Type Of Bisphosphonate Research Articles

Calcium-mediated zoledronate loading onto carbon nanohorns.

Previously, we showed that the anti-osteoclast effect of zoledronate (ZOL), a type of bisphosphonate, is enhanced when it is used as a nanocomposite comprising ZOL, an "oxidized single-walled carbon nanohorn (OxCNH) with a spherical shape" and calcium phosphate (CaP). This nanocomposite, termed OxCNH-CaP-ZOL, is a potential therapeutic agent for patients with bone fragility associated with metastatic bone cancer. Because OxCNH-CaP-ZOL contains by-products that comprise CaP-ZOL nanocomposites, the aim of this study was to prepare more sophisticated nanocomposites lacking such by-products; it was achieved by reducing the availability of calcium and phosphate ions during the preparation process. In this new nanocomposite, ZOL loading onto OxCNH was mediated by Ca, and therefore it is referred to as OxCNH-Ca-ZOL. Because the amount of ZOL in OxCNH-Ca-ZOL was about half that in OxCNH-CaP-ZOL and murine macrophages (RAW264.7 cells) took up less OxCNH-Ca-ZOL than OxCNH-CaP-ZOL, the amount of ZOL inside RAW264.7 cells exposed to OxCNH-Ca-ZOL was less than that inside cells exposed to OxCNH-CaP-ZOL. Despite this drawback, OxCNH-Ca-ZOL had suppressive effects similar to OxCNH-CaP-ZOL on the viability of RAW264.7 cells. The reason for these phenomena is not clear; however, it could be due to the differences in the ZOL release rate between OxCNH-Ca-ZOL and OxCNH-CaP-ZOL. In addition, receptor activator of nuclear factor kappa-B ligand (RANKL)-induced differentiation of RAW264.7 cells into osteoclasts was suppressed by co-administration of RANKL with OxCNH-Ca-ZOL as effectively as with OxCNH-CaP-ZOL, and indeed, their effects were greater than those of free ZOL.

Zoledronic acid relieves steroid-induced avascular necrosis of femoral head via inhibiting FOXD3 mediated ANXA2 transcriptional activation

BackgroundZoledronic acid (ZOL) is a type of bisphosphonate with good therapeutic effects on orthopaedic diseases. However, the pharmacological functions of ZOL on steroid-induced avascular necrosis of femoral head (SANFH) and the underlying mechanism remain unclear, which deserve further research. MethodsSANFH models both in vivo and in vitro were established by dexamethasone (Dex) stimulation. Osteoclastogenesis was examined by TRAP staining. Immunofluorescence was employed to examine autophagy marker (LC3) level. Cell apoptosis was analyzed by TUNEL staining. The interaction between Foxhead box D3 protein (FOXD3) and Annexin A2 (ANXA2) promoter was analyzed using ChIP and dual luciferase reporter gene assays. ResultsDex aggravated osteoclastogenesis and induced osteoclast differentiation and autophagy in vitro, which was abrogated by ZOL treatment. PI3K inhibitor LY294002 abolished the inhibitory effect of ZOL on Dex-induced osteoclast differentiation and autophagy. FOXD3 overexpression neutralized the downregulation effects of ZOL on Dex-induced osteoclasts by transcriptionally activating ANXA2. ANXA2 knockdown reversed the effect of FOXD3 overexpression on ZOL-mediated biological effects in Dex-treated osteoclasts. In addition, ZOL improved SANFH symptoms in rats. ConclusionZOL alleviated SANFH through regulating FOXD3 mediated ANXA2 transcriptional activity and then promoting PI3K/AKT/mTOR pathway, revealing that FOXD3 might be a target for ZOL in SANFH treatment.

A randomised trial comparing 6-monthly adjuvant zoledronate with a single one-time dose in patients with early breast cancer.

