Renal Safety of Intravenous Ibandronic Acid in Breast Cancer Patients with Metastatic Bone Disease

Collapsing focal segmental glomerulosclerosis following long-term treatment with oral ibandronate: case report and review of literature

Background

Renal toxicity has been reported with bisphosphonates such as pamidronate and zolidronate but not with ibandronate, in the treatment of breast cancer patients with bone metastasis. One of the patterns of bisphosphonate-induced nephrotoxicity is focal segmental glomerulosclerosis (FSGS) or its morphological variant, collapsing focal segmental glomerulosclerosis (CFSGS).

Case presentation

We describe a breast cancer patient who developed heavy proteinuria (protein/creatinine ratio 9.1) and nephrotic syndrome following treatment with oral ibandronate for 29 months. CFSGS was proven by biopsy. There was no improvement 1 month after ibandronate was discontinued. Prednisone and tacrolimus were started and she experienced a decreased in proteinuria.

Conclusion

In patient who develops ibandronate-associated CFSGS, proteinuria appears to be at least partially reversible with the treatment of prednisone and/or tacrolimus if the syndrome is recognized early and ibandronate is stopped.

Oral ibandronate in metastatic bone breast cancer: the Florence University experience and a review of the literature

Ibandronate is an amino-bisphosphonate approved in metastatic breast cancer to reduce skeletal complications and to alleviate bone pain. we report our experience about the safety of oral ibandronate and review the literature.We treated 44 patients and administered 524 cycles of oral ibandronate (a single cycle was defined as a 50 mg capsule once daily for 28 days) with a median of 12 cycles (range 6-24). At a median follow-up of 18.5 months (range 6-28) the mean pain score decreased from 1.59 (SD+/-0.97) at baseline to 0.41 (SD+/-0.72) after 48 weeks of treatment. The mean analgesic score was 1.89 (SD+/-1.37) at baseline and 1.46 (SD+/-1.62) after 48 weeks of treatment. Ibandronate was generally well-tolerated; we had no Grade 3-4 adverse events. No patients had deterioration of renal function. No patients developed bisphosphonate-associated osteonecrosis of the jaw. Our experience confirmed that ibandronate may be a useful and safe co-analgesic to conventional treatments for bone pain in selected metastatic breast cancer patients.

Risk of renal impairment after treatment with ibandronate versus zoledronic acid: a retrospective medical records review

PURPOSE

This retrospective study compared renal impairment rates in breast cancer, multiple myeloma, prostate cancer and non-small cell lung cancer patients treated with ibandronate or zoledronic acid.

STUDY DESIGN

Medical records in two German oncology clinics from May 2001 to March 2006 were retrospectively reviewed. Creatinine measurements were analyzed from baseline (before bisphosphonate treatment) to last available measurement for each patient. The Cox proportional hazards model and the Andersen-Gill extension of the Cox model for multiple events analysis were used for multivariate analysis, which controlled for age, clinic site, primary cancer type, baseline SCr or GFR value, prior bisphosphonate use, concomitant use of drugs associated with acute renal failure, and renal-related comorbidities.

RESULTS

Of 333 patients, 109 received ibandronate and 256 received zoledronic acid (32 patients had both drugs). Compared with ibandronate, the zoledronic acid group had a significantly better baseline renal function and fewer patients had a history of renal disease. Zoledronic acid treatment increased the relative risk (RR) and the incidence rate (IR) of renal impairment by approximately 1.5-fold in all assessed patients (all tumors) compared with ibandronate. Multivariate analysis found significantly higher hazards ratios for zoledronic acid over ibandronate (two to sixfold), after adjusting for differences in characteristics between the two treatment groups.

CONCLUSIONS

In this retrospective review, patients were significantly more likely to experience renal impairment with zoledronic acid than with ibandronate.

Renal safety profiles of ibandronate 6 mg infused over 15 and 60 min: a randomized, open-label study

BACKGROUND

Clinical data show that a single, 15-min i.v. infusion of ibandronate 6 mg does not significantly alter renal function. We evaluated the effect on renal function of repeated 15-min infusions of ibandronate 6 mg in women with breast cancer and bone metastases.

