Michael R. McClung

Denosumab for Prevention of Fractures in Postmenopausal Women with Osteoporosis

BACKGROUND Denosumab is a fully human monoclonal antibody to the receptor activator of nuclear factor-kappaB ligand (RANKL) that blocks its binding to RANK, inhibiting the development and activity of osteoclasts, decreasing bone resorption, and increasing bone density. Given its unique actions, denosumab may be useful in the treatment of osteoporosis. METHODS We enrolled 7868 women between the ages of 60 and 90 years who had a bone mineral density T score of less than -2.5 but not less than -4.0 at the lumbar spine or total hip. Subjects were randomly assigned to receive either 60 mg of denosumab or placebo subcutaneously every 6 months for 36 months. The primary end point was new vertebral fracture. Secondary end points included nonvertebral and hip fractures. RESULTS As compared with placebo, denosumab reduced the risk of new radiographic vertebral fracture, with a cumulative incidence of 2.3% in the denosumab group, versus 7.2% in the placebo group (risk ratio, 0.32; 95% confidence interval [CI], 0.26 to 0.41; P<0.001)--a relative decrease of 68%. Denosumab reduced the risk of hip fracture, with a cumulative incidence of 0.7% in the denosumab group, versus 1.2% in the placebo group (hazard ratio, 0.60; 95% CI, 0.37 to 0.97; P=0.04)--a relative decrease of 40%. Denosumab also reduced the risk of nonvertebral fracture, with a cumulative incidence of 6.5% in the denosumab group, versus 8.0% in the placebo group (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01)--a relative decrease of 20%. There was no increase in the risk of cancer, infection, cardiovascular disease, delayed fracture healing, or hypocalcemia, and there were no cases of osteonecrosis of the jaw and no adverse reactions to the injection of denosumab. CONCLUSIONS Denosumab given subcutaneously twice yearly for 36 months was associated with a reduction in the risk of vertebral, nonvertebral, and hip fractures in women with osteoporosis. (ClinicalTrials.gov number, NCT00089791.)

Effect of risedronate on the risk of hip fracture in elderly women. Hip Intervention Program Study Group.

BACKGROUND Risedronate increases bone mineral density in elderly women, but whether it prevents hip fracture is not known. METHODS We studied 5445 women 70 to 79 years old who had osteoporosis (indicated by a T score for bone mineral density at the femoral neck that was more than 4 SD below the mean peak value in young adults [-4] or lower than -3 plus a nonskeletal risk factor for hip fracture, such as poor gait or a propensity to fall) and 3886 women at least 80 years old who had at least one nonskeletal risk factor for hip fracture or low bone mineral density at the femoral neck (T score, lower than -4 or lower than -3 plus a hip-axis length of 11.1 cm or greater). The women were randomly assigned to receive treatment with oral risedronate (2.5 or 5.0 mg daily) or placebo for three years. The primary end point was the occurrence of hip fracture. RESULTS Overall, the incidence of hip fracture among all the women assigned to risedronate was 2.8 percent, as compared with 3.9 percent among those assigned to placebo (relative risk, 0.7; 95 percent confidence interval, 0.6 to 0.9; P=0.02). In the group of women with osteoporosis (those 70 to 79 years old), the incidence of hip fracture among those assigned to risedronate was 1.9 percent, as compared with 3.2 percent among those assigned to placebo (relative risk, 0.6; 95 percent confidence interval, 0.4 to 0.9; P=0.009). In the group of women selected primarily on the basis of nonskeletal risk factors (those at least 80 years of age), the incidence of hip fracture was 4.2 percent among those assigned to risedronate and 5.1 percent among those assigned to placebo (P=0.35). CONCLUSIONS Risedronate significantly reduces the risk of hip fracture among elderly women with confirmed osteoporosis but not among elderly women selected primarily on the basis of risk factors other than low bone mineral density.

