Interferon-gamma with peginterferon alpha-2a and ribavirin in nonresponder patients with chronic hepatitis C (ANRS HC16 GAMMATRI).

BACKGROUND AND AIM: Interferon-gamma-1b (IFN-γ-1b) improves alpha interferon (IFN-α) inhibition of hepatitis C virus (HCV) replication in replicon system. We described virological response after addition of IFN-γ to a combination of ribavirin/peginterferon (PEG-IFN)-α-2a or α-2b. METHODS: In this non-comparative, multicenter trial, patients chronically infected by HCV who were nonresponders to a previous treatment by PEG-IFN and ribavirin were restarted on a regimen of PEG-IFN-α-2a (180 µg/week) + ribavirin (1000-1200 mg/day) for 16 weeks. If HCV-RNA decreased less than 2 log(10) copies/mL (nonresponders), and if PEG-IFN-α-2a and ribavirin dosages were unchanged while tolerance was good, IFNγ-1b (100 µg three times per week) was added for the last 32 weeks of treatment. Virological response was evaluated at week 28 (12 weeks after initiation of IFN-γ-1b). RESULTS: Among the 48 patients started on dual therapy, 23 patients (47%) were nonresponders at week 12 and received IFN-γ-1b from week 16 onward. Their mean HCV-RNA (log(10) IU/mL) was 6.83 at baseline, 5.81 at week 12, and 5.63 at week 28. No patient reached undetectable HCV-RNA at week 28 (upper bound of 95% confidence interval: 14.8%); none had a decrease > 1 log(10) IU/mL. One case of grade 4 neutropenia was reported. CONCLUSION: Among the strictly selected nonresponders, IFN-γ-1b (at a dosage of 100 µg thrice a week) in combination with PEG-IFN-α-2a and ribavirin failed to show virological efficacy.

Neutralizing antibodies to interferon-α and circulating interferon in patients with chronic hepatitis C non-responding to pegylated interferon plus ribavirin re-treated by pegylated interferon-α-2a and ribavirin (ANRS HC16 GAMMATRI substudy).

A lack of antiviral response in patients with chronic hepatitis C treated with pegylated (PEG)-interferon (IFN)-α-2a + ribavirin (RIBA) may be explained by neutralizing antibodies to IFN-α-2a. The aim of this study was to assess neutralizing antibodies to IFN-α-2a and IFN levels in non-responder patients who were re-treated by PEG IFN-α-2a and RIBA for 12 weeks. Non-responders to a first-line treatment of PEG IFN-α-2a + RIBA were included for treatment with PEG IFN-α-2a (180 µg/week) + RIBA (1,000 mg/day if <75 kg, 1,200 mg otherwise) for 48 weeks. HCV RNA was measured at week 12. IFN levels and neutralizing antibodies to IFN-α-2a were measured retrospectively on stored sera at baseline and weeks 4 and 12, using a quantitative sandwich ELISA for neutralizing antibodies to IFN-α-2a. Twenty-three patients were non-responders and 19 patients were responders at week 12 of the initial phase of the second-line treatment. Non-responders and responders did not differ statistically: baseline age (median age 47 vs. 50 years), HCV RNA (median 6.8 vs. 6.4 log(10) copies/ml), gender (70% vs. 73% males), genotype (genotype 1: 91% vs. 80%). The median IFN-α-2a levels (pg/ml) at weeks 0, 4, and 12 (interquartile range) did not differ between the 19 responders to initial phase of second-line treatment and the 23 non-responders: <3.3 (<3.3-371.4), 1457.3 (106.8-3284.8), and 1,652 (90.8-5,000); 84.5 (3.3-277.4), 1407.4 (120.2-2443.4), and 1620.1 (120.2-2287.1), respectively. Among non-selected consecutive non-responder patients, re-treatment with PEG IFN-α-2a + RIBA is associated with virological response regardless of the presence of antibody-mediated resistance to conventional IFN treatment.