Interferon-free regimens containing setrobuvir for patients with genotype 1 chronic hepatitis C: a randomized, multicenter study

BACKGROUND & AIMS

Setrobuvir is a direct-acting antiviral (DAA) non-nucleoside inhibitor of hepatitis C virus (HCV) polymerase. This study examined interferon-free combinations containing setrobuvir, a ritonavir-boosted protease inhibitor (danoprevir/r) and ribavirin, with/without the nucleoside inhibitor mericitabine in HCV genotype (G)1 patients.

METHODS

Non-cirrhotic treatment-naïve patients (N = 110) were randomized to five groups. Three groups received a 14-day mericitabine/ribavirin lead-in followed by treatment with 3 DAAs (setrobuvir, danoprevir/r, mericitabine) plus ribavirin for 12 weeks (Group A: G1a; D: G1b) or 24 weeks (B: G1a), and two groups received 2 DAAs (setrobuvir, danoprevir/r) plus ribavirin for 12 weeks (E: G1b) or 24 weeks (C: G1a). Efficacy was defined as sustained virological response (HCV RNA <25 IU/ml after 12 weeks' follow-up, SVR12).

RESULTS

Two groups met predefined futility criteria for breakthrough (C) or relapse (A) and were discontinued. SVR12 rates were 42.9% (3/7) and 74.1% (20/27) in G1a patients in Groups A and B, respectively, and 95.7% (22/23) and 68.2% (15/22) in G1b patients in Groups D and E respectively. All G1a patients assigned to 24 weeks of treatment who experienced a decrease in HCV RNA of ≥2.3 log10 IU by the end of the lead-in period (n = 28) achieved SVR12. Overall, treatment was well tolerated and most adverse events were mild to moderate. No major safety signals were identified.

CONCLUSIONS

An interferon-free setrobuvir-based regimen (3 DAAs plus ribavirin) is safe and effective in treatment-naïve G1 patients.

DAUPHINE: a randomized phase II study of danoprevir/ritonavir plus peginterferon alpha-2a/ribavirin in HCV genotypes 1 or 4

BACKGROUND & AIMS

Danoprevir is a hepatitis C virus (HCV) protease inhibitor with activity against genotypes (G)1/G4, which is maintained at lower doses by ritonavir-boosting. We report results of a large, randomized, active-controlled phase IIb study of ritonavir-boosted danoprevir (danoprevir/r) plus peginterferon alpha-2a/ribavirin (P/R) in treatment-naive patients with HCV G1/4 infection.

METHODS

Treatment-naive patients with HCV G1/4 infection were randomized to twice-daily danoprevir/r 200/100 mg (A, n = 92); 100/100 mg (B, n = 93); or 50/100 mg (C, n = 94) plus P/R for 24 weeks; twice-daily danoprevir/r 100/100 mg (D, n = 94) plus P/R for 12 or 24 weeks; or P/R alone (E, n = 44) for 48 weeks. Patients in the response-guided therapy arm (D) with an extended rapid virological response (eRVR2: HCV RNA <15 IU/ml during Weeks 2-10) stopped all therapy at Week 12; non-eRVR2 patients continued all treatment to Week 24. The primary efficacy endpoint was sustained the virological response (SVR24: HCV RNA <15 IU/ml after 24 weeks of untreated follow-up).

RESULTS

SVR24 rates in Arms A, B, C, D and E were 89.1%, 78.5%, 66.0%, 69.1% and 36.4%, respectively, in the overall population; 83.6%, 69.6%, 60.3%, 59.2% and 38.5% in G1a-infected patients, 96.6%, 93.1%, 73.1%, 78.4% and 28.6% in G1b-infected patients and 100%, 87.5%, 100%, 100% and 66.7% in G4-infected patients. Danoprevir/r plus P/R was generally well tolerated compared with P/R alone. There was a higher incidence of serious adverse events in danoprevir-treatment arms, but most were associated with P/R.

CONCLUSIONS

The combination of danoprevir/r plus P/R is efficacious in treatment-naïve patients with HCV genotype 1 or 4 infection.

Randomized controlled trial of danoprevir plus peginterferon alfa-2a and ribavirin in treatment-naïve patients with hepatitis C virus genotype 1 infection

BACKGROUND & AIMS

The combination of a hepatitis C virus (HCV) protease inhibitor, peginterferon, and ribavirin is the standard of care for patients with HCV genotype 1 infection. We report the efficacy and safety of response-guided therapy with danoprevir (a potent second-generation protease inhibitor), peginterferon alfa-2a (40 KD), and ribavirin in these patients.

