in the incidence and severity of reversible neutropenia and failed to demonstrate antiviral activity in RSV-infected hospitalized infants. This contrasts with the findings of the previous RSV-A adult challenge study where significant antiviral activity was noted, without incidence of neutropenia. Trial registration ClinicalTrials.gov Identifier: NCT02202356 (phase 1b); NCT03333317 (phase 2b).

The Hospital Recovery Scale: A clinically useful endpoint in patients hospitalized with influenza

BACKGROUND

Currently, no single best primary endpoint exists for measuring the efficacy of treatments in seriously ill patients with respiratory infections, such as influenza, who require hospitalization. The Hospital Recovery Scale is an ordinal endpoint used to evaluate treatment outcomes in clinical studies of hospitalized patients infected with influenza.

METHODS

To determine whether Hospital Recovery Scale outcomes correspond to those for other clinical endpoints in patients hospitalized due to influenza, data from the phase 3 randomized, double-blind ZORO clinical trial (NCT01231620) were analyzed. Randomized influenza-infected patients were divided into subgroups of interest based on prespecified baseline and infection-related characteristics, as well as randomized treatment arms (intravenous zanamivir 300 mg or 600 mg, or oral oseltamivir 75 mg). Clinical endpoints relevant to this population were included to analyze differences in outcomes between the subgroups, and correspondence of these endpoints and hospital recovery endpoint was evaluated.

RESULTS

Data from 488 patients were analyzed. There were strong correlations (ρ_s > 0.8) between the Hospital Recovery Scale assessed on the day after completion of a 5-day antiviral therapy (Day 6) and both time to hospital discharge and time to intensive care unit discharge, and moderate to strong correlations (0.6 < ρ_s < 0.8) between the Hospital Recovery Scale on Day 6 and several other relevant clinical endpoints.

CONCLUSIONS

The Hospital Recovery Scale is applicable as a primary endpoint in trials to evaluate new therapies for severely ill patients hospitalized due to influenza, and may have utility in other severe respiratory illnesses such as COVID-19.

Measuring respiratory syncytial virus infection severity in hospitalized children using the Pediatric Respiratory Syncytial Virus Electronic Severity and Outcome Rating System (PRESORS)

BACKGROUND

The Pediatric Respiratory Syncytial Virus Electronic Severity and Outcome Rating System (PRESORS) was developed to assess the severity of respiratory syncytial virus (RSV) infection in children. Because young children cannot report how they feel or function, ratings are based on observations by the child's caregiver (Observer-Reported Outcome questionnaire [ObsRO]) and clinician (Clinician-Reported Outcome questionnaire [ClinRO]). This prospective study aimed to evaluate the psychometric properties of the PRESORS.

METHODS

The PRESORS version 6 ObsRO and ClinRO were evaluated in children with RSV infection requiring hospitalization in centers in the United States, Argentina, and Chile. Assessments were performed from days 1 to 7 by the child's caregiver and clinician. To assess inter-rater reliability, two clinicians independently performed the ClinRO near in time.

RESULTS

A total of 124 children aged ≤36 months were enrolled (mean age, 8 months). Factor analysis demonstrated that RSV severity consists of two dimensions, respiratory signs and illness behavior, and that these dimensions were consistent over time. The inter-rater reliability for the ClinRO was 0.66 (95% confidence interval [CI], 0.55-0.75) but improved to 0.79 (95% CI, 0.71-0.86) after removing one outlying site, suggesting that quantifying RSV severity is not trivial, even using qualified raters, but that an adequate inter-rater reliability is achievable with the PRESORS through adequate training. ClinRO and ObsRO displayed acceptable internal consistency and acceptable convergent validity with the Respiratory Syncytial Virus Network Scale, global impression scores, and key hospital characteristics.

CONCLUSIONS

The PRESORS is relevant and appropriate for assessing the severity of RSV infection in infants requiring hospitalization.

Risk Factors and Medical Resource Utilization of Respiratory Syncytial Virus, Human Metapneumovirus and Influenza Related Hospitalizations in Adults – A Global Study During the 2017-2019 Epidemic Seasons (Hospitalized Acute Respiratory Tract Infection [HARTI] Study)

Background

Respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and influenza are respiratory pathogens leading to hospitalization in adults. Our understanding of the disease burden is limited to data from single-center or 1-season studies in elderly patients. The HARTI study allows comparison of risk factors for progression to severe disease and medical resources utilization (MRU) during and post-hospitalization in adults diagnosed with influenza, RSV, or hMPV.

Methods

This was a prospective global study in adults hospitalized with acute respiratory tract infection (40 centers, 12 countries). Participants with influenza, RSV, or hMPV were enrolled in a substudy and followed for up to 3 months postdischarge.

Results

Overall, 366 influenza, 238 RSV, and 100 hMPV-infected participants enrolled in the substudy. RSV participants were older and had greater frequency of risk factors and longer duration of symptoms before hospitalization than influenza participants. The RSV and hMPV groups received more bronchodilators, corticosteroids, and oxygen supplementation. No significant differences in intensive care unit admissions or complications were observed. Readmission occurred in 20%–33% of patients within 3 months postdischarge, with the highest rates for RSV and hMPV. In-hospital death occurred in 2.5% of RSV, 1.6% of influenza, and 2% of hMPV participants. In multivariate analyses, length of stay was independently associated with country, renal disease, and increased age; probability of receiving supplemental oxygen was associated with pathogen (hMPV > RSV > influenza), abnormal chest x-ray, and increased age.

Conclusions

Although influenza is more frequent, the HARTI study demonstrates greater frequency of underlying risk factors and MRU for RSV and hMPV vs influenza in hospitalized adults, indicating a need for effective interventions.

Comparative assessment of reported symptoms of influenza, respiratory syncytial virus, and human metapneumovirus infection during hospitalization and post-discharge assessed by Respiratory Intensity and Impact Questionnaire

Background

The hospitalized acute respiratory tract infection (HARTI) study used the Respiratory Intensity and Impact Questionnaire (RiiQ™) Symptom Scale, derived from FluiiQ™, to assess and compare the burden of respiratory infection symptoms for patients with influenza, respiratory syncytial virus (RSV), and human metapneumovirus (hMPV) infection, with or without core risk factors (CRF) (age ≥65; chronic heart, renal, obstructive pulmonary disease; asthma).

Methods

This was a prospective cohort study in adult patients hospitalized with acute respiratory tract infection (40 centers, 12 countries) during two consecutive influenza/RSV/hMPV seasons (2017–2019). The RiiQ™ Symptom Scale and EuroQol 5‐Dimensions 5‐Levels (EQ‐5D‐5L) were assessed by interview at two timepoints during hospitalization and at 1, 2, and 3 months post‐discharge.

Results

Mean lower respiratory tract (LRT) symptom scores were higher for RSV and hMPV participants compared to influenza at 48 h after enrollment/early discharge (p = 0.001) and 3 months post‐discharge (p = 0.007). This was driven by LRT symptoms, including shortness of breath (SOB) (p < 0.01) and wheezing (p < 0.01) during hospitalization, and SOB (p < 0.05) and cough (p < 0.05) post‐discharge. Participants with CRF reported more moderate‐to‐severe SOB (p < 0.05) and wheezing (p < 0.05) compared to CRF(−) participants post‐discharge. EQ‐5D‐5L scores were moderately associated with RiiQ™ LRT and systemic symptoms domains.

