The effect of prior bisphosphonate therapy on the subsequent therapeutic effects of strontium ranelate over 2 years

Repeating Measurement of Bone Mineral Density when Monitoring with Dual-energy X-ray Absorptiometry: 2019 ISCD Official Position

Bone mineral density (BMD) can be measured at multiple skeletal sites using various technologies to aid clinical decision-making in bone and mineral disorders. BMD by dual-energy X-ray absorptiometry (DXA) has a critical role in predicting risk of fracture, diagnosis of osteoporosis, and monitoring patients. In clinical practice, DXA remains the most available and best validated tool for monitoring patients. A quality baseline DXA scan is essential for comparison with all subsequent scans. Monitoring patients with serial measurements requires technical expertise and knowledge of the least significant change in order to determine when follow-up scans should be repeated. Prior ISCD Official Positions have clarified how and when repeat DXA is useful as well as the interpretation of results. The 2019 ISCD Official Positions considered new evidence and clarifies if and when BMD should be repeated. There is good evidence showing that repeat BMD measurement can identify people who experience bone loss, which is an independent predictor of fracture risk. There is good evidence showing that the reduction in spine and hip fractures with osteoporosis medication is proportional to the change in BMD with treatment. There is evidence that measuring BMD is useful following discontinuation of osteoporosis treatment. There is less documentation addressing the effectiveness of monitoring BMD to improve medication adherence, whether monitoring of BMD reduces the risk of fracture, or effectively discriminates patients who should and should not recommence treatment following an interruption of medication. Further research is needed in all of these areas.

Effects of strontium ranelate on bone mass and bone turnover in women with thalassemia major-related osteoporosis

Subjects affected by thalassemia major (TM) often have reduced bone mass and increased fracture risk. Strontium ranelate (SrR) is an effective treatment for postmenopausal and male osteoporosis. To date, no data exist on the use of SrR in the treatment of TM-related osteoporosis. Our aim was to evaluate the effects of SrR on bone mineral density (BMD), bone turnover markers and inhibitors of Wnt signaling (sclerostin and DKK-1). Twenty-four TM osteoporotic women were randomized to receive daily SrR 2 g or placebo in addition to calcium carbonate (1,000 mg) and vitamin D (800 IU). BMD at the lumbar spine and femoral neck, bone turnover markers (C-terminal telopeptide of procollagen type I [CTX], bone-specific alkaline phosphatase [BSAP]) and insulin-like growth factor-1 (IGF-1), sclerostin and DKK-1 were assessed at baseline and after 24 months. Back pain was measured by visual analog scale (VAS) every 6 months. After 24 months, TM women treated with SrR had increased their spine BMD values in comparison to baseline (p < 0.05). Moreover, they also exhibited a reduction of CTX and sclerostin levels (but not DKK-1) and exhibited an increase of BSAP and IGF-1 (p < 0.05); however, no significant changes were observed in the placebo group. In the SrR group, a reduction of back pain was observed after 18 months in comparison to baseline (p < 0.05) and after 24 months in comparison to placebo (p < 0.05). Our study reports for the first time the effects of SrR in the treatment of TM-related osteoporosis. SrR treatment improved BMD and normalized bone turnover markers, as well as lowering sclerostin serum levels.

Italian association of clinical endocrinologists (AME) position statement: drug therapy of osteoporosis

Treatment of osteoporosis is aimed to prevent fragility fractures and to stabilize or increase bone mineral density. Several drugs with different efficacy and safety profiles are available. The long-term therapeutic strategy should be planned, and the initial treatment should be selected according to the individual site-specific fracture risk and the need to give the maximal protection when the fracture risk is highest (i.e. in the late life). The present consensus focused on the strategies for the treatment of postmenopausal osteoporosis taking into consideration all the drugs available for this purpose. A short revision of the literature about treatment of secondary osteoporosis due both to androgen deprivation therapy for prostate cancer and to aromatase inhibitors for breast cancer was also performed. Also premenopausal females and males with osteoporosis are frequently seen in endocrine settings. Finally particular attention was paid to the tailoring of treatment as well as to its duration.

