Titan Pharmaceuticals, Inc. announced that, in a presentation given Nov. 8, 2021 at the Society for Neuroscience 2021 Meeting, Ben Land, Ph.D., Research Assistant Professor at the University of Washington's Department of Pharmacology, reported additional positive data from an ongoing in vivo study of its human kappa-opioid receptor agonist ProNeura?-based implant in an established 5'-guanidinonaltrindole (5'-GNTI) itch-induced mouse model. As previously reported, low dose TP-2021 implants had demonstrated anti-pruritic effects for up to 2 weeks in this model. Higher-dose TP-2021 implants were subsequently formulated and the study repeated after content analysis of the removed low-dose implants indicated potential drug release duration of approximately four months, but at levels below the anti-pruritic efficacy threshold. A significant reduction in scratching behavior was maintained in mice who received the high-dose TP-2021 implant at both Day 28 and Day 56 post-implantation, compared with those that received the placebo implant, with no safety issues observed. In addition, the high-dose TP-2021 implant provided sustained supra-therapeutic plasma levels of TP-2021 through Day 84. As a result, the efficacy assessment is continuing. These results indicate that TP-2021 implants can release drug above the therapeutic threshold in this mouse pruritus model for several months following a single treatment. Chronic pruritus is an often debilitating condition, resulting in the need to scratch that lasts more than 6 weeks. It is a prevalent symptom associated with a number of serious cutaneous and systemic conditions. Due to its complex pathogenesis and numerous contributing factors, effective treatment of chronic pruritus remains challenging.