Daclatasvir and asunaprevir plus peginterferon alfa and ribavirin in HCV genotype 1 or 4 non-responders.

BACKGROUND & AIMS: Improved therapies for peginterferon/ribavirin null or partial responders are needed. This study evaluated daclatasvir (NS5A inhibitor) and asunaprevir (NS3 protease inhibitor) plus peginterferon alfa-2a and ribavirin in this patient population. METHODS: This open-label, phase 3 study (HALLMARK-QUAD; NCT01573351) treated patients with chronic hepatitis C virus (HCV) genotype 1 (n=354) or 4 (n=44) infection who had a prior null or partial response to peginterferon/ribavirin. Patients received daclatasvir 60 mg once-daily plus asunaprevir 100mg twice-daily, with weekly peginterferon alfa-2a and weight-based ribavirin for 24 weeks. The primary endpoint was sustained virological response at post-treatment week 12 (SVR12) among genotype 1-infected patients. RESULTS: Daclatasvir plus asunaprevir and peginterferon/ribavirin demonstrated SVR12 rates of 93% (95% CI 90-96) in prior non-responders infected with HCV genotype 1. SVR12 rates among genotype 4-infected patients were 98% (95% CI 93-100); one patient had a missing post-treatment week-12 HCV-RNA measurement, but achieved an SVR at post-treatment week 24, yielding a 100% SVR rate in genotype 4 patients. Prior peginterferon/ribavirin response, sex, age, IL28B genotype, or cirrhosis status did not influence SVR12 rates. Serious adverse events occurred in 6% of patients; 5% discontinued treatment due to an adverse event. Grade 3/4 laboratory abnormalities included neutropenia (22%), lymphopenia (16%), anemia (6%), thrombocytopenia (4%), and ALT/AST elevations (3% each). CONCLUSIONS: Daclatasvir plus asunaprevir and peginterferon/ribavirin demonstrated high rates of SVR12 in genotype 1- or 4-infected prior null or partial responders. The combination was well tolerated and no additional safety and tolerability concerns were observed compared with peginterferon/ribavirin regimens.

Response-guided telaprevir combination treatment for hepatitis C virus infection.

BACKGROUND: Patients with chronic infection with hepatitis C virus (HCV) genotype 1 often need 48 weeks of peginterferon-ribavirin treatment for a sustained virologic response. We designed a noninferiority trial (noninferiority margin, -10.5%) to compare rates of sustained virologic response among patients receiving two treatment durations. METHODS: We enrolled patients with chronic infection with HCV genotype 1 who had not previously received treatment. All patients received telaprevir at a dose of 750 mg every 8 hours, peginterferon alfa-2a at a dose of 180 µg per week, and ribavirin at a dose of 1000 to 1200 mg per day, for 12 weeks (T12PR12), followed by peginterferon-ribavirin. Patients who had an extended rapid virologic response (undetectable HCV RNA levels at weeks 4 and 12) were randomly assigned after week 20 to receive the dual therapy for 4 more weeks (T12PR24) or 28 more weeks (T12PR48). Patients without an extended rapid virologic response were assigned to T12PR48. RESULTS: Of the 540 patients, a total of 352 (65%) had an extended rapid virologic response. The overall rate of sustained virologic response was 72%. Among the 322 patients with an extended rapid virologic response who were randomly assigned to a study group, 149 (92%) in the T12PR24 group and 140 (88%) in the T12PR48 group had a sustained virologic response (absolute difference, 4 percentage points; 95% confidence interval, -2 to 11), establishing noninferiority. Adverse events included rash (in 37% of patients, severe in 5%) and anemia (in 39%, severe in 6%). Discontinuation of all the study drugs was based on adverse events in 18% of patients overall, as well as in 1% of patients (all of whom were randomly assigned) in the T12PR24 group and 12% of the patients randomly assigned to the T12PR48 group (P<0.001). CONCLUSIONS: In this study, among patients with chronic HCV infection who had not received treatment previously, a regimen of peginterferon-ribavirin for 24 weeks, with telaprevir for the first 12 weeks, was noninferior to the same regimen for 48 weeks in patients with undetectable HCV RNA at weeks 4 and 12, with an extended rapid virologic response achieved in nearly two thirds of patients. (Funded by Vertex Pharmaceuticals and Tibotec; ILLUMINATE ClinicalTrials.gov number, NCT00758043.).

