Efficacy and Safety of Romosozumab Among Postmenopausal Women With Osteoporosis and Mild-to-Moderate Chronic Kidney Disease.

Patients with osteoporosis and chronic kidney disease (CKD) are at increased risk of fracture and associated negative outcomes, including increased mortality. The present post hoc analysis of two randomized, multicenter, phase 3 clinical trials-Fracture Study in Postmenopausal Women with Osteoporosis (FRAME) and Active-Controlled Fracture Study in Postmenopausal Women with Osteoporosis at High Risk (ARCH)-investigated the efficacy and safety of romosozumab in postmenopausal women with osteoporosis and mild-to-moderate CKD. The analysis included data from 7147 patients from FRAME and 4077 from ARCH. Eighty-one percent of patients from FRAME and 85% from ARCH had mild or moderate reduction in estimated glomerular filtration rate (eGFR) at baseline, and part of this reduction is likely age related. During the 1-year double-blind phases of the trials, patients received romosozumab 210 mg sc or placebo monthly in FRAME and romosozumab 210 mg sc monthly or alendronate 70 mg po weekly in ARCH. Bone mineral density (BMD) at the lumbar spine, total hip, and femoral neck and vertebral and nonvertebral fractures were assessed at baseline and month 12. In both trials, the least-square mean percent change from baseline BMD was significantly greater in the romosozumab groups versus controls across all kidney function categories at month 12. Romosozumab reduced the relative risk of new vertebral fractures at month 12 among patients with eGFR of 30-59, 60-89, and ≥90 mL/min by 72% (95% confidence interval [CI] 14-91; p = 0.017), 70% (40-85; p < 0.001), and 84% (30-96; p = 0.005), respectively, in FRAME versus placebo, and by 51% (5-75; p = 0.04), 19% (-28 to 49; p = 0.39), and 57% (1-81, p = 0.04), respectively, in ARCH versus alendronate. Incidences of adverse events, asymptomatic decreases in serum calcium, and evolution of kidney function during the studies were similar across all baseline kidney function groups. Romosozumab is an effective treatment option for postmenopausal women with osteoporosis and mild-to-moderate reduction in kidney function, with a similar safety profile across different levels of kidney function. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

The effects of bazedoxifene on bone structural strength evaluated by hip structure analysis.

Bazedoxifene (BZA) is a selective estrogen receptor modulator that has been shown to prevent and treat postmenopausal osteoporosis. Hip structure analysis (HSA) can be used to extract bone structural properties related to strength from hip bone mineral density (BMD) scans. This exploratory analysis used HSA to evaluate changes in hip structural geometry in postmenopausal women enrolled in a phase 3 osteoporosis treatment study who were treated with BZA 20mg or placebo for 2 years. This analysis cohort included women at increased fracture risk based on known skeletal risk factors (n = 521); 1 or more moderate or severe fractures or 2 or more mild vertebral fractures and/or femoral neck BMD T-score ≤ -3.0 at baseline combined with additional women from the overall study population (n = 475); a subgroup analysis included just those women at increased fracture risk. HSA was applied to duplicate hip dual-energy X-ray absorptiometry (DXA) scans acquired at screening and 24 months. Percent change from baseline was evaluated using an analysis of covariance for BMD and geometric parameters including section modulus (SM), cross-sectional area (CSA), outer diameter (OD), and buckling ratio (BR). In all regions, BZA was associated with increased BMD and improvements in hip structural geometry. In the narrow neck, BZA 20mg significantly increased SM, CSA, OD, and BMD compared with placebo (P < 0.05 for all). In the intertrochanter region, BZA 20mg significantly increased CSA and BMD and decreased BR compared with placebo (P < 0.05 for all). Other than BMD (P < 0.05), effects of BZA 20mg at the shaft did not reach statistical significance. Similar trends toward improvement in structural geometry with BZA 20mg were observed in all three regions of the hip for the subgroup of women at increased fracture risk. Overall, BZA was associated with geometry-related improvements in bone strength with regard to resistance to bending and compressive forces and to local buckling. These improvements were evident at common fracture locations such as the femoral neck and intertrochanter regions, and are consistent with the significant treatment effect reported for BZA on nonvertebral fractures in higher-risk postmenopausal women with osteoporosis.

A 7-year randomized, placebo-controlled trial assessing the long-term efficacy and safety of bazedoxifene in postmenopausal women with osteoporosis: effects on bone density and fracture.

