Sep 25, 2013
The European Commission has extended the indication for eltrombopag (Revolade, GlaxoSmithKline) to include adults with chronic hepatitis C virus (HCV) infection with thrombocytopenia severe enough to prevent the initiation or maintenance of optimal interferon (IFN)-based therapy, the company announced yesterday.
The action follows a positive opinion in July for the expanded indication by the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA).
The US Food and Drug Administration approved eltrombopag (Promacta) in November 2012 to treat thrombocytopenia in patients with chronic HCV, as reported by Medscape Medical News.
Thrombocytopenia can occur in people with chronic HCV as a consequence of liver damage and is also a common adverse effect of IFN therapy. An estimated 25% of patients with chronic HCV have thrombocytopenia, and up to 9% of patients are severely thrombocytopenic. Patients with thrombocytopenia may be unable to start or continue IFN-based treatment, reducing their chances of achieving a sustained virologic response.
Until now, prescribers in Europe "were without an option for treating low platelet counts in patients with chronic hepatitis C infection" Paolo Paoletti, MD, president of GlaxoSmithKline Oncology, said in a statement.
The new indication for eltrombopag means healthcare professionals in Europe can now use it to help patients "start and stay on interferon therapy, which will facilitate achieving the best outcome for these individuals — that being a sustained virologic response," Dr. Paoletti added.
ENABLE Pivotal Trials
Marketing authorization in Europe was granted on the basis of data from 2 randomized, double-blind, placebo-controlled, multicenter phase 3 studies with a total of 1521 patients with platelet counts below 75,000 µL, the Eltrombopag to INitiate and Maintain Interferon Antiviral Treatment to Benefit Subjects with Hepatitis C related Liver DiseasE (ENABLE 1 and 2) trials.
Patients in ENABLE 1 received peginterferon alfa-2a (Pegasys, Genentech) plus ribavirin for antiviral treatment, and patients in ENABLE 2 received peginterferon alfa-2b (Pegintron, Merck) plus ribavirin.
Eltrombopag enabled 95% of patients with chronic HCV-associated thrombocytopenia to achieve platelet counts sufficient for initiation of IFN-based therapy, the company said.
Eltrombopag also enabled more patients to continue receiving IFN-based therapy without dose reduction compared with placebo (45% vs 27%). The drug also allowed roughly 1 in 5 patients who were ineligible or poor candidates for IFN-based therapy resulting form thrombocytopenia to achieve sustained virologic response, the company said.
The most common adverse reactions (experienced by at least 10% of patients) of any grade include headache, anemia, decreased appetite, insomnia, cough, nausea, diarrhea, alopecia, pruritus, myalgia, pyrexia, fatigue, influenza like illness, asthenia, chills, and peripheral edema.
A boxed warning in the United States notes that eltrombopag may cause hepatotoxicity. In addition, in combination with IFN and ribavirin, it may increase the risk for hepatic decompensation. Accordingly, clinicians must regularly monitor serum liver tests. Higher platelet counts with eltrombopag may cause thrombotic and thromboembolic complications.
The most common adverse events reported in the 2 clinical trials included anemia, fever, fatigue, headache, nausea, diarrhea, decreased appetite, and influenza-like illness.
Eltrombopag is also approved to treat thrombocytopenia in patients with chronic immune (idiopathic) thrombocytopenia who have not responded sufficiently to corticosteroids, immunoglobulins, or splenectomy.
For the EU summary of product characteristics for Revolade and full US prescribing information, including the boxed warning and medication guide for Promacta please visit the manufacturer's Web site.