PATIENTS AND METHODS

Patients were randomly assigned to i.v. ibandronate 6 mg every 3-4 weeks for < or =6 months, infusion over 15 min (n = 102) or 60 min (n = 28). The primary end point was the percentage of patients with increased serum creatinine of > or =44.2 micromol/l. Blood chemistry was assessed at each visit.

RESULTS

Two per cent [2/101; 95% confidence interval (CI) 0.2-7.0] of patients in the 15-min infusion arm and no patients (0/26; 95% CI 0.0-13.2) in the 60-min infusion arm had increased serum creatinine that met the primary end point. There were no clinically relevant changes in serum creatinine, creatinine clearance, or N-acetyl-beta-d-glucosaminidase, alpha(1)-microglobulin, or microalbuminuria. Most adverse events were mild or moderate. No clinically relevant changes were observed in vital signs, hematology, blood chemistry, or urine analysis.

CONCLUSIONS

Ibandronate 6 mg by 15-min infusion every 3-4 weeks appear to be consistent with those renal safety profiles of 60-min infusion.

Quarterly intravenous injection of ibandronate to treat osteoporosis in postmenopausal women

Osteoporosis is a chronic condition that generally requires long-term therapy for fracture risk reduction to become apparent. Although the bisphosphonates have made a major contribution to how clinicians manage osteoporosis, compliance with therapy has generally been less in the real-world setting than seen in clinical trials. Less-frequently administered dosage regimens or nonoral routes may enhance compliance and so maximize the therapeutic benefit of bisphosphonates. Ibandronate is a nitrogen-containing bisphosphonate, whose high potency allows it to be administered orally or intravenously with extended dosing intervals. This paper will review the role of intravenous ibandronate in the treatment of postmenopausal osteoporosis.

Safety considerations with bisphosphonates for the treatment of osteoporosis

Bisphosphonates are the most commonly prescribed medications for the treatment of osteoporosis. Although evidence supports a good safety profile for these agents, numerous tolerability issues have been associated with their use. This review provides an overview of the safety issues associated with the nitrogen-containing class of bisphosphonates and discusses the potential effect of these issues on adherence. The review specifically considers upper gastrointestinal (UGI) adverse events (AEs), renal toxicity, influenza-like illness, osteonecrosis of the jaw and evidence on how to treat or prevent these events. In clinical trials, UGI AEs, including severe events such as oesophageal ulcer, oesophagitis and erosive oesophagitis, have been reported at similar frequencies in placebo- and active-treatment arms. However, postmarketing studies have highlighted UGI AEs as a concern. These studies show that a significant portion of patients are less compliant with administration instructions outside strict clinical trial supervision, and when oral bisphosphonates are not administered as directed, patients are more likely to experience UGI AEs. Some clinical trials with oral bisphosphonates have suggested that a decrease in the frequency of administration may lead to improvement in gastrointestinal tolerability. In the authors' experience, the issue of UGI tolerability can be minimised by explaining to the patient and/or caregiver the importance of following administration instructions. Intravenous (IV) bisphosphonates have been recently approved for use in osteoporosis, offering an alternative regimen for patients with osteoporosis. Earlier generation IV bisphosphonates (e.g. etidronate) have been associated with acute renal failure. Alternatively, late-generation IV bisphosphonates (i.e. ibandronate) have shown a better safety profile in relation to renal toxicity. Influenza-like illness, often referred to as an acute-phase reaction, covers symptoms such as fatigue, fever, chills, myalgia and arthralgia. These symptoms are transitory and self-limiting and usually do not recur after subsequent drug administration. Symptoms of influenza-like illness have been associated with both IV and oral bisphosphonates. Osteonecrosis of the jaw has also been associated with IV bisphosphonate treatment, particularly in patients treated with high doses. A small number of patients with cancer and osteoporosis using oral bisphosphonates have also reported this AE. As osteonecrosis of the jaw is difficult to treat and is often associated with dental procedures and poor oral hygiene, preventive measures seem to be the best management option for patients taking bisphosphonates.Overall, the safety and tolerability profile of the nitrogen-containing bisphosphonates is good, and long-term treatment does not appear to carry a risk of serious AEs. By encouraging adherence to administration instructions physicians can minimise certain complications, such as UGI intolerability. By being aware of other potential safety issues, such as renal impairment, influenza-like illness and osteonecrosis of the jaw, physicians can detect these AEs early in the course of treatment.