While adjuvant bisphosphonate use in early breast cancer (EBC) is associated with improvements in breast cancer-specific outcomes, questions remain around optimal bisphosphonate type, dose and scheduling.We evaluated a single zoledronate infusion in a prospective randomised trial. Postmenopausalpatientswith EBC were randomised to receive a single infusion of zoledronate (4mg IV) or 6-monthly treatment for 3years. Outcomes measured were; Quality of Life (QoL; EQ-5D-5L), bisphosphonate-related toxicities, including acute phase reactions (APRs), recurrence-free survival (RFS), bone metastasis-free survival (BMFS) and overall survival (OS). 211 patients were randomized to either a single infusion (n = 107) or six-monthly treatment (n = 104).After 3years of follow up there were no significant differences between the arms for QoL and most toxicity endpoints. APRs following zoledronate occurred in 81% (171/211) of patients (77.6% in single infusion arm and 84.6% in the 6-monthly group).While the frequency of APRs decreased over 3years in the 6-monthly arm, they still remain common. Of 34/104 (32.7%) patients who discontinued zoledronateearlyin the 6-monthly treatment group, the most common reason was APRs (16/34, 47%). At the 3year follow up, there were no differences between arms for RFS, BMFS or OS. A single infusion of zoledronate was associated with increased patient convenience, less toxicity, and lower rates of treatment discontinuation. Despite the common clinical impression that APRs decrease with time, this was not observed when patients were specifically questioned. While the study is not powered for non-inferiority, longer-term follow-up for confirmation of RFS and OS rates is ongoing.

Effect of Oral Bisphosphonate Drug Holiday on Mortality Following Hip Fracture.

Current clinical guidelines recommend a drug holiday after extended use of oral bisphosphonates. However, no studies have investigated the effect of drug holidays before hip fractures on postfracture mortality. This work aimed to investigate the effect of a drug holiday on postfracture mortality in patients with extended use of oral bisphosphonates. This retrospective, population-based cohort study took place among all patients with hip fractures in Victoria, Australia, from 2014 to 2018. Patients were adherent to oral alendronate or risedronate for 5 years or more prior to hip fracture. Group-based trajectory modeling categorized patients into different bisphosphonate usage after 5-year good adherence. The main outcome measure was postfracture mortality. We identified 365 patients with good adherence (medication possession ratio ≥80%) to oral alendronate/risedronate for 5 years or more. Most patients (69%) continued to use oral bisphosphonates until admission for hip fracture; 17% had discontinued for 1 year and 14% had discontinued for 2 years. Postfracture mortality was higher in patients who had discontinued risedronate for 1 year (hazard ratio [HR] 2.37; 95% CI, 1.24-4.53) and 2 years (HR 3.08; 95% CI, 1.48-6.41) prior to hip fracture. No increase or decrease in postfracture mortality was observed in patients who had discontinued alendronate for 1 year (HR 0.59; 95% CI, 0.29-1.18) or 2 years (HR 1.05; 95% CI, 0.57-1.93) prior to hip fracture. Postfracture mortality is higher in people who discontinue risedronate, but not alendronate, for 1 or 2 years after being adherent to treatment for at least 5 years. The type of bisphosphonate may be a factor to consider when planning drug holidays.

Clinical Characteristics and Therapeutic Management of Osteogenesis Imperfecta in Iraqi Children

Background: Osteogenesis imperfecta (OI) is a rare congenital condition that results in bone fragility, recurrent fractures, and various extra-skeletal manifestations. Currently, intravenous bisphosphonate is the mainstay of medical treatment in OI. Objective: To identify the effect of current management strategies on Iraqi children diagnosed with OI. Methods: A retrospective study enrolled OI patients who were registered in Central Child Teaching Hospital, Baghdad, Iraq, from January 2015 to December 2022. We enrolled confirmed OI cases (either clinically and/or radiologically) who received cyclic pamidronate therapy for at least 3 cycles. They neither received other types of bisphosphonates nor underwent surgical intervention. Results: A total of 52 cases of OI had been identified, but only 36 patients were eligible for the current study. The mean age of the patients was 6.64±4.22 years. A statistically significant drop in the annual fracture rate in OI patients who received intravenous pamidronate cycles was seen, along with a significant rise in weight for age Z-score, lumbar spine bone mineral density DEXA Z-score, and alkaline phosphate levels. No significant improvement was documented in height for age Z-score in OI patients. Conclusions: Intravenous pamidronate cycles for Iraqi children with osteogenesis imperfecta work to lower their risk of breaking bones every year and raise their weight, lumbar spine bone mineral density, and alkaline phosphate levels. Pamidronate did not result in an improvement in the height of OI children.