Romosozumab in Postmenopausal Women with Low Bone Mineral Density

BACKGROUND Sclerostin is an osteocyte-derived inhibitor of osteoblast activity. The monoclonal antibody romosozumab binds to sclerostin and increases bone formation. METHODS In a phase 2, multicenter, international, randomized, placebo-controlled, parallel-group, eight-group study, we evaluated the efficacy and safety of romosozumab over a 12-month period in 419 postmenopausal women, 55 to 85 years of age, who had low bone mineral density (a T score of -2.0 or less at the lumbar spine, total hip, or femoral neck and -3.5 or more at each of the three sites). Participants were randomly assigned to receive subcutaneous romosozumab monthly (at a dose of 70 mg, 140 mg, or 210 mg) or every 3 months (140 mg or 210 mg), subcutaneous placebo, or an open-label active comparator--oral alendronate (70 mg weekly) or subcutaneous teriparatide (20 μg daily). The primary end point was the percentage change from baseline in bone mineral density at the lumbar spine at 12 months. Secondary end points included percentage changes in bone mineral density at other sites and in markers of bone turnover. RESULTS All dose levels of romosozumab were associated with significant increases in bone mineral density at the lumbar spine, including an increase of 11.3% with the 210-mg monthly dose, as compared with a decrease of 0.1% with placebo and increases of 4.1% with alendronate and 7.1% with teriparatide. Romosozumab was also associated with large increases in bone mineral density at the total hip and femoral neck, as well as transitory increases in bone-formation markers and sustained decreases in a bone-resorption marker. Except for mild, generally nonrecurring injection-site reactions with romosozumab, adverse events were similar among groups. CONCLUSIONS In postmenopausal women with low bone mass, romosozumab was associated with increased bone mineral density and bone formation and with decreased bone resorption. (Funded by Amgen and UCB Pharma; ClinicalTrials.gov number, NCT00896532.).

PREVENTION OF BONE LOSS WITH ALENDRONATE IN POSTMENOPAUSAL WOMEN UNDER 60 YEARS OF AGE

Background Estrogen-replacement therapy prevents osteoporosis in postmenopausal women by inhibiting bone resorption, but the balance between its long-term risks and benefits remains unclear. Whether other antiresorptive therapies can prevent osteoporosis in these women is also not clear. Methods We studied the effect of 2.5 mg or 5 mg of alendronate per day or placebo on bone mineral density in 1174 postmenopausal women under 60 years of age. An additional 435 women who were prepared to receive a combination of estrogen and progestin were randomly assigned to one of the above treatments or open-label estrogen–progestin. The main outcome measure was the change in bone mineral density of the lumbar spine, hip, distal forearm, and total body measured annually for two years by dual-energy x-ray absorptiometry. Results The women who received placebo lost bone mineral density at all measured sites, whereas the women treated with 5 mg of alendronate daily had a mean (±SE) increase in bone mineral density of 3.5±...

Markers of bone turnover for the prediction of fracture risk and monitoring of osteoporosis treatment: a need for international reference standards

SummaryThe International Osteoporosis Foundation (IOF) and the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) recommend that a marker of bone formation (serum procollagen type I N propeptide, s-PINP) and a marker of bone resorption (serum C-terminal telopeptide of type I collagen, s-CTX) are used as reference analytes for bone turnover markers in clinical studies.IntroductionBone turnover markers (BTM) predict fracture risk, and treatment-induced changes in specific markers account for a substantial proportion of fracture risk reduction. The aims of this report were to determine their clinical potential in the prediction of fracture risk and for monitoring the treatment of osteoporosis and to set an appropriate research agenda.MethodsEvidence from prospective studies was gathered through literature review of the PUBMED database between the years 2000 and 2010 and the systematic review of the Agency for Healthcare Research and Quality up to 2001.ResultsHigh levels of BTMs may predict fracture risk independently from bone mineral density in postmenopausal women. They have been used for this purpose in clinical practice for many years, but there is still a need for stronger evidence on which to base practice. BTMs provide pharmacodynamic information on the response to osteoporosis treatment, and as a result, they are widely used for monitoring treatment in the individual. However, their clinical value for monitoring is limited by inadequate appreciation of the sources of variability, by limited data for comparison of treatments using the same BTM and by inadequate quality control. IOF/IFCC recommend one bone formation marker (s-PINP) and one bone resorption marker (s-CTX) to be used as reference markers and measured by standardised assays in observational and intervention studies in order to compare the performance of alternatives and to enlarge the international experience of the application of markers to clinical medicine.ConclusionBTM hold promise in fracture risk prediction and for monitoring treatment. Uncertainties over their clinical use can be in part resolved by adopting international reference standards.

Therapeutic equivalence of alendronate 70 mg once-weekly and alendronate 10 mg daily in the treatment of osteoporosis