Conclusions

Results from the HARTI study suggest that in the study population, LRT symptoms were more severe for RSV and hMPV groups and for patients with CRF. RiiQ™ Symptom Scale scores shows a moderate association with EQ‐5D‐5L indicating that the RiiQ™ may provide useful insights and offer advantages over other measures for use in interventional RSV adult clinical studies.

Efficacy of telaprevir-based therapy in stable liver transplant patients with chronic genotype 1 hepatitis C

 Background and rationale. The REPLACE study (NCT01571583) investigated telaprevir-based triple therapy in patients who have recurrent genotype 1 hepatitis C virus (HCV) infection following liver transplantation and are on a stable immunosuppressant regimen of tacrolimus or cyclosporin A. Patients received telaprevir 750 mg 8-hourly with pegylated interferon 180 ?g weekly and ribavirin 600 mg daily, followed by a further 36 weeks of pegylated interferon and ribavirin alone and 24 weeks of follow-up. Efficacy (sustained virological response [SVR] 12 weeks after last planned study dose), safety and tolerability of telaprevir throughout the study were assessed. Pharmacokinetics of telaprevir, tacrolimus and cyclosporin A were also examined.

RESULTS

In total, 74 patients were recruited. Overall, 72% (53/74; 95% CI: 59.9 to 81.5) of patients achieved SVR at 12 weeks following completion of treatment. Anticipated increases in plasma concentrations of tacrolimus and cyclosporin A occurred during telaprevir treatment and were successfully managed through immunosuppressant dose reduction and, for tacrolimus, reduced dosing frequency. Safety and tolerability of telaprevir-based triple therapy were generally comparable with previous data in non-transplant patients, although rates of reported anemia (55% [41/74]) were higher. Elevated plasma creatinine (46% [34/74]) was observed during REPLACE - consistent with the post-liver transplant population and the co-administered immunosuppressants.

CONCLUSION

Telaprevir-based triple therapy in patients with recurrent genotype 1 HCV infection following liver transplantation produced high rates of SVR. Therapeutic concentrations of immunosuppressants were maintained successfully through dose modification during telaprevir treatment.

Virology analyses of HCV genotype 4 isolates from patients treated with simeprevir and peginterferon/ribavirin in the Phase III RESTORE study

Simeprevir is a hepatitis C virus NS3/4A protease inhibitor. Hepatitis C virus baseline NS3/4A polymorphisms and emerging mutations were characterized in treatment-naїve and treatment-experienced genotype 4-infected patients treated with simeprevir+peginterferon/ribavirin in the RESTORE study. Population sequencing of the NS3/4A region was performed and in vitro simeprevir activity against site-directed mutants or chimeric replicons with patient-derived NS3 protease sequences was assessed in a transient replicon assay. Simeprevir remained active against most (83/91 [91%]) baseline isolates tested in the chimeric replicon assay. Eight baseline isolates reduced simeprevir activity; these carried I132L or D168E substitutions reducing simeprevir median activity by 4.6- and 39-fold, respectively. Six of these eight isolates were from patients achieving sustained virologic response. Baseline NS3 Q80K polymorphism was not observed in the genotype 4-infected patients. Of the 107 simeprevir-treated patients, 37 did not achieve sustained virologic response for any reason. Of the 32 patients who failed treatment and had sequencing information, 28 (88%) had emerging mutations at NS3 positions 80, 122, 155, 156 and/or 168 at time of failure, similar to those in genotype 1. Emerging mutations were mainly D168V and D168E alone or combined with mutations at position 80. In general, isolates obtained at time of failure displayed high-level in vitro resistance to simeprevir (fold change ≥50) in a chimeric replicon assay with a median simeprevir fold change value of 440, consistent with observed mutations. In conclusion, emerging mutations in genotype 4 patients failing simeprevir+peginterferon/ribavirin treatment were similar to those in genotype 1 and conferred high-level resistance to simeprevir.

Clinical and virological predictors of sustained response with an interferon-based simeprevir regimen for patients with chronic genotype 1 hepatitis C virus infection

Simeprevir plus peg-interferon/ribavirin (PR) is approved to treat chronic hepatitis C (HCV) genotype 1 (GT1) and GT4 infection. This study aimed to assess baseline and on-treatment the factors predictive of sustained virologic response 12-weeks post-treatment (SVR12) in patients receiving 12 weeks of simeprevir plus PR followed by 12 or 36 weeks of PR. Data from participants in four studies (QUEST-1, QUEST-2, ATTAIN and PROMISE) were pooled to examine the efficacy and safety of simeprevir+PR in HCV GT1 patients. The predictive power of baseline variables for SVR12 was assessed using univariate and multivariate logistic regression models while the relationship between early (Week 4) on-treatment response and SVR12 was analyzed by GT1 subtype and treatment experience. Data for 1160 patients were analyzed (overall SVR12: 71%). Baseline factors predictive of SVR12 were: IL28B CC genotype, GT1a/Q80K-negative, treatment-naïve/prior relapser, no cirrhosis, HCV-RNA ≤2,000,000IU/mL, albumin >42g/L, platelets >200x109 /L. Patients with HCV GT1b (86%), IL28B CC genotype (87%), and treatment-naïve patients (83%) were predicted to achieve the highest SVR12 rates and rates of rapid virologic response. Week 4 early on-treatment response identified treatment-naïve and prior relapse patients likely to achieve SVR12. Patients likely to respond to simeprevir+PR can be identified using baseline factors. Early on-treatment response predicts treatment success.

Simeprevir plus sofosbuvir (12 and 8 weeks) in hepatitis C virus genotype 1-infected patients without cirrhosis: OPTIMIST-1, a phase 3, randomized study

Effective antiviral therapy is essential for achieving sustained virological response (SVR) in hepatitis C virus (HCV)-infected patients. The phase 2 COSMOS study reported high SVR rates in treatment-naive and prior null-responder HCV genotype (GT) 1-infected patients receiving simeprevir+sofosbuvir±ribavirin for 12 or 24 weeks. OPTIMIST-1 (NCT02114177) was a multicenter, randomized, open-label study assessing the efficacy and safety of 12 and 8 weeks of simeprevir+sofosbuvir in HCV GT1-infected treatment-naive and treatment-experienced patients without cirrhosis. Patients were randomly assigned (1:1; stratified by HCV GT/subtype and presence or absence of NS3 Q80K polymorphism [GT1b, GT1a with Q80K, GT1a without Q80K]), prior HCV treatment history, and IL28B GT [CC, non-CC]) to simeprevir 150 mg once daily+sofosbuvir 400 mg once daily for 12 or 8 weeks. The primary efficacy endpoint was SVR rate 12 weeks after end of treatment (SVR12). Superiority in SVR12 was assessed for simeprevir+sofosbuvir at 12 and 8 weeks versus a composite historical control SVR rate. Enrolled were 310 patients, who were randomized and received treatment (n = 155 in each arm). SVR12 with simeprevir+sofosbuvir for 12 weeks (97% [150/155; 95% confidence interval 94%-100%]) was superior to the historical control (87%). SVR12 with simeprevir+sofosbuvir for 8 weeks (83% [128/155; 95% confidence interval 76-89%]) was not superior to the historical control (83%). The most frequent adverse events were nausea, headache, and fatigue (12-week arm: 15% [23/155], 14% [22/155], and 12% [19/155]; 8-week arm: 9% [14/155], 17% [26/155], and 15% [23/155], respectively). No patients discontinued treatment due to an adverse event. One (1%, 12-week arm) and three (2%, 8-week arm) patients experienced a serious adverse event (all unrelated to study treatment).

