Impact of Extended-Interval Versus Standard Dosing of Zoledronic Acid on Skeletal Events in Non-Small-Cell Lung Cancer and Small-Cell Lung Cancer Patients With Bone Metastases.

BACKGROUND

Zoledronic acid every 4 weeks (Q4wk) reduces the incidence of skeletal-related events (SREs) in patients with metastatic lung cancer. Lung cancer patients were excluded from extended-interval dosing trials (every 12 weeks [Q12wk]) that demonstrated noninferiority of the 2 dosing schemes. To date, the optimal dosing of zoledronic acid in metastatic lung cancer remains unknown.

OBJECTIVE

To determine whether zoledronic acid dosed Q12wk is similar to Q4wk dosing for prevention of SRE in patients with metastatic lung cancer.

METHODS

A retrospective analysis was performed in patients with non-small-cell lung cancer and small-cell lung cancer with bone metastases who received Q12wk and Q4wk zoledronic acid. The primary outcome was incidence of SRE at 1 year. Secondary analyses included time to first SRE, overall survival (OS), incidence of osteonecrosis of the jaw (ONJ), kidney dysfunction, and hypocalcemia.

RESULTS

A total of 34 patients received Q12wk and 46 patients received Q4wk zoledronic acid. Incidence of SRE at 1 year (Q12wk, 23.5%, vs Q4wk, 23.9%; 95% CI = -0.184 to 0.192; P = 0.968) and median time to SRE (not reached for either cohort; P = 0.530) did not differ. The Q12wk cohort had longer median OS (24.00 vs 8.97 months; P = 0.022). There were no differences in incidence of ONJ, kidney dysfunction, and hypocalcemia.

CONCLUSION AND RELEVANCE: This is the first report examining extended-interval dosing of zoledronic acid in metastatic lung cancer. Incidence and time to SRE at 1 year were similar. This extended-interval dosing may be safe and reasonable for patients with lung cancer with bone metastases.