Validation of NASH-CHECK: a novel patient-reported outcome measure for nonalcoholic steatohepatitis

BACKGROUND

Standardized measures for evaluating patients' experiences with nonalcoholic steatohepatitis (NASH) and their perceived changes with treatment in clinical trials have been limited. To meet this need, a patient-reported outcome (PRO) measure, NASH-CHECK, was developed to evaluate symptoms and health-related quality of life for patients with NASH. The objective of this study was to conduct a quantitative evaluation of the psychometric properties of NASH-CHECK.

METHODS

The study used data from a phase 2, randomized controlled trial of adult patients with NASH (NCT02855164). Analyses were conducted to determine the optimal scoring of NASH-CHECK and to evaluate reliability, construct validity, and ability to detect change in NASH-CHECK scale scores.

RESULTS

Data were available for 253 patients with NASH (61% female; mean [standard deviation] age = 53 [12] years). Following initial item-level analyses, including correlations and exploratory factor analysis, three items were removed from the measure. Confirmatory factor analysis supported the formation of four multi-item scales (Cognitive Symptoms, Activity Limitations, Social Impact, and Emotional Impact) and five single-item scales (Abdominal Pain, Abdominal Bloating, Fatigue, Sleep, and Itchy Skin). Psychometric analyses of the final NASH-CHECK scales provided support for their internal reliability, test-retest reliability, construct validity, and ability to detect change.

CONCLUSION

The results support NASH-CHECK as a reliable, valid, and responsive measure to assess patients' perspectives of symptoms and the health-related quality of life impact of NASH in clinical trials and in routine practice.

Tropifexor for nonalcoholic steatohepatitis: an adaptive, randomized, placebo-controlled phase 2a/b trial

The multimodal activities of farnesoid X receptor (FXR) agonists make this class an attractive option to treat nonalcoholic steatohepatitis. The safety and efficacy of tropifexor, an FXR agonist, in a randomized, multicenter, double-blind, three-part adaptive design, phase 2 study, in patients with nonalcoholic steatohepatitis were therefore assessed. In Parts A + B, 198 patients were randomized to receive tropifexor (10-90 μg) or placebo for 12 weeks. In Part C, 152 patients were randomized to receive tropifexor 140 µg, tropifexor 200 µg or placebo (1:1:1) for 48 weeks. The primary endpoints were safety and tolerability to end-of-study, and dose response on alanine aminotransferase (ALT), aspartate aminotransferase (AST) and hepatic fat fraction (HFF) at week 12. Pruritus was the most common adverse event in all groups, with a higher frequency in the 140- and 200-µg tropifexor groups. Decreases from baseline in ALT and HFF were greater with tropifexor versus placebo at week 12, with a relative decrease in least squares mean from baseline observed with all tropifexor doses for ALT (tropifexor 10-90-μg dose groups ranged from -10.7 to -16.5 U l-1 versus placebo (-7.8 U l-1) and tropifexor 140- and 200-μg groups were -18.0 U l-1 and -23.0 U l-1, respectively, versus placebo (-8.3 U l-1)) and % HFF (tropifexor 10-90-μg dose groups ranged from -7.48% to -15.04% versus placebo (-6.19%) and tropifexor 140- and 200-μg groups were -19.07% and -39.41%, respectively, versus placebo (-10.77%)). Decreases in ALT and HFF were sustained up to week 48; however, similar trends in AST with tropifexor at week 12 were not observed. As with other FXR agonists, dose-related pruritus was frequently observed. Clinicaltrials.gov registration: NCT02855164.

Development of a Patient-Reported Outcome Measure for Non-Alcoholic Steatohepatitis (NASH-CHECK): Results of a Qualitative Study

Background

Non-alcoholic steatohepatitis (NASH) is a progressive form of non-alcoholic fatty liver disease characterized by excessive liver fat accumulation, inflammation, cell injury, and fibrosis. It is viewed as largely asymptomatic in its earlier (non-cirrhotic) stages, and information on the patient-perceived impact of NASH is scarce.

Objective

This study aimed to develop a NASH-specific patient-reported outcome (PRO) measure (NASH-CHECK) for use as a trial endpoint, using methods compliant with regulatory expectations.

Methods

A NASH conceptual model was developed based on the literature and clinical/patient expert review. The model guided concept elicitation (CE) interviews in patients with non-cirrhotic NASH recruited via a US tertiary care center. NASH-CHECK content was generated via thematic analysis of CE data and review by clinical/patient experts. Cognitive debriefing (CD) interviews with US patients evaluated content validity.

Results

The literature review confirmed that NASH impacts on functioning and health-related quality of life (HRQoL). Overall, 23 CE and 20 CD interviews were conducted. Key symptoms reported in CE interviews included pain in the upper-right abdomen (n = 14), fatigue (n = 18), poor sleep quality (n = 12), impaired memory (n = 13), and reduced focus (n = 11); key HRQoL impacts included impaired physical functioning, reduced ability to conduct daily living tasks, reduced quality of relationships, low mood, anxiety, and self-consciousness. The 52-item first-draft NASH-CHECK was reduced to 31 items based on patient feedback on item relevance, acceptability, and comprehension.

Conclusions

The interviews revealed key symptoms and broad HRQoL impacts of NASH. As a disease-specific PRO measure assessing symptoms and HRQoL, the NASH-CHECK is relevant, comprehensive, and acceptable to patients and clinicians.

Health-related quality of life and patient-reported outcome measures in NASH-related cirrhosis

BACKGROUND & AIMS

Non-alcoholic steatohepatitis (NASH) is known to have a negative impact on patients' health-related quality of life (HRQoL), even before progression to cirrhosis has occurred. The burden of NASH-related cirrhosis from the patient perspective remains poorly understood. Herein, we aimed to identify the burden of disease and HRQoL impairment among patients with NASH-related compensated cirrhosis.

METHODS

This targeted literature review sought first to identify the humanistic burden of disease from the perspective of patients with diagnosed NASH-cirrhosis and, secondly, to identify generic or disease-specific patient-reported outcome measures (PROMs) used to assess the impact of NASH-cirrhosis. Searches were conducted in bibliographical databases, grey or unpublished literature, liver disease websites, support group websites and online blogs. A quality assessment of specific PROMs was conducted.

RESULTS

Patients with NASH-cirrhosis are reported to suffer from lower HRQoL than patients with non-cirrhotic NASH and the general population with respect to physical health/functioning, emotional health and worry, and mental health. Thirteen PROMs were identified, of which 4 were liver-disease specific: CLDQ, CLDQ-NAFLD, LDQoL and LDSI. The most commonly used measures do not comply with current industry or regulatory standards for PROMs and/or are not validated for use in a cirrhotic NASH population.

CONCLUSIONS

Patients with NASH-cirrhosis have lower HRQoL and poorer physical health than patients with non-cirrhotic NASH. However, the literature lacked detail of the everyday impact on patients' lives. Currently, a number of PROMs are available to measure the impact of the disease in patients with chronic liver conditions. The lack of studies that include qualitative insights in this population mandates further exploration and research.

LAY SUMMARY

It is not well understood how having non-alcoholic fatty liver disease (NAFLD)-related cirrhosis affects a person's everyday wellbeing and quality of life. Some research has been done with patients who have early stages of liver disease but not people with cirrhosis. We found that patients with NAFLD-related cirrhosis tended to have poorer health than patients without cirrhosis. But there was not very much information from patients themselves and there were no tools or questionnaires just for this group of patients.

Overall safety profile of boceprevir plus peginterferon alfa-2b and ribavirin in patients with chronic hepatitis C genotype 1: a combined analysis of 3 phase 2/3 clinical trials

BACKGROUND & AIMS

Triple therapy with peginterferon/ribavirin (PR) plus an NS3 protease inhibitor has emerged as the standard-of-care for patients with chronic hepatitis C genotype-1. We provide a detailed safety analysis comparing PR to boceprevir plus PR (BOC/PR) across three phase 2/3 studies.

METHODS

SPRINT-1 was an open-label phase 2 study in 595 treatment-naive patients. In the two phase 3 studies, 1500 patients (1097 treatment-naive, SPRINT-2; 403 treatment-failure, RESPOND-2) were randomized to receive PR alone, or one of two regimens where BOC was added to PR after a 4-wk PR lead-in. In this analysis, the respective BOC/PR and PR arms were combined for all three trials. The benefit of shortened duration of treatment using response-guided therapy (RGT) was also explored in the SPRINT-2 trial.

RESULTS

Only two adverse events, anaemia and dysgeusia, occurred 20% more often with the BOC-containing regimens compared with PR. Nausea, diarrhoea and neutropenia were the only other common events with an incidence of at least 5% greater when BOC was added to the PR backbone. The proportions of patients reporting serious adverse events (AE), life-threatening AEs, and study drug discontinuation because of an AE were similar in the PR and BOC/PR arms. In treatment-naive patients, RGT generally did not result in a lower frequency of common AEs; however, RGT led to decreased exposure to all 3 study drugs and to a decrease in the mean duration of several clinically relevant AEs such as anaemia, neutropenia, fatigue and depression, as well as earlier normalization of haemoglobin and neutrophil counts.

CONCLUSIONS

The safety profile of BOC combination therapy largely reflects the known profile of peginterferon and ribavirin, with incremental haematolgical effects and dysgeusia. Shorter treatment duration with RGT significantly reduced the duration of AEs.

Staging chronic hepatitis C in seven categories using fibrosis biomarker (FibroTest™) and transient elastography (FibroScan®)

BACKGROUND & AIMS

FibroTest™ (FT) and Transient Elastography (TE) have been validated as non-invasive markers of METAVIR fibrosis stages from F0 to F4 using biopsy, and as prognostic markers of liver related mortality in patients with chronic hepatitis C. The aim was to extend the validation of FT and TE as markers of critical steps defined by occurrence of cirrhosis without complications (F4.1), esophageal varices (F4.2), and severe complications (F4.3): primary liver cancer, variceal bleeding, or decompensation (ascites, encephalopathy, or jaundice).

METHODS

The updated individual data of 3927 patients (1046 cirrhotics) without complications at baseline were pooled from three prospective cohorts called "EPIC", "Paris", and "Bordeaux" cohorts.