Dosing convenience is a key element in the effective management of any chronic disease, and is particularly important in the long-term management of osteoporosis. Less frequent dosing with any medication may enhance compliance, thereby maximizing the effectiveness of therapy. Animal data support the rationale that once-weekly dosing with alendronate 70 mg (7 times the daily oral treatment dose) could provide similar efficacy to daily dosing with alendronate 10 mg due to its long duration of effect in bone. In addition, dog studies suggest that the potential for esophageal irritation, observed with daily oral bisphosphonates, may be substantially reduced with once-weekly dosing. This dosing regimen would provide patients with increased convenience and would be likely to enhance patient compliance. We compared the efficacy and safety of treatment with oral once-weekly alendronate 70 mg (N=519), twice-weekly alendronate 35 mg (N=369), and daily alendronate 10 mg (N=370) in a one-year, double- blind, multicenter study of postmenopausal women (ages 42 to 95) with osteoporosis (bone mineral density [BMD] of either lumbar spine or femoral neck at least 2.5 SDs below peak premenopausal mean, or prior vertebral or hip fracture). The primary efficacy endpoint was the comparability of increases in lumbar spine BMD, using strict pre-defined equivalence criteria. Secondary endpoints included changes in BMD at the hip and total body and rate of bone turnover, as assessed by biochemical markers. Both of the new regimens fully satisfied the equivalence criteria relative to daily therapy. Mean increases in lumbar spine BMD at 12 months were: 5.1% (95% CI 4.8, 5.4) in the 70 mg once-weekly group, 5.2% (4.9, 5.6) in the 35 mg twice-weekly group, and 5.4% (5.0, 5.8) in the 10 mg daily treatment group. Increases in BMD at the total hip, femoral neck, trochanter, and total body were similar for the three dosing regimens. All three treatment groups similarly reduced biochemical markers of bone resorption (urinary N-telopeptides of type I collagen) and bone formation (serum bone-specific alkaline phosphatase) into the middle of the premenopausal reference range. All treatment regimens were well tolerated with a similar incidence of upper GI adverse experiences. There were fewer serious upper GI adverse experiences and a trend toward a lower incidence of esophageal events in the once-weekly dosing group compared to the daily dosing group. These data are consistent with preclinical animal models, and suggest that once-weekly dosing has the potential for improved upper GI tolerability. Clinical fractures, captured as adverse experiences, were similar among the groups. We conclude that the alendronate 70 mg once-weekly dosing regimen will provide patients with a more convenient, therapeutically equivalent alternative to daily dosing, and may enhance compliance and long-term persistence with therapy.

Effect of denosumab on bone density and turnover in postmenopausal women with low bone mass after long-term continued, discontinued, and restarting of therapy: a randomized blinded phase 2 clinical trial.

INTRODUCTION Denosumab is a fully human monoclonal antibody that inhibits receptor activator of nuclear factor-kappa B ligand (RANKL), an essential mediator of osteoclast formation, function, and survival that has been shown to decrease bone turnover and increase bone mineral density (BMD) in treated patients. We assessed the long-term efficacy and safety of denosumab, and the effects of discontinuing and restarting denosumab treatment in postmenopausal women with low bone mass. METHODS Postmenopausal women with a lumbar spine T-score of -1.8 to -4.0 or proximal femur T-score of -1.8 to -3.5 were randomized to denosumab every 3 months (Q3M; 6, 14, or 30 mg) or every 6 months (Q6M; 14, 60, 100, or 210 mg); placebo; or open-label oral alendronate weekly. After 24 months, patients receiving denosumab either continued treatment at 60 mg Q6M for an additional 24 months, discontinued therapy, or discontinued treatment for 12 months then re-initiated denosumab (60 mg Q6M) for 12 months. The placebo cohort was maintained. Alendronate-treated patients discontinued alendronate and were followed. Changes in BMD and bone turnover markers (BTM) as well as safety outcomes were evaluated. RESULTS Overall, 262/412 (64%) patients completed 48 months of study. Continuous, long-term denosumab treatment increased BMD at the lumbar spine (9.4% to 11.8%) and total hip (4.0% to 6.1%). BTM were consistently suppressed over 48 months. Discontinuation of denosumab was associated with a BMD decrease of 6.6% at the lumbar spine and 5.3% at the total hip within the first 12 months of treatment discontinuation. Retreatment with denosumab increased lumbar spine BMD by 9.0% from original baseline values. Levels of BTM increased upon discontinuation and decreased with retreatment. Adverse event rates were similar among treatment groups. CONCLUSIONS In postmenopausal women with low BMD, long-term denosumab treatment led to gains in BMD and reduction of BTM throughout the course of the study. The effects on bone turnover were fully reversible with discontinuation and restored with subsequent retreatment.

