Albinterferon Research Articles

Comparative efficacy, pharmacokinetic, pharmacodynamic activity, and interferon stimulated gene expression of different interferon formulations in HIV/HCV genotype‐1 infected patients

The effect of different formulations of interferon on therapeutic response in patients coinfected with HIV and HCV is unclear. In this study, the safety, tolerability, viral kinetics (VK) modeling and host responses among HIV/HCV coinfected patients treated with pegylated-IFN or albinterferon alfa-2b (AlbIFN) with weight-based ribavirin were compared. Three trials treated 57 HIV/HCV coinfected genotype-1 patients with PegIFN alfa-2b (1.5 µg/kg/week) (n = 30), PegIFN alfa-2a (180 µg/week) (n = 10), and AlbIFN (900 µg/q2week) (n = 17) in combination with weight-based ribavirin (RBV). HCV RNA, safety labs, and interferon stimulated gene expression (ISG) was evaluated. Adverse events were documented at all study visits. HCV viral kinetics using a full pharmacokinetic/pharmacodynamic model was also evaluated. Baseline patient characteristics were similar across the three studies. All three formulations exhibited comparable safety and tolerability profiles and efficacy. VK/PK/PD parameters for all three studies as measured by mean efficiency and rate of infected cell loss were similar between the three groups. Host responses (ISG expression and immune activation markers) were similar among the three groups. All three regimens induced significant ISG at week 4 (P < 0.05) and ISG expression strongly correlated with therapeutic response (r = 0.65; P < 0.01). In summary, a comprehensive analysis of responses to three different interferon formulations in HIV/HCV coinfected patients demonstrated similar effects. Notably, interferon-based therapy results in a blunted host response followed by modest antiviral effect in HIV/HCV coinfected patients. This suggests that future treatment options that do not rely on host immune responses such as direct antiviral agents would be particularly beneficial in these difficult to treat patients.

Decline in pulmonary function during chronic hepatitis C virus therapy with modified interferon alfa and ribavirin

Rare interstitial lung disease cases have been reported with albinterferon alfa-2b (albIFN) and pegylated interferon alfa-2a (Peg-IFNα-2a) in chronic hepatitis C virus (HCV) patients. Systematic pulmonary function evaluation was conducted in a study of albIFN q4wk vs Peg-IFNα-2a qwk in patients with chronic HCV genotypes 2/3. Three hundred and ninety-one patients were randomly assigned 4:4:4:3 to one of four, open-label, 24-week treatment groups including oral ribavirin 800 mg/d: albIFN 900/1200/1500 μg q4wk or Peg-IFNα-2a 180 μg qwk. Standardized spirometry and diffusing capacity of the lung for carbon monoxide (DLCO) were recorded at baseline, weeks 12 and 24, and 6 months posttreatment, and chest X-rays (CXRs) at baseline and week 24. Baseline spirometry and DLCO were abnormal in 35 (13%) and 98 (26%) patients, respectively. Baseline interstitial CXR findings were rare (4 [1%]). During the study, clinically relevant DLCO declines (≥15%) were observed in 173 patients (48%), and were more frequent with Peg-IFNα-2a and albIFN 1500 μg; 24 weeks posttreatment, 57 patients (18%) still had significantly decreased DLCO, with a pattern for greater rates with albIFN vs Peg-IFNα-2a. One patient developed new interstitial CXR abnormalities, but there were no clinically relevant interstitial lung disease cases. The risk of persistent posttreatment DLCO decrease was not related to smoking, alcohol, HCV genotype, sustained virologic response, or baseline viral load or spirometry. Clinically relevant DLCO declines occurred frequently in chronic HCV patients receiving IFNα/ribavirin therapy and commonly persisted for ≥6 months posttherapy. The underlying mechanism and clinical implications for long-term pulmonary function impairment warrant further research.

