References of "Calvo, Gisèle"
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See detailTotal joint replacement of hip or knee as an outcome measure for structure modifying trials in osteoarthritis
Altman, R. D.; Abadie, Eric ULg; Avouac, B. et al

in Osteoarthritis and Cartilage (2005), 13(1), 13-19

Objective: The Group for the Respect of Ethics and Excellence in Science (GREES) organized a working group to assess the value of time to joint surgery as a potential therapeutic failure outcome criterion ... [more ▼]

Objective: The Group for the Respect of Ethics and Excellence in Science (GREES) organized a working group to assess the value of time to joint surgery as a potential therapeutic failure outcome criterion for osteoarthritis (OA) of the hip or knee in the assessment of potential structure modifying agents. Methods: PubMed was searched for manuscripts from 1976 to 2004. Relevant studies were discussed at a 1-day meeting. Results: There are no accepted guidelines for 'time to' and 'indications for' joint replacement surgery. A limited number of trials have examined joint replacement surgery within the study population. Several parameters, particularly joint space narrowing (interbone distance), correlate with surgical intervention. However, at the level of the knee, none of the parameters have positive predictive value for joint replacement surgery better than 30%. In contrast, lack of significant joint space narrowing has a strong negative predictive value for joint replacement surgery (> 90%), that remains after controlling for OA pain severity. Conclusion: At this time, GREES cannot recommend time to joint surgery as a primary endpoint of failure for structure modifying trials of hip or knee OA-as the parameter has sensitivity but lacks specificity. In contrast, in existing trials, a lack of progression of joint space narrowing has predictive value of > 90% for not having surgery. GREES suggests utilizing joint space narrowing (e.g., > 0.3-0.7 mm) combined with a lack of clinically relevant improvement in symptoms (e.g., greater than or equal to 20-25%) for 'failure' of a secondary outcome in structure modifying trials of the hip and knee. (C) 2004 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved. [less ▲]

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See detailRecommendations for the use of new methods to assess the efficacy of disease-modifying drugs in the treatment of osteoarthritis
Abadie, Eric ULg; Ethgen, Dominique ULg; Avouac, Bernard ULg et al

in Osteoarthritis and Cartilage (2004), 12(4), 263-268

Background: Recent innovations in the pharmaceutical drug discovery environment have generated new chemical entities with the potential to become disease modifying drugs for osteoarthritis (DMOAD's ... [more ▼]

Background: Recent innovations in the pharmaceutical drug discovery environment have generated new chemical entities with the potential to become disease modifying drugs for osteoarthritis (DMOAD's). Regulatory agencies acknowledge that such compounds may be granted a DMOAD indication, providing they demonstrate that they can slow down disease progression; progression would be calibrated by a surrogate for structural change, by measuring joint space narrowing (JSN) on plain X-rays with the caveat that this delayed JSN translate into a clinical benefit for the patient. Recently, new technology has been developed to detect a structural change of the OA joint earlier than conventional X-rays. Objective: The Group for the Respect of Ethics and Excellence in Science (GREES) organized a working party to assess whether these new technologies may be used as surrogates to plain x-rays for assessment of DMOADs. Methods: GREES includes academic scientists, members of regulatory authorities and representatives from the pharmaceutical industry. After an extensive search of the international literature, from 1980 to 2002, two experts meetings were organized to prepare a resource document for regulatory authorities. This document includes recommendations for a possible update of guidelines for the registration of new chemical entities in osteoarthritis. Results: Magnetic resonance imaging (MRI) is now used to measure parameters of cartilage morphology and integrity in OA patients. While some data are encouraging, correlation between short-term changes in cartilage structure observed with MRI and long-term radiographic or clinical changes are needed. Hence, the GREES suggests that MRI maybe used as an outcome in phase II studies, but that further data is needed before accepting MRI as a primary end-point in phase III clinical trials. Biochemical markers of bone and cartilage remodelling are being tested to predict OA and measure disease progression. Recently published data are promising but validation as surrogate end-points for OA disease progression requires additional study. The GREES suggests that biochemical markers remain limited to 'proof of concept' studies or as secondary end-points in phase II and III clinical trials. However, the GREES emphasizes the importance of acquiring additional information on biochemical markers in order to help better understand the mode of action of drugs to be used in OA. Regulatory agencies consider that evidence of improvement in clinical outcomes is critical for approval of DMOAD. Time to total joint replacement surgery is probably the most relevant clinical end-point for the evaluation of efficacy of a DMOAD. However, at this time, time to surgery can not be used in clinical trials because of bias by non disease-related factors like patient willingness for surgery or economic factors. At this stage, it appears that DMOAD should demonstrate a significant difference compared to placebo. Benefit should be measured by 3 co-primary end-points: JSN, pain and function. Secondary end-points should include the percentage of patients who are 'responder' (or 'failure'). The definition of a 'failure' patient would be someone with progression of JSN>0.5 mm over a period of 2-3 years or who has a significant worsening in pain and/or function, based on validated cut-off values. The definition of the clinically relevant cut-off points for pain and function must be based on data evaluating the natural history of the disease (epidemiological cohorts or placebo groups from long-term studies). These cut-offs points should reflect a high propensity, for an individual patient, to later require joint replacement. Conclusion: GREES has outlined a set of guidelines for the development of a DMOAD for OA. Although these guidelines are subject to change as new information becomes available, the information above is based on the present knowledge in the field with the addition of expert opinion. (C) 2004 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved. [less ▲]

