Do you resume zoledronic acid or denosumab at relapse in multiple myeloma?

This is generally a data free zone.

Remember at induction, the overall survival benefit with Zometa is ONLY in patients with myeloma bone disease achieving less than a partial response to induction. The skeletal related event (SRE) risk reduction compared to placebo was dependent on myeloma control - partial response (26% reduced risk), VGPR (13% reduced risk), and with CR, no reduced SRE risk.

Hence these drugs provide their MOST benefit when the patient's myeloma bone disease is out of control. So I tend to use Zometa/Xgeva in patients with uncontrolled disease and quickly stop it if I reach VGPR or better.

XGeva is non-inferior (HR = 0.98) to Zometa but with less renal toxicity, more hypocalcemia, and numerically more osteonecrosis of the...

The impact of response on survival was based on post-hoc analysis of the UK Myeloma IX trial. Methodologically speaking, when facing a decision whether to act based on the original randomization vs. post-hoc subgroup analysis, it is usually safer to stick to the original allocation.