Erik Pulkstenis

Albinterferon alfa-2b dosed every two or four weeks in interferon-naïve patients with genotype 1 chronic hepatitis C†‡

The efficacy and safety of albinterferon alfa‐2b (alb‐IFN), a novel recombinant protein consisting of interferon alfa‐2b genetically fused to human albumin, was evaluated in a phase 2b, open‐label study of patients with genotype 1, chronic hepatitis C. In all, 458 IFN‐alfa treatment‐naïve patients were randomized to 48‐week treatment with peginterferon alfa (PEG‐IFNα)‐2a 180 μg one time per week (qwk), or alb‐IFN 900 or 1,200 μg once every two weeks (q2wk), or 1,200 μg once every four weeks (q4wk), administered subcutaneously, plus weight‐based oral ribavirin 1,000 or 1,200 mg/day. Hepatitis C virus RNA was measured by real‐time polymerase chain reaction (limit of detection: 10 IU/mL). The primary efficacy endpoint was sustained virologic response (hepatitis C virus RNA <10 IU/mL 24 weeks after the end of treatment). By intention‐to‐treat analysis, sustained virologic response rates were 58.5% (69/118) with alb‐IFN 900 μg q2wk, 55.5% (61/110) with 1,200 μg q2wk, and 50.9% (59/116) with 1,200 μg q4wk, and 57.9% (66/114) with PEG‐IFNα‐2a (P = 0.64 for overall test). Discontinuation rates due to adverse events were 9.3% with alb‐IFN 900 μg q2wk, 18.2% with 1,200 μg q2wk and 12.1% with 1,200 μg q4wk, and 6.1% with PEG‐IFNα‐2a (P = 0.04). Hematologic reductions were lowest in the q4wk group and comparable across other groups. At week 12, mean treatment‐associated missed workdays were significantly lower with alb‐IFN 900 μg q2wk versus PEG‐IFNα‐2a (1.1 versus 4.3 days; P = 0.006). Conclusion: Alb‐IFN administered q2wk or q4wk may offer comparable efficacy, with an improved dosing schedule, compared with PEG‐IFNα‐2a. (HEPATOLOGY 2008;48:407–417.)

Albinterferon Alfa-2b Was Not Inferior to Pegylated Interferon-α in a Randomized Trial of Patients With Chronic Hepatitis C Virus Genotype 1

BACKGROUND & AIMS The current standard of care for patients with chronic hepatitis C virus (HCV) genotype 1 is once-weekly pegylated interferon-α (Peg-IFNα) plus daily ribavirin for 48 weeks. We evaluated the efficacy/safety of albinterferon alfa-2b (albIFN), a novel, long-acting, genetic fusion polypeptide of albumin and IFNα-2b. METHODS In the phase 3 ACHIEVE-1 trial, 1331 patients were assigned equally to 3 open-label, 48-week treatment groups: Peg-IFNα-2a 180 μg every week, or albIFN 900 or 1200 μg every 2 weeks administered subcutaneously, with weight-based oral ribavirin 1000-1200 mg/day. During the study, the data monitoring committee recommended dose modification for all patients receiving albIFN 1200 μg to 900 μg because of increased pulmonary adverse events (AEs) in the 1200-μg arms of both ACHIEVE studies. Main outcome measure was sustained virologic response (SVR; undetectable serum HCV RNA at week 72). RESULTS Intention-to-treat SVR rates were 51.0% (225/441), 48.2% (213/442), and 47.3% (208/440) with Peg-IFNα-2a, and albIFN 900 and 1200 μg, respectively. The primary objective of showing noninferiority of albIFN 900 μg (P < .001) and 1200 μg (P = .003) vs Peg-IFNα-2a for SVR was achieved. Multivariate modeling indicated consistency of treatment effect across subgroups. Serious/severe AE rates were 23.1%, 24.0%, 28.2%; treatment discontinuation rates because of AEs were 4.1%, 10.4%, 10.0%; discontinuation rates because of respiratory AEs were 0%, 0.9%, 1.6%; with Peg-IFNα-2a, and albIFN 900 and 1200 μg, respectively. Hematologic abnormality rates were comparable across the Peg-IFNα-2a and albIFN 900-μg groups. CONCLUSIONS albIFN 900 μg every 2 weeks showed comparable efficacy, with similar serious/severe AE rates, although with a higher discontinuation rate, vs Peg-IFNα-2a in patients with chronic HCV genotype 1.

Viral clearance is associated with improved insulin resistance in genotype 1 chronic hepatitis C but not genotype 2/3

Objectives Genotype-specific associations between hepatitis C virus (HCV) and insulin resistance (IR) have been described, but a causal relationship remains unclear. This study investigated the association between a sustained virological response (SVR) and IR after chronic HCV therapy. Methods 2255 treatment-naive patients with chronic HCV genotype 1 or 2/3 were enrolled in two phase 3 trials of albinterferon alpha-2b versus pegylated interferon alpha-2a for 48 or 24 weeks, respectively. IR was measured before treatment and 12 weeks after treatment using homeostasis model assessment (HOMA)-IR. Results Paired HOMA-IR measurements were available in 1038 non-diabetic patients (497 with genotype 1; 541 with genotype 2/3). At baseline the prevalence of HOMA-IR >3 was greater in patients with genotype 1 than 2/3 (33% vs 27%; p=0.048). There was a significant reduction in the prevalence of IR in patients with genotype 1 achieving SVR (δ 10%; p<0.001), but not in genotype 1 non-responders or those with genotype 2/3. Multivariate analysis indicated that SVR was associated with a significant reduction in mean HOMA-IR in patients with genotype 1 (p=0.004), but not in those with genotype 2/3, which was independent of body mass index, alanine transaminase, γ-glutamyl transpeptidase and lipid level changes. Conclusions SVR is associated with a reduction in HOMA-IR in patients with HCV genotype 1 but not in those with genotype 2/3. Genotype 1 may have a direct effect on the development of IR, independent of host metabolic factors, and may be partially reversed by viral eradication.

Steatosis Is an Independent Predictor of Relapse Following Rapid Virologic Response in Patients With HCV Genotype 3

BACKGROUND & AIMS It is recommended that patients with chronic hepatitis C virus (HCV) genotype 3 infections receive 24 weeks of treatment. A rapid virologic response (RVR; at week 4) predicts a sustained virologic response (SVR), although not all patients with an RVR achieve an SVR. We explored the relationships among hepatic steatosis, level of HCV RNA, relapse, and RVR in a phase 3 randomized controlled trial of 932 patients infected with HCV genotype 2 (n = 427) or 3 (n = 505) who received 24 weeks of therapy with interferon-α. METHODS In patients with an RVR (HCV RNA <43 IU/mL), the presence of an SVR was modeled using multivariate logistic regression as a function of age, sex, weight, body mass index, insulin resistance, steatosis, and levels of γ-glutamyl transpeptidase, alanine aminotransferase, liver fibrosis, and baseline HCV RNA. RESULTS RVR, SVR, and relapse rates among patients with HCV genotype 3 were 79.6%, 79.2%, and 15.6%, respectively; corresponding rates among patients with HCV genotype 2 were 86.7%, 84.3%, and 10.1%. An RVR had high predictive value for an SVR in patients with HCV genotypes 2 (88.9%) and 3 (88.1%). The strongest independent predictors of relapse in patients with genotype 3 and an RVR were steatosis (odds ratio 3.0; P = .003) and HCV RNA ≥400,000 IU/mL (odds ratio 2.5; P = .04). Relapse rates in patients with steatosis were 17.4% and 20.9% for low and high baseline levels of HCV RNA, respectively; corresponding rates in those without steatosis were 2.5% and 8.8%. CONCLUSIONS Steatosis was associated with significantly higher rates of relapse, irrespective of viral load, in patients infected with HCV genotype 3 who had an RVR. Further studies are needed to determine if longer treatment durations are effective in patients with an RVR and these risk factors.

