Wnt modulators in the biotech pipeline.
Rey JP, Ellies DL
Dev. Dyn. Jan 2010
PMID: 20014100 | Free Full Text
A more favorable approach to the modulation of the Wnt pathway has been to focus on extracellular mediators of the pathway. Where, Amgen is the first in class to develop a biologic therapeutic against Sclerostin (Human Clinical Phase II). Nuvelo is following Amgen with biologics against LRP5, Dkk1, and R-Spondin (Discovery). Second in class for Sclerostin blocking antibodies will be Novartis and Eli Lilly (Preclinical). Fibrogen, who is taking a different approach, has developed a biologic against CCN family member CTGF (Preclinical). As for small molecules, OsteoGeneX is first in class to develop a Sclerostin small molecule inhibitor, currently in preclinical and lead optimization. Alternatively to Sclerostin, Galapagos is developing small molecule leads against LRP5 in a partnership with Eli-Lilly (Discovery).
Blosozumab is a new sclerostin inhibitor developed by Eli Lilly. According to Wikipedia:
Phase II trial of a monoclonal human antibody to sclerostin from Eli Lilly had positive effects on post-menopausal women. Monthly treatments of the antibody for one year increased the bone mineral density of the spine and hip by 18 percent and 6 percent, respectively, compared to the placebo group.
Romosozumab is a new Sclerostin Inhibitor from Amgen. Specifically it is a humanized monoclonal antibody that targets sclerostin for the treatment of osteoporosis. According to Wikipedia:
Its use has increased bone growth in preclinical trials in osteoporotic rats and monkeys. In a Phase I study, a single dose of anti-sclerostin antibody from Amgen (Romosozumab) increased bone density in the hip and spine in healthy men and postmenopausal women and the drug was well tolerated. In a Phase II trial, one year of the antibody treatment in osteoporotic women increased bone density more than bisphosphonate and teriparatide treatment….
The Amgen drug is expected to be on the market in 2017 and is predicted to be the gold standard in osteoporosis treatment by 2021.
Low bone mineral density is associated with increased arterial stiffness in participants of a health records based study.
Many epidemiological studies have shown that low bone mineral density (BMD) and atherosclerosis appear to be related. However, their precise correlation is not completely understood after full adjustment the shared confounders of atherosclerosis and bone metabolism. The aim of this cross-sectional study was to investigate the relationship between BMD and subclinical atherosclerosis in a healthy Chinese population and the difference in gender.
The study population consisted of 2,487 subjects (1,467 men, 1,020 women) who participated in health check-up programs and were selected to be free of major diseases which might affect atherosclerosis and bone metabolism. Bone status was assessed by BMD in lumbar spine. The brachial-ankle PWV (baPWV) was assessed as a functional marker of atherosclerosis. The ankle-brachial index (ABI), carotid artery intima-media thickness (CIMT), estimated glomerular filtration rate (eGRF) and microalbuminuria were evaluated as indexes of structural markers of atherosclerosis.
After adjustment for risk factors, significant association was shown between baPWV and BMD in both genders (male: r=-0.084, P=0.035; female: r=-0.088, P=0.014). The correlation was stronger in females than in males, and in females, the correlation was stronger after menopause. Similarly, mean baPWV differed significantly according to the decreased BMD (normal BMD, Osteopenia, Osteoporosis). In contrast, no significant differences were observed for ABI, CIMT, eGFR or microalbuminuria with BMD.
Independent of confounding factors, low BMD is associated with the functional marker of subclinical atherosclerosis (increased baPWV), but not with structural markers (ABI, CIMT, eGFR or microalbuminuria) among healthy females and males.
Wang YQ, Yang PT, Yuan H, Cao X…
J Thorac Dis May 2015
PMID: 26101634 | Free Full Text
From the full text discussion:
There are several potential mechanisms to explain this link. Both osteoporosis and atherosclerosis share similar or common risk factors. Bone-associated matrix proteins, homocysteine, high levels of OPG, inflammatory mediators, estrogen and vitamin D deficiency all play an important role both in bone metabolism and in the development of atherosclerosis (32).
Dietary calcium intake and mortality risk from cardiovascular disease and all causes: a meta-analysis of prospective cohort studies.
Considerable controversy exists regarding the association between dietary calcium intake and risk of mortality from cardiovascular disease and all causes. Therefore, we performed a meta-analysis of prospective cohort studies to examine the controversy.