RESULTS

At 5 years, among 501 patients without varices at baseline (F4.1) varices occurred in 19 patients [F4.2 incidence of 4.0% (95% CI 2.2-5.8)]. The predictive performance (AUROC) of FT was 0.77 (0.66-0.84; p<0.001). At 10 years severe complications occurred in 203 patients, [F4.3 incidence of 13.4% (9.6-17.1)], including primary liver cancer in 84 patients [6.4% (3.5-9.3)]. FT was predictive (Cox adjusted on treatment) of severe complications [AUROC 0.79 (76-82); p<0.0001], including primary liver cancer [AUROC 0.84 (80-87); p<0.0001]. Similarly TE was predictive of severe complications [AUROC 0.77 (72-81); p<0.0001], including primary liver cancer [AUROC 0.86 (81-90); p<0.0001].

CONCLUSIONS

FibroTest™ and TE increase were associated with the occurrence of all severe complications including hepatocellular carcinoma, hepatic insufficiency, and variceal bleeding. FibroTest™ increase was also associated with the occurrence of esophageal varices.

Infections during peginterferon/ribavirin therapy are associated with the magnitude of decline in absolute lymphocyte count: results of the IDEAL study

BACKGROUND

Myelosuppression due to pegylated interferon (peg-IFN) is common during treatment for hepatitis C virus. The relationship between infection risk and decreases in leukocyte lines, however, is not well established. The objective of this analysis was to determine the incidence of and risk factors for infections during peg-IFN/ribavirin (RBV) therapy.

METHODS

A total of 3070 treatment-naive, chronic hepatitis C genotype 1-infected patients were treated for up to 48 weeks with peg-IFN alfa-2b 1.5 µg/kg/week or 1 µg/kg/week, or peg-IFN alfa-2a 180 µg/week plus RBV. On-treatment leukocyte counts were obtained every 2-6 weeks. Dose reduction was required for a neutrophil count <0.75 × 10(9) cells/L, and treatment discontinuation was required for a neutrophil count <0.5 × 10(9) cells/L. Granulocyte colony-stimulating factor was prohibited. Data on infections were captured at each study visit and categorized according to MedDRA version 13.0.

RESULTS

A total of 581 (19%) patients experienced moderate, severe, or life-threatening infections as assessed by the investigator; 648 (21%) patients had at least 1 neutrophil count <0.75 × 10(9) cells/L, but only 242 (8%) sustained an infection and had a neutrophil count <0.75 × 10(9) cells/L at any time while on treatment. Twelve patients had severe or life-threatening infection and grade 3/4 neutropenia, but only 4 had temporally related infections. In a multivariate logistic regression model, nadir lymphocyte count, history of depression, and female sex, but not nadir neutrophil count, were associated with moderate, severe, or life-threatening infection.

CONCLUSIONS

Nadir lymphocyte count, not nadir neutrophil count, was independently associated with moderate, severe, or life-threatening infections in the IDEAL study. Clinicians should be aware of their patients' absolute lymphocyte counts during peg-IFN/RBV therapy; peg-IFN dose reductions may be a consideration in patients with significant lymphocytopenia (<0.5 × 10(9) cells/L).

Predictors of consent to pharmacogenomics testing in the IDEAL study

INTRODUCTION

Pharmacogenomic testing is important in developing individualized therapeutic approaches. In the phase 3 IDEAL (Individualized Dosing to Assess Optimal Pegylated Interferon Therapy) clinical trial, a subset of patients receiving peginterferon and ribavirin for treatment of chronic hepatitis C agreed to provide blood samples for genetic testing. Genome-wide association studies subsequently identified associations between IL28B polymorphism and sustained virologic response, and ITPA polymorphism and ribavirin-associated anemia.

OBJECTIVE

To characterize the groups of patients who accepted or declined pharmacogenomic testing in the IDEAL study.

METHODS

Clinical and demographic factors and treatment outcomes were compared at all sites that had approved pharmacogenomic testing. Differences between patients who consented to and declined pharmacogenomic testing were analyzed using Student's t-test and χ²-test.

RESULTS

In total, 109 of 118 sites participated in the pharmacogenomic substudy, and 1674 of 2949 (57%) patients enrolled at these sites consented to pharmacogenomic testing. More patients treated in academic medical centers than in community centers (60 vs. 52%, P<0.001) provided consent. More men than women (58 vs. 54%, P=0.04) consented to pharmacogenomic testing. There was no significant difference in pharmacogenomic participation between patients from different racial groups, including whites and African Americans (58 vs. 54%, P=0.07). Treatment outcomes were also similar according to pharmacogenomic participation.

CONCLUSION

In the IDEAL study, patient consent to pharmacogenomic testing did not introduce selection bias. Treatment at an academic center and male sex were associated with higher rates of pharmacogenomic testing consent. Efficacy and safety outcomes were similar in patients who accepted and declined pharmacogenomic testing.

Effects of ribavirin dose reduction vs erythropoietin for boceprevir-related anemia in patients with chronic hepatitis C virus genotype 1 infection--a randomized trial

BACKGROUND & AIMS

Treatment of hepatitis C virus (HCV) infection with boceprevir, peginterferon, and ribavirin can lead to anemia, which has been managed by reducing ribavirin dose and/or erythropoietin therapy. We assessed the effects of these anemia management strategies on rates of sustained virologic response (SVR) and safety.

METHODS

Patients (n = 687) received 4 weeks of peginterferon and ribavirin followed by 24 or 44 weeks of boceprevir (800 mg, 3 times each day) plus peginterferon and ribavirin. Patients who became anemic (levels of hemoglobin approximately ≤10 g/dL) during the study treatment period (n = 500) were assigned to groups that were managed by ribavirin dosage reduction (n = 249) or erythropoietin therapy (n = 251).

RESULTS

Rates of SVR were comparable between patients whose anemia was managed by ribavirin dosage reduction (71.5%) vs erythropoietin therapy (70.9%), regardless of the timing of the first intervention to manage anemia or the magnitude of ribavirin dosage reduction. There was a threshold for the effect on rate of SVR: patients who received <50% of the total milligrams of ribavirin assigned by the protocol had a significantly lower rate of SVR (P < .0001) than those who received ≥50%. Among patients who did not develop anemia, the rate of SVR was 40.1%. Eleven thromboembolic adverse events were reported in 9 of 295 patients who received erythropoietin, compared with 1 of 392 patients who did not receive erythropoietin.

CONCLUSIONS

Reduction of ribavirin dosage can be the primary approach for management of anemia in patients receiving peginterferon, ribavirin, and boceprevir for HCV infection. Reduction in ribavirin dosage throughout the course of triple therapy does not affect rates of SVR. However, it is important that the patient receives at least 50% of the total amount (milligrams) of ribavirin assigned by response-guided therapy. ClinicalTrials.gov number, NCT01023035.

Long-term clearance of hepatitis C virus following interferon α-2b or peginterferon α-2b, alone or in combination with ribavirin

Sustained virologic response (SVR) is the standard measure for evaluating response to therapy in patients with chronic hepatitis C (CHC). The aim of this study was to prospectively assess the durability of SVR in the pivotal studies of peginterferon (PEG-IFN) α-2b or IFN α-2b. We conducted two phase 3b long-term follow-up studies of patients previously treated for CHC in eight prospective randomized studies of IFN α-2b and/or PEG-IFN α-2b. Patients who achieved SVR [undetectable hepatitis C virus (HCV) RNA 24 weeks after completion of treatment] were eligible for inclusion in these follow-up studies. In total, 636 patients with SVR following treatment with IFN α-2b and 366 with SVR following treatment with PEG-IFN α-2b were enrolled. Definite relapse (quantifiable serum HCV RNA with no subsequent undetectable HCV RNA) was reported in six patients treated with IFN α-2b and three patients treated with PEG-IFN α-2b. Based on these relapses, the point estimate for the likelihood of maintaining response after 5 years was 99.2% [95% confidence interval (CI), 98.1-99.7%] for IFN α-2b and 99.4% (95% CI, 97.7-99.9%) for PEG-IFN α-2b. Successful treatment of hepatitis C with PEG-IFN α-2b or IFN α-2b leads to clinical cure of hepatitis C in the vast majority of cases.

Adherence to assigned dosing regimen and sustained virological response among chronic hepatitis C genotype 1 patients treated with boceprevir plus peginterferon alfa-2b/ribavirin

BACKGROUND

Adherence to therapeutic regimens affects the efficacy of peginterferon alfa (P) and ribavirin (R) therapy in patients with chronic hepatitis C virus genotype 1.

AIM

To determine if medication adherence impacts efficacy [sustained virological response (SVR)] with triple therapy that includes boceprevir (BOC) plus P/R.

METHODS

Adherence was determined in two Phase 3 clinical studies with BOC: SPRINT-2 (previously untreated patients) and RESPOND-2 (patients who failed previous therapy with P/R). Adherence to the assigned duration of the dosing regimen and adherence to the three times a day (t.d.s.) dosing interval of 7-9 h for BOC were assessed by the recording of data from patients' dosing diaries and by the amount of study drug dispensed and returned.

RESULTS

Most patients (63-71%) adhered to ≥80% of their assigned treatment duration and achieved SVR rates of 86-90%. In contrast, patients who adhered to <80% of their assigned treatment duration achieved SVR rates of 8-32% (P < 0.0001), particularly low in patients who failed previous therapy (SVR = 8-15%). Different rates of adherence (<60% to >80%) to the t.d.s. dosing interval (7-9 h) with BOC did not influence the SVR rates (SVR = 60-83%) with the exception of patients who failed previous treatment and adhered to <60% of the t.d.s. dosing interval with BOC (SVR = 48-50%; P = 0.005).

CONCLUSIONS

The achievement of an SVR is more dependent on adherence to the assigned duration of treatment than adherence to the t.d.s. dosing interval with boceprevir. Adherence to >60% of t.d.s. dosing with boceprevir is important in patients who failed previous therapy.

Boceprevir for previously untreated patients with chronic hepatitis C Genotype 1 infection: a US-based cost-effectiveness modeling study

BACKGROUND

SPRINT-2 demonstrated that boceprevir (BOC), an oral hepatitis C virus (HCV) nonstructural 3 (NS3) protease inhibitor, added to peginterferon alfa-2b (P) and ribavirin (R) significantly increased sustained virologic response rates over PR alone in previously untreated adult patients with chronic HCV genotype 1. We estimated the long-term impact of triple therapy vs. dual therapy on the clinical burden of HCV and performed a cost-effectiveness evaluation.

