Dec 28, 2007
For patients with hepatitis C, having a low blood platelet count is a frequent complication associated with advanced disease. This problem is compounded by the fact that standard antiviral treatment for the disease can further reduce platelet numbers to dangerously low levels, effectively denying these patients the treatment they urgently need. Now, research published in the New England Journal of Medicine finds that a new drug, eltrombopag, appears to significantly boost platelet counts, opening the door to effective treatment.
"In this study, eltrombopag increased platelet counts in a dose-dependent manner, allowing more patients to complete the first 12 weeks of antiviral therapy—an important treatment goal," says Dr. Samuel Sigal, who led the study at NewYork-Presbyterian Hospital/Weill Cornell Medical Center in New York City—one of 22 study sites.
Dr. Sigal is assistant professor of medicine in the Division of Gastroenterology and Hepatology at Weill Cornell Medical College and assistant attending hepatologist in the Center for Liver Diseases and Transplantation at NewYork-Presbyterian/Weill Cornell.
The Phase 2 placebo-controlled study followed 74 patients with low platelet counts and cirrhosis of the liver due to hepatitis C virus (HCV) infection. Seventy-four percent of those randomized to take the lowest dose (30 milligrams daily) saw their platelet counts go up significantly, while 79 percent and 95 percent of the participants saw increases with the higher doses (50 or 75 milligrams daily, respectively). And, 12 weeks of antiviral therapy were completed by 36, 53 and 65 percent of patients at the three dose levels—with increased numbers matched to the size of the dose. Underlining the trend, less than a quarter of patients receiving placebo completed their therapy.
The study identified side effects—including headaches, dry mouth, abdominal pain and nausea. None were serious enough to discontinue the therapy.
It's estimated that 4 million people in the U.S. and 170 million worldwide carry the hepatitis C virus. HCV is transmitted primarily by blood and blood products. The majority of infected individuals have either received blood transfusions prior to 1990 (when screening of the blood supply for HCV was implemented) or have used intravenous drugs. More rarely, it can also be transmitted through sexual intercourse and perinatally (mother to baby).
The virus causes inflammation and scarring in the liver, and while it is curable in about half of those who have it, it can lead to significant liver damage, liver cancer and death in others. HCV infection is a common cause of cirrhosis and the most common reason for a liver transplant.
With other eltrombopag findings, NewYork-Presbyterian/Weill Cornell's Dr. James Bussel led research, also reported in the New England Journal of Medicine, finding the platelet growth factor successfully increased platelet counts and decreased bleeding in patients with Immune Thrombocytopenic Purpura (ITP), an autoimmune disease that dramatically reduces the number of platelets in their blood. (Dr. Bussel is an Advisory Board Member for GlaxoSmithKline; has received research grant support, lecture fees, and consulting fees from GlaxoSmithKline; and reports equity ownership in the company.)
The current study was sponsored by GlaxoSmithKline, which is developing eltrombopag. Eltrombopag (marketed as Promacta in the U.S. and Revolade in Europe) is an investigational oral, non-peptide platelet growth factor that induces the proliferation and differentiation of cells to produce platelets. While other drugs that restore normal platelet functions are infusions or injections, eltrombopag is a once-a-day pill.
The study's principal investigator was Dr. John McHutchison, of the Duke Clinical Research Institute, Durham, N.C. Additional participating institutions included Royal Free Hospital, London; Virginia Commonwealth University Medical Center, Richmond; Fundación de Investigación de Diego, San Juan; Hôpital St. Joseph, Marseille; Henry Ford Hospital and Health System, Detroit; GlaxoSmithKline; and Beth Israel Deaconess Medical Center, Boston.
For more information, patients may call 866-NYP-NEWS.
NewYork-Presbyterian Hospital/Weill Cornell Medical Center
NewYork-Presbyterian Hospital/Weill Cornell Medical Center, located in New York City, is one of the leading academic medical centers in the world, comprising the teaching hospital NewYork-Presbyterian and Weill Cornell Medical College, the medical school of Cornell University. NewYork-Presbyterian/Weill Cornell provides state-of-the-art inpatient, ambulatory and preventive care in all areas of medicine, and is committed to excellence in patient care, education, research and community service. Weill Cornell physician-scientists have been responsible for many medical advances—from the development of the Pap test for cervical cancer to the synthesis of penicillin, the first successful embryo-biopsy pregnancy and birth in the U.S., the first clinical trial for gene therapy for Parkinson's disease, the first indication of bone marrow's critical role in tumor growth, and, most recently, the world's first successful use of deep brain stimulation to treat a minimally-conscious brain-injured patient. NewYork-Presbyterian, which is ranked sixth on the U.S.News & World Report's list of top hospitals, also comprises NewYork-Presbyterian Hospital/Columbia University Medical Center, Morgan Stanley Children's Hospital of NewYork-Presbyterian, NewYork-Presbyterian Hospital/Westchester Division and NewYork-Presbyterian Hospital/The Allen Pavilion. Weill Cornell Medical College is the first U.S. medical college to offer a medical degree overseas and maintains a strong global presence in Austria, Brazil, Haiti, Tanzania, Turkey and Qatar. For more information, visit www.med.cornell.edu.