OBJECTIVE: In a 3-year randomized, double-blind, osteoporosis treatment study (N = 7,492), bazedoxifene 20 mg and bazedoxifene 40 mg significantly (P < 0.05) reduced the risk of new vertebral fractures by 42% and 37%, respectively, compared with placebo in postmenopausal women with osteoporosis. This study evaluated the long-term (7-y) efficacy and safety of bazedoxifene in generally healthy postmenopausal women with osteoporosis. METHODS: This was a second 2-year extension of the 3-year multicenter outpatient core study. During extension I (years 4-5), women receiving bazedoxifene 40 mg transitioned to bazedoxifene 20 mg. In extension II (years 6-7; N = 1,530), all bazedoxifene-treated women continued bazedoxifene 20 mg. Main outcome measures included year 7 endpoints: incidences of new vertebral and nonvertebral fractures, bone mineral density changes, and safety assessments. RESULTS: At 7 years, the cumulative incidences of new vertebral fractures were significantly lower in the bazedoxifene (6.4%) and bazedoxifene 20 mg (7.6%) groups than in the placebo group (9.9%); the relative risk reductions were 36.5% and 30.4%, respectively (both P < 0.001). Bazedoxifene had no effect on the overall incidence of nonvertebral fractures (bazedoxifene, 11.2%; bazedoxifene 20 mg, 12.0%; placebo, 10.8%). The mean changes from baseline in lumbar spine bone mineral density were 2.95%, 2.73%, and 2.19%, respectively. Seven-year decreases in total hip bone mineral density were significantly smaller in the bazedoxifene (-1.15%) and bazedoxifene 20 mg (-1.19%) groups than in the placebo group (-2.53%; P ≤ 0.002). Bazedoxifene showed a favorable safety/tolerability profile across 7 years, with similar adverse events, serious adverse events, and study discontinuations in all groups. CONCLUSIONS: Efficacy and safety of bazedoxifene are sustained across 7 years in postmenopausal women with osteoporosis.

Bridging analysis of the efficacy and safety of bazedoxifene in Japanese and global populations of postmenopausal women with osteoporosis.

This study examined whether the global clinical data for bazedoxifene could be extrapolated to a Japanese population by evaluating the results of a phase 2 study in postmenopausal Japanese women with osteoporosis as compared to those of a pivotal, phase 3 study. The efficacy of bazedoxifene 20 and 40 mg versus placebo on lumbar spine bone mineral density (BMD), bone turnover markers, lipid profile, incidence of fractures, and safety parameters was compared between the Japanese phase 2 study (N = 429) and the global phase 3 study (N = 7,492) during a 2-year period. In the primary population for assessment of bridging, differences in the mean percent change from baseline in lumbar spine BMD at 2 years relative to placebo were greater for women treated with bazedoxifene 20 and 40 mg in the phase 2 study than in the phase 3 study. BMD changes in the bazedoxifene groups were confirmed to be similar between the phase 2 study population and a subset of the phase 3 study population with similar baseline characteristics. The effects of bazedoxifene on incidence of fractures, bone turnover markers, and lipid metabolism were similar between studies. There were no major differences in safety parameters between studies. The greater improvement in lumbar spine BMD and similar results in bone turnover markers, fracture incidence, and safety profile observed with bazedoxifene in the phase 2 study compared with the phase 3 study confirmed the feasibility of extrapolating the global clinical data to a Japanese population.

Effects of bazedoxifene/conjugated estrogens on the endometrium and bone: a randomized trial.

OBJECTIVE: This phase 3 study evaluated the endometrial safety of bazedoxifene (BZA)/conjugated estrogens (CE) and bone mineral density (BMD) effects vs BZA alone, hormone therapy, and placebo (PBO). METHODS: The Selective estrogens, Menopause, And Response to Therapy (SMART)-5 trial was a multicenter, randomized, double-blind, PBO- and active-controlled study in postmenopausal women with an intact uterus (N = 1843; aged 40-65 years) seeking treatment for menopausal symptoms. Subjects received daily oral BZA 20 mg/CE 0.45 or 0.625 mg, BZA 20 mg, CE 0.45 mg/medroxyprogesterone acetate (MPA) 1.5 mg, or PBO. Primary endpoints were incidence of endometrial hyperplasia and percent change in lumbar spine BMD at 12 months. Secondary endpoints included additional osteoporosis parameters and assessments of tolerability and safety. RESULTS: At 12 months, endometrial hyperplasia incidence was low (<1%) and similar among groups. The BZA/CE group showed significantly greater increases in lumbar spine and total hip BMD vs decreases with PBO (P < .001); the CE/MPA group had increased lumbar spine BMD compared with that in the BZA/CE group. The BZA 20 mg/CE 0.45 and 0.625 mg groups had cumulative amenorrhea rates similar to those with PBO and BZA and significantly higher than those with CE 0.45 mg/MPA 1.5 mg (P < .001). The incidence of breast tenderness with BZA/CE was similar to that with PBO and BZA and significantly lower than with that with CE/MPA (P < .01). Although adverse event (AE) rates were similar among the groups, the incidence of serious AEs overall and AE-related discontinuation rates were higher with CE/MPA than with BZA/CE, BZA, or PBO. CONCLUSIONS: BZA/CE showed low rates of endometrial hyperplasia and improved lumbar spine and total hip BMD and was generally safe and well tolerated.