METHODS

A Markov model was used to estimate the incidence of liver complications, discounted costs (2010 US$), quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) of three treatment strategies for treatment-naïve patients with chronic HCV genotype 1. The model simulates the treatment regimens studied in SPRINT-2 in which PR was administered for 4 weeks followed by: 1) placebo plus PR for 44 weeks (PR48); 2) BOC plus PR using response guided therapy (BOC/RGT); and 3) BOC plus PR for 44 weeks (BOC/PR48) and makes projections within and beyond the trial. HCV-related state-transition probabilities, costs, and utilities were obtained from previously published studies. All costs and QALYs were discounted at 3%.

RESULTS

The model projected approximately 38% and 43% relative reductions in the lifetime incidence of liver complications in the BOC/RGT and BOC/PR48 regimens compared with PR48, respectively. Treatment with BOC/RGT is associated with an incremental cost of $10,348 and an increase of 0.62 QALYs compared to treatment with PR48. Treatment with BOC/PR48 is associated with an incremental cost of $35,727 and an increase of 0.65 QALYs compared to treatment with PR48. The ICERs were $16,792/QALY and $55,162/QALY for the boceprevir-based treatment groups compared with PR48, respectively. The ICER for BOC/PR48 compared with BOC/RGT was $807,804.

CONCLUSION

The boceprevir-based regimens used in the SPRINT-2 trial were projected to substantially reduce the lifetime incidence of liver complications and increase the QALYs in treatment-naive patients with hepatitis C genotype 1. It was also demonstrated that boceprevir-based regimens offer patients the possibility of experiencing great clinical benefit with a shorter duration of therapy. Both boceprevir-based treatment strategies were projected to be cost-effective at a reasonable threshold in the US when compared to treatment with PR48.

Anemia during treatment with peginterferon Alfa-2b/ribavirin and boceprevir: Analysis from the serine protease inhibitor therapy 2 (SPRINT-2) trial

Boceprevir (BOC) added to peginterferon alfa-2b (PegIFN) and ribavirin (RBV) significantly increases sustained virologic response (SVR) rates over PegIFN/RBV alone in previously untreated adults with chronic hepatitis C genotype 1. We evaluate the relationship of incident anemia with triple therapy. A total of 1,097 patients received a 4-week lead-in of PegIFN/RBV followed by: (1) placebo plus PegIFN/RBV for 44 weeks (PR48); (2) BOC plus PegIFN/RBV using response-guided therapy (BOC/RGT); and (3) BOC plus PegIFN/RBV for 44 weeks (BOC/PR48). The management of anemia (hemoglobin [Hb]<10 g/dL) included RBV dose reduction and/or erythropoietin (EPO) use. A total of 1,080 patients had ≥1 Hb measurement during treatment. The incidence of anemia was 50% in the BOC arms combined (363/726) and 31% in the PR48 arm (108/354, P<0.001). Among BOC recipients, lower baseline Hb and creatinine clearance were associated with incident anemia. In the BOC-containing arms, anemia was managed by the site investigators as follows: EPO without RBV dose reduction, 38%; RBV dose reduction without EPO, 8%; EPO with RBV dose reduction, 40%; and neither RBV dose reduction nor EPO, 14%. SVR rates were not significantly affected by management strategy (70%-74%), and overall patients with anemia had higher rates of SVR than those who did not develop anemia (58%). Serious and life-threatening adverse events (AEs) and discontinuations due to AEs among BOC-treated patients did not differ by EPO use.

CONCLUSION

With BOC/PR therapy, SVR rates in patients with incident anemia were higher than nonanemic patients and did not vary significantly according to the investigator-selected approach for anemia management. Prospective studies are needed to confirm this observation.

Resistance-associated amino acid variants associated with boceprevir plus pegylated interferon-α2b and ribavirin in patients with chronic hepatitis C in the SPRINT-1 trial

BACKGROUND

Resistance to direct-acting antivirals represents a new challenge in the treatment of chronic hepatitis C.

METHODS

SPRINT-1 was a randomized study of treatment-naive patients with genotype (G) 1 hepatitis C infection (n=595) that evaluated the safety and efficacy of boceprevir (BOC) when added to pegylated interferon-α2b plus ribavirin (PR). Plasma samples collected at protocol-specified visits were analysed by population sequencing for detection of BOC-associated resistance-associated variants (RAVs).

RESULTS

A total of 17/24 (71%) patients randomized to BOC with baseline RAVs achieved sustained virological response (SVR). V55A/I (n=14), Q41H (n=11) and T54S (n=9) were the most frequently detected polymorphisms at baseline. Seven non-SVR patients with baseline RAVs had V55A (relapse, n=3; breakthrough, n=1; and non-response, n=1) and/or R155K (non-response, n=2). In total, 63/144 (44%) patients with sequenced post-baseline samples (2 SVR, 61 non-SVR) had detectable RAVs after BOC treatment (G1a: R155K [39/49; 80%], V36M [37/49; 76%] and T54S [24/49; 49%]; G1b: T54S [3/11; 27%], T54A [4/11; 35%], A156S [2/11; 18%] and V170A [2/11; 18%]). RAV frequency varied according to the virological response: 90%, 67%, 27% and 37% of breakthrough, incomplete virological response, relapse and non-responder patients, respectively, had post-baseline RAVs present. Similar RAVs were identified in both the PR lead-in and no-lead-in arms and the frequency of post-baseline RAVs was highest in the low-dose ribavirin arm.

CONCLUSIONS

SVR rates were not compromised among patients with RAVs at baseline; however, a lower starting mg/kg dose of ribavirin was associated with a higher frequency of post-baseline RAVs.

Boceprevir with peginterferon alfa-2a-ribavirin is effective for previously treated chronic hepatitis C genotype 1 infection

BACKGROUND & AIMS

The addition of boceprevir to therapy with peginterferon alfa-2b and ribavirin results in significantly higher rates of sustained virologic response (SVR) in previously treated patients with chronic hepatitis C virus (HCV) genotype-1 infection, compared with peginterferon alfa-2b and ribavirin alone. We assessed SVR with boceprevir plus peginterferon alfa-2a-ribavirin (PEG2a/R) in patients with identical study entry criteria.

METHODS

In a double-blind, placebo-controlled trial, 201 patients with HCV genotype-1 who had relapsed or not responded to previous therapy were assigned to groups (1:2) and given a 4-week lead-in phase of PEG2a/R, followed by placebo plus PEG2a/R for 44 weeks (PEG2a/R) or boceprevir plus PEG2a/R for 44 weeks (BOC/PEG2a/R). The primary end point was SVR 24 weeks after therapy ended.

RESULTS

The addition of boceprevir after 4 weeks of lead-in therapy with PEG2a/R significantly increased the rate of SVR from 21% in the PEG2a/R group to 64% in the BOC/PEG2a/R group (P < .0001). Among patients with poor response to interferon therapy (<1-log(10) decline in HCV RNA at week 4), 39% in the BOC/PEG2a/R group had SVRs, compared with none of the patients in the PEG2a/R group. Among patients with good response to interferon (≥1-log(10) decline), 71% in the BOC/PEG2a/R group had SVRs, compared with 25% in the PEG2a/R group. A ≥1-log(10) decline in HCV RNA at treatment week 4 was the strongest independent predictor of SVR, exceeding that of IL-28B genotype. Among 8 patients who began the study with HCV amino acid variants associated with boceprevir resistance, 3 (38%) achieved SVRs. Fifty percent of patients in the BOC/PEG2a/R group developed anemia (hemoglobin <10.0 g/dL), compared with 27% in the PEG2a/R group; 43% vs 21%, respectively, developed neutropenia (neutrophil count <750/mm(3)).

CONCLUSIONS

The addition of boceprevir after 4 weeks of lead-in therapy with PEG2a/R caused significantly higher rates of SVR in previously treated patients with chronic HCV genotype-1 infection, compared with patients given only PEG2a/R. ClinicalTrials.gov Identifier: NCT00845065.

Factors that predict response of patients with hepatitis C virus infection to boceprevir

BACKGROUND & AIMS

Little is known about factors associated with a sustained virologic response (SVR) among patients with hepatitis C virus (HCV) infection to treatment with protease inhibitors.

METHODS

Previously untreated patients (from the Serine Protease Inhibitor Therapy 2 [SPRINT-2] trial) and those who did not respond to prior therapy (from the Retreatment with HCV Serine Protease Inhibitor Boceprevir and PegIntron/Rebetol 2 [RESPOND-2] trial) received either a combination of peginterferon and ribavirin for 48 weeks or boceprevir, peginterferon, and ribavirin (triple therapy) after 4 weeks of peginterferon and ribavirin (total treatment duration, 28-48 wk). A good response to interferon was defined as a ≥ 1 log(10) decrease in HCV RNA at week 4; a poor response was defined as a <1 log(10) decrease. We used multivariate regression analyses to identify baseline factors of the host (including the polymorphism interleukin [IL]-28B rs12979860) associated with response. The polymorphism IL-28B rs8099917 also was assessed.

RESULTS

In the SPRINT-2 trial, factors that predicted a SVR to triple therapy included low viral load (odds ratio [OR], 11.6), IL-28B genotype (rs 12979860 CC vs TT and CT; ORs, 2.6 and 2.1, respectively), absence of cirrhosis (OR, 4.3), HCV subtype 1b (OR, 2.0), and non-black race (OR, 2.0). In the RESPOND-2 trial, the only factor significantly associated with a SVR was previous relapse, compared with previous nonresponse (OR, 2.6). Most patients with rs12979860 CC who received triple therapy had undetectable levels of HCV RNA by week 8 (76%-89%), and were eligible for shortened therapy. In both studies, IL-28B rs12979860 CC was associated more strongly with a good response to interferon than other baseline factors; however, a ≥ 1 log(10) decrease in HCV-RNA level at week 4 was associated more strongly with SVR than IL-28B rs12979860. Combining the rs8099917 and rs12979860 genotypes does not increase the association with SVR.

CONCLUSIONS

The CC polymorphism at IL-28B rs12979860 is associated with response to triple therapy and can identify candidates for shorter treatment durations. A ≥ 1 log(10) decrease in HCV RNA at week 4 of therapy is the strongest predictor of a SVR, regardless of polymorphisms in IL-28B.