Effects of Solution Conditions on Methionine Oxidation in Albinterferon Alfa-2b and the Role of Oxidation in its Conformation and Aggregation

Physical and chemical degradation of therapeutic proteins can occur simultaneously. In this study, our first objective was to investigate how solution conditions that impact conformational stability of albinterferon alfa-2b, a recombinant fusion protein, modulate rates of methionine (Met) oxidation. Another objective of this work was to determine whether oxidation affects conformation and rate of aggregation of the protein. The protein was subjected to oxidation in solutions of varying pH, ionic strength, and excipients by the addition of 0.02% tertiary-butyl hydroperoxide (TBHP). The rate of formation of Met-sulfoxide species was monitored by reversed-phase high-performance liquid chromatography and compared across solution conditions. Albinterferon alfa-2b exhibited susceptibility to Met oxidation during exposure to TBHP that was highly dependent on solution parameters, but there was not a clear correlation between oxidation rate and protein conformational stability. Met oxidation resulted in significant perturbation of both secondary and tertiary structure of albinterferon alfa-2b as shown by both far-ultraviolet (UV) and near-UV circular dichroism. Moreover, oxidation of the protein caused a noticeable reduction in the protein's resistance to thermal denaturation. Surprisingly, despite its negative effect on solution structure and conformational stability, oxidation actually reduced the protein's aggregation rate during agitation at room temperature as well as during quiescent incubation at 40°C. Oxidation of the protein resulted in improved colloidal stability of the protein, which is manifested by a more positive B(22) value in the oxidized protein. Thus, the reduced aggregation rate after oxidation suggests that increased colloidal stability of oxidized albinterferon alfa-2b counteracted oxidation-induced decreases in conformational stability.

Population Pharmacokinetics and Exposure‐Response of Albinterferon Alfa‐2b

Albinterferon alfa-2b (albIFN) has been studied for treatment of chronic hepatitis C virus (HCV). A population pharmacokinetics model was developed using nonlinear mixed-effects modeling. Efficacy/safety exposure-response relationships were assessed for subcutaneous albIFN doses (900-1800 µg once every 2 or 4 weeks) administered for either 24 weeks (HCV genotypes 2/3) or 48 weeks (genotype 1), plus daily oral ribavirin. Sustained virologic response (SVR) exposure-response was modeled using logistic regression. Adverse event incidence was tabulated versus exposure quartiles. First-order absorption rate constant (0.0148 h(-1)), apparent clearance (38.9 mL/h), and apparent volume of distribution (11.6 L) had interindividual variances (coefficient of variation) of 21%, 34%, and 24%, respectively. Residual variance estimates were 27% (coefficient of variation) and 1.51 ng/mL (standard deviation). For the only explanatory covariate-body weight-exposure decreased as weight increased. Important SVR predictors included baseline HCV RNA, fibrosis score, and black race (genotype 1); SVR was minimally related to exposure. Most adverse events had similar incidence rates across exposure quartiles. Some adverse events had a higher incidence in the upper exposure quartile without evidence of exposure-response across the lower quartiles. Given the lack of consistent efficacy/safety exposure-response relationships, further investigation is necessary to optimize albIFN dosing.

Randomized trial of albinterferon alfa‐2b every 4 weeks for chronic hepatitis C virus genotype 2/3