Review of the Mechanism of Action and Use of Bisphosphonates in Horses

Bisphosphonates are a group of drugs that can reduce bone resorption by incorporating into the crystal structure of exposed hydroxyapatite where they are taken up by osteoclasts. Bisphosphonates have several other mechanisms of action including reducing pain and inflammation and altering macrophage function. There are two types of bisphosphonates - nitrogenous and non-nitrogenous, the latter of which is used in horses. This article provides a literature-based review of the proposed mechanisms of action and therapeutic uses of bisphosphonates including a brief review of bone response to disease. A review of the literature available in horses including safety data and current rules and regulations is also provided.

Osteonecrosis associated with bisphosphonates and its relationship with dental implants - literature review

Bisphosphonates are drugs used to treat diseases such as osteoporosis, Paget's disease, and bone metabolism changes that might be associated with neoplasms. These drugs have some side effects, one of them is a new complication of great interest to the dental class, namely, osteonecrosis of the jaws associated with bisphosphonates (OAB). How bisphosphonates develop such a disease is still unknown. However, the type of bisphosphonate, the treatment duration and the route of administration may have a direct relationship with the occurrence of OAB. Due to the care required by patients who use bisphosphonates and the risk of developing osteonecrosis after implant surgery, this study aims to conduct a literature review about the context of bisphosphonates in implant dentistry, as well as their mechanism of action and most common complications. As this is a recently discovered disease, there is still no consensus on the installation of dental implants in patients who have taken or are taking bisphosphonates, therefore, communication between the dental surgeon and the patient's physician is vital, so that all preventive measures are taken always aiming at the patient's well-being.

Effects of Alendronate and Dexamethasone on Osteoclast Gene Expression and Bone Resorption in Mouse Marrow Cultures.

Osteoclasts are cells whose main function is the resorption of bone matrix. However, several factors, including medications, can interfere with the resorption process. Alendronate (ALN), a nitrogen-containing type of bisphosphonate, and dexamethasone (DEX), a glucocorticoid, are drugs that may affect the resorption activity. The aim of this study is to investigate the effects of ALN, and/or DEX on osteoclast gene expression and resorption activity in primary mouse marrow cultures stimulated with 1,25-dihydroxyvitamin D3, a model for the bone microenvironment. Cultures were treated only with ALN (10-5 M), DEX (10-6 M), and with a combination of both agents. Viability assays performed at days 5, 7, and 9 showed the highest number of viable cells at day 7. All the following assays were then performed at day 7 of cell culture: tartrate resistant acid phosphatase (TRAP) histochemistry, receptor activator of nuclear factor kappa B ligand (RANKL) immunofluorescence, osteoprotegerin (OPG), and RANKL gene expression by qPCR and resorption analysis by scanning electron microscopy. Treatment with ALN, DEX, and the combination of both did not promote significant changes in the number of TRAP+ cells, although larger giant cells were detected in groups treated with DEX. DEX treatment increased the gene expression of RANKL and reduced OPG. The treatment with ALN reduced the depth of the resorption pits, but their inhibitory effect was less effective when administered with DEX.

Duration of Bisphosphonate Drug Holidays in Osteoporosis Patients: A Narrative Review of the Evidence and Considerations for Decision-Making.

Bisphosphonates are first-line therapy for osteoporosis, with alendronate, risedronate, and zoledronate as the main treatments used globally. After one year of therapy, bisphosphonates are retained in bone for extended periods with extended anti-fracture effects after discontinuation. Due to this continued fracture protection and the potential for rare adverse events associated with long-term use (atypical femoral fractures and osteonecrosis of the jaw), a drug holiday of two to three years is recommended for most patients after long-term bisphosphonate therapy. The recommendation for a drug holiday up to three years is derived primarily from extensions of pivotal trials with alendronate and zoledronate and select surrogate marker studies. However, certain factors may modify the duration of bisphosphonate effects on a drug holiday and warrant consideration when determining an appropriate time off-therapy. In this narrative review, we recall what is currently known about drug holidays and discuss what we believe to be the primary considerations and areas for future research regarding drug holiday duration: total bisphosphonate exposure, type of bisphosphonate used, bone mineral density and falls risk, and patient sex and body weight.

