Long-term persistence in patients with osteoporosis receiving denosumab in routine practice: 36-month non-interventional, observational study

Improvement of proportion of days covered for denosumab under implementation of clinical pharmacist adherence management system: normal and COVID-19 period

We established a clinical pharmacist adherence management system (CPAMS) led by clinical pharmacists to examine whether denosumab adherence could be improved. The results showed that CPAMS could effectively improve adherence to denosumab and the treatment of osteoporosis. However, this effect weakened during the spread of infectious diseases such as COVID-19.

PURPOSE

Denosumab is currently one of the drugs that can effectively reduce the risk of clinical fracture. However, as a drug requiring long-term subcutaneous injection, patient adherence to denosumab is the most important factor affecting its therapeutic efficacy. Therefore, we established a clinical pharmacist adherence management system (CPAMS) led by clinical pharmacists and examined whether denosumab adherence could be improved.

METHODS

Data were collected from patients receiving denosumab in our hospital between March 2021 and May 2022. The patients who participated in the CPAMS were in the intervention group, and the rest were in the control group. We analysed the proportion of days covered (PDC) value of denosumab, distribution of subsequent visits, and proportion of patients who continued participating during the normal and coronavirus (COVID-19) periods.

RESULTS

Eighty-five patients were enrolled in this retrospective study: 32 in the intervention group and 53 in the control group. The PDC values were significantly higher in the intervention group (0.9875, 0.9025-1) than in the control group (0.5, 0.5-0.5) after 1 year. The subsequent visit rate in the intervention group was 93.80%. However, none of the patients in the control group returned. In the intervention group, the ratio of timely to delayed subsequent visits was 11:19. After the COVID-19 pandemic, the PDC value of the intervention group (0.957, 0.5-1) was lower than that before COVID-19, and the ratio of timely to delayed subsequent visits was 9:13.

CONCLUSIONS

Clinical pharmacist-led CPAMS could effectively improve adherence to denosumab and the treatment of osteoporosis.

Denosumab treatment lapses, discontinuation, and off-treatment fracture risk: A retrospective study of patients with osteoporosis in a real-world clinical setting

INTRODUCTION

The purpose of this study was to retrospectively examine predictors of fracture risk when adult patients experienced a denosumab treatment lapse or discontinuation in a real-world clinic setting.

MATERIALS AND METHODS

Eligible patients were adults who had received ≥2 doses of denosumab at an academic health center in the United States. Demographics, treatment doses, reasons for missed doses, and fractures, were collected retrospectively from electronic health records, from an 8-year period (2010-2018). The number of times each patient incurred a treatment lapse, defined as ≥240 days between two doses (excluding lapse due to discontinuation, death, or transfer of care) was computed. The occurrence of denosumab discontinuation (excluding discontinuation due to death or transfer of care), whether the patient initiated alternative therapy, and the reason for each lapse and discontinuation were collected. Cox proportional hazards models assessed characteristics associated with risk of fracture and treatment discontinuation. A logistic regression model was used to determine if cumulative amount of time off medication (i.e., cumulative lapse time) was associated with a higher likelihood of incurring a fracture.

RESULTS

We included 534 patients: 95 % White, 86 % women, 33 % tobacco users, 13 % diagnosed with diabetes, median age 69 years (Interquartile Range (IQR): 62-77), and median Body Mass Index (BMI) 25 kg/m2 (IQR: 22-28). Thirty-six percent of patients incurred 250 lapses; 10 % discontinued therapy. Dental problems/procedures and logistical barriers were the most common reasons for lapses and discontinuations. Nineteen percent (n = 103) incurred a total of 190 fractures; of these, 121 were osteoporotic, 50 were vertebral. Risk of any, osteoporotic, and vertebral fractures were associated with off-treatment status (hazard ratio [HR] = 1.7, p = 0.043; HR = 2.0, p = 0.026; and HR = 4.2, p = 0.001, respectively) and older age (HR = 1.3, p = 0.015; HR = 1.5, p = 0.001; and HR = 1.8, p = 0.005, respectively). Older age was associated with higher risk of discontinuation (HR = 1.4, p = 0.022). There was a non-significant trend of a nonlinear association between incurring a fracture and cumulative lapse time (p = 0.087).