Refinement of stopping rules during treatment of hepatitis C genotype 1 infection with boceprevir and peginterferon/ribavirin

In comparison with peginterferon/ribavirin alone, boceprevir with peginterferon/ribavirin significantly improves sustained virological response (SVR) rates in patients with chronic hepatitis C virus (HCV) genotype 1 infections, but treatment failure remains a significant problem. Using phase 3 trial databases, we sought to develop stopping rules for patients destined to fail boceprevir-based combination therapy in order to minimize drug toxicity, resistance, and costs in the face of ultimate futility. Exploratory post hoc analyses using data from the Serine Protease Inhibitor Therapy 2 (SPRINT-2) study (treatment-naive patients) and the Retreatment With HCV Serine Protease Inhibitor Boceprevir and Pegintron/Rebetol 2 (RESPOND-2) study (treatment-experienced patients) were undertaken to determine whether protocol-specified stopping rules (detectable HCV RNA at week 24 for SPRINT-2 and at week 12 for RESPOND-2) could be refined and harmonized. In SPRINT-2, a week 12 rule with an HCV RNA cutoff of ≥ 100 IU/mL would have discontinued therapy in 65 of 195 failures (sensitivity = 33%) without sacrificing a single SVR among 475 successes (specificity = 100%). Viral variants emerged after week 12 in 36 of the 49 evaluable patients (73%) who would have discontinued at week 12 using a ≥ 100 IU/mL stopping rule. In RESPOND-2, five of six patients with week 12 HCV RNA levels between the lower limit of detection (9.3 IU/mL) and the lower limit of quantification (25 IU/mL) who continued therapy despite the protocol-stipulated futility rule achieved SVR; one additional patient with a week 12 HCV RNA level of 148 IU/mL also continued therapy, had undetectable HCV RNA at week 16, and attained SVR.

CONCLUSION

Although a stopping rule of detectable HCV RNA at week 12 would have forfeited some SVR cases, week 12 HCV RNA levels ≥ 100 IU/mL almost universally predicted a failure to achieve SVR in both treatment-naive and treatment-experienced patients. In boceprevir recipients, the combination of 2 stopping rules-an HCV RNA level ≥ 100 IU/mL at week 12 and detectable HCV RNA at week 24--maximized the early discontinuation of futile therapy and minimized premature treatment discontinuation.

Racial differences in hepatitis C treatment eligibility

Black Americans are disproportionally infected with hepatitis C virus (HCV) and are less likely than whites to respond to treatment with peginterferon (PEG-IFN) plus ribavirin (RBV). The impact of race on HCV treatment eligibility is unknown. We therefore performed a retrospective analysis of a phase 3B multicenter clinical trial conducted at 118 United States community and academic medical centers to evaluate the rates of and reasons for HCV treatment ineligibility according to self-reported race. In all, 4,469 patients were screened, of whom 1,038 (23.2%) were treatment ineligible. Although blacks represented 19% of treated patients, they were more likely not to be treated due to ineligibility and/or failure to complete required evaluations (40.2%) than were nonblack patients (28.5%; P < 0.001). After the exclusion of persons not treated due to undetectable HCV RNA or nongenotype 1 infection, blacks were 65% less likely than nonblacks to be eligible for treatment (28.1% > 17.0%; relative risk, 1.65; 95% confidence interval, 1.46-1.87; P < 0.001). Blacks were more likely to be ineligible due to neutropenia (14% versus 3%, P < 0.001), anemia (7% versus 4%, P = 0.02), elevated glucose (8% versus 3%, P < 0.001), and elevated creatinine (5% versus 1%, P < 0.001).

CONCLUSION

Largely due to a higher prevalence of neutropenia and uncontrolled medical conditions, blacks were significantly less likely to be eligible for HCV treatment. Increased access to treatment may be facilitated by less conservative neutrophil requirements and more effective care for chronic diseases, namely, diabetes and renal insufficiency.

Maintenance therapy with peginterferon alfa-2b does not prevent hepatocellular carcinoma in cirrhotic patients with chronic hepatitis C

BACKGROUND & AIMS

Several studies have reported that low doses of interferon can delay the development of hepatocellular carcinoma (HCC) and progression of chronic hepatitis C. We investigated the incidence of clinical events among participants of the Evaluation of PegIntron in Control of Hepatitis C Cirrhosis (EPIC)3 program.

METHODS

Data were analyzed from an open-label randomized study of patients with chronic hepatitis C who had failed to respond to interferon alfa plus ribavirin. All patients had compensated cirrhosis with no evidence of HCC. Patients received peginterferon alfa-2b (0.5 μg/kg/week; n=311) or no treatment (controls, n=315) for a maximum period of 5 years or until 98 patients had a clinical event (hepatic decompensation, HCC, death, or liver transplantation). The primary measure of efficacy was time until the first clinical event.

RESULTS

There was no significant difference in time to first clinical event among patients who received peginterferon alfa-2b compared with controls (hazard ratio [HR], 1.452; 95% confidence interval [CI]: 0.880-2.396). There was no decrease in the development of HCC with therapy. The time to disease progression (clinical events or new or enlarged varices) was significantly longer for patients who received peginterferon alfa-2b compared with controls (HR, 1.564; 95% CI: 1.130-2.166). In a prospectively defined subanalysis of patients with baseline portal hypertension, peginterferon alfa-2b significantly increased the time to first clinical event compared with controls (P=.016). There were no new safety observations.

CONCLUSIONS

Maintenance therapy with peginterferon alfa-2b is not warranted in all patients and does not prevent HCC. However, there is a potential clinical benefit of long-term suppressive therapy in patients with preexisting portal hypertension.

Boceprevir for untreated chronic HCV genotype 1 infection

BACKGROUND

Peginterferon-ribavirin therapy is the current standard of care for chronic infection with hepatitis C virus (HCV). The rate of sustained virologic response has been below 50% in cases of HCV genotype 1 infection. Boceprevir, a potent oral HCV-protease inhibitor, has been evaluated as an additional treatment in phase 1 and phase 2 studies.

METHODS

We conducted a double-blind study in which previously untreated adults with HCV genotype 1 infection were randomly assigned to one of three groups. In all three groups, peginterferon alfa-2b and ribavirin were administered for 4 weeks (the lead-in period). Subsequently, group 1 (the control group) received placebo plus peginterferon-ribavirin for 44 weeks; group 2 received boceprevir plus peginterferon-ribavirin for 24 weeks, and those with a detectable HCV RNA level between weeks 8 and 24 received placebo plus peginterferon-ribavirin for an additional 20 weeks; and group 3 received boceprevir plus peginterferon-ribavirin for 44 weeks. Nonblack patients and black patients were enrolled and analyzed separately.

RESULTS

A total of 938 nonblack and 159 black patients were treated. In the nonblack cohort, a sustained virologic response was achieved in 125 of the 311 patients (40%) in group 1, in 211 of the 316 patients (67%) in group 2 (P<0.001), and in 213 of the 311 patients (68%) in group 3 (P<0.001). In the black cohort, a sustained virologic response was achieved in 12 of the 52 patients (23%) in group 1, in 22 of the 52 patients (42%) in group 2 (P=0.04), and in 29 of the 55 patients (53%) in group 3 (P=0.004). In group 2, a total of 44% of patients received peginterferon-ribavirin for 28 weeks. Anemia led to dose reductions in 13% of controls and 21% of boceprevir recipients, with discontinuations in 1% and 2%, respectively.

CONCLUSIONS

The addition of boceprevir to standard therapy with peginterferon-ribavirin, as compared with standard therapy alone, significantly increased the rates of sustained virologic response in previously untreated adults with chronic HCV genotype 1 infection. The rates were similar with 24 weeks and 44 weeks of boceprevir. (Funded by Schering-Plough [now Merck]; SPRINT-2 ClinicalTrials.gov number, NCT00705432.).

Boceprevir for untreated chronic HCV genotype 1 infection

BACKGROUND

Peginterferon-ribavirin therapy is the current standard of care for chronic infection with hepatitis C virus (HCV). The rate of sustained virologic response has been below 50% in cases of HCV genotype 1 infection. Boceprevir, a potent oral HCV-protease inhibitor, has been evaluated as an additional treatment in phase 1 and phase 2 studies.

METHODS

We conducted a double-blind study in which previously untreated adults with HCV genotype 1 infection were randomly assigned to one of three groups. In all three groups, peginterferon alfa-2b and ribavirin were administered for 4 weeks (the lead-in period). Subsequently, group 1 (the control group) received placebo plus peginterferon-ribavirin for 44 weeks; group 2 received boceprevir plus peginterferon-ribavirin for 24 weeks, and those with a detectable HCV RNA level between weeks 8 and 24 received placebo plus peginterferon-ribavirin for an additional 20 weeks; and group 3 received boceprevir plus peginterferon-ribavirin for 44 weeks. Nonblack patients and black patients were enrolled and analyzed separately.

RESULTS

A total of 938 nonblack and 159 black patients were treated. In the nonblack cohort, a sustained virologic response was achieved in 125 of the 311 patients (40%) in group 1, in 211 of the 316 patients (67%) in group 2 (P<0.001), and in 213 of the 311 patients (68%) in group 3 (P<0.001). In the black cohort, a sustained virologic response was achieved in 12 of the 52 patients (23%) in group 1, in 22 of the 52 patients (42%) in group 2 (P=0.04), and in 29 of the 55 patients (53%) in group 3 (P=0.004). In group 2, a total of 44% of patients received peginterferon-ribavirin for 28 weeks. Anemia led to dose reductions in 13% of controls and 21% of boceprevir recipients, with discontinuations in 1% and 2%, respectively.

CONCLUSIONS

The addition of boceprevir to standard therapy with peginterferon-ribavirin, as compared with standard therapy alone, significantly increased the rates of sustained virologic response in previously untreated adults with chronic HCV genotype 1 infection. The rates were similar with 24 weeks and 44 weeks of boceprevir. (Funded by Schering-Plough [now Merck]; SPRINT-2 ClinicalTrials.gov number, NCT00705432.).

Boceprevir for previously treated chronic HCV genotype 1 infection

BACKGROUND

In patients with chronic infection with hepatitis C virus (HCV) genotype 1 who do not have a sustained response to therapy with peginterferon-ribavirin, outcomes after retreatment are suboptimal. Boceprevir, a protease inhibitor that binds to the HCV nonstructural 3 (NS3) active site, has been suggested as an additional treatment.

