NEW YORK, Sept 2 (Reuters) - In another setback for prominent hedge fund manager Kyle Bass and his campaign to eliminate some drug patents, the U.S. Patent and Trademark Office on Wednesday declined to hold a trial on the validity of a patent on Biogen Inc's multiple sclerosis drug Tecfidera.

Last month the patent office also declined reviews requested by Bass and his Coalition for Affordable Drugs on two Acorda Therapeutics Inc patents. The Biogen patent covered a dosing regimen for Tecfidera, which had $2.9 billion in sales last year.

(Reporting by Andrew Chung; Editing by Alexia Garamfalvi)