Positive Results from Phase III Trial of Gamunex in Patients with CIDP
The study, published last week in The Lancet Neurology entitled "Intravenous immune globulin (10 percent caprylate-chromatography purified) for the treatment of chronic inflammatory demyelinating polyradiculoneuropathy (ICE study): a randomized, placebo-controlled trial," was sponsored by Talecris Biotherapeutics, Inc.(http://www.talecris.com). Conducted as a multicenter, multinational clinical trial in centers in Europe, the Middle East, and North and South America, the trial randomized 117 subjects with CIDP.
CIDP is a progressive or relapsing disease affecting 2 to 7 individuals per 100,000 worldwide. Its course is variable. The most common symptom patients experience is progressive weakness in the arms and legs resulting in disability.
"The ICE study is important for two key reasons," said Peter Donofrio, M.D., study co-author and Professor of Medicine, Dept. of Neurology, Vanderbilt University, Nashville, Tenn. "First, it shows that Gamunex was superior to placebo in this study in reducing functional disability and improving grip strength in CIDP subjects. Second, Gamunex was shown to lengthen the time to relapse during the six month to one year period of the study."
Study Details and Results
Eligible CIDP trial subjects were randomized to treatment with Gamunex (2g/kg as loading dose followed by 1g/kg every three weeks) or placebo for up to 24 weeks. In the first period, subject response (primary endpoint) was assessed based on functional disability measured by Inflammatory Neuropathy Cause And Treatment (INCAT) score. First period non-responders, i.e., those trial subjects with a one point or greater deterioration, no improvement during the first six week treatment period, or initial improvement followed by deterioration, were rescued by crossing over to the alternate therapy for up to 24 weeks or until non-response to alternate therapy was observed. First period responders or rescue responders to either study drug who showed and maintained a one point or greater adjusted INCAT score improvement were randomly reassigned to Gamunex or placebo for an additional 24-week long-term extension phase.
During the first treatment period, the primary endpoint (percentage of responders) for subjects treated with Gamunex was found to be more than twice that of placebo: 54 percent versus 21 percent, respectively (p= 0.0002). Grip strength was also significantly improved in trial subjects treated with Gamunex in both the dominant (p= 0.0008) and the non-dominant hand (p= 0.005).
During the 24-week extension phase, the sub-group of 57 trial subjects who responded to Gamunex during the first treatment or rescue (crossover) period (31 were randomly reassigned to Gamunex and 26 received placebo) were assessed to determine if treatment with Gamunex (up to one year) could maintain long-term benefit. Subjects who continued to receive Gamunex had a significantly longer time to relapse than did placebo trial subjects (p= 0.011). The probability of relapse was 13 percent with Gamunex compared with 45 percent with placebo (hazard ratio= 0.19, 95 percent CI 0.05-0.70).
The incidence of serious adverse events per infusion was low, 0.8 percent for Gamunex, and 0.19 percent for placebo. Adverse events resulting in study discontinuation totaled three trial subjects for Gamunex and two trial subjects for placebo. The most common events seen with Gamunex were headache, fever, and elevated blood pressure.
"Talecris is pleased with the results observed in the ICE study in CIDP," said Steve Petteway, Ph.D., Senior Vice President, Research and Development, Talecris Biotherapeutics. "Consistent with our past efforts, it remains our goal to advance knowledge and improve care for patients with rare and difficult to treat conditions. Results from clinical trials with Gamunex have provided significant scientific contributions. Ultimately, we intend to develop and execute clinical trials that will lead to improved patient care."
Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a neurological disorder often characterized by progressive weakness and impaired sensory function in the legs and arms. This disorder is caused by damage to the myelin sheath (the fatty covering that wraps around and protects nerve fibers) of the peripheral nerves. Signs and symptoms -- which usually develop slowly over weeks and progress over several months -- may include weakness of the arms, legs and face; tingling and numbness in the arms and legs (often beginning in the fingers and toes); as well as muscle aches and fatigue.
CIDP, affecting 2 to 7 individuals per 100,000 worldwide, can occur at any age and in both genders, although it is more common in young adults and in men.
Gamunex is an IGIV therapy that contains antibodies purified from the donated blood plasma of thousands of people. Gamunex is indicated as replacement therapy of primary humoral immunodeficiency disease (PI) and as immunomodulatory therapy for idiopathic thrombocytopenic purpura (ITP).
Important Safety Information
Gamunex is contraindicated in individuals with known anaphylactic or severe systemic response to Immune Globulin (Human). Immune Globulin Intravenous (Human) products have been reported to be associated with renal dysfunction, acute renal failure, osmotic nephrosis and death. Patients should be instructed to immediately report symptoms of decreased urine output, sudden weight gain, fluid retention/edema, and/or shortness of breath (which may suggest kidney damage) to their physicians. While these reports of renal dysfunction and acute renal failure have been associated with the use of many of the licensed IGIV products, those containing sucrose as a stabilizer accounted for a disproportionate share of the total number. Gamunex does not contain sucrose. Glycine, a natural amino acid, is used as a stabilizer.
There have been reports of noncardiogenic pulmonary edema, rare reports of hemolytic anemia, and very rare reports of aseptic meningitis in patients administered with IGIV. Thrombotic events have been reported in association with IGIV. Patients at risk may include those with a history of atherosclerosis, multiple cardiovascular risk factors, advanced age, impaired cardiac output, and/or known or suspected hyperviscosity. The most common side effects noted during clinical trials included headache, vomiting, fever, nausea, rash, and back pain.
As with all plasma-derived therapeutics, the potential to transmit infectious agents cannot be totally eliminated. For additional information about Gamunex, please see www.gamunex.com for Full Prescribing Information.
Talecris Biotherapeutics: Inspiration. Dedication. Innovation.
Talecris Biotherapeutics is a global biotherapeutic and biotechnology company that discovers, develops and produces critical care treatments for people with life-threatening disorders in a variety of therapeutic areas including immunology, pulmonology, and hemostasis. Talecris is proudly building upon a 60-year legacy of innovation and a commitment to improving the lives of people who rely on its therapeutic products. With an emphasis on scientific inquiry and technological excellence, Talecris is expanding its current portfolio of products, programs, and services through its own world-class product development organization as well as through strategic initiatives that leverage its strengths with those of its partners.
Talecris, with revenues of approximately $1.2 billion in 2007, is headquartered in biotech hub Research Triangle Park, N.C., and employs more than 4,000 talented people worldwide.
To learn more about Talecris and how our employees are making a difference in the lives of patients and the healthcare community, visit www.talecris.com.
Lacy McMahon, 919-316-6316
Posted: February 2008