Raloxifene Use After Denosumab Discontinuation Partially Attenuates Bone Loss in the Lumbar Spine in Postmenopausal Osteoporosis

Sequential and Long-term Therapy for Osteoporosis

PURPOSE OF THE REVIEW

Osteoporosis requires life-long management. This involves the use of different drugs in various sequences followed by long-term maintenance therapy. This review highlights the important transitions among osteoporosis therapies and outlines a strategy of intermittent bisphosphonate therapy for long-term maintenance.

RECENT FINDINGS

Over the past few years, the effects and limitations of long-term treatment with bisphosphonates and denosumab have become apparent as have several key factors in the sequential use of anti-remodeling drugs and osteoanabolic agents. Strategies for transitions from estrogen, bisphosphonates, denosumab and the bone-forming drugs will be discussed, based on extant evidence, clinical experience and expert opinion. By appropriate selection of both the initial and subsequent drugs for the prevention and treatment of osteoporosis, therapeutic benefits can be optimized and safety issues minimized. Developing a strategy for long-term maintenance of the benefits of the initial therapies can provide a life plan for managing patients with osteoporosis.

Zoledronate Sequential Therapy After Denosumab Discontinuation to Prevent Bone Mineral Density Reduction: A Randomized Clinical Trial

Importance

Discontinuation of denosumab without transitioning to another antiresorptive agent results in rapid bone loss and an increased risk of fracture. Previous randomized studies reported inconsistent results regarding the efficacy of zoledronate as sequential therapy.

Objective

To investigate the use of sequential therapy with zoledronate to prevent bone loss and decreased bone mineral density (BMD) after denosumab discontinuation in the first year.

Design, Setting, and Participants

The Denosumab Sequential Therapy prospective, open-label, parallel-group randomized clinical trial was conducted at a referral center and 2 affiliated hospitals in Taiwan. Recruitment was conducted from April 1, 2019, to May 31, 2021, and a 2-year follow-up was planned. The trial included postmenopausal women and men aged 50 years or older who received regular denosumab treatment for at least 2 years and did not have previous exposure to other antiosteoporosis medication or meet other exclusion criteria.

Intervention

Participants were assigned via stratified randomization to 1 of 2 groups: group A received continuous denosumab treatment (60 mg twice yearly) as the positive control, whereas group ZOL received 1 dose of zoledronate (5 mg) in the first year.

Main Outcomes and Measures

The coprimary outcomes were BMD percentage changes in the lumbar spine (LS-BMD), total hip (TH-BMD), and femoral neck (FN-BMD), respectively. An intention-to-treat analysis was performed.

Results

This study included 101 patients (95 women [94.1%]; median age, 72.0 [IQR, 67.0-76.0] years). There were 25 patients in group A (23 women [92.0%]; median age, 74.0 [IQR, 70.0 to 78.0] years) and 76 in group ZOL (72 women [94.7%]; median age, 71.0 [IQR, 65.7 to 76.0] years). In the first year, group ZOL had a significant median decrease in LS-BMD (-0.68% [IQR, -3.22% to 2.75%]) compared with group A (1.30% [IQR, -0.68% to 5.24%]) (P = .03). No significant differences between groups A and ZOL were observed for TH-BMD (median, 1.12% [IQR, -0.06% to 2.25%] vs 0% [-1.47% to 2.15%]) (P = .24) and FN-BMD (median, 0.17% [IQR, -2.29% to 2.90%] vs 0.18% [-2.73% to 3.88%]) (P = .71). We observed a significant difference in the median LS-BMD percentage change for the ZOL subgroup with 3 or more years of denosumab treatment before enrollment (-3.20% [IQR, -7.89% to 0.68%]) compared with group A (1.30% [IQR, -0.68% to 5.24%]) (P = .003).

Conclusions and Relevance

In this randomized trial of sequential therapy after denosumab discontinuation, bone loss was observed in LS-BMD in the first year among patients receiving zoledronate. A longer duration of denosumab treatment was associated with a further decrease in LS-BMD after zoledronate sequential therapy. Further randomized clinical trials and large-scale studies that investigate the strategies of sequential therapy after long-term denosumab treatment are needed.

Trial Registration

ClinicalTrials.gov Identifier: NCT03868033.

Treatment Sequence for Osteoporosis

BACKGROUND

Osteoporosis is a chronic progressive disease that requires lifelong monitoring and treatment. Sequencing from one treatment to another at different ages and stages of disease is an approach that can maximize benefits and avoid potential risks from long-term treatment with a single agent.

