U.S. lawmakers unveiled a bipartisan proposal on Wednesday to allow government approval for cheaper copies of biotechnology medicines…Representative Henry Waxman, joined by a Democratic colleague and two Republicans, said…[g]eneric versions could provide safe alternatives while saving money for patients, employers, insurers and the federal government…Waxman's measure would give original products five years of market exclusivity, and three years for modifications of existing drugs in some cases…Brand-name companies, however, are pushing for 14 years of exclusivity for biotech drugs. That time is needed to entice manufacturers to develop new treatments, the companies say. [Refers to Teva Pharmaceutical, Mylan, Genentech, Amgen and General Motors]