Well presumably, if current regulations did not turn out to be a lethal roadblock and a pharma company was lucky enough to become successful - and new regulations were not created as a response to new market entrants (via lobbying/agency collusion) nor were illegal marketing practices utilized [1] - then they will likely just get acquired by the big corps.

There are plenty of good reasons there are only ever ~6 pharma companies and most have been around for 150yrs. There are few markets where oligopolies have maintained power for as long and as consistently as pharma. A few reasons why:

- Plenty of capital to support M&A

- Legendary regulatory hurdles for new entrants

- An obedient judicial system where the annual major legal cases for illegal marketing by big pharma cos result in a slap on the wrist

[1] https://en.wikipedia.org/wiki/List_of_largest_pharmaceutical...