Evaluation of the efficacy and safety of bazedoxifene/conjugated estrogens for secondary outcomes including vasomotor symptoms in postmenopausal women by years since menopause in the Selective estrogens, Menopause and Response to Therapy (SMART) trials.

BACKGROUND: Bazedoxifene/conjugated estrogens (BZA/CE), a novel tissue-selective estrogen complex (TSEC), has been evaluated in the Selective estrogens, Menopause And Response to Therapy (SMART) trials. Secondary outcomes from these trials were evaluated to determine whether the effects of BZA/CE are influenced by years since menopause (YSM). METHODS: SMART-1 and SMART-2 were randomized, double-blind, placebo (PBO)-controlled phase 3 trials in nonhysterectomized postmenopausal women. Outcomes were evaluated for women <5 or ≥5 YSM in SMART-1 (BZA 20 mg/CE 0.45 mg, n=433; BZA 20 mg/CE 0.625 mg, n=414; PBO, n=427) and SMART-2 (BZA 20 mg/CE 0.45 mg, n=127; BZA 20 mg/CE 0.625 mg, n=128; PBO, n=63). Hot-flush frequency and severity, health-related quality of life (HRQoL), sleep, treatment satisfaction, cumulative amenorrhea, and breast pain were assessed for each study individually, using defined statistical analysis protocols. RESULTS: For <5 and ≥5 YSM subgroups, BZA 20 mg/CE 0.45 and 0.625 mg showed significant decreases in hot-flush frequency and severity at 3 months compared with PBO (p<0.05 for both). Both BZA/CE doses showed significant improvements compared with PBO in HRQoL scores, sleep parameters, and satisfaction with treatment at 3 months irrespective of YSM (p≤0.05 vs. PBO for all). Similar to PBO, BZA/CE showed high proportions of cumulative amenorrhea (SMART-1) and low incidences of breast pain (SMART-1 and SMART-2) for women <5 and ≥5 YSM. CONCLUSIONS: The positive effects of BZA/CE on secondary outcomes were consistent among women <5 or ≥5 YSM.

Sleep parameters and health-related quality of life with bazedoxifene/conjugated estrogens: a randomized trial.

OBJECTIVE: The effects of bazedoxifene (BZA)/conjugated estrogens (CE) on sleep and health-related quality of life (HRQoL) were evaluated in nonhysterectomized postmenopausal women who were enrolled in a randomized, double-blind, placebo- and active-controlled phase 3 trial. METHODS: The sleep/HRQoL substudy enrolled 459 women with bothersome moderate to severe vasomotor symptoms who were randomized to BZA 20 mg/CE 0.45 mg, BZA 20 mg/CE 0.625 mg, BZA 20 mg, CE 0.45 mg/medroxyprogesterone acetate (MPA) 1.5 mg, or placebo for 1 year. On months 3 and 12, sleep parameters were evaluated using the Medical Outcomes Study sleep scale, and HRQoL was assessed using the Menopause-Specific Quality of Life (MENQOL) questionnaire. RESULTS: BZA/CE and CE/MPA significantly improved sleep and HRQoL compared with placebo. On month 3, most Medical Outcomes Study sleep parameter improvements with BZA/CE and CE/MPA versus placebo were not significant. On month 12, both BZA/CE doses and CE/MPA significantly improved time to fall asleep and sleep disturbance (P < 0.05 vs. placebo); BZA 20 mg/CE 0.625 mg and CE/MPA also showed significant improvements in sleep adequacy and sleep problem indices I and II (P < 0.01 vs placebo). Both BZA/CE doses and CE/MPA significantly improved MENQOL vasomotor function score versus placebo at 3 and 12 months (P < 0.001). At 3 months, total MENQOL score was significantly improved with BZA 20 mg/CE 0.625 mg and CE/MPA versus placebo (P < 0.05); at 12 months, both BZA/CE doses and CE/MPA showed significant improvements (P < 0.001). CONCLUSIONS: Symptomatic postmenopausal women who are treated with BZA/CE for 1 year demonstrate significant improvements in sleep and HRQoL, similar to women treated with CE/MPA.

