Bisphosphonate Pre-Treatment Diminishes the Therapeutic Benefits of Teriparatide in Japanese Osteoporotic Patients

Sequential and combination therapy with romosozumab

The introduction of the bone-forming agent romosozumab has led to a dramatic improvement in osteoporosis treatment. While bisphosphonates remain the most commonly used drugs for the treatment of osteoporosis, it is recommended that patients at high risk of fractures initially receive bone-forming agents, followed by sequential treatment with bone resorption inhibitors. Romosozumab, an anti-sclerostin antibody, is an osteoporosis medication with both bone formation-stimulating and bone resorption-inhibiting properties, demonstrating significant efficacy in increasing bone mineral density and reducing fracture risk. However, due to the limited 12-month initial treatment period, sequential therapy with other osteoporosis medications is necessary following the completion of romosozumab administration. Due to the current lack of sufficient evidence regarding the use of romosozumab in sequential and combination therapies, this review aims to evaluate the efficacy of romosozumab as a sequential treatment, its effectiveness in combination with other agents, and its role in reducing new fragility fractures and increasing bone mineral density following sequential therapy after romosozumab. This review will summarize clinical trials and real-world data, providing valuable information to guide treatment decisions.

Effects of pre-extraction intermittent PTH administration on extraction socket healing in bisphosphonate administered ovariectomized rats

The purpose of this study was to investigate the effect of administering intermittent parathyroid hormone (iPTH) before tooth extraction versus after tooth extraction on the risk of developing MRONJ in experimental animal model. Twenty-five ovariectomized rats received 6 weeks of bisphosphonate therapy. They were classified into 3 groups, based on the timing of the medication, as Control, Pre-PTH and Post-PTH groups. For Control group, normal saline was administered before and after tooth extraction. iPTH was administered during 4 weeks before tooth extraction for Pre-PTH group and after tooth extraction for Post-PTH group. The animals were euthanized 8 weeks after tooth extraction. Macroscopic, histological, micro-computed tomography (micro-CT), and histomorphometric examinations were conducted. The incidences of impaired healing were 11.11% both in Pre-PTH and Post-PTH groups, which was lower than the Control group (42.86%). Bone healing in the extraction socket, based on micro-CT and histomorphometry evaluations, was best in Post-PTH and worst in Control group. The Pre-PTH group showed moderate healing pattern. Despite of limitations in this study, the authors identified Pre-PTH group seems to have positive effect on extraction socket healing. With regard to timing, administering iPTH after tooth extraction was superior to applying it before tooth extraction.

Pretreatment of daily teriparatide enhances the increase of bone mineral density in cortical bones by denosumab therapy

Background

While it is well known that teriparatide (TPTD) increases bone mineral density (BMD) in osteoporotic patients, it is unknown whether TPTD pretreatment affects BMD after denosumab (DMAb) therapy.

Methods

Fifty-seven patients in TPTD-pretreated group and 35 patients in DMAb-alone group had been further analyzed, all of whom were treated by DMAb for 1.5 years. Vitamin D (400 IU) and Ca (600 mg) supplementation was used in all patients. The BMD of lumbar 1–4 vertebrae (L-BMD), bilateral total hips (H-BMD), and bilateral femoral neck (FN-BMD) was quantified at first visit, and at 4, 8, 12, and 18 months after daily TPTD treatment following four times DMAb treatment.

Results

There were significant differences in L-BMD (p=0.004) and H-BMD (p=0.026) at baseline between TPTD-pretreated and DMAb-alone groups, although there was no significant difference in FN-BMD between the two groups. The increase of L-BMD by DMAb therapy was less in TPTD-pretreated group than in DMAb-alone group. There was no significant difference in H-BMD, although percent changes of H-BMD tended to be higher in the TPTD-pretreated group than those in the DMAb-alone group. Percent change in FN-BMD at 4 months (p=0.067) and 12 months (p=0.057) tended to be higher in TPTD-pretreated group than in DMAb-alone group. Percent change in FN-BMD at 18 months was significantly higher in TPTD-pretreated group (p=0.004) than in DMAb-alone group.

