The FDA has approved eltrombopag (Promacta, GlaxoSmithKline) to treat low blood platelet counts in patients with chronic hepatitis C.
This treatment will enable patients who are otherwise poor candidates to initiate and maintain interferon-based therapy for the liver disease, the manufacturer announced in a press release.
Eltrombopag was initially approved in November 2008 to treat chronic idiopathic thrombocytopenia purpura in patients who do not respond to other drugs.
The medication should only be used in patients with chronic hepatitis C who are unable to start interferon therapy, and should not be used to normalize platelet counts in other patients with hepatitis C, the manufacturer warned.
Safety and efficacy of eltrombopag have not been established in combination with direct-acting antiviral agents approved for treatment of chronic hepatitis C genotype 1 infection.
The FDA approval is based on results from two phase III randomized, double-blinded, controlled studies involving more than 1,500 patients with platelet counts less than 75,000.
More patients who received eltrombopag plus peginterferon alpha 2a (Pegasys) and ribavirin achieved an early virologic response than those assigned to peginterferon 2a, ribavirin and a placebo — 66% vs. 50% (P<0.0001), respectively. A sustained virologic response was achieved in 23% of the eltrombopag group vs. 14% of the placebo group (P=0.0064), study findings show.
Eltrombopag will carry a boxed warning due to the potential for hepatotoxicity, and may increase the risk for hepatic decompensation in combination with interferon and ribavirin.The most common side effects in the two trials included anemia, pyrexia, fatigue and peripheral edema.