Evaluation of the direct and indirect effects of bazedoxifene/conjugated estrogens on sleep disturbance using mediation modeling.

OBJECTIVE: Mediation modeling was used to evaluate the direct effects of bazedoxifene (BZA)/conjugated estrogens (CE) on sleep, compared with its indirect effects via improvements in hot flushes, in postmenopausal women enrolled in the SMART (Selective estrogens, Menopause, And Response to Therapy)-2 and SMART-5 trials. METHODS: Statistical mediation modeling estimated the direct effects of BZA/CE on sleep disturbance (Medical Outcomes Study sleep scale) and its indirect effects via hot flush improvement (item 1 of the Menopause-Specific Quality of Life questionnaire). In SMART-2, a total of 318 women with moderate to severe vasomotor symptoms (VMS) received BZA 20 mg/CE 0.45 mg, BZA 20 mg/CE 0.625 mg, or placebo; in SMART-5, a total of 1,843 women seeking menopausal symptom treatment received BZA 20 mg/CE 0.45 mg, BZA 20 mg/CE 0.625 mg, CE 0.45 mg/medroxyprogesterone acetate 1.5 mg, BZA 20 mg, or placebo. The SMART-5 sleep substudy enrolled 459 women with bothersome VMS and sleep disturbances. RESULTS: In SMART-2, BZA 20 mg/CE 0.45 mg and BZA 20 mg/CE 0.625 mg had a primarily direct effect on sleep in symptomatic women (64% and 66%, respectively; P < 0.001). Conversely, in the overall SMART-5 population, effects were primarily indirect (82% and 75% for BZA 20 mg/CE 0.45 mg and BZA 20 mg/CE 0.625 mg, respectively; P < 0.01), suggesting that sleep improvement was largely mediated via hot flush improvements. In a subpopulation of SMART-5 (participants with bothersome VMS), BZA 20 mg/CE 0.45 mg and BZA 20 mg/CE 0.625 mg affected sleep disturbance directly (82% and 76%, respectively; P < 0.0001). CONCLUSIONS: BZA/CE improves sleep in postmenopausal women with moderate to severe and milder VMS. This study suggests that improvements occur directly in women with moderate to severe VMS and indirectly in less symptomatic women.

A double-blind, randomized, ascending, multiple-dose study of bazedoxifene in healthy postmenopausal women.

Bazedoxifene is a novel selective estrogen receptor modulator in clinical development for the prevention and treatment of postmenopausal osteoporosis. This phase 1, double-blind, randomized, placebo-controlled study (N = 107) of healthy postmenopausal women examined the pharmacokinetics and safety/tolerability profile of multiple doses of bazedoxifene (1, 2.5, 5, 10, 20, 40, and 80 mg) administered orally once daily for 30 days. Bazedoxifene demonstrated a half-life of 25 to 30 hours, reached steady state within 7 days, and exhibited linear pharmacokinetics over a dose range of 5-80 mg. Fibrinogen levels decreased with bazedoxifene doses of 5 mg and greater; these changes were significant for bazedoxifene 20, 40, and 80 mg (P ≤ .05 vs placebo), but were not dose dependent. Bazedoxifene was associated with increased levels of sex hormone-binding globulin, thyroxine-binding globulin, and cortisol-binding globulin (CBG); only increases in the levels of CBG appeared to be dose related. Bazedoxifene was safe and well tolerated within the tested dose range. Bazedoxifene showed no differences from placebo in adverse event reports, vital sign measurements, or electrocardiogram findings.

Assessment of the safety of long-term bazedoxifene treatment on the reproductive tract in postmenopausal women with osteoporosis: results of a 7-year, randomized, placebo-controlled, phase 3 study.

