Does the LLNA offer advantages with respect to animal welfare considerations (refinement, reduction, and replacement alternatives)?
In response to the first question, the consensus of the PRP was that the LLNA results, as submitted and supplemented by the Sponsors, demonstrated that the assay performed at least as well as currently accepted guinea pig methods (GPMT/BA) for the hazard identification of strong to moderate chemical sensitizing agents. The data submitted indicate that the LLNA does not accurately predict all weak sensitizers (false negative) and some strong irritants (false positive). The term weak sensitizer is somewhat arbitrary, since the terms weak, moderate, and strong apply to the percentage of animals reacting in the GPMT/BA as described in the published literature or papers submitted by the Sponsors. When comparing the LLNA with currently accepted methods (i.e., guinea pig methods), the LLNA appears to provide an equivalent prediction of the risk for human ACD. The review involved the evaluation of data on 209 chemicals, of which both LLNA and guinea pig data were available for 126 chemicals an
