Hi @cat1203 your case will be interesting, to start evenity with a past treatment history of fosamax for 4 years.

There was a clinical trial STRUCTURE, showing the results of such sequencing.

In STRUCTURE, after patients had switched from alendronate/fosamax (4+ years) to romosozumab/evenity, serum PINP increased by 34 µg/L above baseline at month 1 and remained above baseline throughout the 1 year of treatment. Serum β-CTX was largely unchanged, decreasing slightly at month 1 and then returning to baseline for the remainder of the 1 year of treatment.

You could use p1np to monitor the bone building effects of evenity. Do a baseline before the start, and do another testing at 1 month. If your doc doesn't like to do bone markers, then you'd just finish the whole year and use dexa to know the results.

In STRUCTURE, after patients stopped alendronate, mean BMD increased 9.8% with 1 year of romosozumab at Lspine, while mean BMD increased 2.9% at total hip; compared with the romosozamab first sequence 13.7% and 6.2% respectively.

Note that not everyone would have equal response. For example, in STRUCTURE, for hip bmds 47% of patients had a greater than 3% increase while 14% of patients had a greater than 6% increase. For lumbar bmds, 91% of patients had a greater than 3% increase while 75% of patients had a greater than 6% increase.

Best of luck!