Comment by bradleyjg

Patents do play a role here, though not the largest role. Both Teva Pharmaceuticals and Sandoz were sued when for patent infringement when they announced plans to introduce competitors to Epipen.

[1] https://www.bloomberg.com/news/articles/2012-04-26/mylan-pfi...

[2] http://www.law360.com/articles/181459/king-pharma-sues-sando...