METHODS

To assess the effect of the combination of boceprevir and peginterferon-ribavirin for retreatment of patients with chronic HCV genotype 1 infection, we randomly assigned patients (in a 1:2:2 ratio) to one of three groups. In all three groups, peginterferon alfa-2b and ribavirin were administered for 4 weeks (the lead-in period). Subsequently, group 1 (control group) received placebo plus peginterferon-ribavirin for 44 weeks; group 2 received boceprevir plus peginterferon-ribavirin for 32 weeks, and patients with a detectable HCV RNA level at week 8 received placebo plus peginterferon-ribavirin for an additional 12 weeks; and group 3 received boceprevir plus peginterferon-ribavirin for 44 weeks.

RESULTS

A total of 403 patients were treated. The rate of sustained virologic response was significantly higher in the two boceprevir groups (group 2, 59%; group 3, 66%) than in the control group (21%, P<0.001). Among patients with an undetectable HCV RNA level at week 8, the rate of sustained virologic response was 86% after 32 weeks of triple therapy and 88% after 44 weeks of triple therapy. Among the 102 patients with a decrease in the HCV RNA level of less than 1 log(10) IU per milliliter at treatment week 4, the rates of sustained virologic response were 0%, 33%, and 34% in groups 1, 2, and 3, respectively. Anemia was significantly more common in the boceprevir groups than in the control group, and erythropoietin was administered in 41 to 46% of boceprevir-treated patients and 21% of controls.

CONCLUSIONS

The addition of boceprevir to peginterferon-ribavirin resulted in significantly higher rates of sustained virologic response in previously treated patients with chronic HCV genotype 1 infection, as compared with peginterferon-ribavirin alone. (Funded by Schering-Plough [now Merck]; HCV RESPOND-2 ClinicalTrials.gov number, NCT00708500.).

Hepatitis C virus treatment-related anemia is associated with higher sustained virologic response rate

BACKGROUND & AIMS

Hepatitis C virus (HCV) treatment is frequently complicated by anemia from ribavirin (RBV)-related hemolysis and peginterferon-alfa (PEG-IFN)-related bone marrow suppression. We investigated the relationships among treatment outcomes, anemia, and their management with RBV dose reduction and/or erythropoiesis-stimulating agents (ESAs).

METHODS

We analyzed data from a trial conducted at 118 United States academic and community centers in treatment-naïve patients with HCV genotype 1. Patients were treated for as many as 48 weeks with 1 of 3 PEG-IFN/RBV regimens. ESAs were permitted for anemic patients (hemoglobin [Hb] <10 g/dL) after RBV dose reduction. Sustained virologic responses (SVR) were assessed based on decreases in Hb, anemia, and ESA use.

RESULTS

While patients received treatment, 3023 had their Hb levels measured at least once. An SVR was associated with the magnitude of Hb decrease: >3 g/dL, 43.7%; ≤3 g/dL, 29.9% (P < .001). Anemia occurred in 865 patients (28.6%); 449 of these (51.9%) used ESAs. In patients with early-onset anemia (≤ 8 weeks of treatment), ESAs were associated with higher SVR rate (45.0% vs 25.9%; P < .001) and reduced discontinuation of treatment because of adverse events (12.6% vs 30.1%, P < .001). ESAs did not affect SVR or discontinuation rates among patients with late-stage anemia.

CONCLUSIONS

Among HCV genotype 1-infected patients treated with PEG-IFN/RBV, anemia was associated with higher rates of SVR. The effect of ESAs varied by time to anemia; patients with early-onset anemia had higher rates of SVR with ESA use, whereas no effect was observed in those with late-onset anemia. Prospective trials are needed to assess the role of ESAs in HCV treatment.

Serum cholesterol and statin use predict virological response to peginterferon and ribavirin therapy

Elevated low-density lipoprotein (LDL) levels and statin use have been associated with higher sustained virological response (SVR) rates in patients receiving chronic hepatitis C therapy. However, these relationships have not been well characterized in randomized controlled trials. Furthermore, little is known about the relationship between high-density lipoprotein (HDL) and virological response. To determine whether baseline LDL or HDL levels and statin use affect SVR rates, we retrospectively evaluated the IDEAL (Individualized Dosing Efficacy Versus Flat Dosing to Assess Optimal Pegylated Interferon Therapy) trial, in which 3070 treatment-naive, hepatitis C virus (HCV) genotype 1-infected patients were treated for up to 48 weeks in one of the following arms: (1) peginterferon (PEG-IFN) alfa-2b at 1.5 microg/kg/week with ribavirin (RBV) at 800 to 1400 mg/day, (2) PEG-IFN alfa-2b at 1.0 microg/kg/week with RBV at 800 to 1400 mg/day, or (3) PEG-IFN alfa-2a at 180 microg/week with RBV at 1000 to 1200 mg/day. Virological responses were assessed by pretreatment statin use and baseline elevated LDL levels (> or =130 mg/dL) or low HDL levels (<40 mg/dL for men and <50 mg/dL for women). In 1464 patients with baseline elevated LDL levels or low HDL levels, the SVR rate was significantly higher than that in patients with normal levels (44.9% versus 34.0%, P < 0.001). In 66 patients receiving a statin pretreatment, the SVR rate was higher than the rate of those not receiving it (53.0% versus 39.3%, P = 0.02). In a multivariate logistic regression analysis using the stepwise selection method with baseline characteristics, a high LDL level [odds ratio (OR) = 1.6, 95% confidence interval (CI) = 1.4-1.8, P < 0.001], a low HDL level (OR = 0.5, 95% CI = 0.3-0.8, P = 0.004), and statin use (OR = 2.0, 95% CI = 1.1-3.7, P = 0.02) were independently associated with SVR.

CONCLUSION

Baseline elevated LDL levels or low HDL levels and preemptive statin usage were associated with higher SVR rates. Prospective studies may be considered to explore the biological impact of these factors on HCV RNA replication and treatment response.

Efficacy of boceprevir, an NS3 protease inhibitor, in combination with peginterferon alfa-2b and ribavirin in treatment-naive patients with genotype 1 hepatitis C infection (SPRINT-1): an open-label, randomised, multicentre phase 2 trial

BACKGROUND

Peginterferon plus ribavirin achieves sustained virological response (SVR) in fewer than half of patients with genotype 1 chronic hepatitis C virus infection treated for 48 weeks. We tested the efficacy of boceprevir, an NS3 hepatitis C virus oral protease inhibitor, when added to peginterferon alfa-2b and ribavirin.

METHODS

In part 1 of this trial, undertaken in 67 sites in the USA, Canada, and Europe, 520 treatment-naive patients with genotype 1 hepatitis C virus infection were randomly assigned to receive peginterferon alfa-2b 1.5 mug/kg plus ribavirin 800-1400 mg daily for 48 weeks (PR48; n=104); peginterferon alfa-2b and ribavirin daily for 4 weeks, followed by peginterferon alfa-2b, ribavirin, and boceprevir 800 mg three times a day for 24 weeks (PR4/PRB24; n=103) or 44 weeks (PR4/PRB44; n=103); or peginterferon alfa-2b, ribavirin, and boceprevir three times a day for 28 weeks (PRB28; n=107) or 48 weeks (PRB48; n=103). In part 2, 75 patients were randomly assigned to receive either PRB48 (n=16) or low-dose ribavirin (400-1000 mg) plus peginterferon alfa-2b and boceprevir three times a day for 48 weeks (low-dose PRB48; n=59). Randomisation was by computer-generated code, and study personnel and patients were not masked to group assignment. The primary endpoint was SVR 24 weeks after treatment. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00423670.

FINDINGS

Patients in all four boceprevir groups had higher rates of SVR than did the control group (58/107 [54%, 95% CI 44-64], p=0.013 for PRB28; 58/103 [56%, 44-66], p=0.005 for PR4/PRB24; 69/103 [67%, 57-76], p<0.0001 for PRB48; and 77/103 [75%, 65-83], p<0.0001 for PR4/PRB44; vs 39/104 [38%, 28-48] for PR48 control). Low-dose ribavirin was associated with a high rate of viral breakthrough (16/59 [27%]), and a rate of relapse (six of 27 [22%]) similar to control (12/51 [24%]). Boceprevir-based groups had higher rates of anaemia (227/416 [55%] vs 35/104 [34%]) and dysgeusia (111/416 [27%] vs nine of 104 [9%]) than did the control group.

INTERPRETATION

In patients with untreated genotype 1 chronic hepatitis C infection, the addition of the direct-acting antiviral agent boceprevir to standard treatment with peginterferon and ribavirin after a 4-week lead-in seems to have the potential to double the sustained response rate compared with that recorded with standard treatment alone.

FUNDING

Merck.

Efficacy of boceprevir, an NS3 protease inhibitor, in combination with peginterferon alfa-2b and ribavirin in treatment-naive patients with genotype 1 hepatitis C infection (SPRINT-1): an open-label, randomised, multicentre phase 2 trial

BACKGROUND

Peginterferon plus ribavirin achieves sustained virological response (SVR) in fewer than half of patients with genotype 1 chronic hepatitis C virus infection treated for 48 weeks. We tested the efficacy of boceprevir, an NS3 hepatitis C virus oral protease inhibitor, when added to peginterferon alfa-2b and ribavirin.

METHODS

In part 1 of this trial, undertaken in 67 sites in the USA, Canada, and Europe, 520 treatment-naive patients with genotype 1 hepatitis C virus infection were randomly assigned to receive peginterferon alfa-2b 1.5 mug/kg plus ribavirin 800-1400 mg daily for 48 weeks (PR48; n=104); peginterferon alfa-2b and ribavirin daily for 4 weeks, followed by peginterferon alfa-2b, ribavirin, and boceprevir 800 mg three times a day for 24 weeks (PR4/PRB24; n=103) or 44 weeks (PR4/PRB44; n=103); or peginterferon alfa-2b, ribavirin, and boceprevir three times a day for 28 weeks (PRB28; n=107) or 48 weeks (PRB48; n=103). In part 2, 75 patients were randomly assigned to receive either PRB48 (n=16) or low-dose ribavirin (400-1000 mg) plus peginterferon alfa-2b and boceprevir three times a day for 48 weeks (low-dose PRB48; n=59). Randomisation was by computer-generated code, and study personnel and patients were not masked to group assignment. The primary endpoint was SVR 24 weeks after treatment. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00423670.