Use of intravenous bisphosphonates in osteoporosis

Bisphosphonates, which are potent bone resorption inhibitors, currently are the mainstay of treatment for osteoporosis. Antifracture efficacy has been demonstrated for at least three nitrogen-containing bisphosphonates in oral formulations that are designed to be administered in weekly or monthly dosing regimens. Frequent reports of adverse events, primarily related to the upper gastrointestinal tract, and the strict dosing schedule necessary for oral bisphosphonate therapy are considered the major reasons for disappointing adherence to therapy. New intravenous formulations have been developed that allow dosing at very long intervals, thus avoiding the gastrointestinal complications associated with oral bisphosphonates and, it is hoped, improving compliance, particularly for patients who are intolerant of oral bisphosphonates or have contraindications to their use. This alternative approach holds promise for improved outcomes of osteoporosis treatment and ultimately for reduced health care costs related to caring for people with fragility fractures.

Differences in Nephrotoxicity of Intravenous Bisphosphonates for the Treatment of Malignancy- Related Bone Disease

Renal dysfunction is a particularly problematic adverse event that requires additional management and can prohibit the use of certain medications. Due to their renal uptake and elimination, some bisphosphonates can cause nephrotoxicity when used for the treatment of skeletal-related events in patients with bone metastases. However, clinical studies and post-marketing experience indicate that renal effects do not appear to be the same for all bisphosphonates. Zoledronic acid and pamidronate appear to be associated with a greater risk of renal toxicity, especially when given in high doses or over short infusion times. In contrast, high loading doses of intravenous ibandronate (3 x 6 mg given on days 1-3) have shown no additional renal safety concerns, and intravenous ibandronate 6 mg appears to have a renal safety profile comparable to placebo. This paper reviews the renal safety of intravenously administered bisphosphonates and makes some suggestions, based on preclinical and clinical data, as to why renal safety profiles may differ.

Ibandronate: efficacy in the treatment of metastatic bone disease

Ibandronate is a bisphosphonate treatment for metastatic bone disease. In Phase III trials in breast cancer patients, intravenous and oral formulations of ibandronate lowered the incidence of skeletal-related events, reduced metastatic bone pain scores throughout 2 years of treatment, and had significant positive effects on patient quality of life, demonstrating its efficacy in this condition. Recent pilot studies in other primary cancers suggest that a loading dose of ibandronate may relieve severe or opioid-resistant metastatic bone pain. In safety analyses, ibandronate was well tolerated with a safety profile comparable to placebo. Ibandronate therefore represents a treatment choice with documented efficacy and safety in metastatic bone disease from breast cancer.

Review of ibandronate in the treatment of metastatic bone disease: experience from phase III trials

BACKGROUND

Metastatic bone disease is a serious clinical problem in patients with advanced cancer. Bisphosphonates inhibit the activity of osteoclasts and are the treatment of choice for bone metastases.

OBJECTIVE

This article reviews the efficacy and safety data from Phase III trials of ibandronate in metastatic bone disease.

METHODS

Phase III data (available as of June 2004) for ibandronate were reviewed. Literature searches using the MEDLINE database and abstracts from scientific meetings were used to obtain data from Phase III trials of ibandronate.

RESULTS

Compared with placebo, patients with bone metastases from breast cancer receiving IV ibandronate (6 mg infused over 1-2 hours every 3-4 weeks) or oral ibandronate (50 mg/d for up to 96 weeks) had a statistically significant reduction in skeletal complications, as measured by the Skeletal Morbidity Period Rate (P = 0.004 vs placebo). Multivariate Poisson regression analysis of the data showed that the risk of a new bone event was reduced by 40% with IV ibandronate 6 mg and by 38% with oral ibandronate 50 mg, compared with placebo (P < or = 0.003). Both formulations also reduced bone pain below baseline levels over 2 years (P < or = 0.001 vs placebo). IV and oral ibandronate were well tolerated, with adverse-event profiles comparable to placebo and no significant renal toxicity.

