Standard interferon-alpha in combination with ribavirin for hepatitis C patients with advanced liver disease and thrombocytopenia

Safety and efficacy of peginterferon-α2a plus ribavirin treatment in renal transplant recipients with chronic hepatitis C

BACKGROUND & AIMS

Interferon (IFN)-based therapy in chronic hepatitis C virus (HCV)-infected renal transplant (RT) recipients has been associated with a high risk of acute allograft rejection (AAR) and poor efficacy. We assessed the safety and efficacy of PegIFNα-2a and ribavirin (RBV) combination therapy in HCV-infected RT recipients.

METHODS

Thirty-two adult RT recipients of >12-month duration, infected with HCV genotypes 1 (62.5%) and 4 (37.5%), and significant fibrosis (Metavir ≥ F2) were recruited in an open-label trial with PegIFNα-2a 135-180 μg/week, plus RBV 200-1200 mg/day for 48 weeks, based on the estimated glomerular filtration rate. Safety assessments were performed weekly for 4 weeks, 2-weekly for 8 weeks, and 6-weekly for 36 weeks. Study end points were sustained virologic response (SVR) or development of AAR. Allograft biopsies were performed for 20% increase in creatinine from pretreatment levels, or optionally at week 12 on surveillance protocol. Renal safety was compared with matched untreated historical controls (n=31).

RESULTS

None of the treated patients showed AAR when biopsied for raised creatinine (12.5%) or during surveillance (37.5%), with incremental and sustained creatinine increases occurring in 6.3% of treated patients and 16.1% of untreated controls (p=0.148), by week 72 assessment. Mean pretreatment and end-of-assessment creatinine in treated patients remained similar (106.8 ± 32.0 vs. 113.4 ± 62.8, respectively; p=0.140), while levels increased significantly in the controls (106.6 ± 35.6 vs. 142.5 ± 93.0, respectively; p=0.013). Rapid, early virologic response (EVR) and SVR occurred in 12.5%, 56.3%, and 37.5% of cases, respectively. SVR was similar in both genotypes (p=1.000). PegIFN and RBV dose reductions were required in 34.4% and 78.1%, respectively; discontinuation was required in 12.5%. Binary logistic regression identified only EVR (OR, 20.4; 95% CI: 2.2-192.6; p=0.008) as an independent predictor of SVR.

CONCLUSIONS

PegIFN/RBV therapy is not associated with AAR in RT recipients at low risk for rejection but has modest efficacy in the treatment of HCV.

Treatment of chronic hepatitis C genotype 1 patients at an academic center in Europe involved in prospective, controlled trials: is there a selection bias?

Pegylated interferon-alpha2/ribavirin (peg-IFN/RBV) is the standard of care (SOC) for patients with chronic hepatitis C (CHC) infection. Currently, direct-acting antiviral agents (DAAs) are evaluated in clinical trials. The aim of this study was to compare baseline characteristics and sustained virologic response (SVR) rates in patients included in clinical trials to those receiving SOC. Medical records of all 503 treatment-naïve patients with CHC, genotype (GT) 1, referred over a 4-year period (January 2006-December 2009) were reviewed. Only 310 of 503 (62%) patients received antiviral therapy, 141 were enrolled in randomized, controlled trials ("study patients"; 101 in DAA studies), and 169 received SOC. At baseline, viral load and platelet count were higher and bilirubin was lower in study patients than in SOC patients. History of psychiatric disorders was more common in SOC patients (43 [25%] versus study patients with 18 [13%]; P < 0.01). Liver biopsy was obtained in 98% of study patients, but only in 59% of SOC patients. Twenty-nine (21%) and 40 (40%) study and SOC patients, respectively, had advanced fibrosis (F3/4; P = 0.001). By intent-to-treat analysis, SVR rates were higher in DAAs (64%; 95% confidence interval [CI]: 53.4-74.4) than in SOC patients (46%; 95% CI: 37.9-53.7; P < 0.01), but not different when calculated on a treated-per-protocol (TPP) basis. Interleukin (IL)28B GT was equally distributed in both cohorts. By chance, more patients treated with IFN/RBV had rs12979860 C/C-GT (up to 44%) than DAA-treated patients. If analyzed according to the IL28B polymorphism, TPP SVR rates did not reach statistically significant differences among study and SOC patients.

