Drug May Help Reverse Clotting Deficiency

WEDNESDAY, Nov. 28 (HealthDay News) -- An experimental drug can boost the number of clotting cells, called platelets, in patients suffering from a dangerous deficiency of these cells, researchers report.

The new drug is called eltrombopag, and in one study, patients with the autoimmune disorder idiopathic thrombocytopenic purpura (ITP) were able to use the medication to boost their platelet levels and cut their risk for bleeding.

In a second study, patients with hepatitis C (HCV)-related cirrhosis of the liver were able to begin antiviral therapy for their condition after eltrombopag raised their platelet counts.

"Eltrombopag is not just used in one disease," explained Dr. John McHutchison, lead author of the hepatitis study and an associate director of the Duke Clinical Research Institute in Durham, N.C. "It could be used in cancer/chemotherapy, ITP; it could have a very, very broad use across many different diseases," said McHutchison, who is also professor of medicine at Duke University.

But the trials, both of which are published in the Nov. 29 issue of theNew England Journal of Medicine, reported only short-term results and should be considered carefully, experts cautioned.

"I stress the preliminary nature of these reports," said Dr. Robert S. Schwartz, deputy editor of theNew England Journal of Medicineand author of an accompanying editorial on the studies. "We thought that these preliminary results were promising, but they will have to be confirmed in bigger trials."

Thrombocytopenia, which refers to any disorder in which there are not enough platelets, can prevent people from receiving necessary treatments.

With ITP, the body destroys its own platelets or not enough platelets are produced.

"This is a condition in which there's a low platelet count, and if it drops very low, usually below 30,000, the clinical manifestations are principally bleeding and bruising," Schwartz explained.

Eltrombopag is thought to stimulate megakaryocytes, the bone marrow cells that produce blood platelets. The drug, also called Promacta, is being developed by GlaxoSmithKline, which funded both studies.

For the first study, 118 people with ITP and low platelet counts were randomized to receive 30, 50 or 75 milligrams of eltrombopag or a placebo. All participants had failed at least one previous treatment.

A platelet count of 50,000 or more per cubic millimeter on day 43 was achieved in 28 percent, 70 percent and 81 percent of participants who received 30, 50 and 75 milligrams of eltrombopag respectively.