CONCLUSIONS

IV and oral ibandronate provide meaningful clinical benefits in patients with bone metastases from breast cancer. Both formulations reduce the risk of skeletal events and provide sustained relief from metastatic bone pain. With its favorable efficacy and safety profile, and the added convenience of the oral formulation, ibandronate provides improved treatment options for managing metastatic bone disease.

Management of bone metastases in breast cancer

Patients with advanced breast cancer who develop bone metastases suffer an ongoing risk of skeletal complications that can have a significant impact on their quality of life (QoL). These complications include bone pain, pathologic fractures, spinal cord compression, and hypercalcemia of malignancy (HCM), a potentially life-threatening condition. Treatment options include radiotherapy to palliate bone pain and/or prevent impending fracture, orthopedic surgery to prevent or repair fractures, analgesics, and bisphosphonates, which can significantly reduce the risk of skeletal complications and delay their onset. Of the known bisphosphonates, zoledronic acid is the most potent. Since its regulatory approval in the United States and Europe in 2001, zoledronic acid (4 mg by 15-minute infusion) has become widely used and has replaced pamidronate (90 mg by 2-hour infusion) as the standard of care for treating bone metastases from breast cancer and bone lesions from multiple myeloma. Zoledronic acid has also demonstrated significant long-term benefits in randomized trials in prostate cancer and other solid tumors, whereas other bisphosphonates have failed. In long-term, phase III clinical testing, zoledronic acid provided significant treatment benefits beyond those of pamidronate in patients with breast cancer and demonstrated a safety profile comparable with pamidronate. Therefore, zoledronic acid is now recommended from the first diagnosis of bone metastasis. Other intravenous bisphosphonates include clodronate and ibandronate. Both are approved in Europe, but their efficacy relative to pamidronate and zoledronic acid is not known.

Efficacy and safety of ibandronate in the treatment of neoplastic bone disease

Bone is an organ commonly involved in spreading neoplastic disease, especially in multiple myeloma and carcinoma of the breast, prostate and lung. Skeletal stabilisation and pain relief are the main treatment goals in metastatic bone disease. Bisphosphonate treatment inhibits osseous breakdown and is well-established as the current standard therapy for reducing complications of neoplastic bone disease (e.g., pain, fractures and hypercalcaemia). Ibandronate is a third-generation bisphosphonate that has recently been approved for the treatment of bone metastases caused by breast cancer. The oral and intravenous formulations of ibandronate appear to have comparable efficacy. Ibandronate has also been shown to provide significant and sustained relief from metastatic bone pain over 2 years of treatment, improving patient functioning and quality of life. With a favourable long-term safety profile and the added convenience and flexibility offered by its efficacious oral formulation, ibandronate represents a new therapeutic option for metastatic bone disease management.

Profiling the safety and tolerability of bisphosphonates

Because patients with metastatic bone disease suffer a significant burden from their illness and from anticancer treatments, it is therefore important to minimize the side effects of bisphosphonates. The intravenous bisphosphonates, zoledronic acid and pamidronate, have tolerability issues that include a flu-like syndrome, injection-site reactions, and occasional renal toxicity. Because of the potentially severe nature of the renal toxicity, renal monitoring is required before each dose, with drug withdrawal if the patients' renal function deteriorates. Oral clodronate often causes gastrointestinal disturbances, particularly diarrhea; compliance is often poor because of the large tablet size and multiple daily dosing. Long-term data have shown that the bisphosphonate ibandronate is well tolerated either intravenously or orally, with a renal safety profile similar to placebo and no evidence of cumulative renal damage. Studies investigating the effects of 15-minute infusions and intensive dosing indicate that intravenous ibandronate given rapidly or at high doses is also well tolerated with no renal safety concerns. Taken together, these results suggest that the favorable safety profile of ibandronate provides an important alternative to existing bisphosphonate options for metastatic bone disease. Using ibandronate could improve patient acceptability and simplify management, with reductions in the need for safety monitoring and management of adverse events.