OBJECTIVE: To evaluate the clinical safety of bazedoxifene (BZA) on the reproductive tract in postmenopausal women with osteoporosis over 7 years. STUDY DESIGN: This was a second, blinded, 2-year extension of a 3-year, randomized, double-blind, placebo (PBO)- and active-controlled phase 3 trial. In the core study, subjects were randomized to receive BZA 20 or 40mg, raloxifene 60mg, or PBO. During years 4-5, the raloxifene arm was discontinued and subjects receiving BZA 40mg were transitioned to BZA 20mg. Subjects continued to receive BZA 20mg or PBO during years 6-7. MAIN OUTCOME MEASURES: The primary endpoint was the incidence of new vertebral fractures at 7 years (reported separately). Reproductive tract safety findings at 7 years are reported here. Endometrial thickness was assessed by transvaginal ultrasonography for subjects in the endometrial safety substudy. Adverse events (AEs) were recorded throughout the study. RESULTS: At 7 years, the adjusted mean (±standard error) change in endometrial thickness was similar with BZA and PBO (-0.11 ± 0.21 and 0.07 ± 0.32 mm, respectively). The incidence of endometrial hyperplasia was low (0.1% for both groups). BZA showed significantly lower rates than PBO of endometrial carcinoma (0.1% vs. 0.4%; P=0.020) and vaginitis (6.1% vs. 7.6%; P=0.035). There were more cases of ovarian carcinoma with BZA (n=4 [0.1%]) than PBO (n=0); the difference was not statistically significant. Rates of breast-related and other gynecologic AEs were similar among groups. CONCLUSIONS: BZA was associated with a favorable reproductive safety profile in postmenopausal women with osteoporosis over 7 years.

Breast effects of bazedoxifene-conjugated estrogens: a randomized controlled trial.

OBJECTIVE: To evaluate the effects of bazedoxifene-conjugated estrogens on mammographic breast density and other breast parameters in nonhysterectomized postmenopausal women enrolled in a randomized, double-blind, placebo-controlled, and active-controlled phase 3 study. METHODS: The 1-year Selective estrogens, Menopause, And Response to Therapy-5 trial estimated the efficacy and safety of bazedoxifene-conjugated estrogens in 1,843 postmenopausal women seeking vasomotor symptom treatment. A substudy enrolled 940 women with technically acceptable digital mammograms at screening and at 1 year. Treatments included bazedoxifene 20 mg and conjugated estrogens 0.45 or 0.625 mg, placebo, bazedoxifene 20 mg, and conjugated estrogens (0.45 mg) and medroxyprogesterone acetate (1.5 mg). Mammograms were centrally read by a single radiologist blinded to treatment and time sequence; percent breast density was determined using validated software. Noninferiority was based on a predefined margin of 1.5% for comparison of adjusted mean differences in breast density at 12 months. RESULTS: Bazedoxifene 20 mg and conjugated estrogens 0.45 and 0.625 mg demonstrated noninferiority to placebo in breast density. Mammographic breast density decreased from baseline with bazedoxifene 20 mg and conjugated estrogens 0.45 and 0.625 mg and placebo (mean -0.38% and standard error [SE] 0.22%, mean -0.44% and SE 0.22%, mean -0.32% and SE 0.23%, respectively). Conjugated estrogens-medroxyprogesterone acetate significantly increased breast density from baseline (mean 1.60%, SE 0.35%; P<.001) compared with placebo. Both bazedoxifene-conjugated estrogens doses showed rates of breast tenderness similar to placebo and significantly (P<.001) lower than conjugated estrogens-medroxyprogesterone acetate. No differences in incidence of breast-related adverse events were identified. CONCLUSION: Bazedoxifene 20 mg and conjugated estrogens 0.45 and 0.625 mg did not increase mammographic breast density or breast tenderness over the course of 1 year with a favorable breast-related safety profile. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00808132. LEVEL OF EVIDENCE: I.

Changes in bone mineral density are correlated with bone markers and reductions in hot flush severity in postmenopausal women treated with bazedoxifene/conjugated estrogens.

OBJECTIVE: A post hoc exploratory analysis was conducted to examine correlations between changes in bone density, bone markers, and hot flushes after the treatment of postmenopausal women with bazedoxifene (BZA)/conjugated estrogens (CE). METHODS: In a 2-year phase 3 study, 3,397 postmenopausal women were randomized to BZA 10 mg/CE 0.45 mg, BZA 20 mg/CE 0.45 mg, BZA 40 mg/CE 0.45 mg, BZA 10 mg/CE 0.625 mg, BZA 20 mg/CE 0.625 mg, BZA 40 mg/CE 0.625 mg, raloxifene 60 mg, or placebo. In this analysis, bone density changes at 2 years were compared with baseline levels of the bone markers serum C-telopeptide and osteocalcin. Correlations between changes in bone density and changes in 12-week hot flush composite scores in symptomatic women were also analyzed. RESULTS: Treatment with BZA 20 mg/CE 0.45 mg or BZA 20 mg/CE 0.625 mg increased lumbar spine bone density more in women with higher bone resorption and formation, categorized by baseline levels of C-telopeptide and osteocalcin (P < 0.001, both BZA/CE doses). With placebo, larger decreases in lumbar spine bone density were seen in the highest tertile of serum C-telopeptide. There was no correlation between changes in total hip bone density and baseline bone markers. There were significant correlations between percent change in hot flush score at week 12 and percent changes in lumbar spine (r = -0.31, P = 0.006) and total hip (r = -0.23, P = 0.044) bone densities at month 24. CONCLUSIONS: With 2-year BZA/CE treatment, women with larger increases in lumbar spine and total hip densities also have higher baseline bone markers. Early reductions in hot flush score (12 wk) are predictive of long-term increases in bone density (24 mo).