Low body mass index is an important risk factor for low bone mass and increased bone loss in early postmenopausal women

Thinness (low percentage of body fat, low body mass index [BMI], or low body weight) was evaluated as a risk factor for low bone mineral density (BMD) or increased bone loss in a randomized trial of alendronate for prevention of osteoporosis in recently postmenopausal women with normal bone mass (n = 1609). The 2‐year data from the placebo group were used (n = 417). Percentage of body fat, BMI, and body weight were correlated with baseline BMD (r = −0.13 to −0.43, p < 0.01) and 2‐year bone loss (r = −0.14 to −0.19, p < 0.01). Women in the lowest tertiles of percentage of body fat or BMI had up to 12% lower BMD at baseline and a more than 2‐fold higher 2‐year bone loss as compared with women in the highest tertiles (p ≤ 0.004). Women with a lower percentage of body fat or BMI had higher baseline levels of urine N‐telopeptide cross‐links (r = −0.24 to −0.31, p < 0.0001) and serum osteocalcin (r = −0.12 to −0.15, p < 0.01). To determine if the magnitude of treatment effect of alendronate was dependent on these risk factors, the group treated with 5 mg of alendronate was included (n = 403). There were no associations between fat mass parameters and response to alendronate treatment, which indicated that risk of low bone mass and increased bone loss caused by thinness could be compensated by alendronate treatment. In conclusion, thinness is an important risk factor for low bone mass and increased bone loss in postmenopausal women. Because the response to alendronate treatment is independent of fat mass parameters, prevention of postmenopausal osteoporosis can be equally achieved in thinner and heavier women.

Alendronate treatment of the postmenopausal osteoporotic woman: Effect of multiple dosages on bone mass and bone remodeling

BACKGROUND The effects of the aminobisphosphonate alendronate sodium on bone mass and markers of bone remodeling were investigated. PATIENTS AND METHODS In a multicenter, randomized, double-blind, placebo-controlled, 2-year study, 188 postmenopausal women, aged 42 to 75 years, with low bone mineral density (BMD) of the lumbar spine were randomly assigned to 1 of 6 daily treatment groups: placebo for 2 years, alendronate 5 or 10 mg for 2 years, alendronate 20 or 40 mg for 1 year followed by placebo for 1 year, or alendronate 40 mg for 3 months followed by 2.5 mg for 21 months. All subjects were given 500 mg/d of elemental calcium as calcium carbonate. RESULTS At each dose, alendronate produced significant reductions in markers of bone resorption and formation, and significantly increased bone mass at the lumbar spine, hip, and total body, as compared with decreases (significant at lumbar spine) in subjects receiving placebo. In the 10-mg group, mean urinary deoxypyridinoline/creatinine had declined by 47% at 3 months, and mean serum osteocalcin by 53% at 6 months. Mean changes in BMD over 24 months with 10 mg alendronate were +7.21% +/- 0.49% for the lumbar spine, +5.27% +/- 0.70% for total hip, and +2.53% +/- 0.68% for total body (each P < 0.01) compared to changes of -1.35% +/- 0.61%, -1.20% +/- 0.64% and -0.31% +/- 0.44% at these sites, respectively, with placebo treatment. Progressive increases in BMD of both lumbar spine and total hip were observed in the second year of treatment with 10 mg alendronate (both P < 0.05). CONCLUSION Alendronate, a potent inhibitor of bone resorption, reduces markers of bone remodeling and significantly increases BMD at the lumbar spine, hip, and total body, and is well tolerated at therapeutic doses (5 or 10 mg daily) in the treatment of osteoporosis in postmenopausal women.

The Efficacy and Tolerability of Risedronate Once a week for the Treatment of Postmenopausal Osteoporosis

This study evaluated the efficacy and tolerability of risedronate once a week (35 mg and 50 mg) compared with risedronate 5 mg once daily in women with osteoporosis. We conducted a randomized, double-blind, active-controlled, 2-year study; the primary efficacy assessment was performed after 1 year. Subjects were women aged 50 years or older who had been postmenopausal for at least 5 years, with either a bone mineral density (BMD) T-score of -2.5 or lower (lumbar spine or proximal femur) or a T-score lower than -2 and at least one prevalent vertebral fracture. Subjects received risedronate 5 mg once daily, 35 mg once a week or 50 mg once a week. All subjects also received 1 g daily of elemental calcium supplementation and supplemental vitamin D if the baseline serum levels were low. The primary efficacy measure was percent change in lumbar spine BMD at 12 months. A total of 1,456 women were randomized and received medication; 1,209 (83%) women completed 12 months. The mean percent change (SE) in lumbar spine BMD after 12 months was 4.0% (0.2%) in the 5 mg daily group, 3.9% (0.2%) in the 35 mg group, and 4.2% (0.2%) in the 50 mg group; each once-a-week treatment was determined to be as effective as the daily treatment. Outcomes of the secondary efficacy measurements and safety assessments were also similar in all 3 groups after 12 months. Risedronate 35 mg and 50 mg once a week provide the same efficacy and safety as the daily 5 mg regimen; therefore, the lower dose, 35 mg once a week, is considered optimal for women with postmenopausal osteoporosis who desire a once-a-week regimen.