A Follow-up Week 12 Viral Count Is Useful in Predicting SVR and Is 100% Accurate in Patients without Cirrhosis

The primary goal of HCV treatment is a sustained virologic response (SVR) determined by a negative HCV RNA at 24 weeks after discontinuation of therapy. One report on early relapse rate in patients treated with standard interferon (IFN) or pegylated interferon (Peg IFN) monotherapy noted only 2% of patients became HCV RNA positive between 12 and 24 weeks after discontinuation of therapy.

No data have been reported on early relapse rates following response to Peg IFN plus ribavirin therapy. Therefore this study was designed to assess the predictive value of the 12 week follow-up viral load in determining SVR.

This was a cohort study of HCV patients treated from 2003 to present. All patients who were HCV RNA undetected (<29 IU/mL) at the end of treatment with viral counts done at follow-up week 12 and 24 were included.

Results

• 154 patients qualified for inclusion (89 men, 65 women). Age range was 18-79 (mean 48.7  +/-  8.8). Race distribution was White 119 (77%), Black 12 (8%), Hispanic 16 (10%), and other 7 (5%).
  
  
• Fibrosis was stage 0-1 in 23, stage 2 in 38, stage 3 in 35, and stage 4 in 44 patients.
  
  
• Genotype distribution was 87 (56%) with 1, 43 (28%) with 2, 18 (12%) with 3, 4 (3%) with other.
  
  
• Duration of treatment in genotype 1 was 44-72 weeks (mean 49.1  +/-  4.9) and genotype 2/3 was 12-60 weeks (mean 27.1  +/-  11.6).
  
  
• This was the first treatment in 114 (74%) patients, 16 (10%) were relapser and 22 (14%) were nonresponders.
  
  
• Treatment was with Peg IFN alfa-2a (Pegasys) in 58 (38%), Peg IFN alfa-2b (PegIntron) in 70 (45%), and CIFN (Infergen) in 26 (17%).
  
  
• In predicting SVR (Table 1), the follow-up week 12 viral counts had a sensitivity of 99%, specificity of 94%, PPV of 97%, and NPV of 98%.
  
  
• Follow-up 12 week viral count did not predict the SVR status in 4 patients all of whom had cirrhosis and were in their first treatment course.
  
  
• One patient positive at follow-up week 12 (HCV RNA 9000 IU/mL) later achieved an SVR.

Table 1: Post Treatment HCV Viral Counts in Patients with EOT Response

The authors conclude, “A follow-up week 12 viral count is useful in predicting attainment of SVR and is 100% accurate in patients without cirrhosis. In this sample, 9% of patients with cirrhosis were misclassified by the follow-up week 12 viral count.”

In addition, they write, “Use of an earlier viral count in patients without cirrhosis would allow earlier retreatment for those with relapse and allow earlier confirmation of successful treatment.”

05/25/07

Reference
D Friedman, S Rashdan, C D Levine, and others. Predictive Value of a 12 Week Follow-up HCV RNA on SVR in Chronic HCV Patients Treated with Peg/RBV. DDW 2007. May 19-25, 2007. Washington, D.C. Abstract # 1859.

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