UPDATE 3-Amgen, Amerisource sued over drug kickback scheme

themselves * Shares of Amgen, AmerisourceBergen fall (Adds background, details from lawsuit) NEW YORK, Oct 30 (Reuters) - Biotechnology giant Amgen Inc (AMGN.O: Quote, Profile, Research) and drug wholesaler AmerisourceBergen Corp (ABC.N: Quote, Profile,...