Combination of zoledronic Acid and targeted therapy is active but may induce osteonecrosis of the jaw in patients with metastatic renal cell carcinoma.

PURPOSE: To investigate the efficacy and safety of zoledronic acid (ZA) combined with targeted therapy (TT).

MATERIALS AND METHODS: A retrospective study was performed in patients with metastatic renal cell carcinoma treated with ZA and TT.

RESULTS: Twenty-one patients received ZA and TT to prevent skeletal-related events and no pretherapy oral and maxillofacial (OM) examination (cohort A). Six patients (29%) developed osteonecrosis of the jaw (ONJ), which was observed only in patients receiving sunitinib and ZA. Sixteen patients received TT and ZA for hypercalcemia and no pretherapy OM examination (cohort B). In these patients, no ONJ was observed. Nine patients received ZA and TT and pretherapy OM examination (cohort C). One patient (11%) developed ONJ during sunitinib and ZA treatment. Mean skeletal morbidity rates were 0.8 for cohort A and 1.2 for cohort C. In the combined cohort (A plus C; n = 30), 47% developed skeletal-related events, 7% pathologic fracture, 7% medullary compression, and 37% progression of bone metastases. Patients who developed ONJ had a significantly improved median survival of 31.6 months compared with 14.5 months in patients without ONJ (P = .039).

CONCLUSION: The combination of ZA and TT resulted in high, clinically meaningful activity. ONJ may be exacerbated by concomitant ZA and sunitinib. Regular OM examinations before and during treatment are recommended.