Fremont-based Quark Pharmaceuticals said Wednesday in a filing that it is dropping its plans for an IPO. The company said that it is dropping the bid because "terms currently obtainable in the public marketplace are not sufficiently attractive" to the company. The firm had originally filed for an IPO on September 24, 2010. Quark is focused on the development of RNAi-based therapeutics. Quark's major investor is Oracle's Larry Ellison.