Combination therapy with telaprevir for chronic hepatitis C virus genotype 1 infection in patients with HIV: a randomized trial.

BACKGROUND: Telaprevir (TVR) plus peginterferon-α2a (PEG-IFN-α2a) and ribavirin substantially increases treatment efficacy for genotype 1 chronic hepatitis C virus (HCV) infection versus PEG-IFN-α2a-ribavirin alone. Its safety and efficacy in patients with HCV and HIV-1 are unknown. OBJECTIVE: To assess the safety and efficacy of TVR plus PEG-IFN-α2a-ribavirin in patients with genotype 1 HCV and HIV-1 and to evaluate pharmacokinetics of TVR and antiretrovirals during coadministration. DESIGN: Phase 2a, randomized, double-blind, placebo-controlled study. (ClinicalTrials.gov: NCT00983853). SETTING: 16 international multicenter sites. PATIENTS: 62 patients with HCV genotype 1 and HIV-1 who were HCV treatment-naive and receiving 0 or 1 of 2 antiretroviral regimens were randomly assigned to TVR plus PEG-IFN-α2a-ribavirin or placebo plus PEG-IFN-α2a-ribavirin for 12 weeks, plus 36 weeks of PEG-IFN-α2a-ribavirin. MEASUREMENTS: HCV RNA concentrations. RESULTS: Pruritus, headache, nausea, rash, and dizziness were higher with TVR plus PEG-IFN-α2a-ribavirin during the first 12 weeks. During this period, serious adverse events occurred in 5% (2 in 38) of those receiving TVR plus PEG-IFN-α2a-ribavirin and 0% (0 in 22) of those receiving placebo plus PEG-IFN-α2a-ribavirin; the same number in both groups discontinued treatment due to adverse events. Sustained virologic response occurred in 74% (28 in 38) of patients receiving TVR plus PEG-IFN-α2a-ribavirin and 45% (10 in 22) of patients receiving placebo plus PEG-IFN-α2a-ribavirin. Rapid HCV suppression was seen with TVR plus PEG-IFN-α2a-ribavirin (68% [26 in 38 patients] vs. 0% [0 in 22 patients] undetectable HCV RNA levels by week 4). Two patients had on-treatment HCV breakthrough with TVR-resistant variants. Patients treated with antiretroviral drugs had no HIV breakthroughs; antiretroviral exposure was not substantially modified by TVR. LIMITATION: Small sample size and appreciable dropout rate. CONCLUSION: In patients with HCV and HIV-1, more adverse events occurred with TVR versus placebo plus PEG-IFN-α2a-ribavirin; these were similar in nature and severity to those in patients with HCV treated with TVR. With or without concomitant antiretrovirals, sustained virologic response rates were higher in patients treated with TVR versus placebo plus PEG-IFN-α2a-ribavirin.

Impact of peginterferon alpha and ribavirin treatment on lipid profiles and insulin resistance in Hepatitis C virus/HIV-coinfected persons: the AIDS Clinical Trials Group A5178 Study.

BACKGROUND: The effect of peginterferon alpha/ribavirin (PEG-IFN/RBV) and hepatitis C virus (HCV) clearance on lipid and insulin resistance (IR) profiles in HCV/human immunodeficiency virus (HIV) coinfection is unknown. METHODS: We measured fasting total cholesterol (TC), low-density lipoprotein (LDL-C), high-density lipoproteins (HDL-C), triglycerides (TG), glucose, and insulin at defined intervals in the A5178 study (N = 329), a prospective treatment trial in HCV/HIV coinfection. Changes from baseline and the relation between baseline values of these variables to sustained virologic response (SVR) were determined. RESULTS: Of 182 subjects with metabolic data, 98 achieved early virologic response (EVR) and continued PEG-IFN/RBV. Among those, median pretreatment HCV RNA was 6.6 log(10 )IU/mL; 73% had HCV genotype 1. Median pretreatment TC was 176 mg/dL (interquartile range [IQR],150-205]; median LDL-C was 99 mg/dL (IQR, 79-123); median HDL-C was 40 mg/dL (IQR, 31-47); and median TG was 147 mg/dL (IQR, 101-221). Median homeostasis model assessment of IR (HOMA-IR) was 3.3 (IQR, 1.7-5.3). The EVRs demonstrated a decline in TC, LDL-C, and HDL-C, whereas TG increased on treatment but returned to near baseline 24 weeks after end of treatment (EOT). The HOMA-IR decline from entry to 24 weeks after EOT was significant among non-sustained virologic responders and nonsignificant among sustained virologic responders; this difference was offset after adjusting for higher HOMA-IR at baseline among the former. Among all 182 subjects, entry LDL-C was associated with SVR in a joint logistic model adjusted for HCV genotype, race, and prior IFN (odds ratio, 1.17 per 10 mg/dL increase; 95% confidence interval, 1.03-1.32), but TC, HDL, TG, and IR were not. CONCLUSIONS: Peginterferon alpha and RBV can significantly affect lipid profile and IR in HCV/HIV-coinfected persons. Although the lipid profile returns to near pretreatment levels after completion of treatment, our data suggest persistent modest improvement in IR with treatment. Clinical Trials Registration. NCT00078403.

Extended therapy with pegylated interferon and weight-based ribavirin for HCV-HIV coinfected patients.

BACKGROUND: It is unknown whether extended treatment with pegylated interferon (PEG) and weight-based ribavirin (WBR) results in higher rates of sustained viro-logic response (SVR) among HCV-HIV coinfected patients compared with standard duration therapy. OBJECTIVE: The study aimed to measure rates of SVR among coinfected patients who received extended therapy with PEG plus WBR. METHODS: HCVHIV coinfected subjects were treated with PEG and WBR, and those who achieved early virologic response (EVR; ≥ 2 log decrease in HCV RNA from baseline or HCV RNA<600 IU/mL) at week 12 were eligible to continue treatment for 72 weeks. SVR (HCV RNA<60 IU/mL) was measured 24 weeks after treatment discontinuation. Predictors of SVR were assessed in simple and multivariate logistic regression. RESULTS: A total of 329 subjects enrolled at 36 sites. Of 184 subjects who achieved EVR, 169 entered Step 3: 89% male, 52% White, 29% Black, and 71% HCV treatment naïve. The overall SVR rate was 27% (95% CI, 22%-32%) among all subjects, and 33% (95% CI, 27%-40%) among the 223 who were HCV treatment naïve. In exploratory analyses, among 120 treatment-naïve subjects who entered Step 3, the SVR rate was 62% (95% CI, 52%-70%). In this subgroup, predictors of SVR were HCV genotype 2 or 3 (P = .03), HCV RNA <800,000 IU/mL at study entry (P = .05), and achievement of complete EVR (HCV RNA<600 IU/mL at week 12;P < .0001). CONCLUSION: Among all subjects, we observed a comparable overall SVR rate to prior studies of subjects treated for 48 weeks. Extended treatment with PEG and WBR may be beneficial to subsets of coinfected patients, specifically those who are treatment naïve and achieve complete EVR.

Peginterferon Alfa-2a plus ribavirin versus interferon alfa-2a plus ribavirin for chronic hepatitis C in HIV-coinfected persons.

BACKGROUND: Chronic hepatitis C virus (HCV) infection is a cause of major complications in persons who are also infected with the human immunodeficiency virus (HIV). However, the treatment of HCV infection in such persons has been associated with a high rate of intolerance and a low rate of response. We conducted a multicenter, randomized trial comparing peginterferon plus ribavirin with interferon plus ribavirin for the treatment of chronic hepatitis C in persons coinfected with HIV. METHODS: A total of 66 subjects were randomly assigned to receive 180 microg of peginterferon alfa-2a weekly for 48 weeks, and 67 subjects were assigned to receive 6 million IU of interferon alfa-2a three times weekly for 12 weeks followed by 3 million IU three times weekly for 36 weeks. Both groups received ribavirin according to a dose-escalation schedule. At week 24, subjects who did not have a virologic response (those who had an HCV RNA level greater than or equal to 60 IU per milliliter) underwent liver biopsy, and medications were continued in subjects with either a virologic response or histologic improvement. RESULTS: Treatment with peginterferon and ribavirin was associated with a significantly higher rate of sustained virologic response (an HCV RNA level of less than 60 IU per milliliter 24 weeks after completion of therapy) than was treatment with interferon and ribavirin (27 percent vs. 12 percent, P=0.03). In the group given peginterferon and ribavirin, only 14 percent of subjects with HCV genotype 1 infection had a sustained virologic response (7 of 51), as compared with 73 percent of subjects with an HCV genotype other than 1 (11 of 15, P<0.001). Histologic responses were observed in 35 percent of subjects with no virologic response who underwent liver biopsy. CONCLUSIONS: In persons infected with HIV, the combination of peginterferon and ribavirin is superior to the combination of interferon and ribavirin in the treatment of chronic hepatitis C. These regimens may provide clinical benefit even in the absence of virologic clearance. The marked discrepancy in the rates of sustained virologic response between HCV genotypes indicates that strategies are needed to improve the outcome in persons infected with HCV genotype 1.

Relationships between cellular immune responses and treatment outcomes with interferon and ribavirin in HIV/hepatitis C virus co-infection.

OBJECTIVE: To test the hypothesis that hepatitis C virus (HCV)-specific interferon (IFN)gamma immune responses are correlated with HCV virological response following treatment in subjects with HIV-1 and HCV co-infection. DESIGN: Immune responses were studied in a treatment trial comparing standard interferon alfa (IFN) to pegylated interferon alfa (PEG-IFN), each with ribavirin (R). METHODS: Using HCV antigens core, NS3 and NS5, and Candida, enzyme-linked immunosorbent spots on peripheral blood mononuclear cells measured IFNgamma and interleukin (IL)-10 production. Immunologic, virologic and clinical variables were modeled using recursive partitioning (CART) to identify factors associated with HCV virological response at week 24 (VR) and week 72 (SVR) in 108 patients. RESULTS: There were no significant differences in baseline IFNgamma immune responses and higher IL-10 to NS3 in subjects with VR versus non-responders. Subjects who had significant decreases in IL-10 responses at week 24 compared to baseline for NS3, NS5, or summed HCV responses were more likely to be VR. Using baseline immunological responses and clinical data in CART models, patients who were randomized to PEG-IFN/R and had high IL-10 responses to summed HCV proteins were more likely to be VR (73%), whereas those on IFN/R who had low IFNgamma responses to Candida were less likely to be VR (5%). The main correlate of SVR for genotype-1 subjects was maintenance of HCV-specific IFNgamma responses from baseline to week 72. CONCLUSIONS: In this cohort of subjects with HIV and HCV, a decrease in HCV-specific IL-10 responses and maintenance of IFNgamma responses during treatment with IFN were associated with week 24 or 72 virological response.

Clinical trials of treatment for hepatitis C virus infection in HIV-infected patients: past, present, and future.

Coinfection with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) type 1 is common. Rates of liver-related morbidity and mortality have been increasing in the coinfected population, and treatment for HCV infection in this group remains a challenge. The HCV-monoinfected population, especially patients infected with HCV genotype 2 or 3, has benefited dramatically from the advent of treatment with pegylated interferon plus ribavirin; rates of sustained virological response approach 55%. Coinfected patients lag behind, with rates of sustained virological response ranging between 26% and 40%; rates of sustained virological response are even lower among patients infected with HCV genotype 1. It is encouraging, however, that therapies known to be safe for treating monoinfected patients have been proven to be generally safe and well tolerated in patients coinfected with HIV and HCV, as well. Future therapies, some of which are currently in development, will likely include new targets, such as helicase and polymerase. It is hoped that, as more-effective agents are discovered, the disparity in treatment response will diminish.