We identified relevant studies by searching MEDLINE, Embase, and the Cochrane Library databases between 1 September 2013 and 30 December 2013. Reference lists of relevant articles were also reviewed. Observational prospective studies that reported relative risks and 95% confidence intervals for the association of calcium intake with cardiovascular and all-cause mortality were eligible. Study-specific relative risks were pooled using a random-effects model.
In this meta-analysis, 11 prospective studies with 12 independent cohorts, involving 757,304 participants, were eligible. There was evidence of a non-linear association between dietary calcium intake and risk of mortality from cardiovascular disease (P for non-linearity <0.01) and all causes (P for non-linearity <0.01). A dose-response analysis showed a U-shaped relationship between dietary calcium intake and cardiovascular mortality. Intakes that were lower and higher than around 800 mg/day were gradually associated with a higher risk of cardiovascular mortality. For all-cause mortality, we also observed a threshold effect at intakes around 900 mg/day. The risk of all-cause mortality did not decrease further at intakes above 900 mg/day.
This meta-analysis of prospective cohort studies suggests that dietary calcium intake is associated with cardiovascular mortality in a U-shaped manner and that high dietary calcium intake (>900 mg/day) is not associated with a decreased risk of all-cause mortality.
Wang X, Chen H, Ouyang Y, Liu J…
BMC Med 2014
PMID: 25252963 | Free Full Text
From the full text:
Dietary calcium intake and risk of fracture and osteoporosis: prospective longitudinal cohort study.
To investigate associations between long term dietary intake of calcium and risk of fracture of any type, hip fractures, and osteoporosis.
A longitudinal and prospective cohort study, based on the Swedish Mammography Cohort, including a subcohort, the Swedish Mammography Cohort Clinical.
A population based cohort in Sweden established in 1987.
61,433 women (born between 1914 and 1948) were followed up for 19 years. 5022 of these women participated in the subcohort.
Primary outcome measures were incident fractures of any type and hip fractures, which were identified from registry data. Secondary outcome was osteoporosis diagnosed by dual energy x ray absorptiometry in the subcohort. Diet was assessed by repeated food frequency questionnaires.
During follow-up, 14,738 women (24%) experienced a first fracture of any type and among them 3871 (6%) a first hip fracture. Of the 5022 women in the subcohort, 1012 (20%) were measured as osteoporotic. The risk patterns with dietary calcium were non-linear. The crude rate of a first fracture of any type was 17.2/1000 person years at risk in the lowest quintile of calcium intake, and 14.0/1000 person years at risk in the third quintile, corresponding to a multivariable adjusted hazard ratio of 1.18 (95% confidence interval 1.12 to 1.25). The hazard ratio for a first hip fracture was 1.29 (1.17 to 1.43) and the odds ratio for osteoporosis was 1.47 (1.09 to 2.00). With a low vitamin D intake, the rate of fracture in the first calcium quintile was more pronounced. The highest quintile of calcium intake did not further reduce the risk of fractures of any type, or of osteoporosis, but was associated with a higher rate of hip fracture, hazard ratio 1.19 (1.06 to 1.32).
Gradual increases in dietary calcium intake above the first quintile in our female population were not associated with further reductions in fracture risk or osteoporosis.
Warensjö E, Byberg L, Melhus H, Gedeborg R…
PMID: 21610048 | Free Full Text
From the full text:
• Dietary calcium intakes below approximately 700 mg per day in women were associated with an increased risk of hip fracture, any fracture, and of osteoporosis
• The highest reported calcium intake did not further reduce the risk of fractures of any type, or of osteoporosis, but was associated with a higher rate of hip fracture
Effect of calcium supplementation on hip fractures.
There have been numerous studies of the effects of calcium supplementation, with or without vitamin D, on fractures. Individually, they have not provided clarity regarding calcium’s anti-fracture efficacy, though they have established that calcium does have beneficial effects on bone density throughout the skeleton in women. Meta-analysis of these data suggests that total fracture numbers are diminished. However, the data from the 5,500 women involved in trials of calcium monotherapy show consistent adverse trends in numbers of hip fractures (relative risk 1.50, 95% CI 1.06-2.12). Observational data from the Study of Osteoporotic Fractures show a similar increase in risk of hip fracture associated with calcium use. We hypothesize that reduced periosteal expansion in women using calcium supplementation might account for the differences in anti-fracture efficacy of calcium at the hip, in comparison with other sites. Until there are further trial results to clarify this area, the present findings suggest that reliance on high calcium intakes to reduce the risk of hip fracture in older women is not appropriate. In addition, those at risk should be looking to other agents with a proven capacity to prevent hip fractures, such as bisphosphonates.
