The predictive value of viral response during HCV treatment to achieve sustained virologic response after therapy varied according to genotype in a recent prospective study.
Researchers evaluated 7,163 patients with chronic HCV who received treatment with pegylated interferon (PEG-IFN) and ribavirin. All participants had an HCV RNA level of 50 IU/mL or more at baseline. Viral response (VR) at 2, 4 and 12 weeks of treatment was assessed as a potential predictor of sustained virologic response (SVR) after 24 weeks of follow-up without treatment, based upon HCV genotype.
Across the entire cohort, SVR was achieved by 49.4% of patients (95% CI, 48.3%-50.6%). SVR according to VR and genotype occurred at 2, 4 and 12 weeks, respectively, at the following rates (all 95% CI):
- Genotype 1: 66.2%, 68.4% and 60.3%
- Genotype 2: 82.0%, 76.3% and 74.2%
- Genotype 3: 67.3%, 67.3% and 63.8%
- Genotype 4: 59.4%, 63.3% and 54.3%
The overall SVR rate among evaluable participants after 24 weeks of untreated follow-up (SVR24) was 55.2%, and 45.9% for genotype 1 (n=4,119 patients), 80.2% for genotype 2 (n=913), 71.8% for genotype 3 (n=1,063) and 46.1% for genotype 4 (n=282).
Patients who achieved VR at weeks 2, 4 or 12 had consistently high SVR24 rates. A VR by week 4 had the highest positive predictive value (PPV) among patients with HCV genotypes 1 (68.4%) and 4 (63.3%), while VR at week 2 had the highest PPV for genotype 2 (82.0%) and weeks 2 and 4 had the highest for genotype 3 (67.3%). The highest negative predictive value was lack of VR at week 12 for all genotypes.
“The results of this large multinational trial demonstrate that, in the ‘real-world’ setting, high SVR24 rates can be achieved with [PEG-IFN] plus ribavirin in patients with HCV genotypes 1-4 who achieve early virologic response,” the researchers concluded. “However, the data also indicate that there is no universal prediction rule for SVR24 that applies to all patients and that the best PPV for SVR24 differs by genotype.”
Disclosure: See the study for a full list of relevant disclosures.