FINDINGS

Patients in all four boceprevir groups had higher rates of SVR than did the control group (58/107 [54%, 95% CI 44-64], p=0.013 for PRB28; 58/103 [56%, 44-66], p=0.005 for PR4/PRB24; 69/103 [67%, 57-76], p<0.0001 for PRB48; and 77/103 [75%, 65-83], p<0.0001 for PR4/PRB44; vs 39/104 [38%, 28-48] for PR48 control). Low-dose ribavirin was associated with a high rate of viral breakthrough (16/59 [27%]), and a rate of relapse (six of 27 [22%]) similar to control (12/51 [24%]). Boceprevir-based groups had higher rates of anaemia (227/416 [55%] vs 35/104 [34%]) and dysgeusia (111/416 [27%] vs nine of 104 [9%]) than did the control group.

INTERPRETATION

In patients with untreated genotype 1 chronic hepatitis C infection, the addition of the direct-acting antiviral agent boceprevir to standard treatment with peginterferon and ribavirin after a 4-week lead-in seems to have the potential to double the sustained response rate compared with that recorded with standard treatment alone.

FUNDING

Merck.

Interleukin-28B polymorphism improves viral kinetics and is the strongest pretreatment predictor of sustained virologic response in genotype 1 hepatitis C virus

BACKGROUND & AIMS

We recently identified a polymorphism upstream of interleukin (IL)-28B to be associated with a 2-fold difference in sustained virologic response (SVR) rates to pegylated interferon-alfa and ribavirin therapy in a large cohort of treatment-naive, adherent patients with chronic hepatitis C virus genotype 1 (HCV-1) infection. We sought to confirm the polymorphism's clinical relevance by intention-to-treat analysis evaluating on-treatment virologic response and SVR.

METHODS

HCV-1 patients were genotyped as CC, CT, or TT at the polymorphic site, rs12979860. Viral kinetics and rates of rapid virologic response (RVR, week 4), complete early virologic response (week 12), and SVR were compared by IL-28B type in 3 self-reported ethnic groups: Caucasians (n = 1171), African Americans (n = 300), and Hispanics (n = 116).

RESULTS

In Caucasians, the CC IL-28B type was associated with improved early viral kinetics and greater likelihood of RVR (28% vs 5% and 5%; P < .0001), complete early virologic response (87% vs 38% and 28%; P < .0001), and SVR (69% vs 33% and 27%; P < .0001) compared with CT and TT. A similar association occurred within African Americans and Hispanics. In a multivariable regression model, CC IL-28B type was the strongest pretreatment predictor of SVR (odds ratio, 5.2; 95% confidence interval, 4.1-6.7). RVR was a strong predictor of SVR regardless of IL-28B type. In non-RVR patients, the CC IL-28B type was associated with a higher rate of SVR (Caucasians, 66% vs 31% and 24%; P < .0001).

CONCLUSIONS

In treatment-naive HCV-1 patients treated with pegylated interferon and ribavirin, a polymorphism upstream of IL-28B is associated with increased on-treatment and sustained virologic response and effectively predicts treatment outcome.

Peginterferon alfa-2b or alfa-2a with ribavirin for treatment of hepatitis C infection

BACKGROUND

Treatment guidelines recommend the use of peginterferon alfa-2b or peginterferon alfa-2a in combination with ribavirin for chronic hepatitis C virus (HCV) infection. However, these regimens have not been adequately compared.

METHODS

At 118 sites, patients who had HCV genotype 1 infection and who had not previously been treated were randomly assigned to undergo 48 weeks of treatment with one of three regimens: peginterferon alfa-2b at a standard dose of 1.5 microg per kilogram of body weight per week or a low dose of 1.0 microg per kilogram per week, plus ribavirin at a dose of 800 to 1400 mg per day, or peginterferon alfa-2a at a dose of 180 microg per week plus ribavirin at a dose of 1000 to 1200 mg per day. We compared the rate of sustained virologic response and the safety and adverse-event profiles between the peginterferon alfa-2b regimens and between the standard-dose peginterferon alfa-2b regimen and the peginterferon alfa-2a regimen.

RESULTS

Among 3070 patients, rates of sustained virologic response were similar among the regimens: 39.8% with standard-dose peginterferon alfa-2b, 38.0% with low-dose peginterferon alfa-2b, and 40.9% with peginterferon alfa-2a (P=0.20 for standard-dose vs. low-dose peginterferon alfa-2b; P=0.57 for standard-dose peginterferon alfa-2b vs. peginterferon alfa-2a). Estimated differences in response rates were 1.8% (95% confidence interval [CI], -2.3 to 6.0) between standard-dose and low-dose peginterferon alfa-2b and -1.1% (95% CI, -5.3 to 3.0) between standard-dose peginterferon alfa-2b and peginterferon alfa-2a. Relapse rates were 23.5% (95% CI, 19.9 to 27.2) for standard-dose peginterferon alfa-2b, 20.0% (95% CI, 16.4 to 23.6) for low-dose peginterferon alfa-2b, and 31.5% (95% CI, 27.9 to 35.2) for peginterferon alfa-2a. The safety profile was similar among the three groups; serious adverse events were observed in 8.6 to 11.7% of patients. Among the patients with undetectable HCV RNA levels at treatment weeks 4 and 12, a sustained virologic response was achieved in 86.2% and 78.7%, respectively.

CONCLUSIONS

In patients infected with HCV genotype 1, the rates of sustained virologic response and tolerability did not differ significantly between the two available peginterferon-ribavirin regimens or between the two doses of peginterferon alfa-2b. (ClinicalTrials.gov number, NCT00081770.)

Peginterferon alfa-2b and weight-based or flat-dose ribavirin in chronic hepatitis C patients: a randomized trial

This prospective, multicenter, community-based and academic-based, open-label, investigator-initiated, U.S. study evaluated efficacy and safety of pegylated interferon (PEG-IFN) alfa-2b plus a flat or weight-based dose of ribavirin (RBV) in adults with chronic hepatitis C. Patients (n = 5027) were randomly assigned to receive PEG-IFN alfa-2b 1.5 microg/kg/week plus flat-dose (800 mg/day) or weight-based (800-1400 mg/day) RBV for 48 weeks (patients with genotype 1, 4, 5, or 6) and for 24 or 48 weeks (genotype 2/3 patients). Primary end point was sustained virologic response (undetectable [<125 IU/mL] serum hepatitis C virus RNA at 24-week follow-up). Sustained virologic response, but not end-of-treatment, rates were significantly higher with weight-based than with flat-dose RBV (44.2% versus 40.5%; P = 0.008). Sustained virologic response rates by intention-to-treat analysis were 34.0% and 28.9%, respectively, in genotype 1 patients (P = 0.005) and 31.2% and 26.7%, respectively, in genotype 1 patients with high baseline viral load (P = 0.056). In genotype 2/3 patients, rates were not significantly different (61.8% and 59.5%, respectively) regardless of treatment duration. Besides greater hemoglobin reductions with weight-based RBV, safety profiles were similar across RBV dosing groups, including the 1400-mg/day group.

CONCLUSION

PEG-IFN alfa-2b plus weight-based RBV is more effective than flat-dose RBV, particularly in genotype 1 patients, providing equivalent efficacy across all weight groups. RBV 1400 mg/day is appropriate for patients 105 to 125 kg. For genotype 2/3 patients, 24 weeks of treatment with flat-dose RBV is adequate; no evidence of additional benefit of extending treatment to 48 weeks was demonstrated.

Impact of weight-based ribavirin with peginterferon alfa-2b in African Americans with hepatitis C virus genotype 1

WIN-R (Weight-based dosing of pegINterferon alfa-2b and Ribavirin) was a multicenter, randomized, open-label, investigator-initiated trial involving 236 community and academic sites in the United States, comparing response to pegylated interferon (PEG-IFN) alfa-2b plus a flat or weight-based dose of ribavirin (RBV) in treatment-naive patients with chronic hepatitis C and compensated liver disease. Patients were randomized to receive PEG-IFN alfa-2b at 1.5 microg/kg/week plus flat-dose (800 mg/day) or weight-based-dose RBV (800 mg/day for weight <65 kg, 1000 mg/day for 65-85 kg, 1200 mg/day for >85-105 kg, or 1400 mg/day for >105-<125 kg). Sustained virologic response (SVR; undetectable [<125 IU/mL] hepatitis C virus [HCV] RNA at end of follow-up) in patients > or =65 kg was the primary end point. Low SVR rates have been reported among African American individuals, in whom there is a preponderance of HCV genotype 1. This subanalysis of WIN-R was conducted to evaluate the efficacy of weight-based dosing among African American individuals with genotype 1 infection enrolled in the trial. Of 362 African American patients in the primary efficacy analysis, 188 received RBV flat dosing and 174 received weight-based dosing. SVR rates were higher (21% versus 10%; P = 0.0006) and relapse rates were lower (22% versus 30%) in the weight-based-dose group than in the flat-dose group. Safety and rates of drug discontinuation were similar between the 2 groups.

CONCLUSION

Weight-based dosing of RBV is more effective than flat dosing in combination with PEG-IFN alfa-2b in African American individuals with HCV genotype 1. Even with weight-based dosing, response rates in African American individuals are lower than reported in other ethnic groups.

Hemopexin decreases spontaneous chemiluminescence of cold preserved liver after reperfusion

Hemopexin is a plasma protein with exceptionally high affinity for heme. During liver transplantation heme is released via lysis of transfused blood. This heme may catalyze peroxidative reactions that contribute to "reperfusion" injury of the organ. Using a rat liver model of cold storage and reperfusion we tested the potential anti-oxidant effects of hemopexin. After 3 h of cold storage rat liver was reperfused with warm oxygenated buffer. Spontaneous liver chemiluminescence, which is a parameter of oxyradical production, was measured during reperfusion and expressed as an index of free radical production (IFRP). Chemiluminescence reached a maximum within 5 min of reperfusion and decreased to baseline within 30 min. Addition of hemopexin to the perfusate (5 microM) significantly decreased the IFRP. By contrast, the control proteins albumin and gamma-globulin (10 microM) had a smaller non-significant effect. The data suggest that heme could be complexed by hemopexin during reperfusion, thus inhibiting heme mediated cellular injury.