Reid IR, Bolland MJ, Grey A
Osteoporos Int Aug 2008
PMID: 18286218 | Free Full Text
Furthermore, our own recent trial of calcium monotherapy suggested that there might be heterogeneity between the responses of hip and other fractures to calcium supplementation , with downward trends in vertebral, forearm, and total osteoporotic fractures, but a significant increase in hip fractures.
Observational studies have also assessed the relationship between calcium use and fractures. While there is a potential problem of confounding by indication, it is noteworthy that the Study of Osteoporotic Fractures reported an increase in hip fracture risk in postmenopausal women taking calcium supplements of almost identical magnitude to that found in the present meta-analysis (relative risk 1.5; 95%CI, 1.1–2.0) . This consistency across the available intervention studies and a large observational study raises doubts regarding the safety of calcium monotherapy in elderly postmenopausal women, though we cannot completely preclude the possibility that these results are a chance finding arising from the smaller numbers of this particular fracture type.
The adverse effect of calcium monotherapy on hip fractures poses the question of how this could occur when the same intervention has the opposite effect on total fracture numbers.
Biological and therapeutic effects of ortho-silicic acid and some ortho-silicic acid-releasing compounds: New perspectives for therapy.
Silicon (Si) is the most abundant element present in the Earth’s crust besides oxygen. However, the exact biological roles of silicon remain unknown. Moreover, the ortho-silicic acid (H4SiO4), as a major form of bioavailable silicon for both humans and animals, has not been given adequate attention so far. Silicon has already been associated with bone mineralization, collagen synthesis, skin, hair and nails health atherosclerosis, Alzheimer disease, immune system enhancement, and with some other disorders or pharmacological effects. Beside the ortho-silicic acid and its stabilized formulations such as choline chloride-stabilized ortho-silicic acid and sodium or potassium silicates (e.g. M2SiO3; M= Na,K), the most important sources that release ortho-silicic acid as a bioavailable form of silicon are: colloidal silicic acid (hydrated silica gel), silica gel (amorphous silicon dioxide), and zeolites. Although all these compounds are characterized by substantial water insolubility, they release small, but significant, equilibrium concentration of ortho-silicic acid (H4SiO4) in contact with water and physiological fluids. Even though certain pharmacological effects of these compounds might be attributed to specific structural characteristics that result in profound adsorption and absorption properties, they all exhibit similar pharmacological profiles readily comparable to ortho-silicic acid effects. The most unusual ortho-silicic acid-releasing agents are certain types of zeolites, a class of aluminosilicates with well described ion(cation)-exchange properties. Numerous biological activities of some types of zeolites documented so far might probably be attributable to the ortho-silicic acid-releasing property. In this review, we therefore discuss biological and potential therapeutic effects of ortho-silicic acid and ortho-silicic acid -releasing silicon compounds as its major natural sources.
Jurkić LM, Cepanec I, Pavelić SK, Pavelić K
Nutr Metab (Lond) 2013
PMID: 23298332 | Free Full Text
The full text article (link above) has a subsection on osteoporosis:
…Interestingly, the administration of silicon in a controlled clinical study induced a significant increase in femoral bone mineral density in osteoporotic women . Direct relationship between silicon content and bone formation has been shown by Moukarzel et al. . They found a correlation between decreased silicon concentrations in total parenterally fed infants with a decreased bone mineral content. This was the first observation of a possible dietary deficiency of silicon in humans. A randomized controlled animal study on aged ovariectomized rats revealed that long-term preventive treatment with ch-OSA prevented partial femoral bone loss and had a positive effect on the bone turnover . Dietary silicon is associated with postmenopausal bone turnover and bone mineral density at the women’s age when the risk of osteoporosis increases. Moreover, in a cohort study on 3198 middle-aged woman (50–62 years) it was shown that silicon interacts with the oestrogen status on bone mineral density, suggesting that oestrogen status is important for the silicon metabolism in bone health .
Choline-stabilized orthosilicic acid supplementation as an adjunct to calcium/vitamin D3 stimulates markers of bone formation in osteopenic females: a randomized, placebo-controlled trial.
Mounting evidence supports a physiological role for silicon (Si) as orthosilicic acid (OSA, Si(OH)4) in bone formation. The effect of oral choline-stabilized orthosilicic acid (ch-OSA) on markers of bone turnover and bone mineral density (BMD) was investigated in a double-blind placebo-controlled trial.
Over 12-months, 136 women out of 184 randomized (T-score spine < -1.5) completed the study and received, daily, 1000 mg Ca and 20 microg cholecalciferol (Vit D3) and three different ch-OSA doses (3, 6 and 12 mg Si) or placebo. Bone formation markers in serum and urinary resorption markers were measured at baseline, and after 6 and 12 months. Femoral and lumbar BMD were measured at baseline and after 12 months by DEXA.
Overall, there was a trend for ch-OSA to confer some additional benefit to Ca and Vit D3 treatment, especially for markers of bone formation, but only the marker for type I collagen formation (PINP) was significant at 12 months for the 6 and 12 mg Si dose (vs. placebo) without a clear dose response effect. A trend for a dose-corresponding increase was observed in the bone resorption marker, collagen type I C-terminal telopeptide (CTX-I). Lumbar spine BMD did not change significantly. Post-hoc subgroup analysis (baseline T-score femur < -1) however was significant for the 6 mg dose at the femoral neck (T-test). There were no ch-OSA related adverse events observed and biochemical safety parameters remained within the normal range.
Combined therapy of ch-OSA and Ca/Vit D3 had a potential beneficial effect on bone collagen compared to Ca/Vit D3 alone which suggests that this treatment is of potential use in osteoporosis.
Spector TD, Calomme MR, Anderson SH, Clement G…
BMC Musculoskelet Disord 2008
PMID: 18547426 | Free Full Text
From the full text:
Collagen provides elasticity and structure in all connective tissues and several studies have indicated that collagen is important for bone toughness [43-45] whereas the mineral component is mainly involved in providing stiffness. Wang et al.  demonstrated that the mechanical integrity of collagen fibres deteriorates with ageing in human cortical bones and is associated with a higher fracture risk. When the collagen network becomes weaker with age, it will result in decreased toughness, possibly due to a reduction in natural cross-links or silicon content. It has previously been suggested that Si may be an integral (structural) component of connective tissues as high levels of non-dialysable Si has been reported in connective tissues and their components suggesting strong (covalent) associations .
Calcium builds strong bones, and more is better–correct? Well, maybe not.
Calcium supplementation has been considered the gold standard therapy for osteoporosis in the general population. It is given in both the placebo and treatment groups of trials evaluating antifracture efficacy of new therapies. Similarly, calcium-based phosphate binders have been considered the gold standard comparator for all new phosphate binders. However, large randomized trials demonstrate conflicting data on the antifracture efficacy of calcium supplementation, particularly in high doses, in patients with osteoporosis without CKD. In addition, recent data suggest an increased risk for cardiovascular events. These new studies raise safety concerns for the general approach with calcium supplementation and binders. This review describes recent data on the adverse effects of calcium supplementation for osteoporosis and how these new data should affect the strategy for phosphate binder use in CKD.
Jamal SA, Moe SM
Clin J Am Soc Nephrol Nov 2012
PMID: 22837272 | Free Full Text
It is important to note that some clinical practice guidelines have been modified on the basis of this new literature suggesting potential risk. For example, in its recently published evidence-based guidelines, Osteoporosis Canada recommended a total intake of calcium (from diet and supplement) of 1200 mg per day, a decrease from the previous recommendation of 1500 mg in supplements (32). The American Society for Bone and Mineral Research issued a statement regarding the potential risks of calcium supplements and suggested, among other points, that “the beneficial effects of calcium are found with relatively low doses. More is not necessarily better. Individuals should discuss the amount of their calcium intake with their healthcare provider” (33). The Institute of Medicine now recommends a daily dietary reference allowance of calcium of 1000–1200 mg per day in the form of diet and supplements (34,35). Finally, the draft United States Preventive Services Task Force statement, pending public comment (http://www.uspreventiveservicestaskforce.org/draftrec3.htm), currently states “the current evidence is insufficient to assess the balance of the benefits and harms of combined vitamin D and calcium supplementation for the primary prevention of fractures in premenopausal women or in men.” Thus, these authorities acknowledge that although some calcium supplements may be beneficial for bone health, too much calcium may be harmful.