Breast density changes in a randomized controlled trial evaluating bazedoxifene/conjugated estrogens.

OBJECTIVE: Breast density is associated with an increased risk of breast cancer. This study assessed changes in mammographic breast density after 24 months of treatment with bazedoxifene (BZA)/conjugated estrogens (CE) in postmenopausal women. METHODS: This was an ancillary study in a subset of nonhysterectomized postmenopausal women enrolled in a randomized, double-blind, placebo-controlled, and active-controlled phase 3 study. Treatments evaluated were BZA 20 mg/CE 0.45 mg, BZA 20 mg/CE 0.625 mg, raloxifene 60 mg, and placebo. Women who were eligible for participation in the ancillary study must have completed 24 months of treatment and have mammograms at baseline and 24 months. The left craniocaudal views from each mammogram pair were digitized and analyzed by a radiologist who was blinded to treatment arm and mammogram date. The percent breast density was determined using validated software. RESULTS: Mammogram pairs were obtained from 507 evaluable participants (mean age range, 55.2-56.3 y). The mean changes (95% CI) in mammographic breast density from baseline to 24 months were comparable among groups (-0.39% [-0.69 to -0.08], -0.05% [-0.38 to 0.27], -0.23% [-0.54 to 0.08], and -0.42% [-0.72 to -0.11] for BZA 20 mg/CE 0.45 mg, BZA 20 mg/CE 0.625 mg, raloxifene 60 mg, and placebo, respectively). These reductions from baseline were statistically significant for BZA 20 mg/CE 0.45 mg and placebo. The effect of both BZA/CE doses on breast density was generally consistent among subgroups based on age, body mass index, and years since menopause. CONCLUSIONS: Treatment with BZA 20 mg/CE 0.45 mg or BZA 20 mg/CE 0.625 mg for 24 months did not affect mammographic breast density in this population of postmenopausal women.

Bazedoxifene: the evolving role of third-generation selective estrogen-receptor modulators in the management of postmenopausal osteoporosis.

Osteoporosis is a significant public health concern, particularly for postmenopausal women. Current treatment options may not be appropriate for all women. Selective estrogen-receptor modulators (SERMs) are a class of molecules with tissue-selective activity. Bazedoxifene is currently in clinical development for the prevention and treatment of postmenopausal osteoporosis. In a 2-year, phase III, osteoporosis prevention study (N = 1583), bazedoxifene 10, 20, and 40 mg was shown to preserve bone mineral density and decrease biochemical markers of bone turnover compared with placebo in postmenopausal women at risk for osteoporosis. In a pivotal 3-year, phase III, osteoporosis treatment study (N = 7492), bazedoxifene 20 and 40 mg significantly reduced the incidence of new vertebral fractures compared with placebo (p < 0.05 for both) in postmenopausal women with osteoporosis. In a post hoc subgroup analysis of women at higher risk for fracture (n = 1772), bazedoxifene 20 mg significantly reduced the risk of nonvertebral fractures versus placebo (p = 0.02) and raloxifene 60 mg (p = 0.05). Bazedoxifene 20 mg has demonstrated sustained efficacy in reducing the risk of vertebral fractures over 5 and 7 years. Overall, bazedoxifene was generally safe and well tolerated, with favorable endometrial and breast safety profiles. As with other SERMs, the rate of deep vein thrombosis was higher in the bazedoxifene groups compared with placebo at 3 and 5 years. Considering its demonstrated efficacy and safety, bazedoxifene may be an appropriate osteoporosis therapy for women who cannot take or are unwilling to take bisphosphonates because of safety or tolerability issues. Bazedoxifene may also be appropriate for younger women at increased fracture risk who are concerned about the effects of long-term bisphosphonate therapy. This article reviews the results of key clinical trials of bazedoxifene for the prevention and treatment of postmenopausal osteoporosis and describes its role in clinical practice.