Albinterferon alfa-2b (albIFN) is a fusion protein of recombinant human albumin/recombinant interferon (IFN)-α-2b, with ∼200-h half-life. Safety/efficacy of albIFN q4wk was evaluated in 391 treatment-naive patients with chronic hepatitis C virus (HCV) genotype 2/3. Patients were randomized 3:4:4:4 to one of four open-label treatment groups: pegylated IFN (Peg-IFN)-α-2a 180 μg qwk or albIFN 900, 1200 or 1500 μg q4wk, plus oral ribavirin 800 mg/day, for 24 weeks. Primary efficacy endpoint was sustained virologic response (SVR; HCV RNA <20 IU/mL 24 weeks post-treatment). SVR rates were as follows: 85%, 76%, 76% and 78% with Peg-IFNα-2a and albIFN 900, 1200 and 1500 μg, respectively (P = NS); corresponding rapid virologic response rates (HCV RNA <43 IU/mL at week 4) were as follows: 78%, 49% (P < 0.001), 60% (P = 0.01) and 71%. SVR rates were not influenced by interleukin 28B genotype, although rapid virologic response rates were greater with interleukin 28B CC (P = NS). Serious adverse event rates were as follows: 4%, 11%, 3% and 3% with Peg-IFNα-2a and albIFN 900, 1200 and 1500 μg, respectively. No increase in serious/severe respiratory events was noted with albIFN. Fewer absolute neutrophil count reductions <750/mm(3) occurred with albIFN (P = 0.03), leading to fewer IFN dose reductions. Haemoglobin reductions <10 g/dL were less frequent with albIFN 900 and 1200 μg vs 1500 μg and Peg-IFNα-2a (P = 0.02), leading to fewer ribavirin dose reductions. albIFN administered q4wk produced fewer haematologic reductions than Peg-IFNα-2a, but had numerically lower SVR rates (P = NS) in patients with chronic HCV genotype 2/3.

Demonstrating the Stability of Albinterferon Alfa-2b in the Presence of Silicone Oil

Silicone oil is often used to decrease glide forces in prefilled syringes and cartridges, common primary container closures for biopharmaceutical products. Silicone oil has been linked to inducing protein aggregation (Diabet Med 1989;6:278; Diabet Care 1987;10:786-790), leading to patient safety and immunogenicity concerns. Because of the silicone oil application process (Biotech Adv 2007;25:318-324), silicone oil levels tend to vary between individual container closures. Various silicone oil levels were applied to a container closure prior to filling and lyophilization of an albumin and interferon alfa-2b fusion protein (albinterferon alfa-2b). Data demonstrated that high silicone oil levels in combination with intended and stress storage conditions had no impact on protein purity, higher order structure, stability trajectory, or biological activity. Subvisible particulate analysis (1-10 µm range) from active and placebo samples from siliconized glass barrels showed similar particle counts. Increases in solution turbidity readings for both active and placebo samples correlated well with increases in silicone oil levels, suggesting that the particles in solution are related to the presence of silicone oil and not large protein aggregates. Results from this study demonstrate that silicone oil is not always detrimental to proteins; nevertheless, assessing the impact of silicone oil on a product case-by-case basis is still recommended.

Insulin resistance is independently associated with significant hepatic fibrosis in Asian chronic hepatitis C genotype 2 or 3 patients

The role of insulin resistance (IR) and hepatic steatosis in fibrogenesis in chronic hepatitis C infection (CHC) has yielded conflicting data and few studies have been performed in Asian-region populations. We retrospectively investigated the relationship between host metabolic variables, including IR and hepatic steatosis, to hepatic fibrosis in Asian-region CHC genotype 2/3 patients. A total of 303 treatment-naïve Asian-region patients with CHC genotype 2/3 were enrolled in a multicenter phase 3 study of albinterferon alfa-2b plus ribavirin for 24 weeks. IR was defined as Homeostasis Model for Assessment of IR (HOMA-IR) > 2. Baseline liver biopsy was evaluated by a single expert histopathologist. Post hoc subgroup logistic regression modeling selected for independent variables associated with significant fibrosis (METAVIR stage F2-F4). Insulin resistance was available in 263 non-diabetic Asian-region patients (hepatitis C virus-2 [HCV-2] = 171, HCV-3 = 92), and 433 non-Asian region patients (407 "Caucasian"); METAVIR fibrosis prevalence F0-F1 (minimal fibrosis)= 201 (77%) and F2-F4 (significant fibrosis) = 59 (23%), and steatosis prevalence of grade 0 = 169 (65%), grade 1 = 64 (25%), grade 2/3 = 27 (10%). Median HOMA-IR was 1.8 (interquartile range: 1.2-2.7); 100 (38%) patients had HOMA-IR > 2. Factors independently associated with significant fibrosis included HOMA-IR (odds ratio [OR]= 8.42), necro-inflammatory grade (OR = 3.17), age (OR = 1.07) and serum total cholesterol levels (OR = 0.008). This was similar to non-Asian region patients, but steatosis was not associated with significant fibrosis in either cohort. In this subgroup study of Asian-region HCV genotype 2 or 3 patients, insulin resistance, along with age, cholesterol levels and necro-inflammation, but not steatosis may be associated with significant hepatic fibrosis.

