Efficacy and safety of oral recombinant calcitonin tablets in postmenopausal women with low bone mass and increased fracture risk: a randomized, placebo-controlled trial

The effect of an investigational oral calcitonin tablet upon bone mineral density (BMD) of the spine was investigated in postmenopausal women with low bone mass and at increased risk of fracture. Compared to placebo, calcitonin tablets increased lumbar spine BMD. This agent may provide an additional choice for patients.

INTRODUCTION

An investigational oral salmon calcitonin preparation was previously shown to increase lumbar spine BMD in postmenopausal women with osteoporosis. Our objective was to evaluate the use of this agent in postmenopausal women with low bone mass and at increased fracture risk but not meeting BMD criteria for osteoporosis.

METHODS

Treatment-naïve women were randomized to receive oral recombinant salmon calcitonin tablets or placebo once daily for 1 year. Dual-energy X-ray absorptiometry was performed at baseline and at study weeks 28 and 54. CTx-1, a bone resorption marker, was obtained at the same time points. Subjects returned periodically for tolerability assessment and adverse event (AE) recording.

RESULTS

One hundred twenty-nine women in the USA were randomized, 86 to calcitonin and 43 to placebo. Calcitonin recipients experienced a significant increase from baseline in lumbar spine BMD; the difference compared with placebo was significant. Dosing at bedtime or with dinner was equally effective. CTx-1 was suppressed in calcitonin recipients but not in placebo subjects. Gastrointestinal AEs were common, but the overall safety profile was comparable between groups.

CONCLUSIONS

Oral calcitonin may provide a useful therapeutic alternative for some women with low bone mass.

Inadequate vitamin D status in adolescents with substantial bone mineral density loss during the use of depot medroxyprogesterone acetate injectable contraceptive: a pilot study

STUDY OBJECTIVE

To examine vitamin D and parathormone (PTH) levels in adolescents who experienced substantial bone mineral density (BMD) loss during depot medroxyprogesterone acetate (DMPA) use.

DESIGN

A non-randomized, multi-center study, during which DMPA was administered every 12 weeks and evaluation of lumbar spine and hip BMD by dual-energy X-ray absorptiometry (DXA) was conducted every 6 months. A blood sample for vitamin D and PTH measurements was obtained from adolescents who experienced >5% BMD loss. Vitamin D deficiency was defined as 25-hydroxyvitamin D (25OHD) level of <20 ng/mL, insufficiency as 25OHD level of 20-30 ng/mL, and sufficiency as 25OHD level of >30 ng/mL.

RESULTS

Evaluation of vitamin D and PTH was carried out in 15 participants who experienced BMD loss of > or = 5% during DMPA use. At initiation of DMPA, participants had mean (+SE) age 17+1 years, gynecologic age 61+4 months, and body mass index 24+1.5 kg/m2. Racial/ethnic distribution was: Caucasian--7 girls, Hispanic--4 girls, African-American--3 girls, and other--1 girl. Six participants had BMD loss of >5% after 2 DMPA injections, five after 3 injections, one after 5 injections, one after 8 injections, one after 10 injections, and one after 13 injections. Only one girl (7%) had sufficient vitamin D. The other participants had vitamin D insufficiency (50%) or deficiency (43%). Participants' mean (+SE) PTH was 22+4 pg/mL (reference range 7-53 pg/mL), and mean (+SE) 1,25-dihydroxyvitamin D was 56+5 pg/mL (reference range 22-67 pg/mL).

CONCLUSIONS

Inadequate vitamin D status was evident among the majority of female adolescents who experienced a substantial BMD loss while using DMPA.

Effect of denosumab on bone mineral density (BMD) in women with breast cancer (BC) and men with prostate cancer (PC) undergoing hormone ablation therapy