CONCLUSION

Simeprevir+sofosbuvir for 12 weeks is highly effective in the treatment of HCV GT1-infected patients without cirrhosis, including those with Q80K. (Hepatology 2016;64:370-380).

Simeprevir plus sofosbuvir in patients with chronic hepatitis C virus genotype 1 infection and cirrhosis: A phase 3 study (OPTIMIST-2)

Hepatitis C virus (HCV)-infected patients with cirrhosis are historically a difficult-to-treat population and are at risk of hepatic decompensation. In the phase 2 COSMOS study that evaluated simeprevir (HCV NS3/4A protease inhibitor) + sofosbuvir (HCV nucleotide analogue NS5B polymerase inhibitor) ± ribavirin for 12 or 24 weeks in HCV genotype (GT)1-infected patients, high rates of sustained virologic response 12 weeks after planned end of treatment (SVR12) were achieved, including in patients with cirrhosis (METAVIR score F4). This phase 3, open-label, single-arm study (OPTIMIST-2 [NCT02114151]) evaluated the efficacy and safety of 12 weeks of simeprevir + sofosbuvir in HCV GT1-infected treatment-naive or treatment-experienced patients with cirrhosis. Patients (aged 18-70 years) with chronic HCV GT1 infection and documented presence of cirrhosis received oral simeprevir 150 mg once daily + sofosbuvir 400 mg once daily for 12 weeks. The primary efficacy endpoint of the study was the proportion of patients achieving SVR12 versus a composite historical control (SVR12 rate of 70%). Safety and patient-reported outcomes were assessed. Overall, 103 patients received treatment. SVR12 with simeprevir + sofosbuvir (83%, 95% confidence interval 76%-91%) met the primary objective of superiority versus the historical control (70%). SVR12 rates for treatment-naive and treatment-experienced patients were 88% (44/50) and 79% (42/53), respectively. Adverse events occurred in 72 (70%) patients, with most (64%) being grade 1 or 2. Serious adverse events (none considered related to study treatment) occurred in five (5%) patients, and three (3%) patients discontinued all study treatment due to adverse events. Patient-reported outcomes improved from baseline to follow-up week 12.

CONCLUSION

Simeprevir + sofosbuvir for 12 weeks achieved superiority in SVR12 rates versus the historical control in treatment-naive and treatment-experienced HCV GT1-infected patients with cirrhosis and was generally safe and well tolerated. (Hepatology 2016;64:360-369).

Simeprevir plus peginterferon/ribavirin for HCV genotype 1-infected treatment-naïve patients in China and South Korea

BACKGROUND AND AIM

Approximately one-third of patients with hepatitis C virus (HCV) genotype (GT) 1 infection live in East Asia. This study evaluated the efficacy, pharmacokinetics, safety, and tolerability of simeprevir plus peginterferon alpha-2a and ribavirin (PR) in HCV GT1-infected, treatment-naïve, Asian patients with compensated liver disease.

METHODS

This phase III, randomized study (NCT01725529) was conducted in China and South Korea. Patients received simeprevir 150 mg once daily (QD), simeprevir 100 mg QD, or placebo, in combination with PR for 12 weeks. Patients in the simeprevir groups received PR alone for a further 12 or 36 weeks based on response-guided treatment criteria. Patients in the placebo group received a further 36 weeks of PR alone. The primary efficacy endpoint was sustained virologic response 12 weeks after planned end of treatment (SVR12). Secondary endpoints were safety, pharmacokinetics, tolerability, and patient-reported outcomes.

RESULTS

Overall, 457 patients were treated; the majority had GT1b infection (452/457 [99%]) and IL28B CC GT (364/457 [80%]). Of the 454 patients who had liver biopsy, 26 had cirrhosis (6%). SVR12 rates were superior for both the simeprevir 100 mg (89%; P = 0.003) and 150 mg (91%; P < 0.001) groups versus placebo (76%). Adverse events were mainly grade 1/2 and occurred at a similar incidence across all treatment groups. Overall, eight patients (2%) discontinued simeprevir or placebo treatment because of adverse events.

CONCLUSIONS

Both simeprevir (100 mg and 150 mg QD) plus PR achieved superiority in SVR12 versus placebo plus PR in treatment-naïve, HCV GT1-infected, Asian patients and were well tolerated.

Pre-existence and Persistence of Resistant Minority Hepatitis C Virus Variants in Genotype 1-Infected Patients Treated With Simeprevir/Peginterferon/Ribavirin

Deep sequencing analyses in HCV genotype 1-infected patients treated with simeprevir/peginterferon/ribavirin showed that pre-existing minority HCV variants did not impact treatment outcome and emerging resistant variants in patients failing treatment were not persisting at minority levels

Background. The pre-existence of minority hepatitis C virus (HCV) variants and their impact on treatment outcome, as well as the persistence of emerging resistant variants posttreatment in patients failing treatment with simeprevir/peginterferon/ribavirin (SMV/PR), were assessed by deep sequencing (DS).

Methods. Population sequencing (PS) and Illumina DS were performed on HCV genotype 1 isolates from patients treated with SMV/PR in Phase 2b (PILLAR [NCT00882908] and ASPIRE [NCT00980330]) and Phase 3 (QUEST-1 [NCT01289782], QUEST-2 [NCT01290679], and PROMISE [NCT01281839]) trials.

Results. Minority polymorphisms (ie, detected pretreatment by DS only) reducing SMV activity in vitro were uncommon (3.6%, 19 of 534 patients). These SMV-resistant minority polymorphisms were detected in similar proportions of patients achieving (3.7%) and not achieving (3.3%) sustained virologic response with SMV/PR and generally did not emerge as major variants at time of failure. SMV-resistant variants emerging at time of failure were no longer detected at end of study in 69.3% and 52.0% of the patients by PS and DS, respectively.

Conclusions. Minority polymorphisms did not impact outcome of SMV/PR treatment. The majority of emerging variants that became undetectable at end of study by PS were also undetectable by DS. These results suggest no added value of DS for clinical usage of SMV.

