***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Abstract Objectives : The purpose of this r and omized open-label study was to assess the efficacy of treatment with pegylated interferon-α-2a versus pegylated interferon-α-2b , both plus ribavirin , in inducing early and sustained virological response ( EVR and SVR ) in chronic hepatitis C non-responders . Patients and methods : A total of 108 patients with chronic hepatitis C who were non-responders to previous combined therapy ( st and ard interferon-α plus ribavirin for ≥3 months ) were enrolled and equally r and omized into two groups in this intention-to-treat analysis . The patients exhibited similar baseline features . One group received subcutaneous pegylated interferon-α-2a 180 μg once weekly , while the other was treated with subcutaneous pegylated interferon-α-2b 1.5 μg/ kg once weekly . Ribavirin 15 mg/kg/day was included in both protocol s. Treatment duration for EVR was 12 weeks . Patients who demonstrated non-detectable hepatitis C virus ( HCV ) RNA or a ≥2 log10 reduction in viral load at week 12 continued therapy up to 48 weeks , with assessment s every 3 months during a follow-up of 24 weeks . Results : All patients in both groups completed the EVR study , then seven patients receiving pegylated interferon-α-2a and seven patients receiving pegylated interferon-α2b discontinued treatment as a result of severe adverse effects . After 12 weeks of treatment , viral load reduction was > 2 log10 with both pegylated interferon-α-2a ( −2.53 ) and pegylated interferon-α-2b ( −2.48 ) with no significant difference . At the end of week 48 , HCV RNA was undetectable in 14 of 54 patients ( 25.9 % ) receiving pegylated interferon-α-2a and in 15 of 54 patients ( 27.7 % ) receiving pegylated interferon-α-2b . When terminating follow-up , an SVR was observed in 11 of 54 patients ( 20.4 % ) who received pegylated interferon-α-2a and 10 of 54 patients ( 18.4 % ) receiving pegylated interferon-α-2b  . The incidence and severity of adverse events was similar in both groups . Conclusions : Our results seem to show that in chronic hepatitis C patients who are non-responsive to previous therapy , EVR to the two pegylated interferons did not significantly differ with a similar therapeutic efficacy defined as SVR UNLABELLED Although two pegylated interferons ( Peg-IFN ) are available to treat chronic hepatitis C virus ( HCV ) infection , no head-to-head comparative studies have been published . We aim to compare the efficacy and safety of PEG IFN alfa-2b ( PEG 2b ) versus PEG IFN alfa-2a ( PEG 2a ) , plus ribavirin ( RBV ) . A prospect i ve , r and omized , multi-center , open-label clinical trial including 182 human immunodeficiency virus (HIV)-hepatitis C virus ( HCV ) patients naïve for HCV therapy was performed . Patients were assigned to PEG 2b ( 80 - 150 mug/week ; n = 96 ) or PEG 2a ( 180 mug/week ; n = 86 ) , plus RBV ( 800 - 1200 mg/day ) for 48 weeks . The primary endpoint was sustained virological response ( SVR : negative HCV-RNA 24 weeks after completion of treatment ) . At baseline , both groups were well balanced : 73 % male ; 63 % HCV genotype 1 or [ corrected ] 4 ; 29 % had fibrosis index of 3 or greater . The overall SVR was 44 % ( 42 % PEG 2b versus 46 % PEG 2a , P = 0.65 ) . Among genotypes 1 or [ corrected ] 4 , SVRs were 28 % versus 32 % ( P = 0.67 ) and 62 % versus 71 % ( P = 0.6 ) in genotypes 2 or [ corrected ] 3 for PEG 2b and PEG 2a , respectively . Early virological response ( EVR ; > or=2 log reduction from baseline or negative