Sustained Virological Response at 12 Weeks Post-treatment May be as Good as 24 Weeks for Determining Interferon Cure

		SUMMARY: People who continue to have undetectable hepatitis C virus (HCV) viral load 12 weeks after completing a course of therapy -- sometimes called SVR-12 -- are as likely to remain free of the virus over the long term as those tested 24 weeks post-treatment, according to a study published in the April 2010 issue of Hepatology. This suggests that clinical trial results 12 weeks after finishing treatment may be an accurate measure of sustained virological response.

By Liz Highleyman

Sustained virological response (SVR) to hepatitis C treatment is usually defined as continued undetectable HCV viral load 24 weeks after completion of therapy. Michelle Martinot-Peignoux and colleagues from France evaluated whether assessment of serum HCV RNA 12 weeks after the end of treatment was as relevant as 24 weeks for determining SVR.

The investigators analyzed sustained treatment outcomes among 573 chronic hepatitis C patients who received pegylated interferon (Pegasys or PegIntron) plus ribavirin and had an end-of-treatment virological response. Viral load was measured using a sensitive TMA assay with a lower limit of 5-10 IU/mL. Viral relapse was defined as reappearance of detectable HCV-RNA between the end of treatment and post-treatment week 24.

Results

	All 573 participants had undetectable HCV RNA at the end of treatment.
	At 12 weeks post-treatment, 409 participants still had undetectable viral load.
	At 24 weeks post-treatment, 408 participants (71%) achieved SVR.
	Looking back at week 12 results, all but 1 of the patients who were undetectable at week 12 remained so at week 24.
	Week 12 response had a positive predictive value of 99.7% for predicting Week 24 SVR.

The researchers concluded that assessment of serum HCV RNA 12 weeks after the end of treatment using a highly sensitive TMA assay "is as relevant as after 24 weeks to predict SVR and make decisions on the management of treated patients, suggesting a new definition for SVR."

Institut National de la Santé et de la Recherche Médicale, Centre de Recherche Biomédicale Bichat-Beaujon CRB3, Université Paris VII, Paris, France; Service d'Hépatologie, Hopital Beaujon, Clichy, France.

6/11/10

Reference
M Martinot-Peignoux, C Stern, S Maylin, and others. Twelve weeks posttreatment follow-up is as relevant as 24 weeks to determine the sustained virologic response in patients with hepatitis C virus receiving pegylated interferon and ribavirin. Hepatology 51(4):1122-1126 (Abstract). April 2010.