Safety and antiviral activity of albinterferon alfa-2b in prior interferon nonresponders with chronic hepatitis C.

BACKGROUND & AIMS Pegylated interferon alfa-2a/2b is used in combination with ribavirin to treat patients with chronic hepatitis C (CHC), although many do not achieve a sustained virologic response (SVR). Albinterferon alfa-2b, a recombinant protein consisting of interferon alfa-2b fused to human albumin, may increase drug exposure. This phase 2 study evaluated the safety/efficacy of albinterferon in CHC patients who had not responded to interferon-based regimens. METHODS A total of 115 patients were assigned to 5 groups given 1200 microg albinterferon every 4 weeks or 900, 1200, 1500, or 1800 microg every 2 weeks, plus oral ribavirin, for 48 weeks. The primary efficacy end point was achievement of an SVR after 24 weeks. Treatment was extended to 72 weeks for 6 slow responders who were negative for hepatitis C virus RNA after 24 weeks. RESULTS The types of adverse events were similar across groups; the overall discontinuation rate as a result of adverse events was 10.4%. Reductions in absolute neutrophil counts were less frequent in the every 4 weeks group and comparable among the every 2 weeks groups. The overall SVR rate was 17% (11% for previous nonresponders to pegylated interferon-alfa/ribavirin with genotype 1 infection). An SVR occurred in 3 of 6 slow responders by 72 weeks. The greatest reductions in hepatitis C virus RNA in nonresponders to pegylated interferon-alfa/ribavirin with genotype 1 infection were observed in the 1800-microg group. CONCLUSIONS In patients with CHC who did not respond to interferon-based regimens, higher doses of albinterferon had significant early antiviral activity and a low incidence of adverse events, with the types of adverse events similar to those observed with interferon.

An independent and prospective comparison of two commercial fibrosis marker panels (HCV FibroSURE and FIBROSpect II) during albinterferon alfa-2b combination therapy for chronic hepatitis C

Summary.  Noninvasive markers that accurately follow changes in fibrosis may provide alternatives to liver biopsy for assessment of histological endpoints of antiviral therapy in chronic hepatitis C (CHC). This study compared two commercially available serum marker panels (HCV FibroSURE™ and FIBROSpect II®) during interferon‐based therapy. Ninety‐five interferon‐naïve patients with genotype 1 CHC were enrolled in a phase 2b, active‐controlled study of albinterferon alfa‐2b/ribavirin for 48 weeks. Proprietary and simple biochemical marker panels were independently evaluated in serum before and during the study. Baseline liver biopsies were evaluated for METAVIR fibrosis by a single pathologist. Index scores were obtained for HCV FibroSURE (n = 84) and FIBROSpect II (n = 95); mean biopsy length: 17.8 ± 8.0 mm. For detecting fibrosis stages 2–4 (prevalence 23% [22/95] and 21% [18/84]), HCV FibroSURE and FIBROSpect II indicated high sensitivity (1.00 and 0.95, respectively), lower but comparable specificity (0.61 and 0.66, respectively), and a good area under the receiver operating characteristic curve (0.89 and 0.90, respectively). Simple indices had high indeterminate rates (31–40%) at baseline. Patients with a sustained virological response had lower baseline scores than nonresponders, and reduced median percent changes in index scores for HCV FibroSURE (−20.0%vs 2.9%; P = 0.14) and FIBROS Spect II (−6.8%vs 18.4%; P = 0.05). The panels demonstrated comparable performance characteristics for differentiating mild from moderate–severe stage disease in CHC. Lower index scores at baseline that continue to decline likely reflect reduced fibrogenesis activity in patients with successful antiviral responses to therapy.

