Reason #1. They supply 80% of all funding for pre-clinical research on anti-cancer drugs.

Reason #2. They also supply 70% of the funding (about $10 billion/yr.) for cancer-related clinical trials.

No Refills. Some of Big Pharma's best selling drugs are losing patent protection, and after that they can be more broadly sold by other companies as "generics."

Cell-Targeted Therapies. There is no legal pathway for these new drugs to go generic -- which appeals to Big Pharma. Some examples: