Here is a list of sofosbuvir trials Read the description of each trial look for the ones that include sofosbuvir+interferon+ribavirin GT1 some may include other GTs but don't look at ones that are GT2/GT3 exclusive.
For the appropriate trials look at the slide show presentation for more details.
http://hepatitisc.uw.edu/page/treatment/drugs/sofosbuvir-drug
If you are still looking for more info Google search by the specific trial name.
I don't know about "is IL28 B genotype is significant in this tx". Other members may be better able to answer your question or provide direct links to more specific information regarding your question.
hepatitisc.uw.edu - Hepatitis C Online
Hepatitis C Online is a free educational, web-based service that functions as a comprehensive resource for diagnosing, monitoring and managing the Hepatitis C virus infection.
and hcvguidelines.org are two of my top go to sources as a starting point for information about HCV and treatment.
Best of luck for you getting the right treatment and achieving SVR
http://www.drugs.com/pro/sovaldi.html#S12.3
In a single-group study of sofosbuvir combined with peginterferon–ribavirin, patients with predominantly genotype 1 or 4 HCV infection had a rate of sustained virologic response of 90% at 12 weeks. Neutrino study
Sovaldi + Peg-IFN alfa + RBV 12 weeks
N=327*
Genotype 1† 89% (261/292)
Genotype 1a 92% (206/225)
Genotype 1b 82% (54/66)
Genotype 4 96% (27/28)
Outcome for subjects without SVR
On-treatment virologic failure 0/327
Relapse‡ 9% (28/326)
Other§ 1% (4/327)
SVR rates were 98% (93/95) in subjects with baseline IL28B C/C allele and 87% (202/232) in subjects with baseline IL28B non-C/C alleles
Good luck to you.
Nan