Normalization of bone mineral density after five years of treatment with strontium ranelate

E.F., female, age 58, mother of 4 children and otherwise healthy, had gone into menopause when she was 42. She had received hormone replacement therapy during 8 years. Due to low bone mass she had been treated with oral alendronate during 7 years. She had a normal calcium intake in her diet and engaged in regular physical activity. She did not smoke, and drank alcohol only occasionally. Her mother had sustained a hip fracture at age 90. Bone densitometry of her lumbar spine by DXA showed a T-score of -3.0; standardized bone mineral density (sBMD) had decreased by 11% in the previous 3 years. She was advised to start treatment with strontium ranelate (SrR) 2 g/day, plus oral cholecalciferol (1,000 IU/day). Three months later serum alkaline phosphatase had increased 10%, and serum osteocalcin was 18.9 ng/ml (upper normal limit 13.7). One year later her lumbar BMD had increased by 13.5%. After five years of treatment the BMD value was normal (1.357 g/cm(2); T-score -0.3). The case presented here is noteworthy for two reasons. Firstly, the patient maintained low bone mass after several years of combined treatment with alendronate and hormone replacement; this combination usually induces greater densitometric responses than either treatment given alone. Secondly, she responded promptly and significantly to SrR in spite of the previous long exposure to alendronate. SrR is widely used for the treatment of osteoporosis. It is an effective and safe drug, provided the patients are properly selected. As shown here, it can help some patients to achieve a normal BMD.

Treatment of osteoporosis after alendronate or risedronate

Alendronate (ALN) and risedronate (RIS) are ideal as first-choice therapy options in the treatment of postmenopausal osteoporosis. What to do for patients who do not respond adequately to bisphosphonates has not been conclusively determined, but transitioning to other therapies should be considered. The aim of this article is to describe potential alternatives for patients switching from ALN or RIS to other therapies for osteoporosis. A systematic search of PubMed was conducted to find papers that evaluate the effects of switching therapies on fractures, bone mineral density (BMD), or bone turnover markers. Results from 11 studies that prospectively assessed treatment after ALN or RIS in women with postmenopausal osteoporosis were reviewed. All studies are of short duration (all 24 months or less) and assess the topic of transitioning therapy from ALN or RIS. None of the studies had the statistical power to assess fracture-reduction efficacy. Transitioning from ALN to zoledronic acid maintains therapeutic effects for 12 months. Switching to strontium ranelate, denosumab, or teriparatide causes further increases in BMD. Specifically, transitioning to teriparatide could be used for a limited time for select patients but needs to be followed up with anti-resorptive treatment to prevent a loss of the bone gained. There are only few studies-of short duration-that assess the topic of transitioning therapy from ALN or RIS, although this is a very frequent occurrence in clinical practice. This is especially true if the patient has not reached his/her therapy goal. Further long-term studies are needed.

Bone markers and osteoporosis therapy

Several factors are involved in determining bone quality including bone density, bone turnover, the extent of trabecular bone connectivity, cortical porosity and geometry. Metabolically active and in a continuous process of remodeling, approximately 20% of bone tissue is renewed annually. Bone turn over markers (BTM) are frequently used in clinical trials and to provide valid information about the effectiveness of osteoporosis treatment, reflecting the state of bone metabolism and its response to treatment, although they are not useful alone to estimate bone loss. In this review the behavior of BTM from different clinical trials or different osteoporotic drugs will be addressed.

Strontium ranelate effect on bone mineral density is modified by previous bisphosphonate treatment

The aim of this study was to evaluate the effect of strontium ranelate (SrR) on bone mineral density (BMD) and bone turnover markers after 1 year of treatment. Additionally, the effect of SrR in bisphosphonate-naïve patients (BP-naïve) compared to patients previously treated with bisphosphonates (BP-prior) was analyzed. This retrospective study included 482 postmenopausal women treated with SrR (2 g/day) for 1 year in ten Argentine centers; 41 patients were excluded due to insufficient data, while 441 were included. Participants were divided according to previous bisphosphonate treatment in two groups: BP-naïve (n = 87) and BP-prior (n = 350). Data are expressed as mean ± SEM. After 1 year of treatment with SrR the bone formation markers total alkaline phosphatase and osteocalcin were increased (p < 0.0001), while the bone resorption marker s-CTX was decreased (p = 0.0579). Also increases in BMD at the lumbar spine (LS, 3.73%), femoral neck (FN, 2.00%) and total hip (TH, 1.54%) [p < 0.0001] were observed. These increments were significant (p < 0.0001) both among BP-naïve and BP-prior patients. Interestingly, the change in BMD after 1 year of SrR treatment was higher in BP-naïve patients: LS: BP-naïve = 4.58 ± 0.62%; BP-prior = 3.45 ± 0.28% (p = 0.078). FN: BP-naïve = 2.79 ± 0.56%; BP-prior = 2.13 ± 0.29% (p = 0.161). TH: BP-naïve = 3.01 ± 0.55%; BP-prior = 1.22 ± 0.27% (p = 0.0006). SrR treatment increased BMD and bone formation markers and decreased a bone resorption marker in the whole group, with better response in BP-naïve patients.