CONCLUSION

Denosumab treatment lapses are common, and off-treatment status may be associated with a higher risk of fractures. Clinical teams should proactively identify and address adverse effects and potential logistical barriers to reduce the risk of treatment lapses.

Analysis of Influencing Factors of Vertebral Height Loss After Pedicle Screw Fixation of Thoracolumbar Fracture

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

To explore the related factors of vertebral height loss (VHL) after pedicle screw fixation of thoracolumbar fracture and to determine the optimum prediction point.

SUMMARY OF BACKGROUND DATA

With the widespread application of thoracolumbar fracture internal fixation, VHL after the operation is increasingly presented. However, there is no unified conclusion on the specific cause of VHL and how to predict it.

METHODS

A total of 186 patients were selected and divided into the loss group (n = 72) and the not-loss group (n = 114) according to whether the fractured vertebral height was lost after the operation. The two groups were compared concerning sex, age, body mass index, osteoporosis self-assessment tool for Asians (OSTA), fracture types, number of fractured vertebrae, preoperative Cobb angle and compression degree, number of screws, and extent of vertebral restore. Univariate analysis and Multivariate logistic regression analysis were performed to identify the independent factors for the VHL with the receiver operating characteristic curve and the optimal prediction value was calculated according to area under the curve.

RESULTS

Multivariate logistic regression analysis showed that OSTA ( P < 0.05) and preoperative vertebral compression ( P < 0.05) were significantly correlated with postoperative VHL, which were independent risk factors for postoperative VHL. The OSTA of 2.32 and the preoperative vertebral compression degree of 38.5% were the best prediction points for postoperative VHL based on the Youden Index analysis.

CONCLUSIONS

The OSTA and preoperative vertebral compression were independent risk factors for VHL. The risk of postoperative VHL was significantly higher when the OSTA was ≤2.32 or the preoperative vertebral compression was ≥38.5%.

LEVEL OF EVIDENCE

Level III.

How the COVID-19 pandemic affected bone health: a retrospective, longitudinal study on denosumab persistence from the epicentre of European spreading

In this study, we investigated how the COVID-19 pandemic involved osteoporosis care in patients treated with denosumab. Almost a third of patients missed the prescription renewal, mandatory to obtain the subsidized drug. Among patients who suspended denosumab, more than half reported fragility fractures.

PURPOSE

This study aimed to evaluate persistence on denosumab (Dmab) treatment during the COVID-19 pandemic and the clinical effects of possible discontinuation.

METHODS

We retrospectively assessed patients affected by osteoporosis and treated with Dmab, scheduled to have the yearly renewal of prescription between March 9, 2020, and May 9, 2021, 2 months after the second pandemic wave. In June 2022, a telephone survey started, by calling all patients who missed the yearly renewal of Dmab. Predictors of missed renewal and fragility fracture occurrence were assessed by logistic analyses.

RESULTS

Patients scheduled to have a renewal of Dmab prescription during the observational period were 538 (age 75.5 ± 9.3 years, female 511). A total of 152 (28.2%) patients did not have the renewal. Patients not renewing Dmab prescription were significantly older (p = 0.01) and more frequently affected by pulmonary (p = 0.04) and cardiovascular comorbidity (p = 0.01). Telephone survey on non-persistent patients showed that 44 had died, 28 patients were missing, 23 shifted to bisphosphonate treatment, and 22 patients suspended Dmab. Following discontinuation, 12/22 patients (54.5%) reported fragility fractures; 5/22 had multiple fractures, for a total number of 18 fractures, mainly vertebral. Logistic analyses showed that the odds of Dmab withdrawal increased in older patients with pulmonary comorbidity and treated for a shorter time. Dmab discontinuation was the only variable that increased the risk of fracture.

CONCLUSION

This study provided real-world data about an impaired persistence of Dmab treatment resulting in an increased number of fragility fractures in a geographic area heavily affected by the outbreak of COVID-19.

Persistence with Denosumab in Male Osteoporosis Patients: A Real-World, Non-Interventional Multicenter Study

BACKGRUOUND

Persistence with denosumab in male patients has not been adequately investigated, although poor denosumab persistence is associated with a significant risk of rebound vertebral fractures.

METHODS

We retrospectively evaluated 294 Korean male osteoporosis patients treated with denosumab at three medical centers and examined their persistence with four doses of denosumab injection over 24 months of treatment. Persistence was defined as the extent to which a patient adhered to denosumab treatment in terms of the prescribed interval and dose, with a permissible gap of 8 weeks. For patients who missed their scheduled treatment appointment(s) during the follow-up period (i.e., no-shows), Cox proportional regression analysis was conducted to explore the factors associated with poor adherence. Several factors were considered, such as age, prior anti-osteoporotic drug use, the treatment provider's medical specialty, the proximity to the medical center, and financial burdens of treatment.

RESULTS

Out of 294 male patients, 77 (26.2%) completed all four sequential rounds of the denosumab treatment. Out of 217 patients who did not complete the denosumab treatment, 138 (63.6%) missed the scheduled treatment(s). Missing treatment was significantly associated with age (odds ratio [OR], 1.03), prior bisphosphonate use (OR, 0.76), and prescription by non-endocrinologists (OR, 2.24). Denosumab was stopped in 44 (20.3%) patients due to medical errors, in 24 (11.1%) patients due to a T-score improvement over -2.5, and in five (2.3%) patients due to expected dental procedures.

CONCLUSION

Our study showed that only one-fourth of Korean male osteoporosis patients were fully adherent to 24 months of denosumab treatment.

The osteoporosis treatment gap in Switzerland between 1998 and 2018

The annual number of patients treated for osteoporosis between 1998 and 2018 in Switzerland increased until 2008 and steadily decreased thereafter. With a continuously growing population at fracture risk exceeding an intervention threshold, the treatment gap has increased and the incidence of hip fractures has stopped declining in the past decade.

INTRODUCTION

The existence of an osteoporosis treatment gap, defined as the percentage of patients at risk for osteoporotic fractures exceeding an intervention threshold but remaining untreated, is widely acknowledged. Between 1998 and 2018, new bone active substances (BAS) indicated for the treatment of osteoporosis became available. Whether and if so to what extent these new introductions have altered the treatment gap is unknown.

METHODS

The annual number of patients treated with a BAS was calculated starting from single-drug unit sales. The number of patients theoretically eligible for treatment with a BAS was estimated based on four scenarios corresponding to different intervention thresholds (one based solely on a bone mineral density T score threshold and three FRAX-based thresholds) and the resulting annual treatment gaps were calculated.

RESULTS

In Switzerland, the estimated number of patients on treatment with a BAS increased from 35,901 in year 1998 to 233,381 in year 2018. However, this number grew regularly since 1998, peaked in 2008, and steadily decreased thereafter, in timely coincidence with the launch of intravenous bisphosphonates and the RANKL inhibitor denosumab. When expressed in numbers of untreated persons at risk for osteoporotic fractures exceeding a given intervention threshold, the treatment gaps were of similar magnitude in 1998 (when the first BSAs just had become available) and 2018. There was a strong association, which does not imply causation, between the proportion of patients treated and hip fracture incidence.

CONCLUSION

In Switzerland, the osteoporosis treatment gap has increased over the past decade. The availability of new BAS has not contributed to its decrease.

Predictive factors for achievement of treatment goals in patients with postmenopausal osteoporosis treated with denosumab

OBJECTIVES

To investigate efficacy of long-term treatment with denosumab and predictive factors for achievement of treatment goals in patients with postmenopausal osteoporosis (PMO).