OBJECTIVE

This article reviews clinical trial data in postmenopausal women that evaluate the effects of antiresorptive agents followed by other antiresorptives, osteoanabolic agents followed by antiresorptives, and antiresorptives followed by osteoanabolic medications.

METHODS

Literature review and discussion.

RESULTS

When medications are discontinued, in the absence of sequential therapy, bone turnover rates return to baseline or above baseline, and bone loss occurs. The rate of bone loss differs for different treatments, with a very slow decline after stopping bisphosphonates and a particularly rapid decline after stopping denosumab. Careful attention to osteoporosis medication transitions can mitigate bone density loss and its consequences. For women who remain at high risk, switching from bisphosphonates to the more potent antiresorptive, denosumab, will result in further improvement in bone mineral density (BMD). When indicated, stopping denosumab can be accomplished safely by transition to an adequate bisphosphonate regimen. For high- and very-high-risk patients, treating with osteoanabolic agents first, followed by antiresorptive agents, produces substantially larger BMD gains than the reverse treatment sequence, with the biggest differences seen for BMD of the hip.

CONCLUSION

Awareness of the importance of treatment sequences can help improve osteoporosis care across the postmenopausal lifespan.

The comparison of alendronate and raloxifene after denosumab (CARD) study: A comparative efficacy trial

Denosumab discontinuation results in accelerated bone remodeling, decreased bone mineral density (BMD), and an increased risk of multiple vertebral fractures. Bisphosphonates are at least partially effective at inhibiting these consequences but there have been no randomized clinical trials assessing the efficacy of alternative antiresorptives.

PURPOSE

The aim of this study was to evaluate the comparative efficacy of alendronate and the SERM, raloxifene, in preventing the post-denosumab high-turnover bone loss.

METHODS

We conducted an open-label randomized controlled trial in which 51 postmenopausal women at increased risk of fracture were randomized with equal probability to receive 12-months of denosumab 60-mg 6-monthly followed by 12-months of either alendronate 70-mg weekly or raloxifene 60-mg daily. Serum bone remodeling markers were measured at 0,6,12,15,18, and 24 and areal BMD of the distal radius, spine, and hip were measured at 0,12,18 and 24 months.

RESULTS

After denosumab discontinuation, serum markers of bone remodeling remained suppressed when followed by alendronate, but gradually increased to baseline when followed by raloxifene. In the denosumab-to-alendronate group, denosumab-induced BMD gains were maintained at all sites whereas in the denosumab-to-raloxifene group, BMD decreased at the spine by 2.0% (95% CI -3.2 to -0.8, P = 0.003) and at the total hip by 1.2% (-2.1 to -0.4%, P = 0.008), but remained stable at the femoral neck and distal radius and above the original baseline at all sites. The decreases in spine and total hip BMD in the denosumab-to-raloxifene group (but not the femoral neck or distal radius) were significant when compared to the denosumab-to-alendronate group.

CONCLUSIONS

These results suggest that after one year of denosumab, one year of alendronate is better able to maintain the inhibition of bone remodeling and BMD gains than raloxifene.

Sequential management of postmenopausal health and osteoporosis: An update

Increased life expectancy means that women are now in a hypoestrogenic state for approximately one-third of their lives. Overall health and specifically bone health during this period evolves in accordance with aging and successive exposure to various risk factors. In this review, we provide a summary of the approaches to the sequential management of osteoporosis within an integrative model of care to offer physicians a useful tool to facilitate therapeutic decision-making. Current evidence suggests that pharmacologic agents should be selected based on the risk of fractures, which does not always correlate with age. Due to their effect on bone turnover and on other hormone-regulated phenomena, such as hot flushes or breast cancer risk, we position hormone therapy and selective estrogen receptor modulators as an early postmenopause intervention for the management of postmenopausal osteoporosis. When the use of these agents is not possible, compelling evidence supports antiresorptive agents as first-line treatment of postmenopausal osteoporosis in many clinical scenarios, with digestive conditions, kidney function, readiness for compliance, or patient preferences playing a role in choosing between bisphosphonates or denosumab during this period. For patients at high risk of osteoporotic fracture, the "anabolic first" approach reduces that risk. The effect on bone health with these bone-forming agents or with denosumab should be consolidated with the subsequent use of antiresorptive agents. Regardless of the strategy, follow-up and treatment should be maintained indefinitely to help prevent fractures.