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Background: Hormone ablation therapies, including adjuvant aromatase inhibitor (AI) therapy and androgen deprivation therapy (ADT), improve recurrence-free survival in patients (pts) with BC and PC, respectively. However, these treatments increase bone resorption, leading to bone loss and fractures. RANKL is a key mediator of osteoclast-mediated bone resorption. In this 24 month (mo) comparison, we investigated the effects of denosumab, a fully human monoclonal antibody against RANKL, on preserving BMD across both populations. Methods: Two trials were conducted: a 24-mo BC study and a 36-mo PC study. Postmenopausal women with low BMD receiving AI therapy for nonmetastatic BC and men receiving ADT for nonmetastatic PC (with low BMD or history of osteoporotic fracture if < 70 yrs) were randomized to receive placebo or denosumab 60mg subcutaneously every 6 mos. All pts in both studies were prescribed calcium and vitamin D supplements. The primary endpoint was % change from baseline in lumbar spine (LS) BMD at 12 mos for the BC study and at 24 mos for the PC study. Herein, we present changes in BMD at 24 mos at LS, total hip (TH), and 1/3 radius from both studies. Power calculations were based on enrollment of at least 208 patients in the BC study (for primary endpoint only) and 1226 in the PC study (for primary and key secondary endpoints). The actual numbers randomized were 252 and 1468, respectively. Results: Denosumab increased BMD of the LS, TH, and 1/3 radius compared with placebo at 24 mos in both pt populations ( Table ). In both studies, differences between denosumab and placebo at each skeletal site were consistent, and the effects of denosumab were statistically significantly different from placebo as early as 1 month at the LS in both studies. The overall safety profile was similar to placebo in each study. Conclusions: Denosumab consistently increased BMD at all 3 skeletal sites compared with placebo in both women with BC undergoing AI therapy and in men with PC undergoing ADT.

[Table: see text]

[Table: see text]

[Diagnosis and therapy of sepsis. Guidelines of the German Sepsis Society Inc. and the German Interdisciplinary Society for Intensive and Emergency Medicine]

A recent survey conducted by the publicly funded Competence Network Sepsis (SepNet) reveals that severe sepsis and/or septic shock occurs in 75,000 inhabitants (110 out of 100,000) and sepsis in 79,000 inhabitants (116 out of 100,000) in Germany annually. This illness is responsible for approximately 60,000 deaths and ranges as the third most frequent cause of death after acute myocardial infarction. Direct costs for the intensive care of patients with severe sepsis alone amount to approximately 1.77 billion euros, which means that about 30% of the budget in intensive care is used to treat severe sepsis. However, until now German guidelines for the diagnosis and therapy of severe sepsis did not exist. Therefore, the German Sepsis Society initiated the development of guidelines which are based on international recommendations by the International Sepsis Forum (ISF) and the Surviving Sepsis Campaign (SSC) and take into account the structure and organization of the German health care system. Priority was given to the following guideline topics: a) diagnosis, b) prevention, c) causative therapy, d) supportive therapy, e) adjunctive therapy. The guidelines development process was carefully planned and strictly adhered to the requirements of the Working Group of Scientific Medical Societies (AWMF).

[Diagnosis and therapy of sepsis: guidelines of the German Sepsis Society Inc. and the German Interdisciplinary Society for Intensive and Emergency Medicine]

A recent survey conducted by the publicly funded Competence Network Sepsis (SepNet) reveals that severe sepsis and/or septic shock occurs in 75,000 inhabitants (110 out of 100,000) and sepsis in 79,000 inhabitants (116 out of 100,000) in Germany annually. This illness is responsible for approximately 60,000 deaths and ranges as the third most frequent cause of death after acute myocardial infarction. Direct costs for the intensive care of patients with severe sepsis alone amount to approximately 1.77 billion euros, which means that about 30% of the budget in intensive care is used to treat severe sepsis. However, until now German guidelines for the diagnosis and therapy of severe sepsis did not exist. Therefore, the German Sepsis Society initiated the development of guidelines which are based on international recommendations by the International Sepsis Forum (ISF) and the Surviving Sepsis Campaign (SSC) and take into account the structure and organization of the German health care system. Priority was given to the following guideline topics: a) diagnosis, b) prevention, c) causative therapy, d) supportive therapy, e) adjunctive therapy. The guidelines development process was carefully planned and strictly adhered to the requirements of the Working Group of Scientific Medical Societies (AWMF).

Managing 'suspicious glaucomatous discs' identified during digital-photography-based diabetic retinopathy screening

PURPOSE

An audit to demonstrate the outcome of patients identified with suspicious glaucomatous discs within a digital-photography-based diabetic retinopathy screening programme.

METHODS

Primary care based digital photographic screening was performed utilising mydriasis and two-field digital photography for all patients with diabetes. Patients identified with discs suspicious of glaucomatous optic neuropathy (GON) were initially referred to an accredited community-based optometrist for further assessment. Some patients were then referred to secondary care where appropriate.

RESULTS

From 1st April 2002 to 31st March 2003 a total of 3868 patients were screened for diabetic retinopathy. This audit revealed that 55 subjects were identified by retinal screeners as having discs suspicious of glaucoma. A total of 29 were already under glaucoma clinic review. A total of 23/26 remaining were referred for an assessment by an accredited optometrist. Of these 13 were normal, 6 were referred to secondary care and 4 failed to attend. The three remaining were referred directly to secondary care.

CONCLUSIONS

All nine referrals to secondary care were deemed appropriate by a glaucoma specialist. This suggests that the system described does not lead to over-referral of suspicious discs - although the issue of how many glaucomatous discs are missed during screening (false negatives) will only be answered in the longer term.

Uncertain future of trials in osteoporosis

The advent of effective agents for the treatment of osteoporosis has led to the view that placebo-controlled trials to test new agents for efficacy are no longer appropriate since proven treatments are available. In this review we argue that, if new agents are to be developed, there is still a place for the placebo-controlled trial. A move to studies of equivalence or non-inferiority raises more problems than it resolves.

Antigen-receptor cross-linking and lipopolysaccharide trigger distinct phosphoinositide 3-kinase-dependent pathways to NF-kappa B activation in primary B cells

The NF-kappaB/Rel transcription factors play an important role in the expression of genes involved in B cell development, differentiation and function. Nuclear NF-kappaB is induced in B cells by engagement of either the BCR or CD40 or by stimulation with lipopolysaccharide (LPS). Despite the importance of NF-kappaB to B cell function, little is known about the signaling pathways leading to NF-kappaB activation. In this report we address the role of phosphoinositide 3'-kinase (PI 3-kinase) in BCR- and LPS-induced NF-kappaB activation using populations of primary murine resting B cells. Using the specific pharmacological inhibitors of PI 3-kinase, Wortmannin and LY294002, we demonstrate that PI 3-kinase activity is vital for BCR-induced NF-kappaB DNA-binding activity. Furthermore, we show that this is achieved via protein kinase C-dependent degradation of IkappaBalpha. Similar analyses reveal that PI 3-kinase is also critical in triggering NF-kappaB DNA-binding activity and IkappaBalpha degradation following LPS stimulation. Interestingly, a PKC inhibitor which blocked the BCR-induced IkappaBalpha degradation had no effect on the degradation of IkappaBalpha after LPS stimulation. Taken together, our results indicate the involvement of PI 3-kinase in at least two distinct signaling pathways leading to activation of NF-kappaB in B cells.

Bisphosphonates: safety and efficacy in the treatment and prevention of osteoporosis

Osteoporosis affects more than 28 million Americans. With the advent of accessible and affordable diagnostic studies, awareness and recognition of this disease by patients and clinicians are growing. Osteoporotic fractures of the spine and hip are costly and associated with significant morbidity and mortality. Over the past decade, a surge of new antiosteoporotic drugs have been labeled or are awaiting labeling by the U.S. Food and Drug Administration. One class of agents used to treat osteoporosis is the bisphosphonates, which inhibit bone resorption, cause an increase in bone mineral density and reduce the risk of future fractures caused by aging, estrogen deficiency and corticosteroid use. Overall, bisphosphonates have been shown to have a strong safety and tolerability profile.

Shc associates with the IL-3 receptor beta subunit, SHIP and Gab2 following IL-3 stimulation. Contribution of Shc PTB and SH2 domains

p46(Shc) and p52(Shc) become heavily tyrosine phosphorylated in response to interleukin 3 (IL-3) treatment. We have investigated the potential of Shc to integrate IL-3 signalling pathways and demonstrate that Shc associates with the beta subunits of the human (betac) and murine (Aic2A) IL-3 receptors, SHIP and Gab2 following IL-3 stimulation. The interaction between Shc and the IL-3 receptor beta chains was direct, mediated by both the SH2 and PTB domains. Interaction with SHIP was via the Shc PTB domain and the Shc SH2 domain mediated the interaction with Gab2. Phosphopeptide competition studies suggest that the SH2 domain interacts primarily with tyrosine 612 of betac (610 of Aic2A), and the PTB domain with tyrosine 577 of betac (575 of Aic2A). PTB binding to IL-3R beta chains was of highest affinity, and appeared to play the primary role in binding. These findings suggest that Shc may play an important role in coordinately integrating IL-3 signalling pathways.