Single-Dose Pharmacokinetics, Safety, and Tolerability of Albinterferon Alfa-2b in Subjects with End-Stage Renal Disease on Hemodialysis Compared to Those in Matched Healthy Volunteers

Albinterferon alfa-2b (albIFN) is being developed, in combination with ribavirin, for the treatment of hepatitis C virus infection. This study was designed to evaluate the pharmacokinetics, safety, and tolerability of a 900-μg dose of albIFN administered as a single subcutaneous injection in end-stage renal disease (ESRD) patients on hemodialysis and matched healthy volunteers (by age [±5 years], weight [±5 kg], and gender). The maximum concentration in plasma (C(max)) and the area under the concentration-time curve from time zero to infinity (AUC(0-∞)) were 42.8 ± 14.0 ng/ml and 16,414 ± 4,203 ng·h/ml, respectively, for healthy volunteers, while the C(max) and AUC(0-∞) were 49.9 ± 20.9 ng/ml and 18,919 ± 8,008 ng·h/ml, respectively, for ESRD patients. The geometric least-squares mean ratios were 1.15 (90% confidence interval [CI], 0.78, 1.68) for C(max) and 1.11 (90% CI, 0.83, 1.48) for AUC(0-∞). Adverse events were as expected for an interferon (e.g., flu-like symptoms), with the main laboratory adverse event being a decline in total white blood cell count, which was specifically related to a decline in the neutrophil count. This effect was somewhat greater in the ESRD patients, with the maximal decreases in neutrophil counts from those at the baseline being (-2.6 ± 0.32) × 10(9) and (-2.19 ± 0.58) × 10(9) cells/liter for the ESRD patients and the healthy volunteers, respectively. This study indicates no significant effect of renal failure on the pharmacokinetics of albIFN. Safety and tolerability were as expected for an interferon.

Albinterferon Alfa-2b Was Not Inferior to Pegylated Interferon-α in a Randomized Trial of Patients With Chronic Hepatitis C Virus Genotype 2 or 3

A phase 3 active-controlled study was conducted to assess the efficacy/safety of albinterferon alfa-2b (albIFN), a novel, long-acting, genetic fusion polypeptide of recombinant human albumin and interferon alfa-2b, in patients with chronic hepatitis C virus (HCV) genotype 2/3. In all, 933 patients were randomized to open-label subcutaneous treatment with pegylated interferon-alfa-2a (Peg-IFNalfa-2a) 180 μg/wk, or albIFN 900 or 1200 μg every 2 weeks for 24 weeks, each administered with oral ribavirin 800 mg/day. The primary end point of the study was sustained virologic response (SVR) (HCV-RNA level, <15 IU/mL at week 48). During the study, the data monitoring committee recommended dose modification for all patients receiving albIFN 1200 μg to 900 μg, impacting 38% of this treatment arm. By intention-to-treat analysis, SVR rates were 84.8% (95% confidence interval, 80.4%-88.6%), 79.8% (95% confidence interval, 74.9%-84.1%), and 80.0% (95% confidence interval, 75.1%-84.3%) with Peg-IFNalfa-2a, and albIFN 900 and 1200 μg, respectively. The primary hypothesis of noninferiority of SVR was established for albIFN 900 μg (P = .009) and 1200 μg (P = .006). Independent positive predictors of SVR by multivariate regression analysis were pretreatment HCV-RNA level less than 400,000 IU/mL, age younger than 45 years, body mass index less than 30 kg/m(2), genotype 2, normal γ-glutamyl transpeptidase and increased alanine aminotransferase levels at baseline, fibrosis stage F0-F2, no steatosis, and Asian geographic region (Peg-IFNalfa-2a only). The 3 treatment groups showed similar rates of serious (7%-8%) and severe (13%-16%) adverse events, and discontinuations owing to adverse events (3.6%-5.5%). Albinterferon alfa-2b 900 μg every 2 weeks provides an alternative efficacious treatment option in patients with chronic HCV genotype 2 or 3.