Mechanistic advances in osteoporosis and anti-osteoporosis therapies

Osteoporosis is a type of bone loss disease characterized by a reduction in bone mass and microarchitectural deterioration of bone tissue. With the intensification of global aging, this disease is now regarded as one of the major public health problems that often leads to unbearable pain, risk of bone fractures, and even death, causing an enormous burden at both the human and socioeconomic layers. Classic anti-osteoporosis pharmacological options include anti-resorptive and anabolic agents, whose ability to improve bone mineral density and resist bone fracture is being gradually confirmed. However, long-term or high-frequency use of these drugs may bring some side effects and adverse reactions. Therefore, an increasing number of studies are devoted to finding new pathogenesis or potential therapeutic targets of osteoporosis, and it is of great importance to comprehensively recognize osteoporosis and develop viable and efficient therapeutic approaches. In this study, we systematically reviewed literatures and clinical evidences to both mechanistically and clinically demonstrate the state-of-art advances in osteoporosis. This work will endow readers with the mechanistical advances and clinical knowledge of osteoporosis and furthermore present the most updated anti-osteoporosis therapies.

Bone loss after denosumab discontinuation is prevented by alendronate and zoledronic acid but not risedronate: a retrospective study

A retrospective study of 121 patients who stopped denosumab (Dmab) then received no treatment (NT), risedronate (RIS), alendronate (ALN), or zoledronic acid (ZOL). Bone density (spine and hip) during and after Dmab discontinuation was measured. Treatment with ALN or ZOL, not NT and RIS, mitigated BMD loss after Dmab discontinuation.

INTRODUCTION

Denosumab (Dmab) discontinuation is associated with bone loss and multiple vertebral fractures. The purpose was to compare bone mineral density (BMD) change in patients following Dmab discontinuation with no subsequent treatment (NT) and three bisphosphonate (BP) treatments: risedronate (RIS), alendronate (ALN), and zoledronic acid (ZOL).

METHODS

In a review of 121 patients aged 71.2 ± 8.1 years, discontinuing Dmab (mean 5.4 doses), 33 received NT and 88 received BP (22 RIS; 34 ALN; 32 ZOL). BMD change after 1 year was compared between groups at the lumbar spine (LS), femoral neck (FN), and total hip (TH). Risk factors for bone loss after Dmab discontinuation were compared between groups and incidence of vertebral fractures was determined.

RESULTS

Following Dmab discontinuation, LS mean change (g/cm2; 95% CI) was for NT: - 0.041 (- 0.062 to - 0.021); RIS: - 0.035 (- 0.052 to - 0.017); ALN: - 0.005 (- 0.020 to 0.009); and ZOL: - 0.009 (- 0.025 to 0.008). Differences in LS were found between NT and ALN (p =  0.015), and NT and ZOL (p=0.037), but not between NT and RIS. The only significant difference in TH was found between NT and ZOL (p 0.034) with no group differences in FN. BMD gains during Dmab treatment were associated with BMD loss after Dmab discontinuation. In a subset, discontinuation after Dmab treatment (> 5 doses) followed by ALN (n = 22) and ZOL (n = 11) showed no difference in BMD. Five of 7 vertebral fractures occurred after Dmab discontinuation in NT.

CONCLUSION

Subsequent treatment with ALN or ZOL but not NT and RIS mitigates BMD loss after Dmab discontinuation.

Denosumab Discontinuation

PURPOSE OF REVIEW

To review the pathophysiology, the clinical consequences as well as way of mitigating the effects of denosumab discontinuation.

RECENT FINDINGS

Treatment with denosumab (DMAB) is reversible and upon discontinuation there is a rapid increase in bone turnover and a subsequent bone loss. During this phase of high bone turnover, an increased risk of fractures has been reported. Therefore, treatment with DMAB could be considered life-long. However, side-effects may prompt the need for discontinuation and moreover, treatment with DMAB may have increased BMD to levels where continuing treatment does not provide further fracture risk reduction. Patients stopping DMAB should be offered subsequent antiresorptive treatment with an intense monitoring regimen during the initial year as most of the bone loss occurs within these initial 12 months. In this review, we evaluated the literature published over the past 1 to 3 years investigating DMAB withdrawal with focus on bone turnover markers, bone mineral density, and fracture risk and the transition to other anti-osteoporosis therapies. Furthermore, we summarized the current recommendations of international guidelines. In this review, we evaluated the literature published over the past 1 to 3 years investigating denosumab (DMAB) discontinuation and the transition to other anti-osteoporosis therapies. Additionally, we summarized the current recommendations of international guidelines.