HCV-RNA at week 12 ) was 70 % in the PEG 2b group and 80 % in the PEG 2a group ( P = 0.13 ) , reaching a positive predictive value of SVR of 64 % and a negative predictive value of 100 % in both arms . Side effects were present in 96 % of patients but led to treatment discontinuation in 10 % of patients ( 8 % on PEG 2b and 13 % on PEG 2a , P = 0.47 ) . CONCLUSION In patients with HIV , HCV therapy with PEG 2b or PEG 2a plus RBV had no significant differences in efficacy and safety BACKGROUND Pegylated interferon ( PEG-IFN ) alpha2a and alpha2b differ in their pharmacokinetic properties , which might have an effect on their antiviral effects against hepatitis C virus ( HCV ) . Differences between PEG-IFN-alpha molecules could be more pronounced in HIV-coinfected individuals , in whom response to HCV treatment is impaired . METHODS All HCV-HIV-coinfected patients included in PRESCO and EXTENT trials recruited at one referral centre were retrospectively analysed . In both trials , ribavirin ( RBV ) 1,000 - 1,200 mg/day was prescribed together with st and ard doses of PEG-IFN-alpha2a or -alpha2b . The attainment of serum HCV RNA < 10 IU/ml at weeks 4 , 12 and 24 was assessed . On-treatment analyses were made to estimate the intrinsic potency of PEG-IFN-alpha2a versus -alpha2b . RESULTS A total of 218 patients were examined , 138 on PEG-IFN-alpha2a and 80 on PEG-IFN-alpha2b .  Baseline characteristics were comparable in both groups . Undetectable serum HCV RNA at weeks 4 , 12 and 24 was more frequently attained using PEG-IFN-alpha2a than -alpha2b ( 45 % versus 27 % [ P=0.02 ] ; 65 % versus 45%/ [ P=0.01 ] ; and 75 % versus 55%/ [ P=0.01 ] , respectively ) , regardless of HCV genotype . Plasma RBV levels did not differ between groups . In multivariate analysis , HCV genotypes 2/3 ( odds ratio [ OR ] 12.5 ; 95 % confidence interval [ 95 % CI ] 3.45 - 33.33 ; P<0.001 ) , use of zidovudine ( OR 0.30 ; 95 % CI 0.11 - 0.85 ; P=0.02 ) and treatment with PEG-IFN-alpha2a ( OR 2.12 ; 95 % CI 1.02 - 4.54 ; P=0.04 ) were independent predictors of undetectable HCV RNA at week 24 . Conversely , the incidence of serious adverse events was more common with PEG-IFN-alpha2a than -alpha2b ( 13.2 % versus 3.6 % ; P=0.018 ) . CONCLUSIONS The antiviral effect against HCV seems to be greater for PEG-IFN-alpha2a than -alpha2b in the HIV setting . A shorter half-life of PEG-IFN-alpha2b could explain this finding BACKGROUND / AIMS To compare the pharmacokinetics , pharmacodynamics , and antiviral activity of  peginterferon alfa-2b and peginterferon alfa-2a in patients with chronic hepatitis C virus genotype 1 . METHODS Thirty-six patients were r and omised to peginterferon alfa-2b ( 1.5 microg/kg/week ) or peginterferon alfa-2a ( 180 microg/week ) for 4 weeks , then in combination with ribavirin ( 13 mg/kg/day ) for a further 4 weeks . The pharmacokinetic profile of both peginterferons , mRNA expression of a selected group of interferon-induced gene transcripts , and serum HCV-RNA levels were assessed . RESULTS Patients receiving peginterferon alfa-2b had significantly greater up-regulation of interferon-alfa response genes compared with those receiving peginterferon alfa-2a . Correspondingly , patients treated with peginterferon alfa-2b also had a significantly greater log10 maximum and log10 time-weighted average decrease in serum HCV-RNA . A greater proportion of peginterferon alfa-2b patients achieved a > or = 2.0 log10 reduction in serum HCV-RNA levels by week 8 ( 72 % vs 44 % of peginterferon alfa-2a patients , P = 0.09 ) . There