Positive and negative prediction of sustained virologic response at weeks 2 and 4 of treatment with albinterferon alfa-2b or peginterferon alfa-2a in treatment-naïve patients with genotype 1, chronic hepatitis C.

BACKGROUND/AIMS Albinterferon alfa-2b is a novel, long-acting, fusion polypeptide that is dosed q2wk or q4wk. The predictive value of early virologic response during albinterferon alfa-2b or peginterferon alfa-2a treatment was investigated in interferon-naïve patients with genotype 1, chronic hepatitis C. METHODS Four hundred and fifty-eight patients were randomized to: albinterferon 900 or 1200 microg q2wk, or 1200 microg q4wk, or peginterferon 180 microg qwk. HCV RNA was measured by real-time PCR. A linear exhaustive search algorithm was used to determine the best SVR prediction algorithm in the per-protocol population (n=368), with inclusion of key ITT analyses to assess impact. RESULTS SVR rate: 54-67% (P=NS between arms). Rapid initial virologic response rate at week 2 (RIVR; viral decline >2 log(10)IU/mL) was 32-50% and gave rise to positive predictive value of 88-97% for SVR. No initial virologic response at week 4 (NIVR; viral decline <2 log(10)IU/mL; viral load >5.5 log(10)IU/mL) demonstrated a 100% negative predictive value for SVR. A sequential prediction algorithm based on viral kinetics at weeks 2 and 4 identified four prediction groups that reliably predicted SVR, positively or negatively, in 65-72% of patients. CONCLUSIONS Improved SVR prediction was obtained by integrating absolute levels and reduction of HCV RNA at treatment week 2 and 4. Patients with RIVR had a high likelihood of achieving SVR.

Safety and Antiviral Activity of Albinterferon Alfa-2b Dosed Every Four Weeks in Genotype 2/3 Chronic Hepatitis C Patients

BACKGROUND & AIMS A phase 2, randomized, multicenter, open-label study evaluated the safety and efficacy of albinterferon alfa-2b in interferon-alpha treatment-naïve patients with genotype 2/3, chronic hepatitis C virus infection. METHODS Forty-three patients were randomly assigned in a 1:1 ratio to receive subcutaneous albinterferon alfa-2b 1500 microg every 4 weeks (q4wk) or every 2 weeks (q2wk) with oral ribavirin 800 mg/day for 24 weeks. Primary efficacy end point was sustained virologic response (undetectable hepatitis C virus RNA 24 weeks after completion of treatment). Insulin resistance was also assessed. RESULTS The safety of albinterferon alfa-2b was acceptable, with a similar adverse event profile in both treatment arms. Discontinuation as a result of adverse events occurred in 4.5% and 14.3% of patients in the q4wk and q2wk arms, respectively. No dose reductions caused by adverse events were reported in the q4wk arm versus 9.5% in the q2wk arm. Rapid viral response rates at week 4 were 68.2% and 76.2% for the q4wk and q2wk arms, respectively; the corresponding sustained virologic response rates were 77.3% and 61.9%. Insulin resistance at baseline was significantly associated with lower sustained virologic response rates independent of body mass index. CONCLUSIONS Albinterferon alfa-2b administered at 4-week intervals was safe and well-tolerated and demonstrated significant antiviral activity in patients with genotype 2/3, chronic hepatitis C virus. Insulin resistance appeared to have an independent effect on treatment response.