Pharmacokinetic interaction between etravirine or rilpivirine and telaprevir in healthy volunteers: A randomized, two-way crossover trial

Coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) may require treatment with an HIV non-nucleoside reverse transcriptase inhibitor (NNRTI), for example, rilpivirine or etravirine, and an HCV direct-acting antiviral drug such as telaprevir. In a two-panel, two-way, crossover study, healthy volunteers were randomized to receive etravirine 200 mg twice daily ± telaprevir 750 mg every 8 hours or rilpivirine 25 mg once daily ± telaprevir 750 mg every 8 hours. Pharmacokinetic assessments were conducted for each drug at steady-state when given alone and when coadministered; statistical analyses were least-square means with 90% confidence intervals. Telaprevir minimum plasma concentration (Cmin), maximum plasma concentration (Cmax), and area under the concentration-time curve (AUC) decreased 25%, 10%, and 16%, respectively, when coadministered with etravirine and 11%, 3%, and 5%, respectively, when coadministered with rilpivirine. Telaprevir did not affect etravirine pharmacokinetics, but increased rilpivirine Cmin, Cmax, and AUC by 93%, 49%, and 78%, respectively. Both combinations were generally well tolerated. The small decrease in telaprevir exposure when coadministered with etravirine is unlikely to be clinically relevant. The interaction between telaprevir and rilpivirine is not likely to be clinically relevant under most circumstances. No dose adjustments are deemed necessary when they are coadministered.

Telaprevir-based therapy in patients coinfected with chronic hepatitis C virus infection and HIV: INSIGHT study

OBJECTIVES

INSIGHT (ClinicalTrials.gov NCT01513941) evaluated the efficacy, safety and pharmacokinetics of telaprevir-based therapy and specific antiretroviral agents in hepatitis C virus genotype 1 (HCV-1)/HIV-1-coinfected patients.

PATIENTS AND METHODS

Open-label, Phase IIIb, multicentre study of telaprevir with pegylated-IFN (Peg-IFN) α2a and ribavirin in treatment-naive or -experienced HCV-1/HIV-1-coinfected patients on stable HIV HAART comprising efavirenz, atazanavir/ritonavir, darunavir/ritonavir, raltegravir, etravirine or rilpivirine with two nucleos(t)ide analogues. Patients received 750 mg telaprevir (1125 mg, if on efavirenz) every 8 h plus 180 μg/week Peg-IFNα2a and 800 mg/day ribavirin for 12 weeks, followed by Peg-IFNα2a and ribavirin alone for 12 weeks (HCV treatment naive and relapsers without cirrhosis, with extended rapid virological response) or 36 weeks (all others).

RESULTS

Overall, 162 patients (median age of 46 years, 78% male, 92% Caucasian and mean CD4 count of 687 cells/mm(3)) were treated; 13% had cirrhosis. One-hundred-and-thirty-two patients (81%) completed telaprevir; 14 (9%) discontinued due to an adverse event (AE). Sustained virological response (SVR) 12 rates (<25 IU/mL HCV RNA 12 weeks after the last planned treatment dose) in treatment-naive patients, relapsers and non-responders were 64% (41 of 64), 62% (18 of 29) and 49% (34 of 69), respectively. SVR12 rates ranged from 51% (33 of 65) (patients receiving efavirenz) to 77% (13 of 17) (patients receiving raltegravir). Most frequently reported AEs during telaprevir treatment were pruritus (43%) and rash (34%) special search categories. Anaemia special search category occurred in 15% of patients; 6% of patients reported a serious AE.

CONCLUSIONS

In treatment-naive/-experienced HCV-1/HIV-1 patients there were significantly higher SVR rates with telaprevir-based therapy compared with pre-specified historical controls, and safety comparable to that in HCV-monoinfected patients.

Ribavirin concentration determines treatment success of first-generation DAA-based chronic HCV therapy

BACKGROUND

Monitoring ribavirin concentrations during hepatitis C treatment with dual therapy can help optimize treatment response and minimize anaemia. A defined therapeutic range for ribavirin during direct-acting antiviral-based therapies is lacking. This analysis explores whether a therapeutic range for ribavirin concentrations can be defined in patients treated with boceprevir- or telaprevir-based triple therapies.

METHODS

Treatment-naive patients from ADVANCE, ILLUMINATE, OPTIMIZE and SPRINT-2, and treatment-experienced patients from RESPOND-2 were included. Multivariable logistic regression analyses were performed to evaluate whether ribavirin concentrations were an independent predictor of sustained virological response or anaemia. Optimal cutoff values and the percentage of patients within the proposed therapeutic range were determined, along with the associated chance of response.

RESULTS

Overall, 1,502 patients were included. In both regimens, ribavirin concentrations were significantly associated with anaemia (haemoglobin level <10 g/dl) at all time points (1.75 < odds ratio [OR] <2.45) and sustained virological response was associated with ribavirin concentrations at week 8 (OR=1.43 for telaprevir and 1.78 for boceprevir). A therapeutic range for ribavirin at week 8 of 2.2-3.5 mg/l was defined for telaprevir treatment. Of the 48% of patients with a concentration within this range, 81% achieved sustained virological response and only 5.1% reported anaemia. For boceprevir treatment, the week 8 optimal range was defined as 2.2-3.6 mg/l and 50% of patients had a concentration within this range, of whom 69% achieved sustained virological response and 46% developed anaemia.

CONCLUSIONS

We established the therapeutic range for ribavirin in boceprevir- and telaprevir-based therapy that balances safety and efficacy.

An OPTIMIZE study retrospective analysis for management of telaprevir-treated hepatitis C virus (HCV)-infected patients by use of the Abbott RealTime HCV RNA assay

Protease inhibitor (PI)-based response-guided triple therapies for hepatitis C virus (HCV) infection are still widely used. Noncirrhotic treatment-naive and prior relapser patients receiving telaprevir-based treatment are eligible for shorter, 24-week total therapy if HCV RNA is undetectable at both weeks 4 and 12. In this study, the concordance in HCV RNA assessments between the Roche High Pure System/Cobas TaqMan and Abbott RealTime HCV RNA assays and the impacts of different HCV RNA cutoffs on treatment outcome were evaluated. A total of 2,629 samples from 663 HCV genotype 1 patients receiving telaprevir/pegylated interferon/ribavirin in OPTIMIZE were analyzed using the High Pure System and reanalyzed using Abbott RealTime (limits of detection, 15.1 IU/ml versus 8.3 IU/ml; limits of quantification, 25 IU/ml versus 12 IU/ml, respectively). Overall, good concordance was observed between the assays. Using undetectable HCV RNA at week 4, 34% of the patients would be eligible for shorter treatment duration with Abbott RealTime versus 72% with the High Pure System. However, using <12 IU/ml for Abbott RealTime, a similar proportion (74%) would be eligible. Of the patients receiving 24-week total therapy, 87% achieved a sustained virologic response with undetectable HCV RNA by the High Pure System or <12 IU/ml by Abbott RealTime; however, 92% of the patients with undetectable HCV RNA by Abbott RealTime achieved a sustained virologic response. Using undetectable HCV RNA as the cutoff, the more sensitive Abbott RealTime assay would identify fewer patients eligible for shorter treatment than the High Pure System. Our data confirm the <12-IU/ml cutoff, as previously established in other studies of the Abbott RealTime assay, to determine eligibility for shortened PI-based HCV treatment. (The study was registered with ClinicalTrials.gov under registration no. NCT01241760.).

