The Inflation Reduction Act lets Medicare set a "maximum fair price" on a drug's Part B or Part D spend once it's been on the market long enough (7 years for small molecules, 11 for biologics) — but it can't touch a drug once a biosimilar is "approved and marketed." That one clause is a loophole big enough to drive a franchise through, and it's splitting Regeneron and Amgen onto opposite sides of the ledger.

Who cashes in: