Landmark Study Demonstrates Benefits of Prophylactic Treatment Regimen in Hemophilia A; Results from Multi-year Clinical Trial Shows Improved Joint Outcomes in Young Children Using Kogenate(R) FS.

ATLANTA -- In the first and only randomized clinical trial of its kind presented today at the 47th Annual Meeting of the American Society of Hematology, children with hemophilia A (factor VIII deficiency) were randomized to receive every other day therapy with Kogenate(R) FS (Antihemophilic Factor (Recombinant) Formulated with Sucrose) (prophylaxis group) showed improved joint function and decreased bone and cartilage damage in comparison to those who were intensively treated with Kogenate(R) FS in response to a joint bleeding episode (on-demand group). Kogenate(R) FS is a hemophilia A treatment produced by the Biological Products (BP) Division of Bayer HealthCare.

"The 'Joint Outcome Study' is a truly unique study in several regards. It is the first and only study of its kind to be conducted with a recombinant factor VIII product. 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," said Marilyn Manco-Johnson, M.D., principal investigator of the study. "This is the first prospective study that provides convincing evidence in support of prophylaxis in the treatment of hemophilia," continued Dr. Manco-Johnson, who is with the Mountain States Regional Hemophilia and Thrombosis Center at the University of Colorado at Denver and Health Sciences Center.

Hemophilic arthropathy, or joint damage caused by repeated bleeding into the joints, is one of the most disabling and costly long-term consequences facing patients with hemophilia. Retrospective patient reviews have suggested that regular infusions of factor VIII given to prevent bleeding episodes may reduce the development of hemophilic arthropathy when initiated in young patients prior to the onset of permanent joint damage.

Landmark Study

This prospective study, which was initiated in August 1996 and conducted at 15 hemophilia treatment centers in the United States, enrolled 65 boys with hemophilia A between the ages of 6 months and 30 months. The study was supported by funding from the Centers for Disease Control and Prevention and the National Institute of Health. Bayer BP provided Kogenate(R) FS for the trial. The children were randomized to receive either a prophylaxis regimen consisting of Kogenate(R) FS 25 IU/kg every other day or intensive on-demand treatment consisting of Kogenate(R) FS 40 IU/kg at the time of a joint bleeding episode followed by 20 IU/kg infusions at 24 and 72 hours after the bleed, with additional infusions possible until resolution of bleeding. The children were followed until the age of six years. At age six, children were assessed for bone or cartilage damage using X-ray and magnetic resonance imaging (MRI) of damage-prone joints (elbows, knees, and ankles). The study also assessed joint function, number of joint hemorrhages, and amount of Kogenate(R) FS consumed.

Of the 65 children, data was available for the evaluation of 30 children in the prophylaxis group and 31 children in the on-demand group. Prophylaxis patients had significantly fewer joint hemorrhages per year and overall number of bleeds per year compared to patients treated on-demand (joint bleeds mean 0.51 vs. 5.1, respectively; total bleeds mean 1.5 vs. 13.7, respectively). When evaluated by MRI at the age of six years, 93% of children in the prophylaxis group had joints that appeared normal, compared to 58% of patients treated on-demand. This translated to an 84% reduction in the risk for joint damage in patients who received prophylaxis from an early age (relative risk for on-demand treatment, 6.29 (95% confidence interval, 1.6-26.6). Bone or cartilage damage was confirmed in 2 of 30 (6.7%) of children in the prophylaxis group compared to 13 of 31 (41.9%) of those in the on-demand group.

Interestingly, although there was a modest correlation between MRI scores and the frequency of joint bleeds (R-squared = 0.13, n = 346 joints), some children (18.8%) developed joint damage despite no evidence for a joint hemorrhage, and 25% had joint damage after between 1 and 5 joint bleeds. This suggests that subclinical hemarthroses may be occurring and leading to joint damage. As expected, the prophylaxis regimen required greater consumption of Kogenate(R) FS than on-demand treatment (mean number of infusions per year was 171 vs. 48, respectively).

The study also incorporated several new techniques for the evaluation of disease parameters in hemophilia, including sensitive new physical and imaging scales to detect the earliest signs of joint damage in young children. The development and validation of these measures are expected to add significantly to the comprehensive clinical care of children living with hemophilia.

Dr. Manco-Johnson added, "This study exemplifies an extraordinary contribution of effort from these patients and families, from the CDC for their management and support, from Bayer for their generous provision of all factor used in this study, and from the co-investigators and study coordinators."

Recognizing the importance of the trial and its potential impact on hemophilia care, Dr. Manco-Johnson is planning to conduct an extension to the Joint Outcome Study that will follow the original patients until 18 years of age. "The value of the continuation trial cannot be overstated since a similar cohort may never be constructed again. Furthermore, following these children into adulthood to confirm the value of prophylactic treatment in preventing joint disease, the most serious morbidity of hemophilia, will provide invaluable information," said Dr. Manco-Johnson.

"We recognize the unprecedented value of this trial and are pleased with the study results," said Eduard Gorina, M.D., head of the Medical Department at Bayer BP. "We remain committed to supporting clinical research that will advance knowledge and the state of care of hemophilia."

Other examples of Bayer BP's leadership in supporting clinical research for hemophilia have included ongoing studies of quality-of-life assessments in children and adults, and efforts to characterize issues related to inhibitor development. Bayer BP also is focusing on longer-term research that includes development of a recombinant factor VIII molecule that requires less frequent dosing for prophylaxis.

About Kogenate(R) FS/KOGENATE(R) Bayer

Kogenate(R) FS/KOGENATE(R) Bayer Antihemophilic Factor (Recombinant), is a recombinant factor VIII treatment currently indicated for the treatment of hemophilia A in which there is a demonstrated deficiency of activity of the plasma clotting factor VIII. Kogenate(R) FS provides a means of temporarily replacing the missing clotting factor in order to correct or prevent bleeding episodes, or in order to perform emergency or elective surgery in hemophiliacs. Through the 17-year clinical experience with Kogenate(R) FS/KOGENATE(R) Bayer or its predecessor product, Kogenate(R), there have been no confirmed cases of virus transmission attributed to either product. Kogenate(R) FS/KOGENATE(R) Bayer is manufactured at Bayer BP's state-of-the-art biotechnology facility in Berkeley, Calif.

About Hemophilia

Approximately 400,000 people around the world have hemophilia. Hemophilia is an inherited bleeding disorder characterized by prolonged or spontaneous bleeding, especially into the muscles, joints, or internal organs. The disease is caused by deficient or defective blood coagulation proteins, known as factor VIII or IX. The most common form of the disease is hemophilia A, or classic hemophilia, in which the clotting factor VIII is either deficient or defective. Hemophilia B is characterized by deficient or defective factor IX.

About Bayer HealthCare AG

Bayer HealthCare, a subgroup of Bayer AG, is one of the world's leading innovative companies in the health care and medical products industry. In 2004, the Bayer HealthCare subgroup generated sales amounting to some EUR 8.5 billion.

The company combines the global activities of the Animal Health, Biological Products, Consumer Care, Diagnostics, Diabetes Care and Pharmaceuticals divisions. 35,300 people were employed by Bayer HealthCare worldwide in 2004.

Our aim is to discover and manufacture innovative products that will improve human and animal health worldwide. Our products enhance well-being and quality of life by diagnosing, preventing and treating disease.

Information about the Biological Products Division of Bayer HealthCare can be found at www.bayerbiologicals.com.

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