was an approximately 16-fold greater exposure to peginterferon in the serum of patients treated with peginterferon alfa-2a . CONCLUSIONS These findings suggest that the biological activity , measured by early interferon-induced gene transcripts and early antiviral responsiveness , may have been greater in patients treated with peginterferon alfa-2b despite their lower exposure to the drug compared with patients treated with peginterferon alfa-2a BACKGROUND & AIMS Ribavirin ( RBV ) combined with either pegylated interferon ( PegIFN ) alpha2a or PegIFNalpha2b is the st and ard of care for chronic hepatitis C virus ( HCV ) infection . Due to the lack of head-to-head studies , the 2 PegIFNs have not been directly compared . The endpoints of our study were safety and antiviral efficacy of the 2 regimens . METHODS Treatment-naïve patients with chronic hepatitis C were r and omly ( 1:1 ) assigned after stratification for HCV genotype to receive either 1.5 mcg/Kg/week PegIFNalpha2b plus RBV 800 - 1200 mg/day or 180 mcg/week PegIFNalpha2a plus RBV 800 - 1200 mg/day for 24 or 48 weeks according to HCV genotype . The study was powered to detect a difference of at least 10 % in safety and efficacy of the 2 regimens . RESULTS The 212 patients on PegIFNalpha2a and the 219 patients on PegIFNalpha2b had similar baseline characteristics , including cirrhosis ( 20 % vs 18 % , respectively ) . By intention to treat , the 2 groups showed similar rates of treatment-related serious adverse events ( 1 % vs 1 % , respectively ) and drop out rates for adverse effects ( 7 % vs 6 % , respectively ) . Overall , sustained virologic response ( SVR ) rate was higher in PegIFNalpha2a than in PegIFNalpha2b patients ( 66 % vs 54 % , respectively , P = .02 ) , being 48 % vs 32 % in the 222 HCV-1 and -4 patients ( P = .04 ) , and 96 % vs 82 % , respectively , in the 143 HCV-2 patients ( P = .01 ) . PegIFNalpha2a independently predicted SVR in the logistic regression analysis ( odds ratio , 1.88 ; 95 % confidence interval : 1.20 - 2.96 ) . CONCLUSIONS Although the 2 regimens showed a similar safety profile , the PegIFNalpha2a-based treatment yielded significantly more SVR than PegIFNalpha2b BACKGROUND Pegylated interferons ( Peg-IFNs ) represent , in association with Ribavirin , the first line of treatment in chronic C viral hepatitis . The AIM of our paper was to compare the efficacy of Peg-IFN alpha 2a ( Pegasys ) and Peg-IFN alpha 2b ( PegIntron ) in a group of patients from the Department of Gastroenterology in Timisoara . MATERIAL AND METHOD 116 patients with chronic C viral hepatitis were treated . The patients were r and omized in chronological order ( 1:1 ) , so that 58 patients were treated with Peg-IFN alpha 2a 180 microg/kg/week + Ribavirin ( group 1 ) and 58 were treated with Peg-IFN alpha 2b 1.5 microg/kg/week + Ribavirin ( group 2 ) . Ribavirin was administered in the recommended doses , according to weight . The mean age was : group 1 -- 49.3 years , group 2 -- 50.9 years ( p=0.37 ) . Group 1 consisted of 37 women and 21 men and group 2 of 44 women 14 men ( p=0.22 ) . In group 1 , 48 patients were naïve ( N1 ) , 7 were relapsers after previous treatment ( RL1 ) and 3 non-responders to previous treatment ( NR1 ) . In group 2 , 33 patients were naive ( N2 ) , 18 relapsers ( RL2 
    Output:
    
PEG-IFN-α2a with similar safety is more  effective than PEG-IFN-α2b .
A longer duration of maximum serum concentration compared with PEG-IFN-α2b ( 168 vs. 48 - 72 h. ) yields a greater SVR and higher neutropenia in PEG-IFN-α2a recipients