Association Use of Bisphosphonates with Risk of Breast Cancer: A Meta-Analysis.

Background Previous studies have investigated the association between the use of bisphosphonates and the development of breast cancer, which presented controversial results. Thus, this meta-analysis was conducted to summarize the current evidence of the association of bisphosphonate use with breast cancer risk. Methods A comprehensive search was conducted in PubMed, ISI Web of Knowledge, the Cochrane Library, and Embase from inception to March 2019 by two researches, who independently selected trials, retrieved relevant data, and assessed study quality. The summary relative risk (RR) for the use of bisphosphonates on the risks of developing breast cancer was calculated using a random-effect model. Results The present meta-analysis, which included four case-control studies, involving 55052 breast cancer cases, and seven retrospective cohort studies, involving 14641 breast cancer cases, assessed the effect of bisphosphonates on breast cancer risk. The random-effect model meta-analysis found a reduced risk of breast cancer with exposure to bisphosphonates with pooled RR of 0.87 (95% confidence interval [CI]: 0.80 to 0.94). The short-term use of bisphosphonates (<1 year) did not render significant alteration (RR = 0.92, 95% CI: 0.82 to 1.03), while a significant 26% risk reduction of breast cancer was noted with long-term use (>1 year) (RR = 0.74, 95% CI: 0.62 to 0.90). A protective effect of bisphosphonates was shown in contralateral breast cancer (RR = 0.41, 95% CI: 0.20 to 0.84). In terms of the type of bisphosphonates, a significant inverse relationship was noted for etidronate, with pooled RR of 0.87 (95% CI: 0.80 to 0.96). Conclusion This meta-analysis suggested that the use of bisphosphonates was associated with reduced risk of breast cancer, including contralateral breast cancer. Compared to other types of bisphosphonates, only etidronate showed a significant inverse relationship. Additionally, the long-term use (>1 year) of bisphosphonates was more significant in lowering breast cancer risk. Further randomized controlled trials are needed to verify this association. This trial is registered with PROSPERO (registration number: CRD42018105024) (registered on 29 August 2018).

Risk factors for bisphosphonate-associated osteonecrosis of the jaw in the prospective randomized trial of adjuvant bisphosphonates for early-stage breast cancer (SWOG 0307).

Bisphosphonates reduce bone metastases in postmenopausal women with early-stage breast cancer but carry the risk of bisphosphonate-related osteonecrosis of the jaw (BRONJ). We describe risk factors for BRONJ and compare BRONJ provoked by infection or trauma with spontaneous lesions, which carry a better prognosis. SWOG 0307 randomized women with stage I-III breast cancer to receive zoledronic acid (ZA), clodronate (CL), or ibandronate (IB) for 3 years, implemented BRONJ prevention guidelines, and collected information about dental health and development of BRONJ. All statistical tests were two-sided. Of 6018 women, 48 developed BRONJ. Infection was present in 21 (43.8%). Median time to BRONJ was 2.1 years for ZA, 2.0 years for IB, and 3.4 years for clodronate (p = 0.04). BRONJ was associated with bisphosphonate type (28/2231 (1.26%) for ZA, 8/2235 (0.36%) for CL, 12/1552 (0.77%) for IB), dental calculus (OR 2.03), gingivitis (OR 2.11), moderate/severe periodontal disease (OR 2.87), and periodontitis > 4 mm (OR 2.20) (p < 0.05). Of 57 lesions, BRONJ occurred spontaneously in 20 (35.1%) and was provoked by dental extraction in 20 (35.1%), periodontal disease in 14 (24.6%), denture trauma in 6 (10.5%), and dental surgery in 2 (3.5%). Spontaneous BRONJ occurred more frequently at the mylohyoid ridge. There were no differences in dental disease, infection, or bisphosphonate type between spontaneous and provoked BRONJ. ZA and worse dental health were associated with increased incidence of BRONJ, with a trend toward additive risk when combined. BRONJ incidence was lower than in similar studies, with prevention strategies likely linked to this. NCT00127205 REGISTRATION DATE: July 2005.