FibroSURE™ and FibroScan® in relation to treatment response in chronic hepatitis C virus

AIM To compare histological endpoint assessment using noninvasive alternatives to biopsy during treatment in a chronic hepatitis C virus (HCV) cohort. METHODS Patients with chronic HCV were randomized to receive interferon-based therapy for 24 (genotypes 2/3) or 48 (genotype 1) wk. FibroSURE™ (FS) was assessed at baseline and at week-12 post-treatment follow-up. Baseline biopsy for METAVIR was assessed by a single pathologist. FibroScan(®) transient elastography (TE) was performed during treatment in a patient subset. RESULTS Two thousand and sixty patients (n = 253 in Asia) were classified as METAVIR F0-1 (n = 1682) or F2-4 (n = 378). For F2-4, FS (n = 2055) had sensitivity and specificity of 0.87 and 0.61, respectively, with area under the receiver-operating curve of 0.82; corresponding values for TE (n = 214) and combined FS/TE (n = 209) were 0.77, 0.88 and 0.88, and 0.93, 0.68 and 0.88. Overall FS/TE agreement for F2-4 was 71% (κ = 0.41) and higher in Asians vs non-Asians (κ = 0.86 vs 0.35; P < 0.001). Combined FS/TE had 97% accuracy in Asians (n = 33). Baseline FS (0.38 vs 0.51, P < 0.001) and TE (8.0 kPa vs 11.9 kPa, P = 0.006) scores were lower in patients with sustained virological response than in nonresponders, and were maintained through follow-up. CONCLUSION FS and TE may reliably differentiate mild from moderate-advanced disease, with a potential for high diagnostic accuracy in Asians with chronic HCV.

Phenotypes of interferon-α-induced thyroid dysfunction among patients treated for hepatitis C are associated with pretreatment serum TSH and female sex

CONTEXT Thyroid dysfunction is a common complication of interferon-α (IFNα) therapy, with many phenotypic patterns and the potential for significant morbidity. OBJECTIVE Our objective was to gain mechanistic insight and predict clinical presentations by determining the risk factors for distinct subtypes of IFNα-induced thyroid dysfunction. DESIGN ACHIEVE-1, a randomized trial conducted from 2005-2009, compared long-acting preparations of IFNα in 1323 patients with hepatitis C, genotype 1. SETTING A total of 149 outpatient clinics in North America, Europe, and Australia participated. PATIENTS We studied 1233 patients who were euthyroid at baseline. This population is 60% male and 82% Caucasian. INTERVENTIONS Patients were treated with pegylated IFNα2a weekly or albumin-IFNα2b every 2 wk for 48 wk. Serum TSH and free T(4) were measured before therapy and 12 or more times over 60 weeks. MAIN OUTCOME MEASURES Thyroid dysfunction was defined as a TSH outside the normal range during the course of therapy. Low serum TSH indicated thyrotoxicosis, elevated TSH indicated hypothyroidism, and both abnormalities occurred in biphasic thyroiditis. RESULTS Of previously euthyroid patients, 16.7% developed abnormal TSH values during therapy, including 24 with TSH below 0.1 mU/liter, 69 with TSH over 5.5 mU/liter, and 76 with biphasic thyroiditis. Biphasic thyroiditis was over 8-fold more common among women than men using multivariate logistic regression analysis [odds ratio (OR) = 8.4; 95% confidence interval (CI) = 4.5-15.8]. Thyrotoxicosis was most strongly associated with a lower pretreatment TSH (OR = 4.1 per -1 mU/liter decline; 95% CI = 1.9-9), whereas hypothyroidism was strongly associated with higher pretreatment TSH (OR = 3.9 per 1 mU/liter increase; 95% CI = 3-5.2). CONCLUSIONS Biphasic thyroiditis is common among women treated for hepatitis C with IFNα. Lower and higher pretreatment serum TSH are associated with greater likelihood of thyrotoxicosis and hypothyroidism, respectively. Antithyroid antibody levels were not available for the cohort, and thus we cannot clarify the role of pretreatment thyroid autoimmunity as a risk factor. Our results do show that readily identifiable patient characteristics are risk factors for specific patterns of IFN-induced thyroid dysfunction. These findings suggest that distinct mechanisms may underlie subtypes of thyroid dysfunction associated with immune-modulatory therapy for hepatitis C.