A recently completed clinical study, involving several hemophilia treatment centers from across the U.S., compared prophylactic (preventive) with on-demand treatment using recombinant clotting factor in young children with factor VIII deficiency (hemophilia A).
The Joint Outcome Study was designed to contrast these two approaches to treatment, measuring key results such as frequency of joint hemorrhages and level of joint function. The trial results demonstrate that an early, every-other-day treatment regimen shows improved joint function in contrast to an aggressive, on-demand approach.
The study subjects were 65 boys with factor VIII deficiency between one and two-and-a-half years of age. While 32 of the prophylaxis patients were given regular, every-other-day infusions of recombinant factor VIII, 33 were treated intensively with multiple infusions of clotting factor but only at the onset of a joint hemorrhage. The boys participated in the study until they reached six years of age Joint structural outcomes and joint functioning were measured using X-rays, magnetic resonance imaging (MRI) and by physical exams. The study also tracked the amount of factor used to treat each child. Results indicated that 93% of children in the prophylaxis group showed normal joints in contrast to 58% in the on-demand group. Overall, there was an 84% reduction in the risk for joint damage in patients receiving prophylaxis from an early age. All outcomes were evaluated independently by two research radiologists without their prior knowledge of the subjects’ bleeding history or treatment.
The principal investigator for the study is Marilyn J. Manco-Johnson, MD, Director of the Mountain States Regional Hemophilia & Thrombosis Center at the University of Colorado. She has expertise in several areas such as pediatric hemophilia and joint disease prevention. Dr. Manco-Johnson, who is also a former member of the National Hemophilia Foundation’s Medical and Scientific Advisory Council (MASAC), stressed the importance of the study. “This is the first prospective study that provides convincing evidence in support of prophylaxis in the treatment of hemophilia.” She added, “The information we are obtaining is extremely comprehensive and will help treaters and parents make informed decisions about how best to manage hemophilia in these young boys.”
Chronic and often spontaneous bleeding into joints is a common symptom for patients with severe bleeding disorders. If left untreated, bleeding into joints such as the elbow, knee or ankle, can cause orthopedic damage resulting in increased pain and diminished mobility. Prophylaxis has been recommended by MASAC (Recommendation #117) as an optimal therapy for young children with severe hemophilia A & B. Even though there are many proponents of this approach in the treatment community, there exist commonly cited drawbacks such as high cost, lack of necessity and medical complications.
The study was funded by the Centers for Disease Control and Prevention and the National Institutes of Health. All the study patients were treated with Kogenate® FS, a recombinant factor VIII product manufactured by Bayer Biological Products. A study abstract, entitled “Initial Results of a Randomized, Prospective Trial of Prophylaxis to Prevent Joint Disease in Young Children with Factor VIII Deficiency,” appeared in the November 16, 2005 issue of the journal Blood.
Source: Business Wire, December 12, 2005