Hepatitis C viral evolution in genotype 1 treatment-naïve and treatment-experienced patients receiving telaprevir-based therapy in clinical trials.

BACKGROUND: In patients with genotype 1 chronic hepatitis C infection, telaprevir (TVR) in combination with peginterferon and ribavirin (PR) significantly increased sustained virologic response (SVR) rates compared with PR alone. However, genotypic changes could be observed in TVR-treated patients who did not achieve an SVR. METHODS: Population sequence analysis of the NS3•4A region was performed in patients who did not achieve SVR with TVR-based treatment. RESULTS: Resistant variants were observed after treatment with a telaprevir-based regimen in 12% of treatment-naïve patients (ADVANCE; T12PR arm), 6% of prior relapsers, 24% of prior partial responders, and 51% of prior null responder patients (REALIZE, T12PR48 arms). NS3 protease variants V36M, R155K, and V36M+R155K emerged frequently in patients with genotype 1a and V36A, T54A, and A156S/T in patients with genotype 1b. Lower-level resistance to telaprevir was conferred by V36A/M, T54A/S, R155K/T, and A156S variants; and higher-level resistance to telaprevir was conferred by A156T and V36M+R155K variants. Virologic failure during telaprevir treatment was more common in patients with genotype 1a and in prior PR nonresponder patients and was associated with higher-level telaprevir-resistant variants. Relapse was usually associated with wild-type or lower-level resistant variants. After treatment, viral populations were wild-type with a median time of 10 months for genotype 1a and 3 weeks for genotype 1b patients. CONCLUSIONS: A consistent, subtype-dependent resistance profile was observed in patients who did not achieve an SVR with telaprevir-based treatment. The primary role of TVR is to inhibit wild-type virus and variants with lower-levels of resistance to telaprevir. The complementary role of PR is to clear any remaining telaprevir-resistant variants, especially higher-level telaprevir-resistant variants. Resistant variants are detectable in most patients who fail to achieve SVR, but their levels decline over time after treatment.

Challenges and opportunities for hepatitis C drug development in HIV-hepatitis C virus-co-infected patients.

The approval of the first direct-acting antivirals (DAAs) against the hepatitis C virus (HCV) has been eagerly expected for treating chronic hepatitis C in HIV individuals given that progression to cirrhosis and end-stage liver disease occurs faster in the co-infected population. The appropriate and judicious use of DAAs may provide cure to a large number of HIV-HCV patients. On the contrary, the widespread use of DAAs will occasionally be off-label or under unsatisfactory medical conditions, which may result in undesirable toxicities, drug interactions or selection of drug resistance in HCV. As a result of using first-generation DAAs in HIV-HCV-co-infected patients, a growing proportion of the remaining hepatitis C individuals will be those harboring non-HCV 1 genotypes or drug-resistant HCV variants. Over time, the largest reservoir of HCV genotype 1 patients will accumulate in resource-poor nations where access to hepatitis C therapy has been elusive and HIV treatment remains the primary health issue for the co-infected population.

IL28B alleles exert an additive dose effect when applied to HCV-HIV coinfected persons undergoing peginterferon and ribavirin therapy.