METHODS

Treatment-naïve patients (N = 237) were randomly assigned to groups given 12 weeks of danoprevir (300 mg every 8 hours; 600 mg every 12 hours, and 900 mg every 12 hours) or placebo plus peginterferon alfa-2a and ribavirin, followed by peginterferon alfa-2a and ribavirin. Patients given danoprevir who had an extended rapid virologic response (eRVR4-20: HCV RNA <15 IU/mL during weeks 4-20) stopped therapy at week 24; those without an eRVR4-20 continued therapy to 48 weeks. Patients who were given placebo received 48 weeks of peginterferon alfa-2a and ribavirin. The primary efficacy end point was sustained virologic response (SVR: HCV RNA <15 IU/mL after 24 weeks without treatment).

RESULTS

Rates of SVR were higher among patients given danoprevir 300 mg (68%), 600 mg (85%), and 900 mg (76%) than placebo (42%) (95% confidence interval: 26%-59%). Seventy-nine percent of patients given danoprevir 600 mg had an eRVR4-20; among these, 96% had an SVR. Serious adverse events were reported in 7% to 8% of patients given danoprevir and 19% given placebo. Four patients given danoprevir (1 patient in the 600-mg group and 3 in the 900-mg group) had reversible, grade 4 increases in alanine aminotransferase, which led to early discontinuation of the 900-mg arm of the study.

CONCLUSIONS

The combination of danoprevir, peginterferon alfa-2a, and ribavirin leads to high rates of SVR in patients with HCV genotype 1 infection, but high doses of danoprevir can lead to grade 4 increases in alanine aminotransferase. Studies of lower doses of danoprevir with ritonavir, to reduce overall danoprevir exposure while maintaining potent antiviral activity, are underway; Clinicaltrials.gov number, NCT00963885.

Morphological basis of pulmonary edema in mice with cytokine-induced vascular leak syndrome

Patients injected systemically with recombinant human interleukin-2 (rhIL-2) for treatment of solid tumor develop a vascular leak syndrome (VLS), characterized mainly by pulmonary edema whose pathogenesis is unknown. We have examined the structure of pulmonary vessels in mice with severe VLS induced by systemic injections of rhIL-2 and recombinant human interferon-alpha-A/D (rhIFN-alpha), which has a synergistic effect with IL-2. The pulmonary edema was associated with lesions of venous and capillary endothelia, alveolar basement membrane, and type I epithelial cells. These changes were more severe and diffuse than those seen in mice systemically injected with rhIL-2 alone, and in beige mice (deficient in NK cells and certain enzymes of polymorphonuclear leukocytes) injected with rhIL-2 and rhIFN-alpha. The endothelial lesions were comparable to those seen when leukocytes activated by cytokines react with activated endothelial cells in vitro, or at the site of injection of cytokines in vivo. The observations are in agreement with the interpretation that the severe lesions occurring in mice systemically injected with rhIL-2 with rhIFN-alpha result from the interaction of leukocytes with the endothelium. The results confirm the validity of previous studies performed in vitro or in animals injected intradermally with cytokines and extend their significance.

Diversity in inhibitory effects of IFN-gamma and IFN-alpha A on the induced DNA synthesis of a hairy cell leukemia B lymphocyte clone reflects the nature of the activating ligand

A hairy cell leukemia population was used as a clonal model for studying the direct immunomodulatory effects of recombinant interferon-alpha A (rIFN-alpha A) and rIFN-gamma on human B-cell proliferation. The leukemic cell population KON was notably quiescent when incubated in medium alone but was induced to significant in vitro DNA synthesis when cultured with any of four activators of human B cells: anti-IgM antibody, Staphylococcus aureus cells (SAC), phorbol myristate acetate (PMA), or B-cell growth factor (BCGF). While both rIFN-gamma and rIFN-alpha A exhibited suppressive effects on these responses, their inhibitory patterns were distinct and reciprocal. Thus, rIFN-gamma exclusively suppressed anti-IgM-and SAC-induced leukemic DNA synthesis, and rIFN-alpha A significantly suppressed only PMA- and BCGF-induced DNA synthesis. The effects of the rIFN preparations were ablated in the presence of IFN type-specific monoclonal antibodies. Kinetic analyses and pulsing studies revealed that inhibition was most notable when cells were exposed concomitantly to IFN and the activating ligand. That the diverse effects of IFN-gamma and IFN-alpha A are manifested on a single B-cell clone was confirmed by Southern blot analysis of restriction enzyme-digested KON cell DNA with a JH-specific probe. These studies suggest that the therapeutic potential of the two types of IFN may be influenced by the nature of the extracellular ligands in the leukemic mileau that promote leukemic clonal expansion.