Among study participants with the same end-of-study response status, HCV RNA declines at 4 weeks were similar between treatment-naive patients and treatment-experienced ones.
Participants in treatment studies of hepatitis C virus (HCV) infection are generally categorized as treatment naive or treatment experienced, based on previous receipt of an interferon-based regimen such as pegylated interferon-α plus ribavirin (P/R). Treatment-experienced individuals with P/R treatment failure can be further subdivided into relapsers, partial responders, and null responders, based on plasma HCV RNA concentrations during and after therapy.
To date, no data have emerged to indicate resistance to interferon-α–based therapy, suggesting that the response rate to P/R should not be lower with retreatment than with initial therapy. To examine this issue, investigators at the FDA examined data for participants in eight earlier trials (2996 treatment-naive and 754 treatment-experienced patients with genotype-1 HCV infection who had completed P/R treatment and had week-4 viral load data available).
In both treatment-naive and treatment-experienced patients, the HCV RNA change from baseline at 4 weeks was strongly correlated with the likelihood of achieving a sustained viral response (i.e., an undetectable viral load 24 weeks after the end of treatment). When therapy response was compared between treatment-experienced patients (stratified according to previous treatment outcomes) and treatment-naive patients (stratified based on end-of-treatment outcomes), the 4-week decline in HCV RNA was similar between the corresponding groups.
Comment: Despite its retrospective nature, this study suggests that responsiveness to Interferon-α/Ribavirin (P/R) does not decrease with retreatment. As the authors point out, this finding has implications for trials of interferon-based triple therapy — P/R plus one of the newer direct-acting antivirals emerging for HCV.
— Neil M. Ampel, MD
Published in Journal Watch Infectious Diseases September 19, 2012
Citation(s):
To date, no data have emerged to indicate resistance to interferon-α–based therapy, suggesting that the response rate to P/R should not be lower with retreatment than with initial therapy. To examine this issue, investigators at the FDA examined data for participants in eight earlier trials (2996 treatment-naive and 754 treatment-experienced patients with genotype-1 HCV infection who had completed P/R treatment and had week-4 viral load data available).
In both treatment-naive and treatment-experienced patients, the HCV RNA change from baseline at 4 weeks was strongly correlated with the likelihood of achieving a sustained viral response (i.e., an undetectable viral load 24 weeks after the end of treatment). When therapy response was compared between treatment-experienced patients (stratified according to previous treatment outcomes) and treatment-naive patients (stratified based on end-of-treatment outcomes), the 4-week decline in HCV RNA was similar between the corresponding groups.
Comment: Despite its retrospective nature, this study suggests that responsiveness to Interferon-α/Ribavirin (P/R) does not decrease with retreatment. As the authors point out, this finding has implications for trials of interferon-based triple therapy — P/R plus one of the newer direct-acting antivirals emerging for HCV.
— Neil M. Ampel, MD
Published in Journal Watch Infectious Diseases September 19, 2012
Citation(s):
Liu J et al. Interferon responsiveness does not change in treatment-experienced hepatitis C subjects: Implications for drug development and clinical decisions. Clin Infect Dis 2012 Sep 1; 55:639.
- Original article (Subscription may be required)
- Medline abstract (Free)
No comments:
Post a Comment