Clinical trial: extended treatment duration of peginterferon-alpha2b plus ribavirin for 72 and 96 weeks in hepatitis C genotype 1-infected late responders

BACKGROUND

The benefits of prolonging peginterferon and ribavirin after 48 weeks of treatment to maximize sustained virological responses (SVR) in hepatitis C virus (HCV) genotype 1-infected patients remain to be understood.

AIM

To investigate whether extended treatment longer than 72 weeks may be superior to 72-week treatment.

METHODS

A total of 120 treatment-naïve or retreated patients with HCV genotype 1 were treated with peginterferon-alpha-2b (1.5 microg/kg/week) plus weight-based ribavirin. We had 34 late responders, in whom HCV RNA first became undetectable at week 12-48, and randomized them into three groups receiving standard-dose peginterferon-alpha-2b plus low-dose ribavirin (200 mg/day) for extended 24 weeks (group A), receiving low-dose peginterferon-alpha-2b (0.75 microg/kg/week) plus low-dose ribavirin for extended 48 weeks (group B) or no extended treatment (group C), and evaluated the outcome according to their virological response.

RESULTS

Multivariate analysis showed that the treatment for 96 weeks was identified as a significant, independent factor associated with SVR in HCV genotype 1-infected late responders in comparison with group A [odds ratio (OR), 10.002; P = 0.080] and group C (OR, 17.748; P = 0.025).

CONCLUSION

Extending the treatment duration from 48 weeks to 96 weeks improves SVR rates in genotype 1-infected patients with late virological response to peginterferon-alpha-2b and ribavirin.

Suppression of mouse skin papilloma by canthaxanthin and beta-carotene in vivo: possibility of the regression of tumorigenesis by carotenoids without conversion to retinoic acid

Using mouse skin papilloma as a model system, we examined whether the antitumorigenic activity of carotenoids was related to their provitamin A activity. Oral administration of canthaxanthin (CX) or beta-carotene at 200 mg/kg/day for 14 days significantly reduced the cumulative size of papillomas induced on the skin by 9,10-dimethyl-1,2-benzanthracene (p < 0.05), after the accumulation of these carotenoids in the tumors. The levels of a protooncogene, c-myc, were simultaneously suppressed in papillomas in carotenoid-treated mice. Because CX cannot be converted metabolically to retinoids, these results suggested that CX directly inhibited the growth of papillomas. Neither the accumulation of retinoids nor the expression of a retinoic acid-inducible gene, retinoic acid receptor-beta, was found in papillomas of CX- and beta-carotene-treated mice, suggesting that, like CX, beta-carotene might exert the tumor-suppressing effect without being converted to retinoids. Thus a certain antitumorigenic activity of carotenoids appears not necessarily to require their provitamin A activity.