Factors associated with inadequate responses to risedronate in Japanese patients with osteoporosis

Use of vitamin D with anti-osteoporotic drugs: are available clinical trials telling us the whole story?

There is a strong rationale for using vitamin D in combination with anti-osteoporotic drugs. Still, available trials do not give clear indications in this setting, presenting a suboptimal and heavily inhomogeneous experimental design. Health authorities should revise requirements for using vitamin D in anti-osteoporotic drug trials to maximise their effect and produce reliable indications for clinical practice in this setting.

Influence of the Osteogenomic Profile in Response to Alendronate Therapy in Postmenopausal Women with Osteoporosis: A Retrospective Cohort Study

BACKGROUND

Postmenopausal osteoporosis is a multifactorial disease. Genetic factors play an essential role in contributing to bone mineral density (BMD) variability, which ranges from 60 to 85%. Alendronate is used as the first line of pharmacological treatment for osteoporosis; however, some patients do not respond adequately to therapy with alendronate.

AIM

The aim of this work was to investigate the influence of combinations of potential risk alleles (genetic profiles) associated with response to anti-osteoporotic treatment in postmenopausal women with primary osteoporosis.

METHODS

A total of 82 postmenopausal women with primary osteoporosis receiving alendronate (70 mg administered orally per week) for one year were observed. The bone mineral density (BMD; g/cm2) of the femoral neck and lumbar spine was measured. According to BMD change, patients were divided into two groups: responders and non-responders to alendronate therapy. Polymorphic variants in CYP19, ESR1, IL-6, PTHR1, TGFβ, OPG and RANKL genes were determined and profiles were generated from the combination of risk alleles.

RESULTS

A total of 56 subjects were responders to alendronate and 26 subjects were non-responders. Carriers of the G-C-G-C profile (constructed from rs700518, rs1800795, rs2073618 and rs3102735) were predisposed to response to alendronate treatment (p = 0.001).

CONCLUSIONS

Our findings highlight the importance of the identified profiles for the pharmacogenetics of alendronate therapy in osteoporosis.

Bone Turnover Markers: Basic Biology to Clinical Applications

Bone turnover markers (BTMs) are used widely, in both research and clinical practice. In the last 20 years, much experience has been gained in measurement and interpretation of these markers, which include commonly used bone formation markers bone alkaline phosphatase, osteocalcin, and procollagen I N-propeptide; and commonly used resorption markers serum C-telopeptides of type I collagen, urinary N-telopeptides of type I collagen and tartrate resistant acid phosphatase type 5b. BTMs are usually measured by enzyme-linked immunosorbent assay or automated immunoassay. Sources contributing to BTM variability include uncontrollable components (e.g., age, gender, ethnicity) and controllable components, particularly relating to collection conditions (e.g., fasting/feeding state, and timing relative to circadian rhythms, menstrual cycling, and exercise). Pregnancy, season, drugs, and recent fracture(s) can also affect BTMs. BTMs correlate with other methods of assessing bone turnover, such as bone biopsies and radiotracer kinetics; and can usefully contribute to diagnosis and management of several diseases such as osteoporosis, osteomalacia, Paget's disease, fibrous dysplasia, hypophosphatasia, primary hyperparathyroidism, and chronic kidney disease-mineral bone disorder.

Bone mineral density response prediction following osteoporosis treatment using machine learning to aid personalized therapy

Osteoporosis is a global health problem for ageing populations. The goals of osteoporosis treatment are to improve bone mineral density (BMD) and prevent fractures. One major obstacle that remains a great challenge to achieve the goals is how to select the best treatment regimen for individual patients. We developed a computational model from 8981 clinical variables, including demographic data, diagnoses, laboratory results, medications, and initial BMD results, taken from 10-year period of electronic medical records to predict BMD response after treatment. We trained 7 machine learning models with 13,562 osteoporosis treatment instances [comprising 5080 (37.46%) inadequate treatment responses and 8482 (62.54%) adequate responses] and selected the best model (Random Forests with area under the receiver operating curve of 0.70, accuracy of 0.69, precision of 0.70, and recall of 0.89) to individually predict treatment responses of 11 therapeutic regimens, then selected the best predicted regimen to compare with the actual regimen. The results showed that the average treatment response of the recommended regimens was 9.54% higher than the actual regimens. In summary, our novel approach using a machine learning-based decision support system is capable of predicting BMD response after osteoporosis treatment and personalising the most appropriate treatment regimen for an individual patient.

