HIGHLIGHTS OF THE MEETING
The 8th ECCEO meeting, here in Istanbul, is the largest meeting in Europe in the field of osteoporosis and osteoarthritis, with about 4000 attendees seeking information on epidemiology, pathogenesis, prevention, and treatment of osteoporosis and osteoarthritis. Over 500 abstracts were submitted addressing all these topics.
The meeting started Wednesday April 9 with the Servier Honorary Lecture given by Professor Karsenty, from Columbia University, who provided scientific evidence that there is a common endocrine regulation of bone and energy metabolism and that it involves a central control of bone mass. After this very informative Lecture, all the participants were invited to the well-organised Welcome Reception at the Grand Cevahir Hotel. However, even after such a nice evening, the attendance was huge to assist, on Thursday, at the first plenary session of the ECCEO 8 meeting dealing mainly with the epidemiology and the clinical management of osteoporosis.
Cost-effectiveness analysis
The first session began with the plenary lecture of Professor Kanis who reminded us that guidelines commonly recommend that treatment is offered to patients in whom a bone mineral density (BMD) test falls below a critical value (e.g. T-score <- 1.5 or -2.5 SD) (PL2). Recent developments have, however, permitted the more accurate assessment of fracture risk, based on prognostic information from clinical risk factors alone or in combination with BMD tests. As a rule of thumb, it has been suggested that intervention is worthwhile in developed countries when the cost/quality of life year gains are 1 to 2 times the Gross Domestic Product of the nation. Using these yard-sticks, Professor Kanis said that it is evident that cost-effective scenarios can be found both for the prevention and treatment of osteoporosis with many of the available treatments.
In close relation with the plenary session, a new Markov microsimulation model was presented, based on a lifetime horizon and 5-year length of therapy, to evaluate the cost-effectiveness of strontium ranelate versus calcium/vitamin D (OC10). The results in the base case analysis and sensitivity analyses indicated that strontium ranelate is a very cost-utility strategy when compared to calcium/vitamin D for postmenopausal Belgian women over 70 years of age either with osteoporosis or with a prevalent vertebral fracture.
Risk factor for fractures
During the previous ECCEO meetings, it has been shown that falls and low bone mineral density are main determinants of low trauma fractures in the elderly. It has also been shown that alterations of bone architecture contribute with low BMD to skeletal fragility. Sornay-Rendu, from Lyon, showed that in postmenopausal women, vertebral fractures were associated with low volumetric bone density and architectural alterations of trabecular and cortical bone at the radius and tibia, independently of spine BMD. Severe and multiple vertebral fractures were associated with even more alterations of cortical architecture assessed at the radius (OC 25). Interestingly, another group demonstrated that accrual of bone mineral content has plateaued before individuals reach their twenties, and the amount added during the 4 years surrounding peak linear growth represents double the amount of bone mineral that will subsequently be lost during the postmenopausal years from 50 to 80 (OC23). At last, it has also been shown that daily selective serotonin reuptake inhibitors (SSRI) use in adults 50 years and older remained associated with a 2-fold increased risk of clinical fragility fracture after adjustment for potential covariates (OC13). The authors also showed that depression and fragility fractures are common in this age group, and the elevated risk attributed to daily SSRI use may have important public health consequences.
Clinical management of osteoporosis
During the two plenary sessions of Thursday April 10, a lot of oral communications were related to the clinical management of osteoporosis. Professor Boonen showed, in a randomized controlled trial, that balloon kyphoplasty improved quality of life, reduced back pain and disability and decreased pain medication and walking aid usage (OC12). New advances in pharmacological strategies have also been presented. The efficacy of anabolic agents in patients previously treated long term with antiresorptive drugs is unknown. Interestingly, an anabolic response to teriparatide has been observed in patients previously treated with alendronate or raloxifene regardless of whether the previous antiresorptive drug was continued or discontinued (OC14).
From a retrospective study of 7345 patients who received monthly ibandronate and 56,837 patients who received a weekly bisphosphonate (alendronate or risedronate), Professor Reginster suggested that monthly ibandronate (150 mg) provides a similar level of non-vertebral and hip antifracture efficacy as the weekly bisphosphonates, alendronate and risedronate (OC17).
Last year, in Porto, the results of the HORIZON-PFT study were presented. HORIZON-PFT was a multinational, 3-year, randomized, double-blind, placebo-controlled trial evaluating the potential of once-yearly zoledronic acid 5 mg, infused over 15 minutes, to decrease risk of fracture in 7736 postmenopausal osteoporotic women 65-89 years of age. This year, pre-planned subanalysis of this study was presented (OC 21). Patients were stratified according to age: <70 years, 70-74 years and ≥75 years. A statistically significant reduction in the 3-year risk of vertebral fractures was observed in all three age groups
Phase I and Phase II
The ECCEO meeting looked also at the future of osteoporosis treatment by giving the opportunity to present results of phase I or II trials. For example, it has been shown, in 54 healthy male subjects that oral administration of the potent CaR antagonist SB-423557 resulted in transient rises in PTH (OC11). These results constitute an early proof of concept in man, providing the basis for further development of this class of compound as a novel oral boneforming osteoporosis treatment.
Osteoarthritis
Two oral communications of Thursday April 10 were related to osteoarthritis. As it has been shown last year, MRI technology has proven to provide reliable and precise assessment of cartilage volume/thickness changes in the knee. However, no systematic method has yet proven capable of accurately and reliably measuring hip cartilage volume/thickness or of discriminating acetabulum from femoral head cartilage throughout the entire joint.
A new study, presented this year at ECCEO, used a novel acquisition protocol using radial slice acquisition (OC15). With this new protocol, 2D MRI acquisition planes are organized around a virtual axis that passes through the fovea and centre of the femoral neck. The cartilage volume test-retest reliability of within-reader showed Pearson correlation coefficients of 0.973 (p<0.0001) for global cartilage and anatomical sites, and 0.983 (p<0.0001) for patient positioning. The authors concluded that this technology will provide insight into the progression of hip joint diseases such as osteoarthritis and will therefore be very useful for monitoring disease progression in DMOAD trials.
The other communication related to osteoarthritis assessed the effect of cathepsin K inhibitor on cartilage volume and biochemical markers of bone and cartilage degradation in patients with knee osteoarthritis (OC18). Treatment with Balicatib, the cathepsin K inhibitor, was terminated at 6 months, plus 6-month off-treatment follow-up. Balicatib induced a significant reduction in CTX-I and CTX-II, but no significant effect on cartilage volume as assessed by MRI was observed. The first day of the ECCEO meeting has thus been a great success due to the high scientific quality of the researches presented either in oral or in poster communication.