Efficacy of interferon monotherapy in the treatment of relapsers and nonresponders with chronic hepatitis C infection

Results of numerous studies have demonstrated similar efficacy profiles for the interferons (IFNs) currently approved for the treatment of chronic hepatitis C virus (HCV) infection. Although it has been suggested that some IFNs are more efficacious in certain patient populations, the current data support an equivalent efficacy and safety profile for these agents. Among patients requiring retreatment, no single study has made a direct comparison of IFN alfa-2b (IFN-alpha 2b) and consensus IFN (CIFN) in patients who have relapsed or have not responded to previous IFN therapy. However, at least 11 studies using IFN-alpha 2b and 1 using CIFN have demonstrated efficacy in the relapsing and nonresponding patient populations. A review of these studies suggests that overall efficacy and tolerability are similar regardless of IFN-alpha subtype. Overall, up to 59% and 83% of relapsed patients retreated with IFN have shown sustained response rates, as measured by negative HCV RNA titer and normalization of alanine aminotransferase (ALT) levels, respectively. Up to 14% and 25% of patients who failed to respond to previous IFN therapy have shown sustained HCV RNA response and normalization of ALT, respectively, after retreatment.

Chemiluminescent measurement of increased free radical formation after ischemia/reperfusion. Mechanisms of free radical formation in the liver

It has been proposed that xanthine oxidase-derived superoxide mediates reperfusion injury in the liver; however, there is a little direct evidence to support this hypothesis. In this paper we describe a model system to directly and noninvasively measure oxyradical formation and hepatic injury in isolated perfused rat liver. Using this sensitive chemiluminescent technique, we clearly demonstrate the theorized burst in oxygen radical production upon reperfusion of previously ischemic liver, without perturbing the system with chemical luminescence enhancers. This increase in chemiluminescence (CL) upon reperfusion was diminished by the free radical scavengers trolox and ascorbate, as well as N-2-mercaptoproprionyl-glycine (MPG), thereby confirming the oxyradical nature of this signal. Additionally, superoxide dismutase and the xanthine oxidase inhibitor allopurinol, but not catalase, attenuated the reperfusion effect, providing the most direct evidence so far that XOD derived superoxide anion is formed during liver reperfusion. Hepatic injury (AST release) did not appear to relate to increased CL, supporting the notion that the oxyradical flux may serve as a signal for other events leading to tissue injury. Further studies using this sensitive chemiluminescent technique should aid in delineating the detailed mechanism(s) of reperfusion injury.

Hepatic free radical production after cold storage: Kupffer cell-dependent and -independent mechanisms in rats

BACKGROUND/AIMS

Free radicals are important mediators of reperfusion injury; however, the mechanism(s) of oxyradical production after liver reimplantation are not well understood. A model of cold storage and reperfusion using low-level chemiluminescence to directly measure oxyradical production during reperfusion was developed.

METHODS

Rat livers were harvested and stored at 4 degrees C in University of Wisconsin cold-storage solution or Euro-Collins solution for 0-48 hours and then flushed and reperfused with warm oxygenated (37 degrees C) Krebs-Henseleit buffer. Liver chemiluminescence was measured using a sensitive photomultiplier tube, and hepatocellular injury was assessed by measuring aspartate aminotransferase release into the perfusate.

RESULTS

Chemiluminescence reached a maximum within 5 minutes of reperfusion and then decreased to a baseline within 30 minutes. There was a marked increase in chemiluminescence after only a short period of storage in University of Wisconsin cold-storage solution. Chemiluminescence decreased with longer periods of storage but steadily increased again after 16 hours of storage. Chemiluminescence after 22 hours of storage, but not after 3 hours of storage, was decreased by pretreatment with the Kupffer cell inactivator gadolinium chloride.

CONCLUSIONS

The data suggest two mechanisms of oxyradical production during cold storage and reperfusion of the rat liver. The later phase seems to be Kupffer cell dependent.

Transjugular intrahepatic portosystemic shunting: decreased survival for patients with high APACHE II scores

OBJECTIVES

To determine which clinical characteristics are associated with decreased survival after transjugular intrahepatic portosystemic shunting (TIPS).

METHODS

Forty-nine consecutive patients were treated with TIPS; 46 of them had refractory variceal bleeding. Univariate statistics and logistic regression analyses were used to determine the relationship between clinical, biochemical, and hemodynamic variables and 30-day) survival.

RESULTS

Shunt insertion was successful in 48 (98.0%) of 49 cases. Median portal-systemic gradient was reduced from 22.5 (range 9-36) [median (5th-95th percentile)] to 12 (range 4-20) mm Hg. Thirty (61.2%) of 49 patients survived more than 30 days; four patients died more than 30 days after TIPS in mean follow-up of 8.4 months. Significant differences (p < 0.05) were found between those who survived more than 30 days and those who did not, with respect to preprocedural prothrombin time, bilirubin, albumin, alanine aminotransferase, and treatment with vasopressin and nitrates, balloon tamponade, or mechanical ventilation. Whereas there were no significant differences between the pre- and post-TIPS portal vein pressures and portal-systemic gradients in survivors and non-survivors, the pre- and post-TIPS hepatic vein pressures were significantly lower in survivors. Survival was inversely proportional to Child-Pugh class (p < 0.01) and to APACHE II score (p < 0.01). The single determinant most closely associated with decreased survival in the month after TIPS was the APACHE II score, a score of 18 stratifying patients into those at low and high risk of mortality [odds ratio 21.7 (CI 3.6-131.7)]. Only 1 (7.7%) of 13 patients with Child-Pugh C cirrhosis and an APACHE II score exceeding 18 survived more than 30 days.

CONCLUSIONS

Patients with advanced cirrhosis, especially those with high pre-TIPS APACHE II scores, are at high risk for reduced survival after TIPS, despite adequate portal decompression.

Endotoxin-stimulated nitric oxide production increases injury and reduces rat liver chemiluminescence during reperfusion

BACKGROUND/AIMS

Nitric oxide has many physiological functions and may play an important role in modulating tissue injury. However, the mechanism of NO action in ischemia/reperfusion injury is completely unknown. This report investigates the role of NO in hepatic reperfusion injury.

METHODS

Rat liver was oxygenated for 30 minutes, followed by 30 minutes of ischemia, and then reperfused for 30 minutes. Perfusate was sampled for aspartate aminotransferase content, as an indication of hepatic injury, and for nitrite, an index of NO production. Spontaneous organ chemiluminescence was continuously monitored as a measure of oxyradical production.

RESULTS

NO production by the perfused rat liver was induced in vivo by pretreatment with Escherichia coli lipopolysaccharide. This induction led to an increase in hepatic injury during reperfusion that was partially ameliorated by the NO synthase inhibitor NG-monomethyl-L-arginine. Chemiluminescence during reperfusion, a measure of superoxide production in this system, was also decreased in the lipopolysaccharide-treated animals, and this effect was blunted by NG-monomethyl-L-arginine.

CONCLUSIONS

These data suggest that NO may combine with superoxide formed during reperfusion to directly cause hepatocellular injury. In vitro work shows that this chemical product is the highly toxic species peroxynitrite.

Evaluation of purine nucleoside phosphorylase release as a measure of hepatic endothelial cell injury

With emerging data that endothelial cell (EC) injury is the limiting factor in liver preservation and hepatic function, a simple and reliable biochemical technique for monitoring EC injury is needed. Measurement of purine nucleoside phosphorylase (PNP) release into the circulation from perfused liver has been proposed as such a method. However, our experiments with perfused rat liver did not display a clear or direct relationship between PNP release and endothelial cell injury. Therefore, we re-examined the suitability of using PNP as a measure of nonparenchymal injury by measuring its distribution in purified populations of hepatocytes, ECs, and Kupffer cells (KCs) and correlating cell injury and enzyme release in short-term cultures at 37 degrees C of each cell type. Purified cells were incubated (4 x 10(6) cells/mL) in oxygen or nitrogen saturated. Wisconsin solution or Krebs buffer for 6 hours, with cell viability and PNP release assayed every 2 hours. ECs had the lowest specific activity (27 +/- 9 U/mg protein; mean +/- standard error of the mean [SEM]) compared with both hepatocytes (115 +/- 15) and KCs (66 +/- 18). Despite a decrement in EC and KC viability over time in each incubation solution, there was poor correlation between time of incubation and PNP release (r = .01 to .22), and between cell viability and PNP release (r = .01 to .16). In contrast, PNP release from incubated hepatocytes correlated with the length of incubation (r = .57 to .78) as well as cell injury (r = .63 to .77) in all four test solutions.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased oxyradical production during reoxygenation of perfused rat liver. Signal versus injury

Despite general agreement on the importance of oxyradicals in mediating "reperfusion" injury, the precise event(s) mediated by increased free radical production remain unclear. In this study we describe for the first time a model of unenhanced chemiluminescence of isolated perfused rat liver demonstrating a marked increase in oxyradical production after reoxygenation. Using aspartate aminotransferase and purine nucleoside phosphorylase release as measures of liver injury, there was no direct link between oxyradical production and hepatic injury. However, there was an abrupt increase in neutrophil chemotaxis activity in the perfusate at the time of reoxygenation with a subsequent decrement, following the pattern of oxyradical production. These data suggest that free radical formation during hepatic reperfusion may mediate signal transduction, as opposed to direct cell injury, as a primary mechanism of action.

Rapid conversion to high xanthine oxidase activity in viable Kupffer cells during hypoxia

It has been widely postulated that the central mechanism of hepatic reperfusion injury involves the conversion, during ischemia, of the enzyme xanthine dehydrogenase (XDH) to its free radical-producing form, xanthine oxidase (XOD). However, this theory has been questioned because (a) XDH to XOD conversion in whole liver occurs very slowly; (b) the cellular distribution of XDH/XOD is unclear; and (c) the direct demonstration of XDH to XOD conversion in viable cells is lacking. In this paper, we address all three issues by measuring XDH to XOD conversion and cell viability in purified populations of hepatic endothelial cells (EC), Kupffer cells (KC), and hepatocytes (HEP). Although XDH/XOD activity on a cellular basis was greater in hepatocytes (0.92 +/- 0.12 mU/10(6) cells) than ECs (0.03 +/- 0.01) or KCs (0.12 +/- 0.04), XDH + XOD specific activity was similar in all three cell types (HEP 1.85 +/- 0.10 U/g protein; EC 1.69 +/- 0.54; KC 2.30 +/- 0.22). Over 150 min of warm (37 degrees C) or 24 h of cold (4 degrees C) hypoxia, percent XOD activity increased slowly in ECs, from 21 +/- 2% (basal) to 39 +/- 3% (warm) and 49 +/- 5% (cold) and in HEPs (29 +/- 2% to 38 +/- 3% and 49 +/- 2%), but converted significantly faster in KCs (28 +/- 3% to 91 +/- 7% and 94 +/- 4%). The dramatic changes in Kupffer cell XOD during cold hypoxia occurred despite only minor changes in cell viability. When hypoxic KCs were reoxygenated after 16 h of cold hypoxia, there was a marked increase in cell death that was significantly blocked by allopurinol. These data suggest that significant conversion to the free radical-producing state occurs within viable KCs, and that Kupffer cell XOD may play an important role in mediating reperfusion injury in the liver.