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See detailDo new methods of investigation allow faster assessment of drugs efficacy in osteoarthritis?
Abadie, Eric ULg; Avouac, B.; Bouvenot, G. et al

in Osteoporosis International (2003, November), 14(Suppl. 7), 2

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See detailThe use of placebo-controlled and non-inferiority trials for the evaluation of new drugs in the treatment of postmenopausal osteoporosis
Delmas, P. D.; Calvo, Gisèle ULg; Boers, M. et al

in Osteoporosis International (2002), 13(1), 1-5

Registration of new agents for the treatment of postmenopausal osteoporosis has been based over the past few years on placebo-controlled phase III trials with the incidence of patients with new vertebral ... [more ▼]

Registration of new agents for the treatment of postmenopausal osteoporosis has been based over the past few years on placebo-controlled phase III trials with the incidence of patients with new vertebral/nonvertebral fractures as the most usual primary endpoint. The use of a placebo in diseases where an active treatment is available has been a matter of debate following the update of the Declaration of Helsinki by the World Medical Association which questioned this trial design. Current regulatory recommendations within the European Union suggest that placebo-controlled trials are still the best option when assessing the efficacy and safety of new drugs intended for the treatment of postmenopausal osteoporosis. This suggestion seems to be in apparent contradiction with the current content of the Declaration of Helsinki. This paper addresses the ethics and feasibility of placebo-controlled trials in the treatment of postmenopausal osteoporosis, in the light of available therapeutic options, and discusses possible alternative approaches in those patients where placebo treatment could be deemed to be unethical. It is concluded that placebo-controlled trials remain the most efficient design to establish the efficacy and safety of a new agent for the treatment of postmenopausal osteoporosis. Such trials are feasible and ethically acceptable in patients with osteoporosis but without prevalent vertebral fractures. Conversely, in patients with prevalent vertebral fractures, placebo-controlled trials are ethically questionable and non-inferiority trials are more appropriate. A relative margin of non inferiority of 20-30% is suggested, to be discussed on a case by case basis. [less ▲]

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See detailBackground for studies on the treatment of male osteoporosis: state of the art.
Kaufman, J M; Johnell, O; Abadie, Eric ULg et al

in Annals of the Rheumatic Diseases (2000), 59(10), 765-72

Male osteoporosis represents an important, although long underestimated, public health problem. Both in men and in women aging is accompanied by continuous bone loss and by an exponential increase in the ... [more ▼]

Male osteoporosis represents an important, although long underestimated, public health problem. Both in men and in women aging is accompanied by continuous bone loss and by an exponential increase in the incidence of osteoporotic fracture, with a female to male incidence ratio of about 2 to 3 to 1 in the elderly for hip and vertebral fractures. Morbidity after osteoporotic fractures appears to be more serious and mortality more common in men than in women. To date, no single treatment has been proved to be effective and safe in published prospective studies. The present report, based on a systematic search of the literature on male osteoporosis, summarises the state of the art on the clinical consequences of male osteoporosis and its risk factors, in relation to the present state of knowledge about female osteoporosis. This constitutes the background for the design of rational clinical development strategies for therapeutic interventions in male osteoporosis. From this review of the literature it is apparent that notwithstanding the existing sex differences in pathophysiology of osteoporosis and the difference in age-specific incidence of osteoporotic fractures, there are also important similarities between osteoporosis in women and men. The higher incidence of fracture in women than in men results from quantitative differences in risk factors rather than from different risk factors. Even though there are sex differences in bone geometry, incidence of fracture seems to be similar in men and women for a same absolute areal bone mineral density. However, the lack of data on the changes in fracture rates in men resulting from pharmacological intervention, leading to changes in bone mineral density or bone turnover, remains the main limitation for extrapolation of established treatment outcomes from women to men. [less ▲]

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