Appeal No. 2003-0564 Page 3
Application No. 08/964,498
Treatments for hyperphosphatemia include “oral administration of
insoluble phosphate binders to reduce gastrointestinal absorption.” Id.
Phosphate binders that have been used in such therapies include calcium salts,
aluminum salts, and ion exchange resins. See id., pages 2-3. All of these
agents, however, can cause serious side effects. See id.
The specification discloses a method of lowering the serum phosphate
level of a patient by administering a polymer having diallylamine repeat units.
These poly(diallylamine) polymers are disclosed to have “excellent phosphate-
binding activity.” Page 4.
Discussion
Claim 9, the broadest claim on appeal, is directed to a method for lowering
the serum phosphate level in a patient by administering a therapeutically
effective amount of a poly(diallylamine) that comprises repeat units having one of
two recited structures. The structures comprise a heterocyclic, five- or six-
membered ring that includes a quaternary ammonium group.
The examiner rejected the claimed method as obvious in view of Howes
and Holmes-Farley. The examiner’s statement of the rejection reads as follows:
[Howes] teaches polymers comprising heterocyclic diallyl
ammonium monomers (Abstract). [Holmes-Farley] teaches
phosphate binding polymers for treating hyper phosphatemia
(Abstract). Quaternary amines are specified (claim 31).
It would have been obvious to one of ordinary skill to use the
polyallylamines of [Howes] to treat hyper phosphatemia in view of
intended to imply an alternative basis for the rejection, we vacate any implied rejection based on
references other than Howes and Holmes-Farley.
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