Re: Superiority of denosumab to zoledronic acid for prevention of skeletal-related events: a combined analysis of three pivotal, randomised, phase 3 trials

Denosumab Versus Zoledronic Acid in Cases of Surgically Unsalvageable Giant Cell Tumor of Bone: A Randomized Clinical Trial

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Denosumab and zoledronic acid had similar tumor responses and clinical benefits.

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Disease progression was observed in patients in the DB group (12.5%) than ZA group (15.0%).

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Denosumab treatment was markedly more expensive than zoledronic acid treatment (p < 0.0001).

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The recurrence-free survival rate at 4-year follow-up is higher in DB group (p = 0.035).

Background

Giant-cell tumor of bone (GCTB) is a relatively benign, but locally aggressive osteoclastogenic stromal tumour of the bone. Although denosumab has been approved as an monoclonal antibody against RANK ligand for the treatment of GCTB, few clinical trials of the benefit in tumor response have been conducted to prove the efficiency in Chinese population.

Objectives

In this multicentric, random controlled, clinical trial, 160 patients were enrolled to compare the therapeutic efficacy and safety of denosumab and zoledronic acid treatment in patients with surgically unsalvageable GCTB.

Methods

Between 2nd Jan 2015 and 1st Jan 2018, 160 adults (aged ≥ 18 years) with ①surgically unsalvageable GCTB, ②surgically salvageable GCTB with planned surgery expected to result in severe morbidity were included in this randomized clinical trial. Patients received either subcutaneous denosumab (DB group; 120 mg once every 4 weeks with loading doses of 120 mg subcutaneously admininstered on days 8 and 15; n = 80) or intravenous zoledronic acid (ZA group; 4 mg once every 4 weeks; n = 80) for six cycles. Disease status, clinical benefits, treatment-emergent adverse effects, overall survival, and cost of treatment were evaluated during the follow-up period. Statistical significance was determined using 95% confidence intervals.

Results

Denosumab and zoledronic acid had similar tumor responses (p = 0.118) and clinical benefits (p = 0.574). Disease progression was observed in fewer patients in the DB group (12.5%) than ZA group (15.0%). Denosumab caused fatigue (p = 0.001) and back pain (p < 0.0001), while zoledronic acid caused hypocalcemia (p < 0.0001), flu-like symptoms (p = 0.059) and hypotension (p = 0.059). Denosumab treatment was markedly more expensive than zoledronic acid treatment (p < 0.0001). The cost to manage treatment-emergent adverse effects was the same for the ZA group and the DB group (p = 0.425). The accumulate recurrence-free survival rate at 4-year follow-up is higher in DB group (p = 0.035).

Conclusions

Denosumab is a safe but costly alternative to zoledronic acid for treatment of surgically unsalvageable GCTB.

Denosumab versus zoledronic acid in cases of surgically unsalvageable giant cell tumor of bone: A randomized clinical trial

BACKGROUND

Although denosumab has been approved as an antiresorptive agent for giant cell tumor of bone, its efficacy has not been proven.

OBJECTIVES

To compare the efficacy and safety of denosumab and zoledronic acid treatment in patients with surgically unsalvageable giant cell tumor of bone.

METHODS

A total of 250 patients with surgically unsalvageable giant cell tumor of bone were included in this randomized clinical trial. Patients received either subcutaneous denosumab (DB group; 120 mg per 4 weeks plus an additional 120 mg on days 8 and 15; n = 125) or intravenous zoledronic acid (ZA group; 4 mg per 4 weeks; n = 125) for six cycles. Disease status, clinical benefits, treatment-emergent adverse effects, overall survival, and cost of treatment were evaluated during the follow-up period. Statistical significance was determined using 95% confidence intervals.

RESULTS

Denosumab and zoledronic acid had similar tumor responses (p = 0.18) and clinical benefits (p = 0.476). Disease progression was observed in fewer patients in the DB group (1%) than ZA group (2%). Denosumab caused fatigue (p = 0.0004) and back pain (p < 0.0001), while zoledronic acid caused hypocalcemia (p < 0.0001), flu-like symptoms (p = 0.021), hypotension (p = 0.021), and hypokalemia (p = 0.021). Denosumab treatment was markedly more expensive than zoledronic acid treatment (p < 0.0001). The cost to manage treatment-emergent adverse effects was higher for the ZA group than the DB group (p = 0.0425). Overall survival was the same for both treatments (p = 0.066).