A Systematic Review and Meta-Analysis about the Effect of Bisphosphonates on the Risk of Skeletal-Related Event in Men with Prostate Cancer.

Although the adjuvant therapy of bisphosphonates in prostate cancer is effective in improving bone mineral density, it is still uncertain whether bisphosphonates could decrease the risk of Skeletal- Related Event (SRE) in patients with prostate cancer. We reviewed and analyzed the effect of different types of bisphosphonates on the risk of SRE, defined as pathological fracture, spinal cord compression, radiation therapy to the bone, surgery to bone, hypercalcemia, bone pain, or death as a result of prostate cancer. A systemic literature search was conducted on PubMed and related bibliographies. The emphasis during data extraction was laid on the Hazard Ratio (HR) and the corresponding 95% Confidence Interval (CI) from every eligible Randomized Controlled Trial (RCT). HR was pooled with the fixed effects model, and preplanned subgroup analyses were performed. 5 RCTs (n = 4651) were included and analyzed finally after screening 51 articles. The meta-analysis of all participants showed no significant decrease in the risk of SRE when adding bisphosphonates to control group (HR = 0.968, 95% CI = 0.874 - 1.072, p = 0.536) with low heterogeneity (I2 = 0.0% (d.f. = 4) p = 0.679). There was no significant improvement on SRE neither in the subgroups with Metastases (M1) or Castration-Sensitive Prostate Cancer (CSPC) (respectively HR = 0.968, 95% CI = 0.874 - 1.072, p = 0.536, I2 = 0.0% (d.f. = 4) p = 0.679; HR = 0.954, 95% CI = 0.837 - 1.088, p = 0.484, I2 = 0.0% (d.f. = 3) p = 0.534). Our study demonstrated that bisphosphonates could not statistically significantly reduce the risk of SRE in patients with prostate cancer, neither in the subgroups with M1 or CSPC.

Safety of Intravenous Bisphosphonates for the Treatment of Hypercalcemia in Patients With Preexisting Renal Dysfunction.

Although intravenous (IV) bisphosphonates are first-line medications for the management of hypercalcemia, studies examining their use in patients with preexisting renal dysfunction are limited. The objective of this study is to describe the safety and efficacy of pamidronate and zoledronic acid in the treatment of hypercalcemia in patients with baseline renal dysfunction. A retrospective analysis was conducted of IV pamidronate and zoledronic acid in adult patients with hypercalcemia and creatinine clearance (CrCl) <60 mL/min. The primary endpoint was incidence of all-grade serum creatinine (SCr) elevations. Secondary endpoints included refractory hypercalcemia, hypocalcemia, osteonecrosis of the jaw (ONJ), corrected serum calcium (CSC) decrease ≥1.0 mg/dL by day 7 of bisphosphonate administration, and normalization of CSC ≤10.5 mg/dL by days 10 and 30. A total of 113 patients were included (n = 55 pamidronate, n = 58 zoledronic acid). The primary endpoint of all-grade SCr elevation occurred in 28 (24.8%) patients. Grades 3/4 SCr elevations occurred in 10.9% of patients treated with pamidronate and 1.7% of patients receiving zoledronic acid. Approximately 16% and 14% of patients developed grades 1 and 2 hypocalcemia, respectively, and there were no cases of ONJ. Overall, 64.6% of patients achieved normalization of CSC by day 10, and there were no statistical differences between bisphosphonate type and renal function. The analysis suggests an association between IV bisphosphonates and increased rates of SCr elevations among patients with preexisting renal dysfunction. Future prospective studies are necessary to elucidate these findings.

The Influence of Demographic Factors on the Location of Bisphosphonate-related Atypical Femoral Fractures.

The location of bisphosphonate-related atypical femoral fractures (AFFs) is related to the femoral bow. Other factors that might also be related to the distribution of AFFs are not well studied. In this study, we attempt to define the demographic factors that influence the distribution AFFs in our local population. The medical records of all the patients diagnosed with AFFs treated in our institution between 2008 and 2017 were retrospectively reviewed and divided based on fracture location into subtrochanteric and mid-shaft groups. Demographic data were collected and compared between the two groups. Independent factors affecting the location of AFFs were identified via multivariate analysis. Seventy-nine AFFs in 71 patients were included. Thirty-two fractures occurred at the subtrochanteric region and 47 occurred at the mid-shaft. Age, bone density, anterior femoral bow and lateral femoral bow were significantly different between the two groups, whereas height, weight, body mass index, presence of prodromal symptoms, type and duration of bisphosphonates were not significantly different. Multivariate analysis showed anterior femoral bow was the only independent factor associated with the location of AFFs. Anterior femoral bow is the only factor that can predict the location of AFFs. In our population, other demographic factors were not found to be predictive.

Influence of Bisphosphonates on the Behavior of Osteoblasts Seeded Onto Titanium Discs.

Among other factors, types of bisphosphonates and treatment regimens seem to be strongly associated with the success or failure of installation of osseointegrated implants. This study investigated the influence of two bisphosphonates, sodium alendronate (SA) and zoledronic acid (ZA), on the metabolism of osteoblasts. Human osteoblasts (Saos-2) were seeded onto machined or acid-treated titanium discs previously placed on 24-well plates in complete culture medium. After 24 h, cells were exposed to bisphosphonates at 0.5, 1 or 5 µM for 24 h, 48 h or 7 days. The effects of SA and ZA on osteoblasts were assessed based on the adhesion of these cells to the titanium surfaces by direct fluorescence, cell viability, total protein and collagen synthesis. Alkaline phosphatase activity and mineral nodule deposition by these cells were also evaluated. Data were evaluated by ANOVA and Tukey tests (α=0.05). Decreased adhesion of cells to the titanium discs was observed when exposed to both bisphosphonates; however, this lack of cell adhesion was more evident for ZA-treated cells. In addition, the exposure of osteoblasts to ZA decreased the viability, ALP activity and mineral nodule deposition, which may be related to poor osseointegration after implant installation.

Abstract P2-18-02: Fractures in women with breast cancer receiving high-dose bisphosphonates to prevent breast cancer metastases as part of the SWOG S0307 trial (ClinicalTrials.gov Identifier: NCT00127205)

Abstract Background: Evidence from randomized trials, including a recent meta-analysis, suggests that adjuvant bisphosphonates can decrease recurrence and death in postmenopausal women with early-stage breast cancer. Bisphosphonates (BP) have been included as adjuvant therapy for postmenopausal breast cancer patients in multiple guidelines. SWOG S0307 compared efficacy of 3 BPs in early stage breast cancer, with no evidence of differences in efficacy on breast cancer outcomes by type of bisphosphonate, either in the overall analysis or subgroups. BPs are generally well tolerated, with a relatively low risk of serious adverse effects. Treatment for hormone sensitive breast cancer frequently includes treatment with an aromatase inhibitor (AI) or ovarian function suppression (OFS), both of which can accelerate bone loss, decrease bone density, and increase fractures. In addition to decreasing breast cancer events, BPs have been shown to decrease fractures in breast cancer patients receiving AIs or OFS. However, concerns have been raised about the risk of atypical femur fractures (AFF), a rare subtype of fragility fractures, which appear to increase with longer BP use (3-100/100,000 person-years) (Shane 2013). This substudy evaluated all fractures occurring in patients enrolled on S0307. Methods: Patients with stage I-III breast cancer who were receiving adjuvant systemic therapy were randomized to receive 3 years of intravenous zoledronic acid (ZA) 4 mg IV given every 4 weeks for the first six months, and then every 3 months for the following 2.5 years, oral clodronate (CLOD) 1,600 mg/day orally, or oral ibandronate (IBAN) 50 mg/day orally. The primary endpoint was disease-free survival (DFS). On-treatment data collection forms specifically queried whether a fracture had occurred during the reporting period, the site of the fracture, and whether or not it was associated with trauma. Results: A total of 6,097 patients were randomized to S0307, with a median age of 53 years. Rates for overall fractures at 7.7 years were higher for CLOD (9.3%) compared to IBAN (7.4%) and ZA (7.1%) (p=0.02), with differences being mostly in the spine. Traumatic fracture differences were not significant (CLOD 2.0%, ZA 1.9%, IBAN 1.7%; p=0.83). Fragility fracture rates were 5.2% with ZA, 7.2% with CLOD, and 5.6% with IBAN. Ankle fractures were the most common fracture site at 2.8% overall. Leg fractures, including femur fractures, were relatively low with a rate of 1.5% overall and not different between agents. AFF were not specifically queried/determined. Conclusion: In S0307, BPs were used in higher doses than is recommended for treatment of postmenopausal osteoporosis. There is limited data comparing the long-term effects across BP drugs used at these higher doses on the skeleton. In S0307, an overall fracture rate of 8% was seen in early stage breast cancer patients despite receiving BPs along with conventional systemic therapy. Fracture rates were slightly higher for CLOD than ZA and IBAN for fragility and overall fractures, but similar for traumatic fractures. This may reflect the potency of CLOD or the dosing schedule. Rates of femur fractures were relatively low in all arms without evidence of excess femur fractures. Funding: NIH/NCI CA180888, CA180819, CA180820, CA180821, CA180868, CA180863, CA196175; BCRF, Komen, Berlex (Bayer), Roche/Genentech, Novartis. Citation Format: Rachel L (MD) Yung, Jieling Miao, Alexander HG Paterson, Mark Clemons, Elizabeth C Dees, James N Ingle, Carla I Falkson, William Barlow, Gabriel N Hortobagyi, Julie R Gralow. Fractures in women with breast cancer receiving high-dose bisphosphonates to prevent breast cancer metastases as part of the SWOG S0307 trial (ClinicalTrials.gov Identifier: NCT00127205) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-18-02.

Long-term outcomes of prolonged bisphosphonates more than 2 years in bone metastatic breast cancer: risk vs benefit.

Bisphosphonates are the mainstay therapeutic options for prevention of skeletal-related events and generally used for up to 2 years in bone metastatic cancer patients. We aimed to evaluate the long-term outcomes of prolonged (> 2 years) bisphosphonate usage in bone metastatic breast cancer (BMBC) patients. Ninety-nine BMBC patients who had prolonged bisphosphonates were evaluated retrospectively for long-term outcomes and survival rates. Median duration of bisphosphonate therapy was 46.8 (24-198) months. Seven patients had bisphosphonate-related adverse events (osteonecrosis of the jaw (ONJ) (n = 6), ONJ and renal failure (n = 1)). Bisphosphonate was switched to another one because of bone metastasis progression in more than one-third of the patients (n = 36, 36.3%). The patients who had bisphosphonate switch therapy had statistically significant longer overall survival (p < 0.01). Neither duration nor type of bisphosphonates had effect on frequency of bisphosphonate-related adverse events. Bisphosphonates might be prolonged for more than 2 years in BMBC patients with an acceptable toxicity profile. In addition, bisphosphonates switch therapy should be preferred in those with progressive bone metastasis since it might contribute to better survival despite bisphosphonates could not have been shown to have survival benefit in previous studies.

Pharmacoepidemiology and clinical characteristics of medication-related osteonecrosis of the jaw

BackgroundThe aim of this study was to investigate clinical and pharmacoepidemiologic characteristics of medication-related osteonecrosis of the jaw.MethodsThe study population is comprised of 86patients who were diagnosed with ONJ at Ewha Womans University Mokdong Hospital from 2008 to 2015. Factors for epidemiologic evaluation were gender, age, location of lesion, and clinical history. The types of bisphosphonates, duration of intake, and the amount of accumulated dose were evaluated for therapeutic response. Clinical symptoms and radiographic images were utilized for the assessment of prognosis.ResultsAmong the 86 patients, five were male, whereas 81 were female with mean age of 73.98 (range 45–97). Location of the lesion was in the mandible for 58 patients and maxilla in 25 patients. Three patients had both mandible and maxilla affected. This shows that the mandible is more prone to the formation of ONJ lesions compared to the maxilla. ONJ occurred in 38 cases after extraction, nine cases after implant surgery, six cases were denture use, and spontaneously in 33 cases. Seventy-six patients were taking other drugs aside from drugs indicated for osteoporosis. Most of these patients were diagnosed as osteoporosis, rheumatic arthritis, multiple myeloma, or had a history of cancer therapy. Higher weighted total accumulation doses were significantly associated with poorer prognosis (P < 0.05).ConclusionDose, duration, route, and relative potency of bisphosphonates are significantly associated with treatment prognosis of osteonecrosis of the jaw.

Suppressive effects of N-bisphosphonate in osteoblastic cells mitigated by non-N-bisphosphonate but not by sodium-dependent phosphate cotransporter inhibitor.

There are two types of bisphosphonates (BPs), nitrogen-containing (N-BPs) and those free from nitrogen (non-N-BPs). Although N-BPs show greater inhibition of bone resorption than non-N-BPs, their effects are likely accompanied with inflammation, which non-N-BPs mitigate. We examined the competitive effects of zoledronate (ZOL), an N-BP, and etidronate (ETI), a non-N-BP, in osteoblasts. ZOL, but not ETI, markedly reduced alkaline phosphatase activity and cell viability in osteoblastic MC3T3-E1 and Saos2 cells, while that inhibition was relieved by simultaneous administration of ETI, possibly because of competition with ZOL for cellular uptake. However, phosphonoformate, an inhibitor of the phosphonate transporters SLC20A and SLC34A, did not mitigate the reducing effects of ZOL, suggesting that those transporters are not involved in BP uptake in osteoblastic cells. Additionally, ZOL reduced fibroblastic NIH3T3 and C3H10T1/2 cell viability, which was relieved by administration of both ETI and phosphonoformate. Transporter gene expression levels were significantly lower in osteoblasts as compared with fibroblasts, which may account for the distinct effects of phosphonoformate with different cell types. Together, our results suggest existence of a common uptake route of N-BPs and non-N-BPs into osteoblastic cells that is unrelated to the SLC20A and SLC34A families. SIGNIFICANCE OF THE STUDY: N-BP ZOL was shown to suppress differentiation and viability of osteoblasts. ZOL-induced cell viability suppression was also observed in fibroblasts, which was markedly relieved by addition of the non-N-BP ETI. Additionally, mitigation of the effects of ZOL was achieved with phosphonoformate, a sodium-phosphate cotransporter inhibitor, in fibroblastic cells but not osteoblasts. Expression levels of SLC20A and SLC34A family genes were significantly lower in osteoblasts as compared with fibroblasts. These observations suggest that incorporation of N-BPs and non-N-BPs in osteoblasts is mediated via common transporters that appear to be distinct from SLC20A and 34A, which operate in fibroblasts.

Time trends in oral bisphosphonate initiation in Ontario, Canada over 20years reflect drug policy and healthcare delivery changes.

To describe the type of oral bisphosphonate initiated and characteristics of patients starting oral bisphosphonate therapy over time. We identified community-dwelling older adults (ages ≥ 66years) initiating oral bisphosphonate therapy from April 1996 to March 2016 (1996 to 2015 fiscal years) using healthcare administrative data in Ontario. Patients with conditions other than osteoporosis that may impact bisphosphonate prescribing were excluded. The bisphosphonate initiated and patient characteristics were summarized by fiscal year and stratified by sex. We identified 560,817 eligible patients (81% women). Most patients initiated cyclical etidronate from 1996 until 2005, and then weekly regimens became dominant. In 2008, risedronate became the main oral bisphosphonate (46% risedronate, 43% alendronate, 11% etidronate); with its use increasing after availability of monthly and delayed-release risedronate formulations. In 2015, 71% of patients started risedronate, 28% started alendronate, and less than 2% started etidronate. Characteristics of patients changed over time, reflecting changes in osteoporosis management and general healthcare delivery. Over time, a larger proportion of men (9% to 28%) and patients with diabetes (women 10% to 17%, men 14% to 22%) initiated therapy; benzodiazepine (women 22% to 13%, men 20% to 10%) and estrogen-based hormone replacement therapy (12% to 15% of women 1996-2002 to 3% since 2008) decreased, while statin use increased (women 15% to 39%, men 14% to 52%). The characteristics of patients starting oral bisphosphonate therapy have changed over time. Consideration must be given to these time trends when designing studies that examine osteoporosis drug effects.