Sienna planning Phase III trials of pegcantratinib in psoriasis

Sienna Biopharmaceuticals Inc. (NASDAQ:SNNA) plans to start Phase III trials in 2H19 of pegcantratinib (SNA-120) to treat psoriasis despite reporting that the compound missed the primary endpoint in a Phase IIb trial to treat pruritus associated with psoriasis. The company said it will pursue a psoriasis indication for the topical inhibitor of neurotrophic tyrosine kinase receptor 1 (TrkA; NTRK1) with pruritus measured as a secondary endpoint.

The double-blind, U.S. trial enrolled 208 patients with mild to moderate psoriasis with at least moderate pruritus to receive vehicle or twice-daily topical 0.05% or 0.5% pegcantratinib for 12 weeks. On the primary endpoint, both doses of pegcantratinib failed to improve mean Itch Numeric Rating Scale (I-NRS) score from baseline to week eight vs. vehicle (4.3 points for low-dose pegcantratinib vs. 4 points for vehicle, p=0.244). Sienna said the miss may be partially due to the "beneficial emollient effect of the vehicle and the inherent variability in patient-reported assessments."...