https://www.biopharmadive.com/news/pharma-patent-cliff-biologic-d...

https://www.biopharmadive.com/news/pharma-patent-cliff-biologic-drugs-humira-keytruda/642660/

Extract:

“If you track the sales of a typical small molecule that goes generic it really goes off the cliff — 80% of the market can be gone in 30 to 90 days and the price goes down even more,”

…

Another reason is that, after years of industry consolidation, there are not many major large drugmakers left as attractive merger targets. Those that remain have patent cliffs of their own, Goldstein said.

Instead, the hunt for new products will either be in big drugmakers’ own laboratories or in those of smaller biotechnology companies. By having two successor blockbusters already in waiting, AbbVie has shown it can execute on the former approach.