METHODS

We enrolled 111 PMO patients who had T-scores ≤-2.5 either at the lumbar spine (L-) or femoral neck (FN-), who had never been treated for osteoporosis, and who could be followed for at least 3 years. We first evaluated changes in bone mineral density (BMD) for up to 7 years. We next defined the treatment goal as the achievement of a T-score >-2.5 at month 36 and performed multivariate analysis to identify predictive factors for achievement of the goal.

RESULTS

Lumbar spine- and femoral neck bone-mineral density increased yearly for 7 years. Among 87 patients with baseline L-T-scores ≤-2.5, better baseline L-T-scores predicted achievement of L-T-scores >-2.5 at month 36. The cut-off value for baseline L-T-score was -3.4. Among 76 patients with baseline FN-T-scores ≤-2.5, better baseline FN-T-scores predicted achievement of FN-T-scores >-2.5 at month 36. The cut-off value for baseline FN-T-scores was -2.8.

CONCLUSIONS

Long-term treatment with denosumab was effective in PMO patients. As better baseline T-score predicted achievement of T-scores >-2.5, early initiation of treatment will contribute to better outcome.

Treatment patterns of long-dose-interval medication for persistent management of osteoporosis in Taiwan

Treatment persistence was higher among the patients who initially received an anti-osteoporosis medication (AOM) with a long-dose-interval.

PURPOSE

With long-dose-interval anti-osteoporosis medications (AOMs) available for osteoporosis management, it is important to evaluate persistence of any AOM as long as it is continuously used. The purpose of this study was to investigate the treatment pattern and persistence of AOMs, allowing for medication switch.

METHODS

This study was an observational retrospective cohort study using Taiwan's National Health Insurance claims data. We selected patients who first initiated an AOM between January 1, 2013, and June 30, 2016. AOM therapy included alendronate, raloxifene, teriparatide, denosumab, zoledronate, and ibandronate; the latter three were categorized as long-dose-interval medications. Persistence was defined as continual prescription of any AOM at a given time point with a grace period of 45 days within which to obtain prescription refill. The competing risk model was used to examine the factors affecting patients switching their initial AOM.

RESULTS

During the study period, 126,539 patients with mean age of 75 years met the inclusion criteria; 85% were female. For initial AOM, 43.3%, 25.6%, 14.6%, 9.3%, 5.3%, and 1.9% of the patients received alendronate, denosumab, raloxifene, zoledronate, ibandronate, and teriparatide, respectively. During a mean 36-month follow-up, 29.6% of the patients who received at least two AOM pharmacy claims throughout the study period have ever switched their initial medication. Long-dose-interval medications, mainly denosumab and zoledronate, were the preferred choice for medication switch. Treatment persistence was higher in patients who initiated with long-dose-interval AOMs.

CONCLUSION

The real-world data reveal long-dose-interval therapy as an initial treatment or at the first switch stage may improve management of persistent AOM treatment.

Effect of denosumab on renal function in women with osteoporosis evaluated using cystatin C

Objectives

To investigate renal function during denosumab therapy using the estimated glomerular filtration rate based on cystatin C (eGFRcys) which is more accurate than creatinine (eGFRcr) for renal function.

Methods

Bone mineral densities (BMDs) of lumbar spine and hip regions, eGFRcys, eGFRcr, creatinine clearance (Ccr), and serum total homocysteine (S-Hcy) were measured during 2-year denosumab therapy in 53 women with osteoporosis naïve to anti-osteoporosis drugs (new group) and 64 women who were switched from long-term bisphosphonate treatment to denosumab therapy (switch group).

Results

There were no significant differences in age, eGFRcr, Ccr, eGFRcys, and S-Hcy levels at baseline between the groups. BMDs in the lumbar spine, femoral neck, and total hip increased significantly after 2-year denosumab therapy in both groups. eGFRcr decreased in the switch group, and Ccr decreased in both groups; however, eGFRcys and S-Hcy levels did not change significantly in either group. To investigate the causal factors associated with the decrease in eGFRcr and Ccr, multiple regression analysis was performed in all patients. Denosumab initiation within 3 months after fracture and eGFRcr or Ccr at baseline were independent factors for the decrease in eGFRcr or Ccr during the 2-year denosumab therapy. Decline in creatinine-based renal function could be reflected by increased muscle mass during the ongoing recovery from fracture.

Conclusions

Renal function was preserved in all patients, including those in the switch group during denosumab therapy. Creatinine-based renal function should be cautiously interpreted during denosumab therapy in patients with recent fractures.

Long-term persistence with denosumab: real-world data from the Austrian Osteoporosis Clinic (AOC). A retrospective data analysis

In short-term studies, persistence with denosumab has been higher than with other osteoporosis drugs. This study shows that persistence can be maintained in the long-term and is associated with efficacy and safety parameters.

PURPOSE

To assess long-term persistence with denosumab in postmenopausal women with osteoporosis. Secondary purposes were the evaluation of changes in efficacy and tolerance/safety parameters over time.

METHODS

Persistence was determined by number and rate of patients receiving denosumab on time in 6-month intervals (+ / - 8 weeks). The total population was stratified by internal patients (injections and monitoring at the Austrian Osteoporosis Clinic [AOC], 74%) and external patients (injections at the practitioner's office with occasional monitoring at the AOC, 26%). In internal patients, efficacy parameters including bone mineral density (BMD) and the bone marker CTX were assessed at fixed time points and tolerance/safety parameters including side effects (SEs), adverse events (AEs), and serious AEs (SAEs) evaluated.

RESULTS

Of 851 patients, 71% (73% internal and 64% external) were persistent at 7.5 years of follow-up. The mean rate of cumulative persistence in internal patients decreased from 94% at the time of the second dose to 73% at the time of the fifteenth dose. BMD increased and CTX decreased, overall and in pairwise comparisons (all p < .001). AEs and SAEs, but not SEs, were lower in persistent than non-persistent patients.

CONCLUSIONS

This is the first study showing that long-term (> 3 years) real-world persistence with denosumab could be maintained at a high level (> 70%) in most patients. Denosumab was well tolerated and associated with decreased CTX levels and increased BMD.

Treatment patterns and long-term persistence with osteoporosis therapies in women with Medicare fee-for-service (FFS) coverage

Osteoporosis, a chronic disease, requires long-term therapy. In Medicare-insured women, denosumab persistence was higher than oral bisphosphonate persistence over up to 3 years of follow-up. Longer-term persistence was higher among women who persisted in the first year of therapy.

INTRODUCTION

Osteoporosis, a chronic, progressive disease, requires long-term therapy; this study assessed long-term persistence with anti-resorptive therapies in postmenopausal women.

METHODS

This retrospective cohort study used administrative claims for women with data in the 100% Medicare osteoporosis sample who initiated (index date) denosumab, oral/intravenous (IV) bisphosphonate, or raloxifene between 2011 and 2014 and who had ≥ 1 year (zoledronic acid: 14 months) of pre-initiation medical/pharmacy coverage (baseline). Persistence was assessed from index date through end of continuous coverage, post-index evidence of censoring events (e.g., incident cancer), death, or end of study (December 31, 2015).

RESULTS

The study included 318,419 oral bisphosphonate users (78% alendronate), 145,056 denosumab users, 48,066 IV bisphosphonate users, and 31,400 raloxifene users; mean age ranged from 75.5 years (raloxifene) to 78.5 years (denosumab). In women with at least 36 months of follow-up (denosumab N = 25,107; oral bisphosphonates N = 79,710), more denosumab than oral bisphosphonate initiators were persistent at 1 year (73% vs. 39%), 2 years (50% vs. 25%), and 3 years (38% vs. 17%). Persistence decreased over time for all treatment groups, with denosumab users having the highest persistence in every follow-up time interval at or after 18 months. Women using denosumab, oral bisphosphonates, or raloxifene who persisted in a given year were more likely to remain persistent through the subsequent year.