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

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. 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). 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. 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.

307 HIGH PREVALENCE OF PRE-EXISTING ANTIBODIES AGAINST POLYETHYLENE GLYCOL (PEG) IN HEPATITIS C (HCV) PATIENTS WHICH IS NOT ASSOCIATED WITH IMPAIRED RESPONSE TO PEG-INTERFERON

(peginterferon alfa-2a) studies of albinterferon alfa-2b plus ribavirin for 48 or 24 weeks, respectively. IR was measured at baseline using the homeostasis model for assessment of IR (HOMA-IR). Baseline liver biopsy was evaluated for steatosis, METAVIR grade, and fibrosis stage by a single expert histopathologist. Advanced fibrosis was defined as METAVIR stage F2–4. Steatosis was scored as grade 0 (≤5% steatosis), 1 (6–30%), 2 (31–60%), and 3 (≥61%). Other clinical variables considered included age, gender, race, body mass index, alcohol history, HCV viral load and genotype, and serum total cholesterol level. Independent factors associated with advanced hepatic fibrosis were modeled using logistic regression with backwards elimination (SAS v9.1 statistical software). Results: A complete data set was available for analysis in 1515 nondiabetic patients (genotype 1 = 819; genotype 2 = 327; genotype 3 = 369). Prevalence of METAVIR stages: F0 = 546 (37%); F1 = 680 (46%); F2 = 117 (8%); F3 = 74 (5%); and F4 = 76 (5%). Prevalence of steatosis: grade 0 = 1058 (70%); grade 1 = 329 (22%); grade 2 = 81 (5%); and grade 3 = 34 (2%). Median HOMAIR was 2.0 (interquartile range 1.3–3.6). The factors identified by multivariable logistic regression to be independently associated with advanced fibrosis were: age, HOMA-IR, hepatic steatosis grade, hepatic inflammatory grade, and serum total cholesterol levels (P < 0.001); in a subanalysis excluding cirrhotic patients (n = 76) that compared patients with significant (F2–3) vs minimal (F0–1) fibrosis, the same 5 factors were independently associated with advanced fibrosis (P < 0.01). Conclusions: In this large, well characterized cohort of CHC patients, advanced hepatic fibrosis was independently and positively associated with both IR and hepatic steatosis, in addition to age and hepatic inflammation. Serum total cholesterol was independently, but negatively associated with advanced fibrosis.

Changes in B‐lymphocyte stimulator protein levels during treatment with albinterferon alfa‐2b in patients with chronic hepatitis C who have failed previous interferon therapy

