Effective Treatment Found For Hepatitis C Patients With Low Blood-platelet Counts, Study Suggests
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; Hopital St. Joseph, Marseille; Henry Ford Hospital and Health System, Detroit; GlaxoSmithKline; and Beth Israel Deaconess Medical Center, Boston.
N Engl J Med. 2007 Nov 29;357(22):2237-47.
Eltrombopag for the treatment of chronic idiopathic thrombocytopenic purpura.
Bussel JB, Cheng G, Saleh MN, Psaila B, Kovaleva L, Meddeb B, Kloczko J, Hassani H, Mayer B, Stone NL, Arning M, Provan D, Jenkins JM.
Weill Cornell Medical College of Cornell University, New York, NY 10065, USA. email@example.com
BACKGROUND: The pathogenesis of chronic idiopathic thrombocytopenic purpura (ITP) involves antibody-mediated platelet destruction and reduced platelet production. Stimulation of platelet production may be an effective treatment for this disorder. METHODS: We conducted a trial in which 118 adults with chronic ITP and platelet counts of less than 30,000 per cubic millimeter who had had relapses or whose platelet count was refractory to at least one standard treatment for ITP were randomly assigned to receive the oral thrombopoietin-receptor agonist eltrombopag (30, 50, or 75 mg daily) or placebo. The primary end point was a platelet count of 50,000 or more per cubic millimeter on day 43. RESULTS: In the eltrombopag groups receiving 30, 50, and 75 mg per day, the primary end point was achieved in 28%, 70%, and 81% of patients, respectively. In the placebo group, the end point was achieved in 11% of patients. The median platelet counts on day 43 for the groups receiving 30, 50, and 75 mg of eltrombopag were 26,000, 128,000, and 183,000 per cubic millimeter, respectively; for the placebo group the count was 16,000 per cubic millimeter. By day 15, more than 80% of patients receiving 50 or 75 mg of eltrombopag daily had an increased platelet count. Bleeding also decreased during treatment in these two groups. The incidence and severity of adverse events were similar in the placebo and eltrombopag groups. CONCLUSIONS: Eltrombopag increased platelet counts in a dose-dependent manner in patients with relapsed or refractory ITP. (ClinicalTrials.gov number, NCT00102739.) 2007 Massachusetts Medical Society