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The Expert Meeting on alternative methods for Botulinum neurotoxin (BoNT) potency testing was held at the BfR as the result of a decree from the German Federal Ministry of Food, Agriculture and Consumer Protection (BMELV), after it was informed by German state authorities about an increase in animal numbers being used in the LD50 potency test in mice for the purposes of BoNT potency testing. Ethical concerns have been raised in both Europe and the United States about the animal suffering involved in this type of testing, especially in the context of BoNT’s aesthetic applications. There had been increased public pressure on the German Government, due to successful campaigning by animal welfare/anti-vivisectionist organisations on the issue of BoNT animal testing. As a result, the BMELV asked ZEBET to assess the status of the different alternative methods to the BoNT LD50 potency test that are cited in the European Pharmacopoeia (EP) 6.0, Monograph 2113, Botulinum Toxin Type 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.