Prevalence of the hepatitis C virus NS3 polymorphism Q80K in genotype 1 patients in the European region

Hepatitis C virus (HCV) NS3 polymorphism Q80K is mainly found in patients with HCV genotype (G) 1a, and has been associated with a reduced treatment response to simeprevir with pegylated interferon (P) and ribavirin (R). Prevalence of Q80K among G1 patients may vary geographically. Q80K prevalence in the North-American G1 population in a recent study was 34%. We conducted a post hoc meta-analysis of Q80K polymorphism prevalence among HCV G1-infected patients enrolled in simeprevir and telaprevir Phase II/III studies. Baseline HCV NS3/4A protease sequences were analysed by population sequencing to determine Q80K prevalence. Overall, of 3349 patients from 25 countries in the European region analysed, 35.8%, 63.8% and 0.3% of patients had G1a, G1b and other/unknown HCV G1 subtypes, respectively. Q80K was detected at baseline in 7.5% of HCV G1 patients overall. Examination by subtype showed that 19.8%, 0.5% and 18.2% of patients with G1a, G1b and other/unknown HCV G1 subtypes had the Q80K polymorphism, respectively. Among countries in the European region with sequencing data available for either ⩾20 patients with G1a and/or ⩾40 G1 patients overall, the Q80K prevalence in G1 ranged from 0% in Bulgaria to 18.2% in the UK. Q80K prevalence also varied within G1a across different countries. HCV subtype 1a was correctly determined in 99% of patients by the LiPA v2 assay. A low overall prevalence of Q80K was observed in HCV G1-infected patients in the European region, compared with North America. However, the prevalence varied by country, due to differing ratios of G1a/G1b and differing Q80K prevalence within the G1a populations.

Incidence of virological failure and emergence of resistance with twice-daily vs every 8-h administration of telaprevir in the OPTIMIZE study

The OPTIMIZE study demonstrated noninferior efficacy between telaprevir (TVR) twice daily (bid) vs every 8-h (q8h) administration. This analysis compared the selective pressure of both dosing regimens by characterisation of the hepatitis C virus (HCV) variants emerging in genotype 1 (G1) HCV-infected patients who did not achieve sustained virological response (SVR). HCV NS3•4A population sequencing was performed at baseline and time of failure (viral breakthrough, stopping rule or relapse). TVR-resistant variants were classified by fold change in inhibitory concentration (IC50 ). Baseline TVR-resistance was low (<5%) and did not preclude achieving SVR in either arm. The proportion of patients with TVR-resistant variants at time of failure was similar in the bid (15%) and q8h (17%) dosing arms. The majority of variants and virological failures occurred in G1a patients, and mutations V36M, R155K and R155T (G1a), and V36A, T54A and A156S (G1b) were significantly enriched in both treatment arms. The number and type of emerging TVR-resistant variants in non-SVR patients were comparable between treatment arms and were consistent with previous observations. No differences in viral resistance profiles were observed between TVR-based treatment arms in non-SVR patients, indicating a similar selective pressure of TVR bid and q8h dosing.

Risk factors predictive of anemia development during telaprevir plus peginterferon/ribavirin therapy in treatment-experienced patients

BACKGROUND & AIMS

Anemia is a common adverse event associated with telaprevir-based triple therapy of chronic, genotype 1 hepatitis C. Identification of patients at risk of developing anemia could allow evaluation of suitability for therapy, and aid in determining frequency of anemia monitoring and treatment management.

METHODS

This post-hoc analysis utilized data from the no lead-in telaprevir, peginterferon and ribavirin arm of the REALIZE study. Anemia was defined as a single occurrence of hemoglobin <10 g/dl at any point during treatment. Pre-treatment factors with potential to act as prognostic indicators of anemia including age, sex, BMI, and baseline hemoglobin were analysed by univariate and multivariate logistic regression analyses. Nomograms (graphical representations of risk factors) were developed to predict the likelihood of developing anemia.

RESULTS

Among the 265 patients, 102 (38%) had anemia, with 78/102 (77%) developing anemia on or before week 12. Most patients developed anemia after week 2 and an inverse correlation was found between week 2 hemoglobin and the likelihood of developing anemia. Overall, 60% of patients (60/100) with week 2 hemoglobin <13 g/dl subsequently developed anemia. The multivariate analysis revealed older age (>45 years), lower BMI (≤25 mg/m(2)) and baseline hemoglobin (continuous variable) were significantly associated with the probability of developing anemia during telaprevir treatment.

CONCLUSIONS

These analyses indicate the potential of using predictive risk factors such as low baseline and on-treatment hemoglobin to identify patients at risk of developing anemia on telaprevir-based triple therapy, which may increase the potential for treatment success by careful patient monitoring.

Telaprevir twice daily is noninferior to telaprevir every 8 hours for patients with chronic hepatitis C

BACKGROUND & AIMS

We performed an open-label, multicenter, phase 3 study of the safety and efficacy of twice-daily telaprevir in treatment-naive patients with chronic hepatitis C virus (HCV) genotype 1 infection, including those with cirrhosis.

METHODS

Patients were randomly assigned to groups treated with telaprevir 1125 mg twice daily or 750 mg every 8 hours plus peginterferon alfa-2a and ribavirin for 12 weeks; patients were then treated with peginterferon alfa-2a and ribavirin alone for 12 weeks if their level of HCV RNA at week 4 was <25 IU/mL or for 36 weeks if their level was higher. The primary objective was to demonstrate noninferiority of telaprevir twice daily versus every 8 hours in producing a sustained virological response 12 weeks after the end of therapy (SVR12) (based on a -11% lower limit of the 95% lower confidence interval for the difference between groups).

RESULTS

At baseline, of 740 patients, 85% had levels of HCV RNA ≥800,000 IU/mL, 28% had fibrosis (F3-F4), 14% had cirrhosis (F4), 57% were infected with HCV genotype 1a, and 71% had the non-CC IL28B genotype. Of patients who were treated with telaprevir twice daily, 74.3% achieved SVR12 compared with 72.8% of patients who were treated with telaprevir every 8 hours (difference in response, 1.5%; 95% confidence interval, -4.9% to 12.0%), so telaprevir twice daily is noninferior to telaprevir every 8 hours. All subgroups of patients who were treated with telaprevir twice daily versus those who were treated every 8 hours had similar rates of SVR12. The most frequent adverse events (AEs) in the telaprevir phase were fatigue (47%), pruritus (43%), anemia (42%), nausea (37%), rash (35%), and headache (26%); serious AEs were reported in 9% of patients. Rates of AEs and serious AEs were similar or slightly higher among patients treated with telaprevir every 8 hours.

CONCLUSIONS

Based on a phase 3 trial, telaprevir twice daily is noninferior to every 8 hours in producing SVR12, with similar levels of safety and tolerability. These results support use of telaprevir twice daily in patients with chronic HCV genotype 1 infection, including those with cirrhosis. ClinicalTrials.gov, Number: NCT01241760.