Trajectories of Bone Remodeling Markers and Bone Mineral Density during Treatment with Strontium Ranelate in Postmenopausal Women Previously Treated with Bisphosphonates

OBJECTIVE

To evaluate the responses of C-terminal telopeptide (CTX) and serum osteocalcin after the first 4 months of treatment with strontium ranelate (SR) and demonstrate their association with long-term bone density changes.

SUBJECTS AND METHODS

A sample of 13 postmenopausal women with osteoporosis was analyzed (mean age 65 ± 7.7 years), who were treated with SR for an average of 2.56 ± 0.86 years. All patients had undergone previous treatment with bisphosphonates for an average period of 4.88 ± 2.27 years. Serum CTX and osteocalcin levels were determined before and after four months of treatment with SR. Bone mineral density in the lumbar spine and femoral neck were obtained before and after treatment with SR.

RESULTS

We observed an average increase of 53.7% in the CTX levels, and 30.7% in the osteocalcin levels. The increase in bone markers was associated with a mean 4.8% increase in lumbar spine bone mineral density (BMD) from 0.820 to 0.860 g/cm² (T-score from −2.67 to −1.92; P = 0.001), after 2.5 years of treatment with SR.

CONCLUSION

These data suggest an anabolic effect of SR on postmenopausal women who were previously treated with long-term bisphosphonates.

European guidance for the diagnosis and management of osteoporosis in postmenopausal women

Guidance is provided in a European setting on the assessment and treatment of postmenopausal women at risk of fractures due to osteoporosis.

INTRODUCTION

The International Osteoporosis Foundation and European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis published guidance for the diagnosis and management of osteoporosis in 2008. This manuscript updates these in a European setting.

METHODS

Systematic literature reviews.

RESULTS

The following areas are reviewed: the role of bone mineral density measurement for the diagnosis of osteoporosis and assessment of fracture risk, general and pharmacological management of osteoporosis, monitoring of treatment, assessment of fracture risk, case finding strategies, investigation of patients and health economics of treatment.

CONCLUSIONS

A platform is provided on which specific guidelines can be developed for national use.

The use of combination therapy in the treatment of postmenopausal osteoporosis

In recent years, there has been growing interest in the potential use of combination therapy in the management of osteoporosis in postmenopausal women. Possible regimens include sequential or combined use of anti-resorptive drugs or combinations of anabolic and anti-resorptive agents, given concurrently or in sequence. Combined therapy with anti-resorptive drugs usually produces greater increases in bone mineral density (BMD) than monotherapy but there is no evidence that this results in greater anti-fracture efficacy. The use of bisphosphonates before strontium ranelate or PTH peptides blunts the BMD response. Combined PTH and anti-resorptive therapy results in more rapid gains in spine BMD and a greater increase in hip BMD than PTH monotherapy in the first year of treatment but greater gains in both spine and hip BMD are seen with PTH monotherapy than combined therapy after 2 years of treatment. Anti-resorptive therapy after PTH therapy maintains or increases the gains in BMD. Further research is required to establish the cost-effectiveness and safety of combined and sequential regimens.

Sequential osteoporosis treatments

Osteoporosis is a major public health concern due both to its high prevalence and to its association with potentially serious fractures. The chronic nature of osteoporosis, together with the aging of the population, may result in a need for prolonged treatment consisting in the sequential use of several osteoporosis drugs. Situations in which switching from one osteoporosis drug to another may be considered include the occurrence of a fracture despite treatment, poor treatment adherence, side effects, and completion of a first-line treatment course. The available recommendations for postmenopausal women deal only with the indications for first-line osteoporosis treatment. Studies on drug sequences used an open-label design and failed to collect data on fractures. Thus, there is no scientific evidence supporting a specific treatment sequence, the only exception being teriparatide followed by a bone resorption inhibitor. Consequently, selection of the second drug in an osteoporotic woman is a matter of clinical judgment, which can be guided by several factors such as health insurance reimbursement restrictions, characteristics of the osteoporosis (e.g., severity and whether there is a predominant risk of peripheral fractures), co-morbidities, contraindications to specific drugs, and patient adherence to prescriptions.