SHP1 and SHP2 protein-tyrosine phosphatases associate with betac after interleukin-3-induced receptor tyrosine phosphorylation. Identification of potential binding sites and substrates

The cytoplasmic tyrosine phosphatases, SHP1 and SHP2, are implicated in the control of cellular proliferation and survival. Here we demonstrate that both SHP1 and SHP2 associate with the betac subunit of the human interleukin-3 (IL-3) receptor following IL-3 stimulation and that the src homology region 2 (SH2) domains of these phosphatases mediate this interaction. Sequential immunoprecipitation analyses suggest this interaction is direct. Competition studies, using phosphotyrosine-containing peptides based on sequences surrounding key tyrosine residues within betac, suggest that phosphorylation of tyrosine 612 is the key event mediating the association of betac with SHP1 and SHP2. However, inhibition of SHP2 binding to betac, did not prevent tyrosine phosphorylation of SHP2. Interestingly, this same phosphopeptide served as a substrate for the tyrosine phosphatase activity of both SHP1 and SHP2. Binding of these protein-tyrosine phosphatases to the IL-3 receptor may regulate IL-3 signal transduction pathways, both through their catalytic activity and through the recruitment of other molecules to the receptor complex.

Insulin receptor substrate-2 is the major 170-kDa protein phosphorylated on tyrosine in response to cytokines in murine lymphohemopoietic cells

Insulin receptor substrate 1 (IRS-1), and its structural relative IRS-2, are both phosphorylated on tyrosine following treatment of cells with interleukin-4 (IL-4) and insulin. We have investigated whether both IRS-1 and IRS-2 are expressed in murine lymphohemopoietic cells. T and B lymphocytes and macrophages from primary cultures expressed only IRS-2, which became phosphorylated on tyrosine following stimulation with both IL-4 and insulin. Likewise, the murine myeloid cell line FD-5 expressed only IRS-2, which was tyrosine phosphorylated in response to IL-4 and insulin, as well as interleukin-3 and granulocyte-macrophage colony stimulating factor. Neither IRS-1 nor IRS-2 were expressed at detectable levels in primary bone marrow mast cells although these cells do respond to IL-4. Moreover, a factor-dependent lymphocyte cell line, CT.4S, which grows continuously in IL-4, did not express detectable levels of IRS-1 or IRS-2. IRS-2 from FD-5 cells stimulated with either IL-4 or insulin bound to glutathione S-transferase fusion proteins of the p85 subunit of phosphoinositol 3'-kinase, Grb2, and Syp, paralleling reported associations of IRS-1 with these molecules and indicating phosphorylation of the corresponding residues on IRS-2.

Interleukin-13 signal transduction in lymphohemopoietic cells. Similarities and differences in signal transduction with interleukin-4 and insulin

Interleukin-13 (IL-13) and interleukin-4 (IL-4) are related in structure and function and are thought to share a common receptor component. We have investigated the signal transduction pathways activated by these two growth factors, as well as insulin, in cell-lines and primary cells of lymphohemopoietic origin. All three factors induced the tyrosine phosphorylation of a protein of 170 kDa (p170), which coimmunoprecipitated with the p85 subunit of P13'-kinase, via high affinity interactions mediated by the SH2 domains of p85. Antibodies raised against the entire insulin-receptor substrate-1 (IRS-1) protein immunoprecipitated p170 much less efficiently than they did IRS-1 from 3T3 cells. However, antibodies directed against the conserved pleckstrin homology domain of IRS-1 immunoprecipitated both p170 and IRS-1 with similar efficiency, suggesting they share structural similarities in this region. In lymphohemopoietic cells, IL-13, IL-4, and insulin failed to induce increased tyrosine phosphorylation of Shc, or its association with grb2, modification of Sos1, or activation of erk-1 and erk-2 mitogen-activated protein kinases, suggesting that p170 mediates downstream pathways distinct from those mediated by IRS-1. Both IL-13 and IL-4 induced low levels of tyrosine phosphorylation of Tyk-2 and Jak-1. IL-4 also activated the Jak-3-kinase, but, despite other similarities, IL-13 did not. Insulin failed to activate any of the known members of the Janus family of kinases. In that Jak-3 is reported to associate with the IL-2 gamma c chain, these data suggest that the IL-13 receptor does not utilize this subunit. However, both IL-13 and IL-4 induced tyrosine phosphorylation of the IL-4-140 kDa receptor chain, suggesting that this is a component of both receptors in these cells and accounts for the similarities in signaling pathways shared by IL-13 and IL-4.

