Details for Patent: 8,778,324

Title:	Ion binding polymers and uses thereof
Abstract:	The present invention provides methods and compositions for the treatment of ion imbalances. In particular, the invention provides compositions comprising potassium binding polymers and pharmaceutical compositions thereof. Methods of use of the polymeric and pharmaceutical compositions for therapeutic and/or prophylactic benefits are disclosed herein. Examples of these methods include the treatment of hyperkalemia, such as hyperkalemia caused by renal failure and/or the use of hyperkalemia causing drugs.
Inventor(s):	Charmot; Dominique (Campbell, CA), Chang; Han-Ting (Livermore, CA), Liu; Mingjun (Campbell, CA), Klaerner; Gerrit (Los Gatos, CA)
Assignee:	Relypsa, Inc. (Redwood City, CA)
Filing Date:	Oct 09, 2012
Application Number:	13/647,690
Claims:	1. A method for treating hyperkalemia comprising administering a potassium binding polymer to an animal subject in need thereof, the potassium binding polymer being a crosslinked cation exchange polymer comprising acid groups in their acid or salt form, and the acid groups having an electron-withdrawing substituent attached to a carbon atom alpha or beta to the acid group. 2. The method of claim 1 wherein the electron-withdrawing substituent is selected from the group consisting of a hydroxyl group, an ether group, an ester group, and a halide atom. 3. The method of claim 1 wherein the acid group is carboxylic. 4. The method of claim 1 wherein the acid group is phosphonic. 5. The method of claim 3 wherein the potassium-binding polymer comprises a crosslinked carboxylic polymer having fluoride attached to the carbon atom alpha to the carboxylic acid group. 6. The method of claim 1 wherein the potassium binding polymer has a swelling ratio of less than 5. 7. The method of claim 1 wherein the potassium binding polymer has a swelling ratio of less than 3. 8. The method of claim 1 wherein the subject is a human. 9. The method of claim 1 wherein the pharmaceutical composition is administered in the form of a chewable tablet. 10. The method of claim 1 wherein the potassium-binding polymer is administered in a dose of about 0.5 gram/day to about 30 grams/day. 11. The method of claim 1 wherein the ionization of the acid groups is greater than 75% at the physiological pH in the colon. 12. The method of claim 1 wherein the potassium-binding polymer comprises a Ca.sup.2+ cationic counterion. 13. A method for treating hyperkalemia comprising administering a potassium binding polymer to an animal subject in need thereof, the potassium binding polymer being a crosslinked alpha-fluoroacrylic acid polymer. 14. The method of claim 13 wherein the alpha-fluoroacrylic acid polymer is crosslinked with divinylbenzene, ethylene bisacrylamide, N,N'-bis(vinylsulfonylacetyl)ethylene diamine, 1,3-bis(vinylsulfonyl) 2-propanol, vinylsulfone, N,N'-methylenebisacrylamide polyvinyl ether, polyallylether, or a combination thereof. 15. The method of claim 13 wherein the alpha-fluoroacrylic acid polymer is crosslinked with divinyl benzene. 16. The method of claim 13 wherein the potassium-binding polymer comprises a Ca.sup.2+ cationic counterion. 17. A method for treating hyperkalemia comprising administering a potassium binding polymer to an animal subject in need thereof, the potassium binding polymer being a crosslinked alpha-fluoroacrylic acid polymer comprising a Ca.sup.2+ cationic counterion. 18. The method of claim 17 wherein the crosslinked alpha-fluoroacrylic acid polymer has a swelling ratio of less than 3. 19. The method of claim 17 wherein the alpha-fluoroacrylic acid polymer is crosslinked with divinylbenzene, ethylene bisacrylamide, N,N'-bis(vinylsulfonylacetyl)ethylene diamine, 1,3-bis(vinylsulfonyl) 2-propanol, vinylsulfone, N,N'-methylenebisacrylamide polyvinyl ether, polyallylether, or a combination thereof. 20. The method of claim 17 wherein the potassium-binding polymer is in a bead form.