Significant early higher ribavirin plasma concentrations in patients receiving a triple therapy with pegylated interferon, ribavirin and telaprevir

The new standard of care for treatment for infection with genotype 1a/b of HCV now is the combination of telaprevir (TLV) with ribavirin (RBV) and pegylated interferon (Peg-IFN). Although this new therapy gives a higher response rate than the Peg-IFNα plus RBV treatment, a greatly higher rate of anaemia onset has been reported in all clinical trials. Because haemolysis is a typical concentration-dependent side effect of RBV, modulated by ITPA gene polymorphisms, we aimed to compare the early RBV plasma exposure of nine patients after 2 weeks of treatment with triple therapy with RBV concentrations of 187 patients treated with RBV and Peg-IFNα over the same time scale; this comparison was performed also stratifying patients according to ITPA polymorphism genotype and anaemia onset after 1 month of treatment. All TLV-treated patients had unfavourable ITPA genetic profile and developed anaemia. Moreover, both the rate of anaemia onset and the haemoglobin loss at 1 month were significantly higher in patients treated with TLV. This observation has been confirmed also in patients with the same ITPA genetic profile in double therapy. Strikingly, also early RBV plasma concentrations were significantly higher in patients treated with TLV. These unbiased results confirm the observations recently reported and suggest that the high rate of anaemia onset could be mainly due to the increased RBV exposure, probably caused by a 'boosting effect' by TLV. These data highlight the great importance of early therapeutic drug monitoring of RBV in the management of anaemia in the triple therapy.

Safety of direct antiviral agents in real life

Advanced liver fibrosis is a recognized barrier to both access and response to triple therapy with protease inhibitors Boceprevir and Telaprevir, and is associated with an increased risk of severe treatment-related adverse events. While not properly addressed by registration trials enrolling highly selected populations, this nuance of protease inhibitors triple therapy for hepatitis C virus genotype 1 was highlighted by the observational study CUPIC conducted in France. The study enrolled a large number of patients, beyond the safety criteria of registration trials, thereby ending in worrisome safety profiles of protease inhibitors regimens in patients with severe liver impairment who in the past had safely, but unsuccessfully, been exposed to dual therapy with interferon and ribavirin. Indeed, protease inhibitors therapy led to alarming rates of infection and clinical decompensation, particularly in patients with reduced hepatic reserve as predicted by the low platelets and albumin levels. Ultimately antiviral therapy resulted in a death rate of up to 2% and a treatment discontinuation rate of 26%, not to mention the increased need of bone marrow stimulating factors and blood transfusions. The 16-week interim report of the HEP3002 trial expanded the access program to Telaprevir, enrolling patients with advanced fibrosis who fulfilled the safety criteria of registration trials only, and offered an unbiased evaluation of Telaprevir tolerability and safety in this most in-need population, since the rates of treatment discontinuation due to adverse events were up to 14%.

Clinical utility of host genetic IL-28B variants in hepatitis C virus genotype 1 Asian patients retreated with pegylated interferon plus ribavirin

BACKGROUND AND AIM

Host interleukin-28B (IL-28B) genetic variants determine a sustained virological response (SVR) in hepatitis C virus genotype 1 (HCV-1) treatment-naïve patients. Its impact on treatment-experienced Asian patients with peginterferon/ribavirin in is to be elucidated.

METHODS

IL-28B rs8099917 genotype was determined in 70 HCV-1 treatment-experienced patients retreated with 48-week peginterferon/ribavirin.

RESULTS

The SVR rate was 60.0% and was significantly higher in previous relapsers than in nonresponders (72.7% and 13.3%, P < 0.001). Multivariate analysis revealed that the most important factor predictive of an SVR was previous relapse (Odds ratio [OR]/95% confidence interval [CI]: 14.76/2.72-80.06, P = 0.002), followed by the carriage of rs8099917 TT genotype (OR/95% C.I.: 7.67/1.27-46.49, P = 0.03). Comparing to patients with TG/GG genotype, those with TT genotype had significantly higher rates of rapid virological response (29.3% vs 0%, P = 0.03), end-of-treatment virological response (86.2% vs 50.0%, P = 0.01), SVR (69.0% vs 16.7%, P = 0.002), and lower relapse rate (22.0 % vs 66.7%, P = 0.04). The SVR rate was similarly low between previous nonresponders with different rs8099917 genotypes (12.5% vs 14.3%, P = 1). On the contrary, previous relapsers with rs8099917 TT genotype had a significantly higher SVR rate than those who carried rs8099917 TG/GG genotype (78.0 % vs 20.0%, P = 0.02). Stepwise logistic regression analysis revealed that the only factor predictive of an SVR in previous relapsers was the carriage of rs809997 TT genotype (OR/95% CI:18.50/1.82-188.39, P = 0.014).

CONCLUSIONS

Host IL-28B genetic variants played a role in Asian relapsers but not nonresponders retreated with peginterferon/ribavirin. Direct antiviral agents might be possibly avoidable in Asian relapsers with favorable IL-28B genotype.