An update on selective estrogen receptor modulators for the prevention and treatment of osteoporosis.

Several selective estrogen receptor modulators are in clinical development for postmenopausal osteoporosis. Bazedoxifene has shown significant reductions in vertebral and non-vertebral (in higher-risk women) fracture risk, with no evidence of breast or endometrial stimulation. Lasofoxifene has demonstrated significant reductions in vertebral and non-vertebral fracture risk, but has been associated with endometrial/uterine effects. Both selective estrogen receptor modulators were generally safe and well tolerated but have been associated with some "class effects" (e.g., hot flushes, venous thromboembolic events). A tissue selective estrogen complex partnering bazedoxifene with conjugated estrogens is under clinical investigation for the treatment of menopausal symptoms and osteoporosis prevention. Future directions in selective estrogen receptor modulator research include ospemifene and RAD 1901.

Effects of bazedoxifene on bone mineral density, bone turnover, and safety in postmenopausal Japanese women with osteoporosis.

This randomized, double-blind, placebo-controlled, dose-response late phase 2 study evaluated the efficacy and safety of bazedoxifene in postmenopausal Japanese women 85 years of age or younger with osteoporosis. Eligible subjects received daily treatment with oral doses of bazedoxifene 20 or 40 mg or placebo for 2 years. Efficacy assessments included bone mineral density (BMD) at the lumbar spine and other skeletal sites, bone turnover marker levels, lipid parameters, and incidence of new fractures. Of 429 randomized subjects, 387 were evaluable for efficacy, and 423 were included in the safety analyses (mean age, 64 years). At 2 years, the mean percent changes from baseline in lumbar spine BMD were significantly greater with bazedoxifene 20 and 40 mg (2.43% and 2.74%, respectively) than with placebo (-0.65%, p < .001 for both). Both bazedoxifene doses significantly improved BMD at the total hip, femoral neck, and greater trochanter compared with placebo (p < .001 for all). Decreases in bone turnover markers were observed with bazedoxifene 20 and 40 mg as early as 12 weeks (p < .05 for all) and were sustained throughout the study. Total and low-density lipoprotein cholesterol levels were significantly decreased from baseline with both bazedoxifene doses compared with placebo (p < .05 for all). Incidences of new vertebral and nonvertebral fractures were similar among the bazedoxifene and placebo groups. Overall, the incidence of adverse events with bazedoxifene 20 and 40 mg was similar to that with placebo. Bazedoxifene significantly improved BMD, reduced bone turnover, and was well tolerated in postmenopausal Japanese women with osteoporosis.

Safety of bazedoxifene in a randomized, double-blind, placebo- and active-controlled Phase 3 study of postmenopausal women with osteoporosis.

BACKGROUND: We report the safety findings from a 3-year phase 3 study (NCT00205777) of bazedoxifene, a novel selective estrogen receptor modulator under development for the prevention and treatment of postmenopausal osteoporosis. METHODS: Healthy postmenopausal osteoporotic women (N = 7,492; mean age, 66.4 years) were randomized to daily doses of bazedoxifene 20 or 40 mg, raloxifene 60 mg, or placebo for 3 years. Safety and tolerability were assessed by adverse event (AE) reporting and routine physical, gynecologic, and breast examination. RESULTS: Overall, the incidence of AEs, serious AEs, and discontinuations due to AEs in the bazedoxifene groups was not different from that seen in the placebo group. The incidence of hot flushes and leg cramps was higher with bazedoxifene or raloxifene compared with placebo. The rates of cardiac disorders and cerebrovascular events were low and evenly distributed among groups. Venous thromboembolic events, primarily deep vein thromboses, were more frequently reported in the active treatment groups compared with the placebo group; rates were similar with bazedoxifene and raloxifene. Bazedoxifene showed a neutral effect on the breast and an excellent endometrial safety profile. The incidence of fibrocystic breast disease was lower with bazedoxifene 20 and 40 mg versus raloxifene or placebo. Reductions in total and low-density lipoprotein levels and increases in high-density lipoprotein levels were seen with bazedoxifene versus placebo; similar results were seen with raloxifene. Triglyceride levels were similar among groups. CONCLUSION: Bazedoxifene showed a favorable safety and tolerability profile in women with postmenopausal osteoporosis. TRIAL REGISTRATION NUMBER: NCT00205777; Trial registration date: September 16, 2005.

Bazedoxifene acetate: a novel selective estrogen receptor modulator for the prevention and treatment of postmenopausal osteoporosis.

Postmenopausal osteoporosis is an increasing worldwide health concern affecting an estimated 200 million individuals. Despite a wide range of available treatment options, many patients are not being treated or discontinue therapy. The ongoing need for new osteoporosis therapies has led to the development of new selective estrogen receptor modulators (SERMs) with an ideal tissue selectivity profile and beneficial effects on bone without undesirable effects on the endometrium and breast. Bazedoxifene acetate, a novel SERM in clinical development for the prevention and treatment of postmenopausal osteoporosis, resembles this ideal profile more closely than other currently available SERMs. Results from large prospective phase III trials showed that it increases bone mineral density, reduces bone turnover rate and decreases the risk for new vertebral fractures. Moreover, based on a post hoc analysis of a subgroup of women with a higher risk for fracture, bazedoxifene was demonstrated to significantly reduce the incidence of nonvertebral fractures compared with both raloxifene hydrochloride and placebo. Furthermore, it was reported to be well tolerated, with a favorable safety profile and no evidence of endometrial or breast tissue stimulation. Bazedoxifene represents an important new treatment option for women at risk for osteoporosis and fracture.

Bazedoxifene effects on the reproductive tract in postmenopausal women at risk for osteoporosis.

OBJECTIVE: The aim of this study was to examine the endometrial, ovarian, and breast safety of bazedoxifene, a novel selective estrogen-receptor modulator, in postmenopausal women at risk for osteoporosis. METHODS: Healthy postmenopausal women (N = 1,583; mean age, 57.6 y) with lumbar spine or femoral neck bone mineral density T scores between -1 and -2.5 and/or other clinical risk factors for osteoporosis were enrolled in a 24-month, phase 3, randomized, double-blind, placebo- and active-controlled trial. They received daily treatment with bazedoxifene 10, 20, or 40 mg; placebo; or raloxifene 60 mg. Reproductive safety assessments included periodic transvaginal ultrasound measurements of endometrial thickness, ovarian volume, and presence of ovarian cysts; periodic endometrial biopsies; and adverse event reporting. RESULTS: Bazedoxifene was not associated with a significant change from baseline in mean endometrial thickness at month 24. The percentage of participants with a change from baseline in endometrial thickness or endometrial thickness greater than 5 mm at month 24 was similar among groups. There was no consensus diagnosis of endometrial hyperplasia or malignancy in the bazedoxifene or raloxifene groups; the rates of other histologic findings, including endometrial polyps, were low (<5%) and similar among groups. No significant between-group differences were found in the change from baseline in ovarian volume, number or size of ovarian cysts, or incidence of ovarian cancer. Reports of breast pain (<4%) and breast cancer (<1%) were low and evenly distributed among groups. CONCLUSION: A favorable endometrial, ovarian, and breast safety profile was found after 2 years of treatment with bazedoxifene in healthy, recently postmenopausal women at risk for osteoporosis.

Bazedoxifene, a selective estrogen receptor modulator: effects on the endometrium, ovaries, and breast from a randomized controlled trial in osteoporotic postmenopausal women.

OBJECTIVE: The aim of this study was to evaluate the endometrial, ovarian, and breast safety of bazedoxifene used as a treatment for postmenopausal osteoporosis. METHODS: Healthy women (aged 55-85 y) with osteoporosis were enrolled in a randomized, double-blind, placebo-controlled phase 3 trial. Participants were randomized to treatment with bazedoxifene 20 or 40 mg, raloxifene 60 mg, or placebo daily for 3 years. Endometrial and ovarian safety was assessed by periodic transvaginal ultrasonography and endometrial biopsy through 24 months. Gynecologic and breast-related adverse events were recorded throughout the study. RESULTS: Among 753 participants with available transvaginal ultrasonography data, there were no significant between-group differences in overall endometrial thickness or in the percentage of participants with endometrial thickness greater than 5 mm at 12 or 24 months. Changes in the mean endometrial thickness (+/-SE) from baseline were -0.07 +/- 0.11 mm (bazedoxifene 20 mg), 0.10 +/- 0.11 mm (bazedoxifene 40 mg), 0.16 +/- 0.12 mm (raloxifene 60 mg), and -0.08 +/- 0.11 mm (placebo) at 24 months. There was one report of endometrial hyperplasia in each group, and there were zero, two, two, and three reports of endometrial carcinoma with bazedoxifene 20 and 40 mg, raloxifene 60 mg, and placebo, respectively. There were no clinically important changes from baseline in the number or size of ovarian cysts among groups. There was a significantly lower incidence of fibrocystic breast disease (P