FDA
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Food and Drug Administration
U.S. Department of Health and Human Services
Public Health Service 5600 Fishers Lane Rockville, MD 20857
FDA Talk Papers are prepared by the Press Office to guide FDA personnel in responding with consistency and accuracy to questions from the public on subjects of current interest. Talk Papers are subject to change as more information becomes available. 

T97-9                       Lenore Gelb
February 11, 1997           
                            

            New Recombinant Product for Hemophilia B

     The Food and Drug Administration today approved a new
recombinant DNA-derived clotting factor for people with
hemophilia B, a rare congenital blood disorder.  The product,
Coagulation Factor IX (Recombinant) is intended for the
prevention and control of excessive, potentially life-threatening
bleeding in hemophilia B patients, including those who require
surgery.
     Hemophilia B, also known as Christmas Disease, affects
approximately 3,000 Americans who are unable to form blood clots
adequately because of a deficiency or defect in clotting factor
IX. Treatment with factor IX products, given by intravenous
infusion, corrects the defect temporarily.  Highly purified
factor IX products obtained from pooled human plasma are also
available for people with hemopilia B.
       This new purified recombinant product is free from the
risk of transmitting plasma-derived human viruses because it is
produced in Chinese hamster ovary cells that have been modified
to express the gene for human factor IX.
     Clinical trials assessing the safety and efficacy of this
recombinant factor IX product include a trial with 36 patients
who had previously received plasma-derived products.  The trials
indicated that higher doses of the recombinant product may be
needed in some patients, as compared to plasma-derived products. 
The product was also studied in 12 surgical patients. 
     Few data are available regarding the rare, serious side-
effects that can occur with any factor IX product.  These side-
effects include antibody responses that neutralize the effects of
factor IX, and excessive blood clotting.  
     In clinical trials of this recombinant factor IX product,
one patient developed low levels of neutralizing antibodies that
later disappeared.  Another patient developed a renal infarct, or
damage to the kidney, that may have been related to a blood clot. 
     Information regarding the use of this product in previously
untreated patients is limited.  Therefore, a clinical trial
involving up to 50 such patients for up to 5 years is ongoing. 
The sponsor will also follow previously treated patients for two
years.         
     Coagulation factor IX (recombinant) is manufactured by
Genetics Institute, Cambridge Mass, and will be marketed as
BeneFix.
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