The 47th Annual Meeting of the European Association for the Study of the Liver (EASL), also called the International Liver Congress, was held in Barcelona, Spain, April 18 – 22, 2012.

As expected, most of the excitement at the meeting focused on advances in the development of interferon-free treatment regimens. New results reported at the meeting, some of which were embargoed or otherwise unavailable at the time of our Pre-EASL report, provide an improved understanding of the features needed to provide high sustained viral response (SVR) rates in an interferon-free treatment regimen. Several of these treatment regimens provide attractive SVR rates in important patient subgroups, with substantially reduced adverse event rates and treatment duration relative to available interferon-containing regimens.

This report provides an update of progress on interferon-free treatment regimens for HCV, factors potentially impacting the approvability and market potential for specific treatment regimens, and offers an overview of factors that might be important in predicting the success of interferon-free drug combinations for which results have not yet been reported.

Key Points:

• Gilead and BMS disclosed achievement of 100% SVR4 in a predominantly GT-1a treatment population with a 24 week interferon-free treatment regimen of GS-7977 and daclatasvir.
  • Although the companies have not committed to developing this combination, this result and the 73% SVR rate observed in the combined ELECTRON and QUANTUM GT-1a subject populations suggest that two drug nucleoside based regimens should be readily achievable
  • With the possible exception of IHX-189, other nucleotide-based interferon-free treatment regimens are earlier in development. The success achieved by Pharmasset and Inhibitex using phosphoramidate prodrug technology to enhance the potency of their nucleoside analogs has spurred several other companies to pursue early stage nucleotide programs. Results of short term monotherapy studies with these are expected in coming months.
• Abbott’s interferon-free treatment regimen of ABT-450/r, ribavirin, and ABT-333 provided 95% SVR24 in treatment naïve GT-1 patients and 47% in treatment experienced patients.
  • This protocol demonstrated that high SVR rates can be obtained with a 12 week treatment duration, but its AE profile is less attractive than that of Gilead’s nucleoside based regimen.
  • The observation of a single late viral relapse (occurring between post treatment weeks 24 and 36) caused some concern that this might be a general feature of interferon-free treatment regimens
  • Among protease inhibitors currently in development, MK-5172 appears particularly promising for incorporation into interferon-free treatment regimens. Compelling evidence that others will provide sufficient potency, activity against resistance variants, and a sufficiently high therapeutic ratio to allow equally high Ctrough/EC50 values is not readily apparent.

For the full report, please download the PDF version at the top of this page.

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