George Rathmann, the founding CEO of Thousand Oaks biotech giant Amgen, has died, the company announced late Monday evening. Rathmann served as founding CEO of Amgen from 1980 to 1988, and was Chairman of the company until 1990. Rathman helped secure Amgen's venture capital funding and guide Amgen to its IPO, as well as growing the company to one of the largest biotech firms in the world. Rathmann was 84.