AIM:To evaluates the effectiveness and safety of the first generation,NS3/4A protease inhibitors(PIs) in clinical practice against chronic C virus,especially in patients with advanced fibrosis. METHODS:Prospective study and non-experimental analysis of a multicentre cohort of 38 Spanish hospitals that includes patients with chronic hepatitis C genotype 1,treatment-na?ve(TN) or treatment-experienced(TE),who underwent triple therapy with the first generation NS3/4A protease inhibitors,boceprevir(BOC) and telaprevir(TVR),in combination with pegylated interferon and ribavirin. The patients were treatment in routine practice settings. Data on the study population and on adverse clinical and virologic effects were compiled during the treatment period and during follow up.RESULTS:One thousand and fifty seven patients were included,405(38%) were treated with BOC and 652(62%) with TVR. Of this total,30%(n = 319) were TN and the remaining were TE:28%(n = 298) relapsers,12%(n = 123) partial responders(PR),25%(n = 260) null-responders(NR) and for 5%(n = 57) with prior response unknown. The rate of sustained virologic response(SVR) by intention-to-treatment(ITT) was greater in those treated with TVR(65%) than in those treated with BOC(52%)(P < 0.0001),whereas by modified intention-to-treatment(m ITT) no were found significant differences. By degree of fibrosis,56% of patients were F4 and the highest SVR rates were recorded in the non-F4 patients,both TN and TE. In the analysis by groups,the TN patients treated with TVR by ITT showed a higher SVR(P = 0.005). However,by m ITT there were no significant differences between BOC and TVR. In the multivariate analysis by m ITT,the significant SVR factors were relapsers,IL28 B CC and non-F4; the type of treatment(BOC or TVR) was not significant. The lowest SVR values were presented by the F4-NR patients,treated with BOC(46%) or with TVR(45%). 28% of the patients interrupted the treatment,mainly by non-viral response(51%):this outcome was more frequent in the TE than in the TN patients(57% vs 40%,P = 0.01). With respect to severe haematological disorders,neutropaenia was more likely to affect the patients treated with BOC(33% vs 20%,P ≤ 0.0001),and thrombocytopaenia and anaemia,the F4 patients(P = 0.000,P = 0.025,respectively). CONCLUSION:In a real clinical practice setting with a high proportion of patients with advanced fibrosis,effectiveness of first-generation PIs was high except for NR patients,with similar SVR rates being achieved by BOC and TVR. AIM: To evaluates the effectiveness and safety of the first generation, NS3 / 4A protease inhibitors (PIs) in clinical practice against chronic C virus, especially in patients with advanced fibrosis. METHODS: Prospective study and non-experimental analysis of a multicentre cohort of 38 Spanish hospitals that includes patients with chronic hepatitis C genotype 1, treatment-nañ ve (TN) or treatment-experienced (TE), who underwent triple therapy with the first generation NS3 / 4A protease inhibitors, boceprevir (BOC) and telaprevir TVR), in combination with pegylated interferon and ribavirin. The patients were treatment in routine practice settings. Data on the study population and on adverse clinical and virologic effects were compiled during the treatment period and follow up .RESULTS: One thousand and fifty seven Of this total, 30% (n = 319) were TN and the remaining were TE: 28% (n = 298) relapsers, 12% (n = 123) partial respo The rate of sustained virologic response (SVR) by intention-to-treatment (ITT) was 25% (n = 260) null-responders (NR) and for 5% (n = 57) with prior response unknown. was greater in those treated with TVR (65%) than those treated with BOC (52%) (P <0.0001), while by modified intention-to-treatment In the analysis by groups, the TN patients treated with TVR by ITT showed a higher SVR (P = 0.005). 56% of patients were F4 and the highest SVR rates were recorded in the non-F4 patients, both TN and TE. , by m ITT there was no significant differences between BOC and TVR. In the multivariate analysis by m ITT, the significant SVR factors were relapsers, IL28 B CC and non-F4; the type of treatment (BOC or TVR) was not significant. The lowest SVR values ​​were presented by the F4-NR patients, treated with BOC (46%) or with TVR (45%). 28% of the patients interrupted the treatment, mainly by non-viral response wasMore frequent in the TE than in the TN patients (57% vs 40%, P = 0.01). With respect to severe haematological disorders, neutropaenia was more likely to affect the patients treated with BOC (33% vs 20%, P ≤ 0.0001 ), and thrombocytopaenia and anaemia, the F4 patients (P = 0.000, P = 0.025, respectively). CONCLUSION: In a real clinical practice setting with a high proportion of patients with advanced fibrosis, effectiveness of first-generation PIs was high except for NR patients, with similar SVR rates being achieved by BOC and TVR.