Sofosbuvir clinical studies
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sheng Shi, M.D. [2]
Clinical Studies
Description of Clinical Trials
The safety and efficacy of SOVALDI was evaluated in five Phase 3 trials in a total of 1724 HCV mono-infected subjects with genotypes 1 to 6 chronic hepatitis C (CHC) and one Phase 3 trial in 223 HCV/HIV-1 co-infected subjects with genotype 1, 2 or 3 CHC. Among the five trials in HCV mono-infected subjects, one was conducted in treatment-naïve subjects with genotype 1, 4, 5 or 6 CHC in combination with peginterferon alfa 2a and ribavirin and the other four were conducted in subjects with genotype 2 or 3 CHC in combination with ribavirin, including one in treatment-naïve subjects, one in interferon intolerant, ineligible or unwilling subjects, one in subjects previously treated with an interferon-based regimen, and one in all subjects irrespective of prior treatment history or ability to take interferon. The trial in HCV/HIV-1 co-infected subjects was conducted in combination with ribavirin in treatment-naïve subjects with genotype 1 CHC and all subjects with genotype 2 or 3 CHC irrespective of prior treatment history or ability to take interferon. Subjects in these trials had compensated liver disease including cirrhosis. SOVALDI was administered at a dose of 400 mg once daily. The ribavirin (RBV) dose was weight-based at 1000–1200 mg daily administered in two divided doses when used in combination with SOVALDI, and the peginterferon alfa 2a dose, where applicable, was 180 micrograms per week. Treatment duration was fixed in each trial and was not guided by subjects' HCV RNA levels (no response guided algorithm). Plasma HCV RNA values were measured during the clinical trials using the COBAS TaqMan HCV test (version 2.0), for use with the High Pure System. The assay had a lower limit of quantification (LLOQ) of 25 IU per mL. Sustained virologic response (SVR) was the primary endpoint which was defined as HCV RNA less than LLOQ at 12 weeks after the end of treatment.
Clinical Trials in Subjects with Genotype 1 or 4 CHC
Treatment-Naïve Adults — NEUTRINO (Study 110)
NEUTRINO was an open-label, single-arm trial that evaluated 12 weeks of treatment with SOVALDI in combination with peginterferon alfa 2a and ribavirin in treatment-naïve subjects with genotype 1, 4, 5 or 6 HCV infection compared to pre-specified historical control.
Treated subjects (N=327) had a median age of 54 years (range: 19 to 70); 64% of the subjects were male; 79% were White, 17% were Black; 14% were Hispanic or Latino; mean body mass index was 29 kg/m2 (range: 18 to 56 kg/m2); 78% had baseline HCV RNA greater than 6 log10 IU per mL; 17% had cirrhosis; 89% had HCV genotype 1; 9% had HCV genotype 4 and 2% had HCV genotype 5 or 6. Table 8 presents the response rates for the treatment group of SOVALDI + peginterferon alfa + ribavirin.
 |
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.
It is estimated that the response rate in patients who previously failed pegylated interferon and ribavirin therapy will approximate the observed response rate in NEUTRINO subjects with multiple baseline factors traditionally associated with a lower response to interferon-based treatment (Table 9). The SVR rate in the NEUTRINO trial in genotype 1 subjects with IL28B non-C/C alleles, HCV RNA >800,000 IU/mL and Metavir F3/F4 fibrosis was 71% (37/52).
Clinical Trials in Subjects with Genotype 2 or 3 CHC
Treatment-Naïve Adults — FISSION (Study 1231)
FISSION was a randomized, open-label, active-controlled trial that evaluated 12 weeks of treatment with SOVALDI and ribavirin compared to 24 weeks of treatment with peginterferon alfa 2a and ribavirin in treatment-naïve subjects with genotype 2 and 3 HCV. The ribavirin doses used in the SOVALDI + ribavirin and peginterferon alfa 2a + ribavirin arms were weight-based 1000–1200 mg per day and 800 mg per day regardless of weight, respectively. Subjects were randomized in a 1:1 ratio and stratified by cirrhosis (presence vs. absence), HCV genotype (2 vs. 3) and baseline HCV RNA level (<6 log10IU/mL vs. ≥6 log10IU/mL). Subjects with genotype 2 or 3 HCV were enrolled in an approximately 1:3 ratio.
Treated subjects (N=499) had a median age of 50 years (range: 19 to 77); 66% of the subjects were male; 87% were White, 3% were Black; 14% were Hispanic or Latino; mean body mass index was 28 kg/m2 (range: 17 to 52 kg/m2); 57% had baseline HCV RNA levels greater than 6 log10 IU per mL; 20% had cirrhosis; 72% had HCV genotype 3. Table 10 presents the response rates for the treatment groups of SOVALDI + ribavirin and peginterferon alfa + ribavirin.
 |
Response rates for subjects with cirrhosis at baseline are presented in Table 11 by genotype.
 |
Interferon Intolerant, Ineligible or Unwilling Adults — POSITRON (Study 107)
POSITRON was a randomized, double-blinded, placebo-controlled trial that evaluated 12 weeks of treatment with SOVALDI and ribavirin (N=207) compared to placebo (N=71) in subjects who are interferon intolerant, ineligible or unwilling. Subjects were randomized in 3:1 ratio and stratified by cirrhosis (presence vs. absence).
Treated subjects (N=278) had a median age of 54 years (range: 21 to 75); 54% of the subjects were male; 91% were White, 5% were Black; 11% were Hispanic or Latino; mean body mass index was 28 kg/m2 (range: 18 to 53 kg/m2); 70% had baseline HCV RNA levels greater than 6 log10 IU per mL; 16% had cirrhosis; 49% had HCV genotype 3. The proportions of subjects who were interferon intolerant, ineligible, or unwilling were 9%, 44%, and 47%, respectively. Most subjects had no prior HCV treatment (81%). Table 12 presents the response rates for the treatment groups of SOVALDI + ribavirin and placebo.
References
Adapted from the FDA Package Insert.