Tuesday, January 8, 2013

A New Tool for HCV Patients With Low Platelet Counts

A New Tool for HCV Patients With Low Platelet Counts

Although the use of a platelet-boosting agent will assist certain subsets of patients who cannot wait for the approval of direct-acting antivirals, we can envision that the need for such a strategy will steadily wane over time.

Raymond T. Chung, MD - 1/7/2013 More from this author

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The US Food and Drug Administration recently approved an additional indication for eltrombopag for the treatment of thrombocytopenia in patients with chronic hepatitis C to enable the initiation and maintenance of interferon-based therapy. This will come as welcome news for those patients sidelined from treatment because of the relative or absolute contraindication of low platelet counts, which are aggravated by the marrow suppressive effects of interferon.

Expectation for Limited Use

The availability of expanded therapeutic options is always good news. However, I suspect the uptake of this thrombopoietin receptor agonist will likely be limited for several reasons related to clinical population and timing:

  • Clinical need: The clinical need among patients with HCV would appear to be restricted primarily to those patients with cirrhosis and portal hypertension who have very low platelet counts.
  • Tolerability of HCV therapy: The ability of such patients to be safely treated with peginterferon, ribavirin, and, in the case of genotype 1–infected persons, telaprevir or boceprevir will also be constrained by concerns about the risk of more serious adverse events, including anemia, and even hepatic decompensation described in several reports from Europe and the United States. Indeed, one of the largest such studies, the CUPIC study, found that an important risk factor for decompensation was platelet count < 100,000. Conversely, eltrombopag provides a new tool that may boost platelet counts and theoretically reduce this risk of decompensation.
  • Safety concerns: There was a small but finite excess occurrence of portal vein thrombosis described in study participants receiving eltrombopag, along with hepatic decompensation. There exists the concern, then, that adding this profile onto a cirrhotic population, in conjunction with interferon-based treatment, raises the stakes for adverse outcomes. Real vigilance will need to be practiced in this group of patients who start eltrombopag.
  • The interferon-free future: Finally, and perhaps most importantly, help in the form of other agents (direct-acting antivirals [DAAs]) is rapidly on the way, and we can envision success in the form of SVR being accomplished with interferon-sparing regimens in patients with cirrhosis. Evidence that this will be possible has come from the SOUND-C2 trial, which found comparable SVR rates between patients with and without cirrhosis using an all-oral 2 DAAs plus ribavirin regimen.
Although the use of a platelet-boosting agent will assist certain subsets of patients who cannot wait for the approval of DAAs, it seems to me that the need for such a strategy will steadily wane over time.

Your Thoughts
What are your expectations? Do you envision using eltrombopag in your practice? If so, for which patients? In your opinion, what are the greatest advantages and disadvantages?

 

 

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