The short version
Just 3 companies supply this market — thin enough that a single exit would be felt immediately. The generic price is down 8% over the past year, to $1.24 per mL. The brand (Xatmep) runs $21.76 per mL — 18× more. It is in shortage right now. Put together: worth watching — several of the pressures that precede supply trouble are present at once.
The numbers behind every sentence are on this page below — and the Watch button emails you when any of them move.