Efficacy of denosumab co-administered with vitamin D and Ca by baseline vitamin D status

INTRODUCTION

In anti-osteoporosis drug trials, vitamin D and calcium (Ca) are common supplements; however, the optimal dose of each is unclear. Using data from the randomized, double-blind, placebo-controlled DIRECT trial, we assessed whether baseline serum 25-hydroxy vitamin D (25[OH]D) level influences the efficacy of denosumab co-administered with vitamin D and Ca.

MATERIALS AND METHODS

In this prespecified sub-analysis, subjects with primary osteoporosis who received denosumab or placebo, plus vitamin D (≥ 400 IU/day) and Ca (≥ 600 mg/day), were classified as 25(OH)D deficient (< 20 ng/mL), insufficient (≥ 20 to < 30 ng/mL), and sufficient (≥ 30 ng/mL). Study endpoints included absolute serum 25(OH)D level at baseline, 12 months, and 24 months; change in serum 25(OH)D and bone mineral density (BMD) status from baseline; and incidence of new vertebral fractures at 24 months.

RESULTS

In 475 denosumab-treated and 481 placebo-treated subjects, proportions with deficient/insufficient/sufficient 25(OH)D at baseline were 53.1%/37.1%/9.9% and 50.9%/42.0%/7.1%, respectively. Supplementation significantly increased mean serum 25(OH)D levels; at 24 months, mean levels were > 30 ng/mL (sufficient) in both treatment groups. Increase in BMD over time was higher in the denosumab group vs. placebo group in all three vitamin D status groups. At month 24, denosumab-treated subjects with deficient/insufficient baseline 25(OH)D had a significantly lower risk of new vertebral fracture vs. placebo-treated subjects.

CONCLUSION

Among DIRECT trial subjects supplemented with ≥ 400 IU/day of vitamin D and ≥ 600 mg/day of Ca, baseline 25(OH)D sufficiency may not influence the efficacy of denosumab in increasing BMD or preventing vertebral fractures.

Relationship between P1NP, a biochemical marker of bone turnover, and bone mineral density in patients transitioned from alendronate to romosozumab or teriparatide: a post hoc analysis of the STRUCTURE trial

INTRODUCTION

Procollagen type I N-terminal propeptide (P1NP), a bone formation marker, reportedly predicts bone mineral density (BMD) response to teriparatide treatment in treatment-naive patients with osteoporosis. Results from a randomized, phase 3, open-label, active-controlled trial- STRUCTURE-showed that in patients previously treated with bisphosphonates, romosozumab led to gains in hip BMD, which were not observed with teriparatide. This post hoc analysis investigated the comparative utility of early changes in P1NP in predicting BMD response in patients who participated in the STRUCTURE trial, which enrolled patients who switched treatment from bisphosphonates to romosozumab/teriparatide.

MATERIALS AND METHODS

Postmenopausal women (aged 55-90 years) with osteoporosis who had previously taken bisphosphonates were randomized to receive open-label subcutaneous romosozumab (210 mg once monthly; n = 218) or teriparatide (20 µg once daily; n = 218) for 12 months. BMD was assessed by dual-energy X-ray absorptiometry at the proximal femur and lumbar spine (LS) at baseline and months 6 and 12. To assess the utility of P1NP, the positive predictive value of increase from baseline in P1NP of > 10 µg/L at month 1 and achievement of various thresholds of percent change from baseline in BMD at month 12 were evaluated.