CONCLUSIONS

Denosumab users persisted longer with therapy than women using other anti-resorptive medications, including oral bisphosphonates. Early persistence may predict long-term persistence. Overall persistence with osteoporosis medications is suboptimal and may impact fracture risk. Efforts to improve first year persistence are needed.

Persistence with osteoporosis treatment in patients from the Lille University Hospital Fracture Liaison Service

PURPOSE/INTRODUCTION

A Fracture Liaison Service (FLS) was set up at Lille University Hospital in 2016. The purpose of this study was to assess persistence with osteoporosis treatment in patients from the FLS over a period of 1 year, and to determine predictors of discontinuation.

METHODS

The study population comprised adults of both genders, aged 50 or over, admitted to Lille University Hospital between January 2016 and January 2019 for a low-trauma fracture and managed in our FLS. Outcomes included (1) persistence rate at 1 year after treatment initiation, (2) persistence rate at 2 years after treatment initiation, (3) persistence rate at 1 and 2 years after treatment initiation according to type of treatment, (4) predictors of non-persistence, and (5) reasons for discontinuing treatment over 1 year after initiation. Persistence was determined using the Kaplan-Meier method.

RESULTS

In all, 1224 patients (≥50 years old) with a recent history of low-trauma fracture (≤12 months) were identified. Of these, 380 patients - 79.2% female; mean (SD) age 76 (11) years - were seen at the FLS. In those 380 patients, 410 fractures were found and 360 of them (87.8%) were major fractures, breaking down as follows: vertebra (44%), hip (19%), proximal humerus (10%), and pelvis (8%). Osteoporosis treatment was prescribed for 367 (96.6%) patients and 275 of them began the prescribed treatment. The following anti-osteoporosis drugs were prescribed: zoledronic acid (n=150, 54.5%), teriparatide (n=63, 22.9%), and denosumab (n=39, 14.2%). Oral bisphosphonates were prescribed for a few patients (n=23, 8.4%). Persistence with osteoporosis medication (any class) was estimated at 84.1% (95% CI: 79.1% to 88.1%) at 12-month follow-up, and dropped to 70.3% (95% CI: 63.7% to 75.9%) at 24 months. When drug-specific analyses were performed using the Kaplan-Meier method, persistence rates at 12 and 24 months were found to be higher with denosumab than with any other treatment. Independent predictors of non-persistence at 12 months were 'follow-up performed by a general practitioner (GP)' - Odds Ratio (OR) for GP vs. FLS = 3.68; 95% CI, 1.52 to 8.90, p=0.004 - and 'treatment with zoledronic acid' - OR for zoledronic acid vs. denosumab = 3.39; 95% CI, 1.21 to 9.50, p=0.019; OR for zoledronic acid vs. teriparatide = 8.86; 95% CI, 1.15 to 68.10, p=0.035.

CONCLUSIONS

This study provides evidence of the success of our FLS in terms of long-term persistence with osteoporosis treatments. However, osteoporosis treatment initiation still needs to be improved.

Should denosumab treatment for osteoporosis be continued indefinitely?

Denosumab was approved for the treatment of postmenopausal osteoporosis in 2010, based on the FREEDOM study, which indicated a benefit in terms of increased bone mineral density and reduced risk of major osteoporotic fracture. In the initial clinical studies it was noted that discontinuation of denosumab can lead to a rebound of bone turnover markers and loss of accrued bone mineral density. An increased risk of fractures (multiple vertebral fractures in particular) associated with discontinuation was noted after approval and marketing of denosumab. For many patients experiencing gain in bone mineral density and fracture prevention while taking denosumab, there is no reason to stop therapy. However, discontinuation of denosumab may happen due to non-adherence; potential lack of efficacy in an individual; where reimbursement for therapy is limited to those with bone mineral density in the osteoporosis range, when assessment reveals this has been exceeded; or patient or physician concern regarding side effects. This review paper aims to discuss these concerns and to summarize the data available to date regarding sequential osteoporosis therapy following denosumab cessation to reduce the risk of multiple vertebral fracture.