Homeostasis model assessment of insulin resistance does not seem to predict response to telaprevir in chronic hepatitis C in the REALIZE trial

Baseline homeostasis model assessment-estimated insulin resistance (HOMA-IR), a marker for insulin resistance, has been associated with poor virologic response to peginterferon alpha/ribavirin (PR) in chronic hepatitis C. We evaluated the association between baseline HOMA-IR and pretreatment factors on sustained virologic response (SVR) to telaprevir (TVR) in genotype 1 patients with hepatitis C and prior peginterferon/ribavirin (PR) treatment failure. Patients were randomized to 12 weeks of TVR (750 mg q8h) plus peginterferon (180 μg/week) and ribavirin (1,000-1,200 mg/day) (with or without a 4-week lead-in) followed by PR, or PR alone (PR48), for 48 weeks. Univariate and multiple logistic regression analyses explored the prognostic significance of baseline HOMA-IR alone and adjusted for other pretreatment factors and SVR. The TVR arms were pooled for the purposes of this analysis. In all, 662 patients were randomized; 578 had baseline HOMA-IR and other prognostic data and were included in this analysis. Median baseline HOMA-IR was 2.6 (interquartile range [IQR] 1.7-4.3); 207 (36%), 206 (36%), and 165 (29%) patients had baseline HOMA-IR <2, 2 to <4, and ≥ 4, respectively. Male gender, higher body mass index, triglycerides, gamma-glutamyl transpeptidase, maximum alanine aminotransferase/aspartate aminotransferase, and fibrosis stage were associated with higher baseline HOMA-IR. Baseline HOMA-IR was associated with SVR in univariate analysis, but not after adjustment for other baseline prognostic factors (TVR: OR = 0.95, 95% confidence interval [CI]: 0.71,1.29; PR48: 0.60; 95% CI: 0.25,1.43).

CONCLUSION

In patients with prior PR treatment failure, baseline HOMA-IR correlated with SVR in univariate but not multivariate analyses, suggesting other factors have a more direct causal relationship with virologic response to TVR-based therapy than HOMA-IR.

Pooled week 96 results of the phase III DUET-1 and DUET-2 trials of etravirine: further analysis of adverse events and laboratory abnormalities of special interest

OBJECTIVES

The aim of the study was to investigate the frequency and severity of adverse events (AEs) and laboratory abnormalities of interest over 96 weeks of treatment with etravirine or placebo in the pooled TMC125 DUET (Demonstrate Undetectable viral load in patients Experienced with ARV Therapy) trials.

METHODS

Treatment-experienced, HIV-1-infected patients randomly received etravirine 200 mg twice a day (bid) or placebo, plus a background regimen. The frequency and severity of neuropsychiatric, rash, hepatic and lipid AEs were analysed; frequencies were also adjusted for total patient-years of exposure (PYE).

RESULTS

A total of 599 and 604 patients received etravirine and placebo, respectively (median treatment duration 96.0 and 69.6 weeks, respectively). There was no significant difference between the treatment groups in the frequency of neuropsychiatric AEs. However, a significant difference in the frequency of rash was observed (20.5% vs. 11.8%, respectively; P < 0.0001); rash was generally mild to moderate in severity; the rate of discontinuation because of rash was low (2.2% vs. 0% in the etravirine and placebo groups, respectively). The frequency of hepatic AEs was low and similar between the treatment groups (8.7% vs. 7.1%, respectively; P = 0.3370); hepatic enzyme levels did not increase over time. Lipid-related laboratory abnormalities and changes over time in lipid levels were generally comparable between treatment groups. Adjusting for treatment exposure, the frequency of AEs remained similar between treatment groups, with the exception of rash [13.7 vs. 9.3 per 100 PYE; relative risk (95% confidence interval) 1.48 (1.02-1.95)].

CONCLUSIONS

The frequency of AEs of interest was generally similar between the treatment groups, both overall and when adjusted for treatment exposure, with the exception of rash which was more frequent in the etravirine group.

Short communication prevalence of susceptibility to etravirine by genotype and phenotype in samples received for routine HIV type 1 resistance testing in the United States

Abstract The prevalence of susceptibility to etravirine was investigated among clinical samples submitted for routine clinical testing in the United States using two separate weighted genotypic scoring systems. The presence of etravirine mutations and susceptibility to etravirine by phenotype of clinical samples from HIV-1-infected patients, submitted to Monogram Biosciences for routine resistance testing between June 2008 and June 2009, were analyzed. Susceptibility by genotype was determined using the Monogram and Tibotec etravirine-weighted genotypic scoring systems, with scores of ≤3 and ≤2, respectively, indicating full susceptibility. Susceptibility by phenotype was determined using the PhenoSense HIV assay, with lower and higher clinical cut-offs of 2.9 and 10, respectively. The frequency of individual etravirine mutations and the impact of the K103N mutation on susceptibility to etravirine by genotype were also determined. Among the 5482 samples with ≥1 defined nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations associated with resistance, 67% were classed as susceptible to etravirine by genotype by both scoring systems. Susceptibility to etravirine by phenotype was higher (76%). The proportion of first-generation NNRTI-resistant samples with (n=3598) and without (n=1884) K103N with susceptibility to etravirine by genotype was 77% and 49%, respectively. Among samples susceptible to first-generation NNRTIs (n=9458), >99% of samples were susceptible to etravirine by phenotype (FC <2.9); the remaining samples had FC ≥2.9-10. In summary, among samples submitted for routine clinical testing in the United States, a high proportion of samples with first-generation NNRTI resistance was susceptible to etravirine by genotype and phenotype. A higher proportion of NNRTI-resistant samples with K103N than without was susceptible to etravirine.

Virological response with fully active etravirine: pooled results from the DUET-1 and DUET-2 trials

The objective of this subanalysis of the Phase III DUET trials was to examine virological response to an etravirine-containing regimen in patients harbouring virus fully sensitive to etravirine. Full etravirine sensitivity was defined as fold change in 50% effective concentration (FC) ≤3 or weighted genotypic score ≤2. At Week 48 in the etravirine group, 74% of patients with etravirine FC ≤3 and 77% with etravirine genotypic score ≤2 had viral load <50 HIV-1 RNA copies/mL, versus 48% and 46%, respectively, in the placebo group (P < 0.0001). Response rates increased with baseline phenotypic sensitivity score, but were consistently higher with etravirine (56-82%) than placebo (2-72%). Similar observations were made in patients harbouring virus with full etravirine and darunavir sensitivity. Our findings support current recommendations to include three active agents in treatment-experienced patients' regimens.

Efficacy and safety of etravirine at week 96 in treatment-experienced HIV type-1-infected patients in the DUET-1 and DUET-2 trials

BACKGROUND

Durable efficacy and long-term safety of antiretroviral therapy are important goals in the management of treatment-experienced patients. The 96-week efficacy and safety of the non-nucleoside reverse transcriptase inhibitor (NNRTI) etravirine were evaluated in the Phase III DUET trials.

METHODS

HIV type-1-infected treatment-experienced adults with viral loads >5,000 copies/ml and NNRTI and protease inhibitor resistance were randomized to receive etravirine 200 mg or placebo, each twice daily and in combination with a background regimen of darunavir/ritonavir twice daily, nucleoside/nucleotide reverse transcriptase inhibitors and optional enfuvirtide. The primary end point was the proportion of patients with viral load <50 copies/ml (intent-to-treat analysis, time-to-loss of virological response algorithm) at week 24. Results from both trials were combined in the pre-specified pooled 96-week analysis.

RESULTS

In total, 599 patients received etravirine and 604 received placebo. At week 96, 57% of patients in the etravirine group versus 36% in the placebo group had a viral load <50 copies/ml (P<0.0001); 91% and 88% of patients, respectively, had maintained this response from week 48. Mean increases in CD4(+) T-cell count from baseline at week 96 were 128 cells/mm(3) with etravirine versus 86 cells/mm(3) with placebo (P<0.0001). With the exception of rash, which was reported more frequently with etravirine than placebo (21% versus 12%, respectively; P<0.0001), the safety and tolerability profile of etravirine was similar to placebo over the treatment period.