RESULTS

Overall, 95% (191/202) of patients in the romosozumab group and 91% (183/201) in the teriparatide group demonstrated an increase in P1NP of > 10 µg/L from baseline at month 1. Among these patients, 18% and 3% of romosozumab-treated patients versus 60% and 12% of teriparatide-treated patients showed no increase from baseline (i.e., ≤ 0%) in total hip and LS BMD, respectively, at month 12. These data indicate that in patients switching from bisphosphonates to a bone-forming therapy, increases in P1NP do not help predict the hip BMD response. Although most patients treated with either teriparatide or romosozumab showed an increase in P1NP, the majority of patients on romosozumab showed an increase in hip BMD, while more than half of the patients on teriparatide did not. Teriparatide therapy did not increase total hip BMD in the majority of patients who transitioned from bisphosphonates to teriparatide.

CONCLUSIONS

Thus, increases in P1NP were not predictive of BMD response in the teriparatide group because in approximately 60% of the patients who were administered teriparatide, the hip BMD decreased independent of the change in P1NP levels.

Assessment of baseline bone turnover marker levels and response to risedronate treatment: Data from a Japanese phase III trial

Background

Risedronate increases bone mineral density (BMD) and reduces fracture risk, but treatment response may depend on the baseline state of bone turnover. Data regarding the selection of therapeutic drugs or the prediction of therapeutic effects with baseline levels of bone turnover markers (BTMs) as a reference are insufficient. We hypothesized that when the baseline levels of BTMs are higher, baseline BMD might be lower, changes in BMD at 12 months after risedronate treatment might be higher, and the reduction of fracture incidence might be greater. This study aimed to analyze the data of a phase III clinical trial of risedronate from Japan to investigate the relationships between baseline BTM levels and (1) baseline BMD, (2) changes in BMD at 12 months after the start of treatment, and (3) the incidence of new vertebral fractures.

Methods

This post-hoc analysis included 788 postmenopausal women with osteoporosis whose baseline BTM levels as well as baseline and endpoint BMDs were measured. Relationships between baseline BTM levels and BMD at baseline and 12 months after risedronate treatment and new vertebral fractures were examined. One-way analysis of variance, two-tailed Student's t-test, and Fisher's exact test were used to analyze the data.

Results

Baseline BMD showed a significant upward trend when baseline BTM levels were lower in the analysis by tertiles. New vertebral fractures tended to occur in patients with prevalent vertebral fractures, but the relationship between new fractures and BTM levels was not statistically significant. Regardless of BTM types, BMD percentage increments (%) and increments (g/cm²) with the 12-month treatment were high when pretreatment BTM levels were high (P < 0.0001), and a >5.0% increase in BMD was observed even if baseline BTM levels were within the normal range. A new vertebral fracture occurred in only six patients (0.77%), and there was not enough statistical power to clarify the relationship between baseline BTM levels and fracture risk reduction.

Conclusions

When pretreatment BTM levels increased, baseline BMD tended to be lower and the increase in BMD with 12-month risedronate treatment was higher. However, BMD could still be increased even if the baseline BTM levels are within the normal range. Combined with available evidence, baseline BTMs may not have an important role in deciding the optimal therapy. To elucidate the relationship between baseline BTM levels and long-term fracture risk, it will be necessary to conduct more large-scale studies with a longer follow-up period in severe osteoporotic patients with a high fracture risk.

Mini abstract

We evaluated the significance of baseline bone turnover markers in the response to risedronate treatment. The increase in the bone mineral density (BMD) with the 12-month treatment may be higher when the state of bone turnover at baseline is higher, and BMD could still be increased even if the baseline bone turnover is within the normal range.

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Baseline bone turnover markers in response to risedronate treatment are unknown.

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Higher BMD may be achieved when the state of bone turnover at baseline is higher.

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Further increase in BMD is possible even if the baseline bone turnover is normal.