The role of 1 alpha, 25-dihydroxyvitamin D in the mediation of intestinal hyperabsorption of calcium in primary hyperparathyroidism and absorptive hypercalciuria

The cuase for the intestinal hyperabsorptionof calcium (Ca) in various forms of hypercalciurias was explored by a careful measurement of plasma 1 alpha, 25-dihydroxycholecalciferol [1 alpha, 25-(OH)I D] and by an assessment of intestinal Ca absorption and of parathyroid function. In 18 cases of primary hyperparathyroidism (PHPT), the mean plasma concentration of 1 alpha, 25-(OH)2D was significantly increased (4.9 +/- 2.2 SD ng/dl vs. 3.4 +/- 0.9 ng/dl for the control group), and was significantly correlated with fractional Ca absorption (alpha) (r = 0.80, P less than 0.001). Plasma 1 alpha, 25-(OH)2D was also correlated with urinary Ca (P less than 0.05), but not with serum Ca or phosphorus (P), P clearance, urinary cyclic AMP, or serum immunoreactive parathyroid hormone. In 21 cases of absorptive hypercalciuria (AH), plasma 1 alpha, 25-(OH)2D was elevated in one-third of cases, and the mean value of 4.5 +/- 1.1 ng/dl was significantly higher than that of the control group (P less than 0.01). Since relative hypoparathyroidism may be present, the normal absolute value of plasma 1 alpha, 25-(OH)2D, found in two-thirds of cases of AH, may be considered to be inappropriately high. Moreover, in the majority of cases of AH, the data points relating plasma 1 alpha, 25-(OH)2D and alpha fell within 95% confidence limits of values found in non-AH groups (including PHPT). The results suggest that the intestinal hyperabsorption of Ca in PHPT aw AH may be vitamin D dependent. However, the disturbance in vitamin D metabolism may not be the sole cause for the high Ca absorption in AH, since in some patients with AH, the intestinal Ca absorption appears to be inapp

Photon absorptiometric analysis of bone density in primary hyperparathyroidism

The density of bone in the distal third of the radius was measured in 13 men and 17 women with primary hyperparathyroidism. The bone density was significantly reduced (as compared to age-matched controls) in 7 of 11 postmenopausal women. However, it was reduced in only 2 of 13 men and in 1 of 6 premenopausal women. Thus, most of the postmenopausal women with primary hyperparathyroidism had low bone density, whereas most men and premenopausal women with this condition had normal bone density. The results support the conclusion that oestrogen deficiency may contribute to the development of bone disease by sensitising bone to the action of parathyroid hormone.

A simple test for the diagnosis of absorptive, resorptive and renal hypercalciurias

A test was developed to diagnose various forms of hypercalciuria. A two-hour urine sample after an overnight fast and a four-hour urine sample after 1 g of calcium by mouth were tested for calcium, cyclic AMP and creatinine. The 24 patients with absorptive hypercalciuria had normocalcemia and normal fasting urinary calcium (less than 0.11 mg per milligram of urinary creatnine). Urinary calcium was high (greater than or equal to 0.2 mg per milligram of creatinine) after a calcium load. Of the 28 patients with primary hyperparathyroidism (resorptive hypercalciuria), 25 had hypercalcemia and 21 had high fasting urinary calcium. Urinary cyclic AMP, elevated in 30 per cent of fasting patients, was high (greater than 4.60 mu moles per gram of creatinine) in 82 per cent of cases after calcium load. Six patients with renal hypercalciuria had normocalcemia, high fasting urinary calcium, and high (greater than 6.86 mu moles per gram of creatinine) or high-normal fasting urinary cyclic AMP was normal. This simple test should facilitate the differentiation of various causes of hypercalciuria.