Evaluation of University of Wisconsin cold-storage solution in warm hypoxic perfusion of rat liver: the addition of fructose reduces injury

BACKGROUND

University of Wisconsin cold-storage solution (UW solution) has markedly improved organ preservation for liver transplantation. However, the efficacy of this solution in preserving hepatocyte viability during warm ischemia is undefined; hence, the effects of UW solution on warm hypoxic injury in the isolated perfused rat liver were examined.

METHODS

Livers were perfused using a modified protocol that included a period of hypoxic perfusion with isosmotic Krebs' solution at the end of each experiment. Hepatic injury was evaluated by aspartate aminotransferase (AST) release into the perfusate and the trypan blue perfusion technique.

RESULTS

Although UW solution appeared to decrease hepatic injury during hypoxic perfusion, as reflected by low AST release, perfusion with UW solution led to hepatocyte shrinkage and cessation of bile flow even under oxygenated conditions. UW solution did not protect against warm hypoxic injury, as assessed by AST release into the perfusate (182 +/- 15 U/mL, mean +/- SD) or trypan blue staining of the dead hepatocyte nuclei (56% +/- 5%). However, the addition of fructose to UW solution resulted in a significant decrease in AST release (66 +/- 15 U/mL) and parenchymal cell death (39% +/- 7%).

CONCLUSIONS

These data suggest that the addition of fructose or other gluconeogenic substrates may complement the overall hepatoprotective effects of UW solution, particularly during periods of warm hypoxia.

Recurrent bleeding from anorectal varices: successful treatment with a transjugular intrahepatic portosystemic shunt

Anorectal varices are portal-systemic collaterals commonly found in patients with portal hypertension. Although these varices rarely bleed, when bleeding does occur it may be massive and life threatening. Anorectal varices may be mistaken for hemorrhoids and there is no agreed upon method for their definitive diagnosis. Additionally, there is no standard therapy for bleeding anorectal varices, and when techniques designed for the control of hemorrhoidal bleeding are employed the results can be disastrous. We report here the first use of a transjugular intrahepatic portosystemic shunt (TIPS) for the permanent control of bleeding anorectal varices. Magnetic resonance imaging/magnetic resonance venography (MRI/V) was used as a non-invasive method for the identification of anorectal varices and to confirm the successful decompression of these varices with TIPS placement. MRI/V and TIPS may provide significant advances in the diagnosis and treatment of rectal variceal bleeding.

Hypoxic liver injury and the ameliorating effects of fructose: the "glucose paradox" revisited

It has been independently postulated that nutritional status is a modulator of the hepatic injury response to hypoxia and that glucose may be a poor substrate for hepatocellular metabolism. This study provides data linking these two concepts within the framework of metabolic zonation of the liver. With the use of a hypoxically perfused isolated rat liver model, cellular injury, as reflected by aspartate aminotransferase (AST) release, was significantly greater in the liver of fasted (mean AST 489 U/g liver at 3 h) than fed (40 U/g) animals. The extent of injury during hypoxia was decreased to a comparable degree in fasted livers perfused with Wisconsin solution (27 U/g) or 20 mM fructose (51 U/g). Perfusion with (11.5 mM) glucose plus insulin provided no hepatoprotection (791 U/g); however, supraphysiological amounts of glucose (100 mM) with (310 U/g) or without (321 U/g) insulin (10 U) or dihydroxyacetone (220 U/g) provided a modest reduction in AST release. Cellular injury measured by trypan blue uptake showed a marked zonal pattern, with upstream regions incurring greater parenchymal and nonparenchymal injury than downstream areas. These data that indicate that exogenous glucose is poorly utilized as an energy substrate by the liver during hypoxia are consistent with data from the fasted-refed rat model, suggesting a "glucose paradox" in the liver. The findings also suggest that low levels of oxygen are an important factor mediating "hypoxic" liver injury.

Enhanced activity of the free radical producing enzyme xanthine oxidase in hypoxic rat liver. Regulation and pathophysiologic significance

It has been widely proposed that conversion of xanthine dehydrogenase (XDH) to its free radical-producing form, xanthine oxidase (XOD), underlies ischemic/reperfusion injury, although the relationship of this conversion to hypoxia and its physiologic control have not been defined. This study details the time course and control of this enzymatic interconversion. In a functionally intact, isolated perfused rat liver model, mean % XOD activity increased as a function of both the duration (25 to 45% in 3 h) and degree (r = 0.97) of hypoxia. This process was markedly accelerated in ischemic liver by an overnight fast (45 vs. 30% at 2 h), and by imposing a short period of in vivo ischemia (cardiopulmonary arrest 72%). Moreover, only under these conditions was there a significant rise in the XOD activity due to the conformationally altered XDH molecule (XODc, 18%), as well as concomitant morphologic injury. Neither circulating white blood cells nor thrombosis appeared to contribute to the effects of in vivo ischemia on enzyme conversion. Thus, it is apparent that conversion to the free radical-producing state, with high levels of XOD activity and concurrent cellular injury, can be achieved during a relatively short period of hypoxia under certain well-defined physiologic conditions, in a time course consistent with its purported role in modulating reperfusion injury. These data also suggest that the premorbid condition of organ donors (e.g., nutritional status and relative state of hypoxia) is important in achieving optimal organ preservation.

Developmental changes of cerebral phenylalanine uptake from severely elevated blood levels

Brain phenylalanine concentrations at plasma levels raised to that in phenylketonuric subjects were studied in rats from fetal through postnatal life. Suppression of the hepatic phenylalanine hydroxylase with alpha methylphenylalanine, and injections of age-adjusted doses of phenylalanine on the next day, assured the persistence of the same elevation of plasma levels for at least four hours prior to assay. The net phenylalanine uptake determined under these conditions underwent several-fold decreases between the fourth day and the end of the suckling period, and by about the age of 30 days it was as low as in adulthood. The development of transport properties studied here could contribute to the change with age in the vulnerability of the brain to the same degree of hyperphenylalaninemia and, since the cerebral phenylalanine uptake may decrease to non-damaging levels during childhood, it is pertinent to defining the age at which the rigorous diet of phenylketonurics might be safely relaxed.

Modulation of cerebral catecholamine concentrations during hyperphenylalaninaemia

Hyperphenylalaninaemia induced by daily injections of alpha-methylphenylalanine plus phenylalanine caused 20-40% decreases in cerebral dopamine (3,4-dihydroxyphenethylamine) and noradrenaline in 7- and 11-day-old rats. alpha-Methylphenylalanine alone as well as phenylalanine alone caused cerebral dopamine depletion. However, the effects were not additive, in that the depletion caused by alpha-methylphenylalanine was greater, not less, than that after treatment with both it and phenylalanine. Increased concentrations of tyrosine in the brain, owing to administered or endogenously formed tyrosine, could overcome the effect of excess phenylalanine on cerebral dopamine content. The fact that the inhibition of tyrosine hydroxylase by phenylalanine (or alpha-methylphenylalanine) in vitro was overcome by tyrosine concentrations similar to those effective in vivo further implicates the tyrosine hydroxylase inhibition as the mechanism underlying the dopamine depletion in hyperphenylalaninaemia. These results provide a theoretical basis for elevation, by tyrosine supplementation, of the cerebral phenylalanine/tyrosine ratio as a possible treatment modality for phenylketonuria.

The effects of hyperphenylalaninemia on fetal development: a new animal model of maternal phenylketonuria

A new model has been developed for the study of maternal phenylketonuria. Beginning on the 12th day of gestation the diet of pregnant rats was supplemented with 0.5% alpha-methylphenylalanine and 3% phenylalanine. This resulted in an 83% reduction of hepatic phenylalanine hydroxylase activity. The maternal plasma phenylalanine was elevated 10-20-fold for two-thirds of the day, but the degree and persistence of the fetal hyperphenylalaninemia may have been even greater. The brain phenylalanine concentrations in the fetus were raised up to 2900 nmole/g brain, whereas the highest level observed in the dam was 382 nmole/g. Experimentally-treated fetuses showed small reductions in both body and brain weight when compared to age-matched controls; however, no differences were seen in crown to rump length, litter size, DNA and protein concentrations per g, or in postnatal survival. Initiation of the diet at conception rather than on the 12th day caused a significantly greater inhibition of fetal growth, and 21% mortality. The fetal cerebral concentrations of methionine and the branched chain amino acids (valine, leucine and isoleucine) were decreased by hyperphenylalaninemia. From the 16th day on, the concentration of the inhibitor neurotransmitter glycine was elevated. Cerebral serotonin showed a 20-30% deficit and its primary metabolite 5-hydroxyindoleacetic acid a 71-77% deficit. Of twelve enzymes quantified in the brains of hyperphenylalaninemic fetuses only phosphoserine phosphatase showed any change. From the 20th to the 22nd day of gestation its activity was 46-67% higher in experimental than in normal fetuses. Measurement on the 22nd day of gestation showed that the increases in phosphoserine phosphatase activity and glycine content were present in brain stem, cerebellum, and forebrain.

Sex differences in drug-induced rotation in two strains of rats

Female Fischer and Sprague-Dawley rats rotate significantly more in response to D-amphetamine sulfate (1 mg/kg, i.p.) than their male littermates. Although Sprague-Dawley males rotate more than females when injected with apomorphine hydrochloride (10 mg/kg, i.p.), Fischer males and females respond similarly to this drug. The sexually dimorphic behavioral response to amphetamine appears to be due to differences in brain sensitivity to this drug, and may relate to reports of sex-related differences in nigrostriatal dopaminergic activity.