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Safey, Efficacy Endpoints Achieved in Gamunex Trial, Treatment for Idiopathic Thrombocytopenic Purpura
RESEARCH TRIANGLE PARK, N.C., June 1 /PRNewswire-FirstCall/ -- Bayer HealthCare LLC, Biological Products Division (Bayer BP), announced today that recently published data surrounding its novel IGIV, Gamunex®, Immune Globulin Intravenous (Human), 10% Caprylate/Chromatography Purified, met both primary and secondary endpoints for safety and efficacy in an evaluation of the drug's use in the treatment of ITP (Idiopathic [immune] Thrombocytopenic Purpura). Gamunex was approved for the treatment of ITP and other indications in the United States and Canada in August 2003, as well as in Germany earlier this year.
The primary endpoint was to achieve similar platelet count elevation after treatment with Gamunex compared with standard treatment, IGIV- S/D. Ninety percent of patients who were treated with Gamunex achieved target platelet counts within seven days of dosing compared to 83 percent in the IGIV-S/D group. The secondary endpoint was to maintain platelet counts for at least seven days, which 74 percent of the Gamunex group achieved compared with 60 percent of the IGIV-S/D control group.
A Personal Account of Idiopathic [immune] Thrombocytopenic Purpura
ITP is an autoimmune disorder of unknown cause that affects both children and adults. In children, it is usually an acute, temporary condition with rapid onset typically following an infection. In adults, ITP is a chronic condition distinguished by a severe onset. ITP occurs when the immune system malfunctions and produces antibodies against the body's own platelets. These antibodies destroy the platelets, resulting in a decreased level of blood platelets needed for normal blood clotting. Characterized by a low platelet count, notwithstanding normal bone marrow production and the absence of other specific causes (such as leukemia or aplastic anemia), ITP can lead to life- threatening bleeding episodes.
Retired NASA employee, Ted Gull, experienced a typical rapid onset of ITP. "It all started during the holiday season when I just couldn't shake the flu. Next thing I knew, I noticed deep purple bruises on my body and persistent nose bleeds that never seemed to end," said Gull. "A normal platelet count ranges from 150,000 to about 400,000 platelets/mL of blood while my count was nearly undetectable. I could have bled to death."
The disorder becomes life-threatening if a patient's platelet count becomes so low that brain hemorrhaging occurs. Hemorrhaging is the key concern for ITP patients. When platelet counts are too low, internal bleeding can be difficult to stop. Rarely, life-threatening bleeding occurs with intracranial hemorrhage or other serious hemorrhaging.
Childhood ITP is typically resolved quickly - more than 70 percent of children with ITP will have a spontaneous and permanent remission within one year of onset. In contrast, the majority of adults have persistent ITP, or "chronic state" ITP, that must be treated when platelets fall below a critical level.
After several treatments failed to raise Gull's platelet count, his hematologist prescribed a regular treatment regimen of Bayer's IGIV to keep his platelet count within a safe range. Gull's wife, Connie, is a registered nurse, which allows him to receive his IGIV treatments at home. "Getting infused in an out-patient setting opened up my world again, allowing me and my wife to travel the globe like we did before I was diagnosed," said Gull. "Not since my early days at NASA had I felt like I had the entire galaxy at my disposal." He and his wife recently decided to pack their bags (and their cooler to keep Gull's IGIV refrigerated) and head to Hawaii for their 30th wedding anniversary.
Significance of Study
This study resulted in the most comprehensive prospective data on this patient population to date. Although more than 100 studies on IGIV have been done since 1981 (the first report of the efficacy of IGIV in the treatment of ITP), most were data analyses completed after treatment was started (retrospective data analysis), and most were done in children. By contrast, this was a prospective study that included both acute and chronic patients, and looked at children and adults with ITP.
Ninety-seven patients were enrolled and randomized from 26 sites in the United States, Canada, South Africa, and Israel. Seventy-five percent of the patients were adults and 72 percent female. Forty-eight patients were treated with Gamunex®, Immune Globulin Intravenous (Human), 10% Caprylate/Chromatography Purified, and 49 patients were treated with IGIV-S/D as a control group.
Adverse events observed in this study were consistent with those in previous IGIV studies, and most frequently included headache, vomiting, fever, nausea. Most were mild to moderate. For additional information on Gamunex, see Full Prescribing Information at http://www.gamunex.com/.
Each vial of Gamunex contains antibodies purified from the donated blood plasma of thousands of people and can be a lifesaving therapy for individuals with compromised or malfunctioning immune systems. The immune system serves as the body's natural defense system, constantly fighting off infections caused by harmful bacteria and viruses that invade the body. When parts of the immune system are missing, as in patients with primary immune deficiencies, the body is vulnerable to attack by these invaders. In those cases, the broad spectrum of antibodies in Gamunex acts as an immune system replacement and provides a shield of protection against infection.
For people with autoimmune disorders and other conditions that cause the immune system to malfunction, such as idiopathic thrombocytopenia purpura (ITP), Gamunex acts as an immune modulator and resets the immune system so it can function normally again.
Gamunex®, Immune Globulin Intravenous (Human), 10% Caprylate/Chromatography Purified, is formulated without sugar stabilizers, which have been associated with severe adverse reactions in other IGIV products. In addition Gamunex offers IGIV patients the unique combination of a ready-to-use, highly purified, 10% formulation, and a safe and rapid infusion rate, giving time back to patients and the health care providers that care for them.