The effect of denosumab in breast cancer patients receiving adjuvant aromatase inhibitors: 36-month results.

INTRODUCTION: Aromatase inhibitor (AI)-associated bone loss increases the risk of bone fracture and reduces patients' quality of life, making it a critical issue worldwide. We conducted a prospective non-randomized clinical trial (UMIN-CTR, UMIN 000016173) to assess the effect of denosumab on bone loss in patients treated with adjuvant AI and have previously reported the results at 12 and 24 months. This study aimed to present the results at 36 months of treatment with denosumab for osteopenia in breast cancer patients who were undergoing treatment with adjuvant AI; 36 months is the longest denosumab treatment period reported so far. MATERIALS AND METHODS: Patients received 60-mg denosumab subcutaneously every 6 months. Daily supplements containing 500-mg elemental calcium and at least 400 international units of vitamin D were highly recommended throughout the study period. The levels of bone mineral density (BMD) and bone turnover markers, serum tartrate-resistant acid phosphatase isoform 5b, and bone alkaline phosphatase were determined at baseline and 6, 12, 18, 24, and 36 months. RESULTS: At 36 months, the bone mineral density of the lumbar spine, right femoral neck, and left femoral neck were found to increase by 8.8% (95% confidence interval CI 7.6-10.1), 4.3% (95% CI 3.0-5.5), and 3.1% (95% CI 2.1-4.1), respectively. No non-traumatic clinical fractures occurred in patients receiving AI and denosumab. CONCLUSION: Twice-yearly administration of denosumab to the breast cancer patients treated with adjuvant AI, regardless of the skeletal site, resulted in consistent increases in BMD without severe adverse events at 36 months.

Predictive factors for the efficacy of denosumab in postmenopausal Japanese women with non-metastatic breast cancer receiving adjuvant aromatase inhibitors: a combined analysis of two prospective clinical trials.

Aromatase inhibitors (AIs) are the gold standard therapy for breast cancer in postmenopausal women. AI suppresses the conversion of androgens to estrogens; however, this results in osteopenia, osteoporosis, and bone fracture, thus reducing the patient's quality of life. The use of adjuvant denosumab reduces the risk of clinical fractures in postmenopausal patients with breast cancer receiving AI. However, the efficacy of denosumab in the treatment of AI-associated bone loss has not been prospectively evaluated in Japan. In this study, we aimed to investigate the predictive factors for the efficacy of denosumab in postmenopausal patients with breast cancer treated with AI by analyzing the results of two prospective trials. The patients received 60 mg denosumab subcutaneously every 6 months. The primary endpoint was percentage change in lumbar spine bone mineral density (BMD) from baseline to month 12 in lumbar spine. Post hoc analysis and T tests were performed. A total of 205 patients were enrolled. At 12 and 24 months, the lumbar spine BMD increased by 5.6% [95% confidence interval (CI) 4.9-6.3] and 8.3% (95% CI 7.5-9.1), respectively. Subgroup analysis was conducted according to the time of AI therapy initiation, type of AI therapy, age, time since menopause, baseline body mass index, and BMD. The results showed that baseline lumbar and left femoral BMD was significantly associated with a percentage change in these sites, respectively. In addition, baseline left femoral BMD was also associated with a change in lumbar BMD. In conclusion, the baseline BMD in the lumbar spine was a predictive indicator for the efficacy of denosumab in this site and the baseline BMD in left femoral neck was a predictive indicator in lumbar spine and left femur.

Effects of denosumab on bone mineral density in Japanese women with osteoporosis treated with aromatase inhibitors for breast cancer.

Adjuvant aromatase inhibitor (AI) therapy, for hormone receptor-positive breast cancer, in postmenopausal women is associated with bone loss, leading to an increased risk of fractures. Denosumab, an antibody raised against the receptor activator of nuclear factor-κB ligand, has been proven to protect against AI-induced bone loss. Hence, we aimed to determine whether denosumab is effective in postmenopausal Japanese women with osteoporosis, treated with AI. We prospectively evaluated the bone mineral density (BMD) in the lumbar spine and the bilateral femoral neck in 102 postmenopausal women with clinical hormone receptor-positive breast cancer, stages I-IIIA, during a postoperative period of 12 months. The other inclusion criteria for this study were: women that should receive AIs as adjuvant therapy and those with evidence of osteoporosis (lumbar spine or bilateral femoral neck BMD, equivalent to T-score classification of ≤ - 2.5) upon enrollment. The patients received supplemental calcium, vitamin D, and 60 mg of subcutaneous denosumab every 6 months. The BMD of the lumber spine increased by 4.9 and 6.6% at 6 and 12 months, respectively. An increase in BMD was observed at the femoral neck, bilaterally. Hypocalcemia ≥ grade 2, osteonecrosis of the jaw, and non-traumatic clinical fracture were not observed in this study. Our findings revealed that biannual treatment with denosumab is associated with a great increase of BMD in Japanese women receiving adjuvant AI therapy, irrespective of their previous history of AI therapy.

Effect of denosumab on low bone mineral density in postmenopausal Japanese women receiving adjuvant aromatase inhibitors for non-metastatic breast cancer: 24-month results.

