Résumé :
|
Introduction Double blind randomization in rare neuromuscular diseases is extremely difficult to conduct, particularly if the tested "drug" has to be blind in design and to be compared to a placebo or a standard treatment which does not exist yet for the rare disease. As regards to these difficulties, is it valid to accept the new methodology practised in the USA for market approval of some medical devices as an alternative to prove the effectiveness of innovative treatments in Myology ? MethodsFor some investigational devices (cardiac ablation catheters, replacement heart valves, ophthalmics, hip replacement systems), the Food and Drug administration (FDA) has allowed the approval process to include single arm clinical studies where the control group has been replaced by expected standard results known as OPC (Objective Performance Criteria). The OPC concept allows the FDA to lighten the regulatory approval process for medical devices without compromising the scientific integrity needed to its mission of public health protection.It is a number used as a comparator in single arms trials where randomization is impractical or impossible. The OPC is a criterion of performance based on a great number of data from literature publishings or reliable registries. It results from the discussion between physicians and statisticians. It represents an objective and significant fixed standard used as a comparator. Organizing a conference of consensus is needed to establish OPC in cooperation with experts of the multidisciplinary teams, followed by a detailed analysis on how it was derived in a peer-review journal. OPC must reflect the current level of care and must be periodically re-evaluated. Discussion & ConclusionThe OPC use offers several advantages: smaller sample, standardized comparator for the future trials, less cost, time-saver, easier logistics. However the determination of an OPC is not always a simple exercise: problems associated with historical controls, validity of data and analysis, advances in the practice of medicine, single arm trials selection bias.In neuromuscular clinical trials with small samples, an approach based on OPC methodology could represent an acceptable and scientifically valid alternative to determine the safety or efficacy of innovative treatments when randomization and double-blindness are problematic
|