Despite their efficacy in treating complications associated with metastatic
bone disease, there are concerns about the potential nephrotoxicity of certain i.v.
bisphosphonates for the long-term management of
cancer patients. Clinical data suggest, however, that i.v.
ibandronate (
Bondronat); F. Hoffman-La Roche Ltd., Basel, Switzerland, http://www.roche.com), unlike other
bisphosphonates, has a renal safety profile comparable with that of placebo. In a 2-year, phase III study of patients with
breast cancer metastatic to bone, the incidence of adverse renal events in patients treated with 6 mg i.v.
ibandronate was low and comparable with that of placebo (4% versus 4.5% with placebo). Two-year assessments of time to serum
creatinine increase also demonstrated renal safety comparable with that of placebo (patients with
creatinine increase: 6% versus 12% with placebo). Long-term (4-year) renal safety of
ibandronate was demonstrated in a 2-year extension of the trial. Phase II, open-label studies show that intensive
ibandronate dosing does not compromise renal safety in patients with metastatic bone
pain from a variety of
tumor types. In addition, i.v.
ibandronate is well tolerated, with no evidence of renal toxicity in
multiple myeloma and
urologic cancer patients with existing renal impairment. The potential nephrotoxicity of some
bisphosphonates has prompted additional renal safety precautions in product labeling for these agents. The precautions are not, however, contained in the label for
ibandronate, which may thus simplify patient management.