CONCLUSIONS

Denosumab is a safe but costly alternative to zoledronic acid for treatment of surgically unsalvageable giant cell tumor of bone.

Addition of Zoledronate to Chemotherapy in Patients with Osteosarcoma Treated with Limb-Sparing Surgery: A Phase III Clinical Trial

Background

Zoledronate has anti-bone resorption activity and is reported to reduce skeletal-related events. The objective of this study was to test the hypothesis that addition of zoledronate in chemotherapy is safe and effective in osteosarcoma.

Material/Methods

A total of 798 patients, age 25 years and above, with newly diagnosed high-grade surgically salvageable malignant osteosarcoma, were included in the trial. All patients had received standard chemotherapies (n=399). In addition, in a standard chemotherapy regimen, patients enrolled in the zoledronate group also received 10 courses of 4 mg intravenous infusions of zoledronate (n=399). Limb-sparing surgery was performed by orthopedic surgeons (n=798). Clinical assessment, laboratory monitoring, overall survival, event-free survival, and treatment-emergent adverse effects were evaluated. The chi-square independence-samples test was used for statistical analysis at 95% confidence level.

Results

The histopathological response was the same for both groups (p=0.12). Addition of zoledronate to chemotherapy improved skeletal event-free survival (p=0.04) but decreased overall survival (p=0.02). Zoledronate induced hypocalcemia (p<0.0001), hypophosphatemia (p<0.0001), cardiotoxicity (p<0.0001), lung metastases (p=0.03), flu-like syndrome (p<0.0001), and ototoxicity (p=0.02), and elevated serum aspartate aminotransferase (p<0.0001) and serum alanine aminotransferase (p<0.0001).

Conclusions

The addition of zoledronate to standard chemotherapy in high-grade resectable osteosarcoma is detrimental and is not advised.

Denosumab versus zoledronic acid for preventing symptomatic skeletal events in Asian postmenopausal women with oestrogen-receptor-positive advanced breast cancer: an outcome analyses with a mean follow-up of 3 years

Background

The purpose of this study was to evaluate the efficacy of denosumab or zoledronic acid (ZA) using symptomatic skeletal events (SSEs) as the primary endpoint in Asian postmenopausal women with oestrogen-receptor-positive advanced breast cancer.

Methods

Asian postmenopausal women with oestrogen-receptor-positive advanced breast cancer receiving subcutaneous denosumab 120 mg Q4W, or intravenous ZA 4 mg Q4W until the primary analysis cut-off date were retrospectively analysed in the Hong Kong Practice-Based Cancer Research Center(HKCRC) from March 2011 to March 2013. The time to first on-study SSE that was assessed either clinically or through routine radiographic scans was the primary endpoint.

Results

242 patients received denosumab or ZA treatment (n = 120, mean age of 64.9 years (SD 3.01) and n = 122, 65.4 years (3.44), respectively). The median times to first on-study SSE were 14.7 months (12.9–45.6) and 11.7 months (9.9–45.6) for denosumab and ZA, respectively (hazard ratio, HR 0.44, 95% CI 0.71–2.95; p = 0·0002). Compared with the ZA group, denosumab-treated patients had a significantly delayed time to first SSE (HR 0.65 [95% CI 0.29–1.45], p < 0.0001). An increased incidence of SSE was found in the 16-month follow-up with rates of 2.1 and 10.7% for denosumab and ZA, respectively (P = 0.033). The difference persisted with time with rates of 8.3 and 17.2% at the final follow-up, respectively (P < 0.05).

Conclusion

In postmenopausal women aged ≥60 years with oestrogen-receptor-positive advanced breast cancer, denosumab significantly reduced the risk of developing SSEs compared with ZA. The findings of this pilot trial justify a larger study to determine whether the result is more generally applicable to a broader population.