BACKGROUND: Aromatase inhibitors (AI) have been established as the gold-standard therapy for postmenopausal patients. Worldwide, adjuvant denosumab at a dose of 60 mg twice per year reduces the risk of clinical fractures in postmenopausal patients with breast cancer who received AI. However, the efficacy of denosumab in the treatment of AI-associated bone loss had not been prospectively evaluated in Japan. Previously, we reported the 12-month effect of denosumab in Japanese patients for the first time; the primary endpoint was the change in the percentage of bone mineral density (BMD) of the lumbar spine from baseline to 12 months. METHODS: This secondary follow-up study prospectively evaluated the change in the percentage of BMD of the lumbar spine from baseline to 24 months. Postmenopausal women with early-stage, histologically confirmed, hormone receptor-positive, invasive breast cancer who were receiving or scheduled to receive AI were included. Denosumab was administered subcutaneously on day 1 of the study and then 6, 12, 18, and 24 months. The lumbar spine and bilateral femoral neck BMD was measured at baseline and 6, 12, 18, and 24 months. RESULTS: At 18 and 24 months, the lumbar spine BMD increased by 5.9 and 7.0%, respectively. The femoral neck BMD also increased. Grade ≥ 2 hypocalcemia, osteonecrosis of the jaw, and atypical femoral fractures did not occur. CONCLUSIONS: Our prospective study showed that semiannual treatment with denosumab was associated with continuously increased BMD in Japanese women receiving adjuvant AI therapy for up to 24 months, regardless of prior AI treatment.

Effect of denosumab on bone mineral density in Japanese women with osteopenia treated with aromatase inhibitors for breast cancer: subgroup analyses of a Phase II study.

BACKGROUND: The aim of the study was to conduct subgroup analyses of therapeutic effects of 12-month denosumab therapy on the percentage change in bone mineral density (BMD) from baseline in the lumber spine and femoral neck. MATERIALS AND METHODS: We prospectively evaluated the BMD of the lumbar spine and femoral neck of 100 hormone receptor-positive, clinical stage I-IIIA postoperative postmenopausal breast cancer patients, for whom treatment with aromatase inhibitors (AIs) as adjuvant endocrine therapy was scheduled. The primary endpoint was the percent change in lumbar spine BMD from baseline to 12 months. Patient subgroups were analyzed according to baseline variables that are known risk factors for bone loss, including previous AI therapy, age, time since menopause, baseline body mass index (BMI), and baseline BMD T-score. RESULTS: At 12 months, lumbar spine BMD increased by 4.7%; the patients who were administered AI therapy prior to denosumab (n=70) demonstrated a 4.7% increase in BMD, and the patients who received denosumab at the start of AI therapy (n=30) demonstrated a 4.5% increase in BMD (p=0.8385). Additionally, 2.4% and 1.4% increases in BMD of the right and left femoral neck, respectively, were observed. Initiation of AI (with denosumab, before denosumab), type of AI (non-steroidal, steroidal), age (<65, ≥65 years), time since menopause (≤5, >5 years), BMI (<25, ≥25 kg/m2), and T-score (≤-1.0, >-1.0) of the right femoral neck were as follows: (2.2%, 2.5%, p=0.7773), (2.6%, 0.9%, p=0.1726), (2.5%, 2.3%, p=0.7594), (2.1%, 2.4%, p=0.2034), (2.1%, 2.9%, p=0.2034), and (2.3%, 2.7%, p=0.6823), respectively. Initiation of AI (with denosumab, before denosumab), type of AI (non-steroidal, steroidal), age (<65, ≥65 years), time since menopause (≤5, >5 years), BMI (<25, ≥25 kg/m2), and T-score (≤-1.0, >-1.0) of the left femoral neck were as follows: (1.0%, 1.5%, p=0.1972), (1.2%, 2.7%, p=0.2931), (1.4%, 1.3%, p=0.8817), (-0.1%, 1.6%, p=0.1766), (1.3%, 1.9%, p=0.6465), and (1.5%, 1.1%, p=0.6573), respectively. CONCLUSION: Twice-yearly treatment with denosumab was associated with increased BMD among Japanese women receiving adjuvant AI therapy, regardless of the baseline characteristics or skeletal site.

Effect of denosumab administration on low bone mineral density (T-score -1.0 to -2.5) in postmenopausal Japanese women receiving adjuvant aromatase inhibitors for non-metastatic breast cancer.

Although adjuvant aromatase inhibitor (AI) therapy is widely used in postmenopausal women with hormone receptor-positive breast cancer, it is known to be associated with bone loss and increased fracture risk. Denosumab, a fully human monoclonal antibody against the receptor activator of nuclear factor-κB ligand, has been shown to protect against AI-induced bone loss. However, the efficacy of denosumab in the treatment of AI-associated bone loss has not been prospectively evaluated in Japan. We prospectively monitored bone mineral density (BMD) of the lumbar spine and bilateral femoral necks in 100 postmenopausal women with hormone receptor-positive postoperative breast cancer of clinical stage I-IIIA in whom treatment with AI as adjuvant endocrine therapy was planned or had been ongoing. Study participants received supplemental calcium and vitamin D every day and denosumab (60 mg) subcutaneously every 6 months. At enrollment, patients were required to have evidence of low bone mass without meeting the criteria for osteoporosis. The primary endpoint was percentage change from baseline in lumbar spine BMD at month 12. At 6 and 12 months, lumbar spine BMD increased by 3.3 and 4.7%, respectively. BMD of the femoral necks also increased. Hypocalcemia of grade ≥2, osteonecrosis of the jaw, and non-traumatic clinical fracture did not occur. In conclusion, semi-annual treatment with denosumab was associated with increased BMD in Japanese women receiving adjuvant AI therapy, regardless of prior AI treatment.