The pharmacodynamics of albinterferon alfa-2b (alb-IFN), a novel recombinant protein consisting of interferon-α-2b genetically fused to human albumin, was evaluated in patients with chronic hepatitis C with a previous non-response to interferon-α-based therapy. B-lymphocyte stimulator (BLyS) is an essential in vivo regulator of B-lymphocyte homeostasis. This analysis examined the relationship between serum BLyS level and virologic response across a range of alb-IFN doses. In all, 115 patients were randomized initially to three alb-IFN treatment arms (900 and 1200 µg every two weeks [q2wk], and 1200 µg every four weeks) with weight-based ribavirin, followed by sequential enrollment in two higher dose arms (1500 and 1800 µg q2wk). Serum BLyS level was assessed by enzyme-linked immunosorbent assay. Serum BLyS levels at baseline were lower in African-Americans (P < 0.001). Significant BLyS inductions were observed at weeks 12 and 24 versus pretreatment; in general, serum BLyS levels returned to pretreatment levels following treatment completion. Induction of BLyS was greater in the highest dose group; a significant dose-response trend was observed at weeks 12 (P = 0.002) and 24 (P < 0.001), as well as a significant time trend, with further BLyS induction increases at week 24 versus 12 (P < 0.001). Week 24 BLyS level change correlated with hepatitis C virus RNA reduction (r = -0.28; P = 0.006), driven primarily by patients with BLyS increases > 400%, but did not correlate with sustained virologic response. Higher alb-IFN doses demonstrated dose-related BLyS increases, although the correlation with virologic response was modest.

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

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. 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. 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. 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.

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

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.

Safety and Antiviral Activity of Albinterferon Alfa-2b in Prior Interferon Nonresponders With Chronic Hepatitis C

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. 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. 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. 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.

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-IFNalpha)-2a 180 microg one time per week (qwk), or alb-IFN 900 or 1,200 microg once every two weeks (q2wk), or 1,200 microg 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 microg q2wk, 55.5% (61/110) with 1,200 microg q2wk, and 50.9% (59/116) with 1,200 microg q4wk, and 57.9% (66/114) with PEG-IFNalpha-2a (P = 0.64 for overall test). Discontinuation rates due to adverse events were 9.3% with alb-IFN 900 microg q2wk, 18.2% with 1,200 microg q2wk and 12.1% with 1,200 microg q4wk, and 6.1% with PEG-IFNalpha-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 mug q2wk versus PEG-IFNalpha-2a (1.1 versus 4.3 days; P = 0.006). Alb-IFN administered q2wk or q4wk may offer comparable efficacy, with an improved dosing schedule, compared with PEG-IFNalpha-2a.

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

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. 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. 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. 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.

Anti‐hepatitis C virus activity of albinterferon alfa‐2b in cell culture

Interferon-based combination therapy is the standard treatment for chronic hepatitis C virus (HCV) infection. The weekly administration of long-acting pegylated interferons (PEG-IFNalpha-2a or PEG-IFNalpha-2b) provides superior antiviral efficacy over standard interferon alfa (IFNalpha) for the treatment of HCV infection. Albinterferon alfa-2b (alb-IFN) is a novel recombinant protein consisting of IFNalpha-2b that is genetically fused to human albumin. To test alb-IFN antiviral efficacy, we compared the antiviral activity of unmodified IFNalpha with the three modified interferons (PEG-IFNalpha-2a, PEG-IFNalpha-2b, and alb-IFN) at clinically relevant serum concentrations using liver cell-based and non-liver cell-based HCV replicon cell lines. The EC(50) in GSB cells for IFNalpha-2b, PEG-IFNalpha-2a, PEG-IFNalpha-2b and alb-IFN was 7 U/mL, 1.1 ng/mL, 18 ng/mL, and 15 ng/mL, respectively. At clinically relevant patient serum concentrations, alb-IFN exhibits more antiviral activity than the pegylated interferons. Alb-IFN showed similar inhibition of HCV replication in human liver cells and non-liver cells, indicating it has anti-HCV activity in non-liver cells. The magnitude of induction of interferon-stimulated genes (MxA, 2'5'OAS1, IFI44, and IFI27) at 6 h and 48 h was comparable for all the modified IFNs in human liver cells at the drug concentrations evaluated. The present study indicates that alb-IFN has a potent, direct anti-HCV activity in both liver and non-liver cells.