Botulinum neurotoxin type A (BTX-A) weakens voluntary muscle strength and is an effective therapy for focal dystonia, including cervical dystonia (CD) and benign essential blepharospasm (BEB). It is also known to relieve hemifacial spasm and focal spasticity in children and adults. In addition, BTX-A has been shown to be effective in a wide range of other indications, such as gastrointestinal disorders, hyperhidrosis and cosmetic wrinkle correction (e.g. glabellar frown lines). A new formulation of BTX-A, NT 201 (XEOMIN((R))) has been developed. NT 201 is a formulation of pure BTX-A free of complexing proteins and, therefore, may have a reduced immunogenic potential compared with other BTX-A preparations. The pre-clinical and clinical development of NT 201 is reviewed in this article.A total of five clinical trials were completed in Europe and Israel. Two studies were conducted in 46 healthy volunteers. A further three studies in 816 patients were conducted to provide data on the safety and efficacy of NT 201 in the treatment of CD and BEB. NT 201 was found to provide non-inferior efficacy and safety profiles in the treatment of CD and BEB compared with a BTX-A preparation containing complexing proteins (BOT [BOTOX((R))]). The clinical development programme of NT 201 showed a 1 : 1 NT 201 to BOT dose ratio. The pre-clinical studies conducted with NT 201 showed an acceptable safety profile and support the use of NT 201 in an intramuscular administration regimen for patients with CD and BEB. NT 201 was effective, well tolerated and non-inferior to BOT in the treatment of both CD and BEB. In addition, there were no differences between the two therapies in terms of onset of action, duration and waning of effect. Further research is required to determine the long-term efficacy and safety profile of NT 201.
A for Injection (1), and the most promising approaches for their validation. Experts from industry, regulatory authorities, German ministries, academia, research, national and international validation centres, and animal welfare organisations, were invited to actively participate in the meeting. The objective of the Expert Meeting was to review available alternative methods for BoNT potency testing, and to formulate recommendations for making progress toward implementing the Three Rs, i.e. Refinement, Reduction, and Replacement, in BoNT potency testing. In addition, ways in which communication on BoNT issues between manufacturers, researchers and regulators could be encouraged, and how improvements in regulatory harmonisation between different countries and continents could be achieved, were discussed. The meeting started with presentations by the individual participants, giving an overview on the regulatory and scientific status of alternative methods to the LD50 test for BoNT potency testing. Afterwards, the participants were divided into two separate break-out groups. Break-out Group 1 discussed the regulatory requirements for BoNT potency testing and the validation and implementation of alternative methods. Break-out Group 2 discussed the developed and available alternative methods and their suitability for reducing, refining or replacing the LD50 potency test.
We recently presented a modified local lymph node test which made it possible to quickly and reliably differentiate between irritative and allergic skin reactions with extremely simple parameters. The Integrated Model for the Differentiation of Skin Reactions (IMDS) test combines measurement of cell proliferation in draining lymph nodes with measurement of primary ear swelling after topical application of the test substance on three consecutive days. In contrast to the 'classic' skin sensitisation test in guinea-pigs the IMDS test is considerably faster and is based on objective measured data, not subjective skin evaluations. Like the Local Lymph Node Assay (LLNA), measurement of allergic potential in the IMDS test is based on the underlying immunological mechanisms, but also considers the behaviour of immune competent cells following non-specific activation by irritants. In addition, the IMDS test can employ UV radiation after application of the substance and, therefore, make differentiation possible between different types of skin photoreaction (photoallergy and photoirritation) after both topical and systemic administration. Attempts to achieve this kind of discrimination with the LLNA necessitate considerably greater expenditure, as proliferation in the draining lymph nodes can also be induced by moderate to extreme (photo)irritants. In a previous paper in which we presented the IMDS test, we examined each type of reaction in reference to one single standard; the next logical step was therefore a broad-based intra-laboratory validation. An important factor in the validation was the use of standards that had been thoroughly examined in both guinea pig and mouse systems and were also relevant with regard to estimation of the risk for humans. The data presented here show that the IMDS is a simple and reliable tool for obtaining fast and reproducible assessments of potential (photo)allergic and (photo)irritant skin reactions to substances.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.