There may be a confusion between [Fosomax] Fosamax (approved in 1996) and Evenity the last osteoporosis medication approved by the FDA in 2019.
MHRA, the UK equivalent for drug approval in the UK approved Eldynos ( abaloparatide-- US Tymlos) in 2024
I'm not aware of any osteoporosis medications "titrated by wax and wane," though the markers are used in determining if a medication is working.