Clinical

Eltrombopag increases platelets in patients with ITP and hepatitis C cirrhosis

Last Updated: 2007-11-28 17:17:42 -0400 (Reuters Health)

By Anthony J. Brown, MD

NEW YORK (Reuters Health) - Treatment with eltrombopag, a new thrombopoietin-receptor agonist, can increase platelet counts in patients with thrombocytopenia due to hepatitis C virus (HCV)-related cirrhosis and idiopathic thrombocytopenic purpura (ITP), according to the results of two studies in The New England Journal of Medicine for November 29.

"We have not previously had a drug to use in patients with cirrhosis and thrombocytopenia...that increases platelet counts, so this class of agents is potentially very exciting for our hepatitis C patients and for liver disease patients in a more general sense," Dr. John G. McHutchison, lead author of the first study, told Reuters Health.

By increasing platelet counts in these patients, eltrombopag "allowed us to initiate and complete the first 12 weeks of antiviral therapy for their hepatitis C infection," added Dr. McHutchison, from Duke University in Durham, North Carolina.

The study involved 74 patients who were randomized to receive eltrombopag (30, 50, or 75 mg) or placebo daily for 4 weeks. The subjects had platelet counts between 20,000 and 70,000 per cubic millimeter before treatment.

None of the patients treated with placebo achieved a platelet count above 100,000 per cubic millimeter at week 4. By contrast, the percentage of eltrombopag-treated patients achieving this goal rose steadily as the dose increased, from 75% to 95%.

The majority of patients in all of the eltrombopag groups were able to receive antiviral therapy. By contrast, just 4 of 18 patients in the placebo group could start therapy.

Headache was the most common side effect associated with eltrombopag treatment.

In the second placebo-controlled trial, Dr. James B. Bussel, from the Weill Cornell Medical College of Cornell University in New York, and colleagues investigated the use of eltrombopag (30, 50, or 75 mg daily) in 118 patients with relapsed or refractory ITP and platelet counts less than 30,000 per cubic millimeter.

Eltrombopag therapy was associated with a dose-dependent increase in the percentage of patients achieving the main end point, a platelet count of 50,000 or more per cubic millimeter on day 43. With the highest dose, 81% of patients achieved this end point. By contrast, just 11% of control patients had counts increase to this extent.

No significant difference in the rate or severity of adverse events was noted between the placebo group and the eltrombopag groups.

"Hematologists everywhere are thwarted by patients with ITP in whom every available treatment has failed to improve the platelet count," Dr. Robert S. Schwartz, from The New England Journal of Medicine, writes in a related editorial. "A new, safe way of treating the disease would be a considerable advance."

N Engl J Med 2007;357:2227-2247,2299-2301.