It’s always externalized exploitation because they’re all multinational corporations.

It’s true that many of the big players are based in the US, e.g. Pfizer, J&J, Merck, AbbVie, Abbott, EliLily, etc.

But there are plenty that aren’t:

• Bayer, Boehringer Ingelheim, BioNTech, and Merck Group (MilliporeSigma in the US, distinct from Merck & Co) are headquartered in Germany.
• AstraZeneca and GlaxoSmithKline are in the UK.
• Roche and Novartis are in Switzerland.
• Novo Nordisk in Denmark.
• Sanofi in France.
• Takeda, Otsuka, and Astellas in Japan.

https://en.wikipedia.org/wiki/List_of_largest_biomedical_companies_by_revenue

It’s important to note that much of the R&D pharma relies on is publicly funded via academic grants in research carried out at universities. It’s not to say that pharma doesn’t also carry out clinical research, which of course does carry a cost, but a lot of the development dollars for a given drug are spent well before they make it into pharma’s hands.