Conclusion

These findings suggest that the pretreatment of TPTD might have enhanced the increase of BMD in cortical bones treated by DMAb. Thus, it is favorable that TPTD can be used for osteoporotic patients who have high fracture risks with cortical bones.

Two-year clinical outcome of denosumab treatment alone and in combination with teriparatide in Japanese treatment-naive postmenopausal osteoporotic women

This randomized prospective study aimed to evaluate the clinical outcome of denosumab treatment alone and in combination with teriparatide in treatment-naive postmenopausal Japanese female patients with osteoporosis. Thirty patients were randomly assigned to two groups: (1) denosumab group (denosumab alone, n=13); and (2) combination group (denosumab+teriparatide, n=17). Serum bone-specific alkaline phosphatase (BAP), serum tartrate-resistant acid phosphatase (TRACP)-5b, urinary cross-linked N-terminal telopeptides of type I collagen (NTX), and bone mineral density (BMD) of L1–4 lumbar vertebrae (L-BMD) and bilateral total hips (H-BMD) were determined at the first visit and at various time points up to 24 months post-treatment to determine percentage changes. Serum TRACP-5b and urinary NTX were equally suppressed in both groups and maintained at low levels, with slight increases at 12, 18 and 24 months. BAP was significantly decreased in both groups from 4 to 24 months, with significant differences between the groups at 4, 8 and 15 months (P<0.05). L-BMD was significantly increased at most time points in both groups, with a significant difference between the combination group and denosumab group at 24 months (17.2% increase versus 9.6% increase; P<0.05). There was no significant difference in H-BMD between the two groups, although the levels tended to be higher in the combination group than in the denosumab group (9.5% increase versus 5.6% increase). These findings suggest that denosumab+teriparatide combination therapy may represent an important treatment for primary osteoporotic patients at high risk of vertebral fracture.

Significant improvement of bone mineral density and bone turnover markers by denosumab therapy in bisphosphonate-unresponsive patients

Bone mineral density (BMD) sometimes cannot be improved by long-term bisphosphonate (BP) therapy in osteoporosis (OP). This study showed that lumbar as well as hip BMD significantly increased after denosumab treatment in patients not responsive to BPs. Thus, denosumab may be a strong OP treatment option for BP-unresponsive patients.

INTRODUCTION

BMD sometimes cannot be improved by long-term BP therapy.

METHODS

We administered denosumab to osteoporotic patients with a poor response to BPs who had been taking them for 2 years or longer. Ninety-eight women with BP-poor responsive OP were enrolled in this study. Mean (standard deviation [SD]) age was 71.2 (6.9) years and mean (SD) duration of BP treatment was 59.9 (34.3) months. We distinguished BP responders from non-responders based on changes in BMD values at denosumab commencement (baseline) from 2 years beforehand.

RESULTS

There were no significant differences in age, duration of BP use, bone turnover markers, or BMD at baseline between the groups. Prior to denosumab, BMD had increased significantly in responders and decreased significantly in non-responders. Bone turnover markers had decreased significantly at 4 months of denosumab treatment (P < 0.001) and lumbar and hip BMD were significantly increased at 1 year of therapy in both groups (P < 0.001). Simple correlation coefficients were -0.337 for lumbar and -0.339 for hip BMD changes (both P = 0.001) before and after denosumab treatment. Both at the lumbar spine and hips, decreased BMD before denosumab therapy was significantly associated with an increase in BMD at 1 year of treatment (spine, t value = -3.502, P = 0.001, R = 0.113; hip, t value = -3.526, P = 0.001, R = 0.115).

CONCLUSIONS

These results suggest that denosumab may be a strong OP treatment option for BP-unresponsive patients.