Patients discharged from a fracture liaison service still require follow-up and bone health advice

Fracture liaison services (FLSs) were established to address the well-recognised gap in bone health management after a fragility fracture. However, it is unclear what happens to patients after discharge from an FLS. Our study suggests FLSs should include a patient bone health education session and a follow-up telephone call 12-18 months post-discharge to optimise management, in particular, to assess therapy adherence and to reinforce bone health advice.

PURPOSE

While fracture liaison services (FLSs) have improved bone health management following fragility fracture, it is unclear what happens to patients following discharge from these services. We sought to determine patient self-reported medication adherence and the need for bone-specific health advice ≥ 12 months following discharge from one of the first FLSs in Australia.

METHODS

Patients were contacted by telephone ≥ 12 months following discharge from the Coffs Fracture Prevention Clinic (CFPC)/FLS to determine if the patient was still taking prescribed bone protective therapy (BPT). Bone health advice was provided, if appropriate, during the telephone interview.

RESULTS

Of the 516 consecutive patients seen in CFPC from July 2012-December 2018, 326 (63.2%) were assessed and discharged from the clinic. One hundred and two patients (19.8%) were lost to follow-up/uncontactable. Of 190 patients commenced on BPT at CFPC and who were discharged ≥ 12 months prior, 141 (74.2%) self-reported adherence with BPT. Bone health advice was required during the telephone call in 60/190 (31.6%) of these patients. Of the 141 adherent patients, 40 (28.4%) had attended a bone health education session, compared to 4/49 (8.2%) patients in the non-adherent group (p = 0.004).

CONCLUSION

At 19 months following discharge from our FLS, self-reported adherence with treatment was 74%. One bone health education session at baseline was associated with increased treatment adherence. At time of telephone contact, one third of patients required further advice to optimise bone health.

Zoledronate for the Prevention of Bone Loss in Women Discontinuing Denosumab Treatment. A Prospective 2-Year Clinical Trial

Cessation of denosumab treatment is associated with increases in bone turnover above baseline values and rapid bone loss. We investigated the efficacy of zoledronate to prevent this bone loss in women with postmenopausal osteoporosis who were treated with denosumab (mean duration 2.2 years) and discontinued treatment after achieving osteopenia. Women were randomized to receive a single 5-mg infusion of zoledronate (ZOL) (n = 27) or two additional 60-mg injections of denosumab (Dmab) (n = 30). Both groups were followed for a total period of 24 months. At 24 months lumbar spine-bone mineral density (LS-BMD) was not different from baseline in the ZOL group, but decreased in the Dmab group by (mean ± SD) 4.82% ± 0.7% (p < 0.001) from the 12-month value; the difference in BMD changes between the two groups, the primary endpoint of the study, was statistically significant (p = 0.025). Results of femoral neck (FN)-BMD changes were similar. ZOL infusion was followed by small but significant increases in serum procollagen type 1 N-terminal propeptide (P1NP) and C-terminal telopeptide of type 1 collagen (CTX) during the first year and stabilization thereafter. In the Dmab group, bone turnover marker values did not change during the first 12 months but increased significantly at 15 months and in the majority of women these remained elevated at 24 months. Neither baseline nor 12-month bone turnover marker values were associated with BMD changes in either group of women. In the Dmab group, three patients sustained vertebral fractures (two patients multiple clinical, one patient morphometric) whereas one patient in the ZOL group sustained clinical vertebral fractures 12 months after the infusion. In conclusion, a single intravenous infusion of ZOL given 6 months after the last Dmab injection prevents bone loss for at least 2 years independently of the rate of bone turnover. Follow-up is recommended, because in a few patients ZOL treatment might not have the expected effect at 2 years. © 2019 American Society for Bone and Mineral Research.