Tradipitant, an inhibitor of neurokinin 1/substance P, a neuropeptide released after TRPV1 activation on sensory nerves, ameliorated pruritis though not statistically significant in a phase II clinical trial and the results of another phase II trial for tradipitant in AD-associated treatment-resistant pruritus have yet to be published [72]. This evidence concerns the gene TAC1 and Alzheimer disease.