CONCLUSIONS

Etravirine, in combination with an antiretroviral background regimen, provided durable virological and immunological responses with no new safety concerns in treatment-experienced patients over 96 weeks in the DUET trials.

A 48-week pilot study switching suppressed patients to darunavir/ritonavir and etravirine from enfuvirtide, protease inhibitor(s), and non-nucleoside reverse transcriptase inhibitor(s)

Treatment options for HIV-infected patients can be limited due to viral drug resistance to antiretroviral agents. Enfuvirtide (ENF) is an injectable entry/fusion inhibitor that is effective in achieving viral suppression when used in combination with protease inhibitors (PIs) in patients with pre-existing resistance. However, ENF treatment is associated with injection site reactions and dosing fatigue. This multicenter, open-label, Phase IIIb, 48-week pilot study assessed safety, tolerability, and effectiveness of the PI darunavir (DRV), boosted with ritonavir (DRV/r), and the non-nucleoside reverse transcriptase inhibitor (NNRTI) etravirine (ETR), when substituted for ENF/PI (±NNRTI)-based therapy. Ten virologically suppressed (HIV RNA less than 50 copies/ml) men who were intolerant to ENF were enrolled. Median (range) CD4+ count was 301 (187-663) cells/mm(3). Two patients discontinued the study; all remaining patients maintained a viral load of less than 50 copies/ml at Week 48. Viral load increased to greater than 50 copies/ml in two patients, but was eventually re-suppressed without the need for changes in treatment. Median (range) increase (last observation carried forward) in CD4+ count from baseline to Week 48 was 64 (-53-100) cells/mm(3). Two grade 3 adverse events (AEs), nausea and weight loss, and one serious AE, acute cholecystitis, were reported; each AE resolved without treatment interruption. Most common AEs related to study drug were fatigue, rash, headache, and diarrhea. Decreases in triglycerides, low-density lipoprotein, and high-density lipoprotein, were observed. This study suggests that a DRV/r- and ETR-based regimen can be substituted for an ENF-based regimen while maintaining virologic suppression.

Pharmacoeconomics of etravirine

HIV infection, particularly multidrug-resistant HIV, continues to be a major societal and economic challenge worldwide. Etravirine, a new (US FDA approved in 2008) non-nucleoside reverse transcriptase inhibitor, has been shown to be very effective in treating patients who have failed prior antiretroviral therapy. Clinical studies demonstrated that etravirine in combination with other antiretrovirals achieved superior levels of undetectable plasma HIV RNA and CD4 cell count increases that led to reductions in risk of death and development of AIDS-defining illnesses when compared with placebo. Etravirine was also shown to be generally well tolerated, with favorable CNS and psychiatric tolerability profiles. In addition, etravirine in combination with other antiretrovirals has been shown to improve quality of life and quality-adjusted life expectancy. Economic evaluations showed that the addition of etravirine to a regimen was associated with lower costs per person with an undetectable viral load and lower hospital-related costs compared with placebo.

The impact of baseline characteristics on virologic response to etravirine: 48-week pooled analysis of DUET-1 and DUET-2

Aims: The impact of baseline characteristics on response to the non-nucleoside reverse transcriptase inhibitor etravirine was investigated at 48 weeks in the Phase III DUET trials. Methods: Logistic regression was used to examine the effect of baseline demographics, disease characteristics and characteristics of antiretroviral therapy on virologic response (viral load <50 HIV-1 RNA copies/ml) to etravirine in pre-specified pooled subgroup analyses. Results: Several nondemographic characteristics were significant predictors of response in univariate analyses. Baseline viral load, adherence to study medication and use of enfuvirtide were predictive of response in the multivariate analysis. Patients treated with etravirine consistently achieved higher response rates than placebo-treated patients. Conclusions: The clinical benefits of etravirine in the DUET trials were observed irrespective of baseline characteristics.

HIV-specific CD8+ T cells exhibit markedly reduced levels of Bcl-2 and Bcl-xL

Human immunodeficiency virus-specific CD8(+) T cells are highly sensitive to spontaneous and CD95/Fas-induced apoptosis, and this sensitivity may impair their ability to control HIV infection. To elucidate the mechanism behind this sensitivity, in this study we examined the levels of antiapoptotic molecules Bcl-2 and Bcl-x(L) in HIV-specific CD8(+) T cells from HIV-infected individuals. Bcl-2 expression was markedly decreased in HIV-specific CD8(+) T cells compared with CMV-specific and total CD8(+) T cells from HIV-infected individuals as well as total CD8(+) T cells from healthy donors. CD8(+) T cell Bcl-2 levels inversely correlated with spontaneous and CD95/Fas-induced apoptosis of CD8(+) T cells from HIV-infected individuals. HIV-specific CD8(+) T cells also had significantly lower levels of Bcl-x(L) compared with CMV-specific CD8(+) T cells. Finally, IL-15 induces both Bcl-2 and Bcl-x(L) expression in HIV-specific and total CD8(+) T cells, and this correlated with apoptosis inhibition and increased survival in both short- and long-term cultures. Our data indicate that reduced Bcl-2 and Bcl-x(L) may play an important role in the increased sensitivity to apoptosis of HIV-specific CD8(+) T cells and suggest a possible mechanism by which IL-15 increases their survival.

Maximizing treatment outcome: key considerations for antiretroviral-experienced patients

Managing antiretroviral-experienced patients presents a significant challenge to the clinician, requiring not only individualized patient care and regimen selection but also knowledge of the patient's antiretroviral history and disease status and the estimated availability of novel antiretrovirals. The clinician's thorough understanding of these interrelated factors and their degree of influence is essential for maximizing treatment outcomes. It is important to consider patient adherence and tolerance of previous antiretrovirals when deciding on regimens subsequent to treatment failure. Resistance testing will help select "active" antiretrovirals that can be combined to develop the most potent regimen. In cases where resistance testing indicates little or no antiretroviral activity, the clinician must consider the individual risks and benefits of the continued use of a partially active regimen. The optimal timing for the introduction of new and soon-to-be-available antiretroviral agents must also be taken into consideration in order to maximize their efficacy.

IL-15 enhances survival and function of HIV-specific CD8+ T cells

HIV-specific CD8(+) T cells are prone to undergo apoptosis, and this may affect their ability to control HIV infection. Because CD8-mediated immune responses play a key role in controlling HIV infection, enhancing the survival and effector function of HIV-specific CD8(+) T cells may augment their ability to control HIV virus. We show here that interleukin 15 (IL-15) potently inhibits spontaneous and CD95/Fas-induced apoptosis of HIV-specific CD8(+) T cells. IL-15 inhibits apoptosis in both CD45RA(-)CD62L(-) and CD45RA(+)CD62L(-) effector memory subpopulations of these cells. Furthermore, IL-15 greatly enhances the survival of HIV-specific CD8(+) T cells in long-term cultures. Finally, IL-15 directly enhances activation, interferon gamma (IFNgamma) production, and direct ex vivo cytotoxicity of HIV-specific CD8(+) T cells. Thus, IL-15 potently enhances the survival and effector function of HIV-specific CD8(+) T cells and, therefore, may prove useful in augmenting the antiviral function of these cells.

