Most R&D, in the US as elsewhere, make massive use of public funds.
https://en.wikipedia.org/wiki/Medical_research#Privately_(in...
Private R&D is around 60% - however a large part of that is making minor changes to existing molecules in order to obtain fresh patents.The bigger, riskier research is done by the NIH and other publicly funded bodies. See
https://marianamazzucato.com/entrepreneurial-state/
Also - the quality of privately funded research is much worse, with non-reporting of negative results, data dredging and other dodgy activities being routine - see
Goldacre's book (he also has a blog) is well worth reading - describing _many_ ways in which drug companies can cheat.