CONCLUSIONS

Baseline characteristics slightly favored study patients, but IL28B GT and treatment adherence were the most important factors determining outcome. Thus, the applicability of the results of controlled studies has to be tested in a "real-world" setting.

Antiviral treatment of chronic hepatitis C in clinical routine

OBJECTIVE

Pegylated interferon plus ribavirin is the standard treatment for chronic hepatitis C. Sustained virological response (SVR) rates of up to 60% are reported in randomized controlled trials, but it is unclear whether the results from such trials are reproducible in the clinical routine setting. We investigated consecutive treatment-naïve chronic hepatitis C patients at our center to examine the efficacy of treatment with pegylated interferon plus ribavirin in clinical routine.

MATERIALS AND METHODS

Between 2000 and 2006 we treated a total of 219 patients with pegylated interferon alpha (2a or 2b) and ribavirin (800-1200 mg/d). Among them, 34.8% of patients infected with HCV genotypes 1/4/6 and 18.4% of those with genotypes 2/3 had advanced fibrosis or cirrhosis (F3-F4). For analysis of outcome we subdivided our series into two groups of patients: those who fulfilled standard inclusion criteria in randomized controlled trials and those who did not.

RESULTS

The overall SVR rate was 44.3%. In patients with F0-F2 an SVR was achieved in 52.5%; in those with F3-F4 the SVR rate was 20.8%. In patients infected with genotypes 1/4/6 the SVR rate was 35.4% (SVR: F0-F2 47.7%; F3-F4 19.6%); in those with genotypes 2/3 the rate was 67.8%. The SVR rate in patients with unfavorable baseline factors was significantly lower (32.4% vs. 50%; P = 0.017) and they were more likely to be non-responders (30.9% vs. 13.8%).

CONCLUSION

In everyday clinical practice, up to one-third of patients show unfavorable baseline factors for antiviral therapy, resulting in worse therapeutic outcome. Differences in therapeutic outcome are influenced by patient selection and by the proportion and severity of the underlying liver disease.

Interferon-alpha 2b-induced thrombocytopenia is caused by inhibition of platelet production but not proliferation and endomitosis in human megakaryocytes

Human interferon (IFN)-alpha is the standard therapy for chronic hepatitis C to prevent its progression to liver cirrhosis and hepatocellular carcinoma. Thrombocytopenia is one of the major adverse effects of IFN-alpha and often leads to dose reduction or treatment discontinuation. However, there is little information on how IFN-alpha inhibits human megakaryopoiesis. In this study, we demonstrated that IFN-alpha did not inhibit colony formation of megakaryocytes from human CD34(+) hematopoietic stem cells. IFN-alpha did not inhibit endomitosis but did inhibit cytoplasmic maturation of megakaryocytes and platelet production in vitro. IFN-alpha suppressed the expression of transcription factors regulating late-stage megakaryopoiesis, such as GATA-1, p45(NF-E2), MafG. IFN-alpha also significantly reduced the number of human platelets but not megakaryocytes, and did not inhibit endomitosis of human megakaryocytes in immunodeficient NOD/Shi-scid/IL-2R gamma(null) (NOG) mice transplanted with human CD34(+) cells (hu-NOG). We also demonstrated that a novel thrombopoietin mimetic, NIP-004, was effective for treating IFN-alpha-induced thrombocytopenia in hu-NOG mice. From ultrastructural study, IFN-alpha inhibited the maturation of demarcation membranes in megakaryocytes, although NIP-004 prevented the inhibitory effects of IFN-alpha. These results defined the pathogenesis of IFN-alpha-induced thrombocytopenia and suggested possible future clinical applications for thrombopoietin mimetics.