IL-15 enhances the function and inhibits CD95/Fas-induced apoptosis of human CD4+ and CD8+ effector-memory T cells

Although the effect of IL-15 has been described on murine cells in vitro and in vivo, its effect on human memory CD8(+) T cells is not well characterized. We show here that IL-15 preferentially enhances the activation and effector function of human effector-memory CD45RA(-)CD62L(-) and CD45RA(+)CD62L(-) CD4(+) and CD8(+) T cells in both healthy and HIV-infected individuals. We find that IL-15 increases 2- to 5-fold both the activation and secretion of the effector cytokines IFN-gamma and tumor necrosis factor (TNF)-alpha by anti-CD3-stimulated purified CD4(+) and CD8(+) T cells and peripheral blood mononuclear cells from healthy and HIV-infected individuals. Furthermore, IL-15 potently inhibits CD95/Fas-induced apoptosis of the effector-memory CD4(+) and CD8(+) T cells from HIV-infected individuals. These findings suggest that in addition to being a growth and survival factor for memory CD8(+) T cells, IL-15 is also a potent activator of human effector-memory CD8(+) T cells both in healthy and in HIV-infected individuals.

Increased CD95/Fas-induced apoptosis of HIV-specific CD8(+) T cells

Why HIV-specific CD8(+) T cells ultimately fail to clear or control HIV infection is not known. We show here that HIV-specific CD8(+) T cells exhibit increased sensitivity to CD95/Fas-induced apoptosis. This apoptosis is 3-fold higher compared to CMV-specific CD8(+) T cells from the same patients. HIV-specific CD8(+) T cells express the CD45RA(-)CD62L(-) but lack the CD45RA(+)CD62L(-) T cell effector memory (T(EM)) phenotype. This skewing is not found in CMV- and EBV-specific CD8(+) T cells in HIV-infected individuals. CD95/Fas-induced apoptosis is much higher in the CD45RA(-)CD62L(-) T(EM) cells. However, cytotoxicity and IFNgamma production by HIV-specific CD8(+) T cells is not impaired. Our data suggest that the survival and differentiation of HIV-specific CD8(+) T cells may be compromised by CD95/Fas apoptosis induced by FasL-expressing HIV-infected cells.

Residual HIV-1 RNA in blood plasma of patients taking suppressive highly active antiretroviral therapy

CONTEXT

Despite suppressive treatment with highly active antiretroviral therapy (HAART), replication-competent virus can still be isolated from peripheral blood mononuclear cells and genital cells of many individuals receiving suppressive HAART.

OBJECTIVE

To determine whether free virion RNA can be detected in the blood plasma and/or genital tract fluids from patients receiving suppressive HAART.

DESIGN

Prospective cohort study conducted from November 1998 to May 1999.

SETTING

Academic medical center.

PATIENTS

Human immunodeficiency virus 1-infected individuals (20 men and 2 women) shown in our laboratories to have fewer than 50 copies/mL of HIV-1 RNA in peripheral blood plasma while taking suppressive HAART.

MAIN OUTCOME MEASURES

Free virion RNA levels in peripheral blood plasma and genital fluids, quantified using an ultrasensitive reverse transcriptase polymerase chain reaction able to quantify cell-free virion RNA to a lower limit of 5 copies/mL and qualitatively detect viral RNA below this level.

RESULTS

In all 22 patients, residual viral RNA could be detected in the peripheral blood plasma (mean level, 17 copies/mL). The presence of viral RNA suggests that ongoing viral replication is occurring, albeit at low levels, in each patient evaluated. Viral RNA levels were lower in most patients' genital fluids compared with blood plasma and in 12 patients were undetectable.

CONCLUSIONS

These data suggest that low-level replication of HIV-1 in patients taking suppressive HAART may be demonstrated not only in peripheral blood mononuclear cells but also in peripheral plasma as cell-free virion RNA. Complete ablation of viral replication may require intensification of antiretroviral therapies beyond standard suppressive HAART.

Acute and long-term treatment of hypertension with nifedipine in the elderly

The acute hypotensive effect of nifedipine was evaluated, and the possibility of its long-term use in hypertensives over 60 years of age was studied. Sublingual nifedipine in a dose of 20 mg was given to 28 patients, mean age 73.1 yrs, and blood pressure, heart rate, and plasma drug concentration were monitored at 15 min, and every 30 min thereafter for 3 hrs. Systolic and diastolic blood pressure decreased at 15 min by 22.1 and 7.0 mmHg, respectively, reaching a maximal decrease two hours after drug administration. The decrease in blood pressure level did not correlate with nifedipine plasma concentration, but only with the initial systolic blood pressure. Long-term treatment with nifedipine was initiated in 60 patients, with 45 patients completing the study. Mean age was 66.2 years. An initial dose of 30 mg daily had to be increased to 60-80 mg in one-third of the patients. Monotherapy was not satisfactory in some patients. Blood pressure gradually decreased from 173/99 to 148/85 mmHg at three months, and to 141/84 mmHg at six months. Drug tolerance was fairly good. Nifedipine was withdrawn due to a considerable increase in heart rate in three patients and skin allergy in one. The most frequent adverse symptoms were: rash, headache, and leg oedema. Laboratory tests revealed no changes in urea and creatinine, and an increase in fasting glycaemia. Lipid parameters did not change significantly. These data proved that a single dose of 20 mg of nifedipine produced therapeutic plasma concentration of the drug and good hypotensive effect, positively correlating with initial systolic blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

[Diagnostic problems in patients with superior vena cava syndrome]

Diagnostical difficulties were shown in 275 patients with the superior vena cava syndrome (SVCS) evaluated in the years 1970-1982. Men consisted 84 percent of the group. In 68 percent the symptoms preceded hospitalization by less than one month. 31 percent of the patients were treated without histopathological verification. In 83 percent the cause of the SVCS was lung cancer. Only in 10 patients (5.3%) non-malignant causes were present. Basing on analysis of their material the authors conclude that it it possible to make a diagnosis of SVCS etiology in the majority of the patients. This is mandatory because the etiology of this syndrome is variable, and the therapy may produce unwarranted and unjustified side effects in many cases.

Pharmacokinetic investigations of Craviten. IV. First-pass metabolism in rats

Pharmacokinetic analysis of serum levels of Craviten found after oral and iv injection suggests, that the examined drug has a relatively low systemic availability. This lack of availability may be attributed to the metabolism of Craviten during the first passage into the circulation after oral administration.

Pharmacokinetic investigations of Craviten. II. Dose-dependent elimination kinetics in rats following rapid intravenous injection

Serum and urine levels of iv administered Craviten were determined. Comparison of the decline of the same absolute and relative serum concentrations of the drug and the variation of pharmacokinetic parameters with the dose leads to the conclusion, that the elimination of Craviten in rats cannot be described by first-order kinetics. The amount of the drug found in urine indicates, that the fraction of Craviten eliminated in the intact form is about 1.27 per cent of the iv administered dose.