Safety and Efficacy of TGF-β1/COX-2 Silencing Therapeutic in Adults With Cutaneous Squamous Cell Carcinoma In Situ.

This single-center, open label, dose escalation cohort study evaluated the safety and efficacy of various doses of intralesional injections of TGF-β1/COX-2 combined with histidine-lysine polypeptide (siRNA/HKP) nanoparticle silencing therapeutic in patients with cutaneous in situ squamous cell carcinoma. Twenty-five patients (mean age: 67, SD: 10 years; 52% men) with cutaneous in situ squamous cell carcinoma participated. TGF-β1/COX-2 siRNA/HKP nanoparticle therapeutic was injected weekly for up to 6 weeks based on the following dosing cohorts: 10 μg/treatment, 20 μg/treatment, 30 μg/treatment, 60 μg/treatment, and 120 μg/treatment. The primary endpoint was the proportion of subjects with complete histological clearance. Also evaluated were the incidence/severity of treatment emergent adverse events and serious adverse events and incidence/severity of Local Skin Response. Twenty-five subjects received the TGF-β1/COX-2 siRNA/HKP nanoparticle therapeutic; 19 (76%) achieved histological clearance. In the 30 μg/treatment group and 60 μg/treatment group, percent cleared was 80% and 100%, respectively. Five subjects had 7 adverse events. There were no severe or serious adverse events; none led to treatment discontinuation, study interruption, or were related to the investigational product. Local skin response was none to minimal in most subjects, with improvement observed in the 10 μg/treatment, 20 μg/treatment, 30 μg/treatment, and 60 μg/treatment cohorts. Intralesional TGF-β1/COX-2 siRNA/HKP nanoparticle therapeutic injections appear to be noninvasive, safe, and efficacious in treating cutaneous in situ squamous cell carcinoma. The recommended doses for future study of the investigational product are 30 μg/treatment and 60 μg/treatment. J Drugs Dermatol. 2022;21(5):472-477. doi:10.36849/JDD.6384.