BACKGROUND: Genetic studies have demonstrated a strong association between single nucleotide polymorphisms (SNPs) at IL28B and response to treatment with peginterferon (PEG) and ribavirin (RBV) in HCV monoinfected persons. We sought to test these associations in a prospective PEG / weight based ribavirin (WBR) treatment trial (ACTG A5178) (National Institution of Health registration number NCT00078403) in persons with HCV-HIV coinfection, and to develop a prediction score. METHODS: We selected subjects enrolled in A5178 who completed at least the first 12 weeks of the trial and had DNA available, and genotyped three SNPs at IL28B (rs12979860, rs12980275, rs8099917). We used multivariate logistic regression analysis to evaluate the association between IL28B SNPs and HCV treatment outcomes and to develop the prediction score. RESULTS: 231 HCV/HIV coinfected subjects were included. We observed a strong association between IL28B genotype and response to therapy among those with genotypes 1 or 4 (odds ratio for complete early virologic responses (cEVR) and sustained virologic response (SVR) was 2.98 [1.7-5.3] and 3.4 [1.7-6.9], respectively, for each additional copy of the C allele of rs12979860). Differences in frequency of the responder allele explained some of the discrepancy in HCV treatment outcomes between blacks and whites. A simple pretreatment prediction score that incorporates the IL28B genotype and baseline HCV viral load has a 93% negative predictive value (NPV) for SVR. CONCLUSIONS: IL28B SNPs have an additive allele dose effect in predicting HCV treatment outcomes in HCV/HIV coinfected persons and can be incorporated into a simple pretreatment prediction score that could minimize the risk of exposure to PEG/RBV therapy for persons with unfavorable scores.

Sustained long-term antiviral maintenance therapy in HCV/HIV-coinfected patients (SLAM-C).

BACKGROUND: Hepatitis C virus (HCV)/HIV coinfection treatment is suboptimal with low sustained viral response rates to standard therapies. A multicenter randomized clinical trial designed to assess the efficacy/safety of pegylated interferon maintenance therapy was performed by the National Institutes of Health-funded AIDS Clinical Trials Group network. METHODS: HCV treatment-naive and nonresponding interferon-experienced subjects with confirmed HCV and HIV, CD4 >200 cells per cubic millimeter, and at least stage 1 fibrosis were enrolled and treated for 12 weeks with pegylated interferon alfa 2a 180 mcg per week (PEG) + weight-based ribavirin to determine response status. Nonresponder subjects (failure to clear HCV RNA or achieve 2-log drop) underwent liver biopsy and were randomized to receive full dose PEG or observation only for 72 weeks. Paired biopsies were evaluated by a central pathologist. RESULTS: Three hundred thirty subjects were enrolled; median age was 48 years; 43% white, 37% black, non-Hispanic; 83% male; CD4+ 498 cells per cubic millimeter; 32% were interferon experienced; 74% had entry HIV RNA <50 copies per milliliter. early virologic responder was observed in 55.9% and 42.5% achieved complete Early Viral Response (cEVR). A planned interim analysis of occurred when 84 subjects were randomized. With data on 40 paired biopsies available, a safety monitoring board stopped the trial due to lack of fibrosis progression (median = 0 Metavir units/year) in the observation arm. CONCLUSIONS: Lack of fibrotic progression in the control arm was unexpected and may represent a short-term PEG/ribavirin therapy effect, high levels of HIV viral suppression, and use of antiretroviral regimens that may be less toxic than prior generations of therapy.

New paradigms in the management of hepatitis C virus co-infections.

Liver disease has emerged as a major contributor to morbidity and mortality in patients with HIV infection. Hepatitis C virus (HCV) infection is a key element in the etiology of liver-associated injury in this population. Increased rates of fibrotic progression have been described and are mediated by alcohol use, the severity of immunosuppression, the use of antiretroviral therapy, and other factors. Large clinical trials have demonstrated the efficacy of treatment with pegylated interferon plus ribavirin and highlighted issues related to management of patients with HIV/HCV co-infection. Although treatment for HCV infection in this group remains a challenge, achievement of a sustained virologic response is feasible in approximately 35% of patients. Treatment must be individualized and attention must be paid to the potential for drug-drug interactions.

Pilot study of low-dose interleukin-2, pegylated interferon-alpha 2b, and ribavirin for the treatment of hepatitis C virus infection in patients with HIV infection.

