definiens: means, on a Royalty - Bearing Product - by - Royalty - Bearing Product and country - by - country basis, the period beginning on the date of First Commercial Sale of a Royalty - Bearing Product in a country and ending on the laterto occur of ( a ) expiration of the last to expire Valid Claim of the Licensed Patent Rights, Program Aptamer - Specific PatentRights, Co - Developed Program Patent Rights or Joint Patent Rights in such country that covers such Royalty - Bearing Productor its identification, manufacture, use, import, offer for sale or sale or ( b ) ( i ) with regard to the first Royalty - Bearing Productfor each Program Target sold in such country, fifteen ( 15 ) years from the date of the First Commercial Sale of such firstRoyalty - Bearing Product in such country or ( ii ) with regard to each additional Royalty - Bearing Product for such ProgramTarget sold in such country, ten ( 10 ) years from the date of the First Commercial Sale of each such additional Royalty - BearingProduct in such country