Just because a big pharma company is successful today doesn't mean it will be successful in a few years. Even the biggest blockbuster drugs eventually lose patent exclusivity or face new and improved competition. That's why continued research and development (R&D) is a must.
Throwing money at R&D doesn't guarantee success -- but not making smart investments in developing pipeline candidates will almost certainly ensure failure. The odds for success are better for drugmakers that can invest in plenty of experimental drugs.