BACKGROUND: Patients infected with hepatitis C virus (HCV) and human immunodeficiency virus have a diminished HCV virologic response to standard interferon (IFN)-based therapies. We explored the strategy of initial immunostimulatory therapy with interleukin (IL)-2, followed by the addition of specific anti-HCV therapy, as a possible synergistic approach to treatment. METHODS: Coinfected subjects (n=23) with CD4 cell counts >300 cells/ micro L received low-dose IL-2 daily for 12 weeks, followed by pegylated IFN- alpha 2b and ribavirin for an additional 48 weeks. The primary end point was permanent discontinuation of treatment before week 24 due to toxicity or intolerance. RESULTS: Six subjects (26.1%) discontinued treatment before week 24, and 11 (47.8%) discontinued treatment before week 60. Overall, 4 subjects discontinued because of adverse events. Four of 23 (17%; 95% confidence interval [CI], 5%-39%) had sustained virologic responses. Of 17 subjects with increased levels of alanine aminotransferase at baseline, 13 had follow-up measurements at week 60, of which 6 (46%) were normal. CONCLUSIONS: Low-dose IL-2 plus PEG-IFN and ribavirin was associated with a high discontinuation rate. Although the study was not powered for efficacy, CIs surrounding the treatment response rate suggest that this strategy should not be pursued in larger trials.

Viral kinetics in hepatitis C or hepatitis C/human immunodeficiency virus-infected patients.

BACKGROUND AND AIMS: Kinetic modeling of hepatitis C virus (HCV) response to interferon (IFN)-based therapy provides insights into factors associated with treatment outcomes. HCV/human immunodeficiency virus (HIV)-co-infected patients show lower response rates vs. HCV-monoinfected patients. Reasons for this remain unclear. This study evaluated kinetic parameters and treatment responses in co-infected vs monoinfected patients. METHODS: Co-infected patients were randomized within a US multicenter trial (ACTG 5071) to receive pegylated-interferon (PEG-IFN) alfa-2a + ribavirin vs. IFN alfa-2a + ribavirin. Monoinfected controls were matched prospectively for treatment, genotype, age, sex, race, and histology. Quantitative HCV-RNA testing was performed at hours 0, 6, 12, 24, 48, and 72; days 7, 10, 14, 28, and 56; and weeks 12, 24, 48, and 72. RESULTS: Twelve HCV/HIV-co-infected and 15 HCV-monoinfected patients underwent viral kinetic sampling. Among HIV-positive patients the mean CD4(+) count was 325 cells/mm(3). Seventy-five percent of patients were genotype 1. The HCV-RNA level was undetectable at 72 weeks in 25% and 40% of co-infected and monoinfected patients, respectively. Phase 1/2 declines, free virus clearance rate, and infected hepatocyte death rate were not affected by co-infection status but differed by treatment. Efficiency (epsilon) > or = 90% at 60 hours was associated with viral clearance ( P = .02). Modeling with pooled parameters suggests baseline viral load is a key factor in time to response in this cohort. Predicted clearance time increased by 28% in co-infected patients. CONCLUSIONS: Co-infection status did not affect key kinetic parameters. Among kinetic parameters, efficiency was associated significantly with viral clearance. Co-infected patients may require longer treatment duration than monoinfected patients given their generally higher baseline viral loads.

Implications of peginterferon use in special populations infected with HCV.

Rapid progress in the treatment of hepatitis C virus (HCV) infection has led to highly successful therapies that lead to viral eradication and sustained viral response in more than 50% of patients. Despite these advances, certain identifiable subpopulations appear to have reduced rates of treatment response. These include patients co-infected with HCV/HIV, alcohol abusers, and African Americans infected with HCV. Using research tools including viral kinetic modeling, factor analysis, and laboratory evaluation of viral and host genomic characteristics, a number of key elements of response have been identified. Examination of special populations reveals that these groups comprise complex mixes of poor prognostic markers. These include both host and viral factors. Use of peginterferons with ribavirin improves response rates in these groups, but does not fully ameliorate the response deficit relative to patients enrolled in typical drug registration clinical trials.