282 Modulation of inflammatory proteins in blood may reflect cutaneous immune responses in topical cancer immunotherapy

Diphencyprone (DPCP), a hapten that causes delayed-type hypersensitivity reactions, has shown up to 84% efficacy in treating cutaneous metastases melanoma patients. While transcriptomic analysis of skin biopsies from treated with topical DPCP revealed increases Th1-related genes, serum proteomic these patients not yet been done. We evaluated the proteome five twice weekly until day 112, assessing 96 proteins using Olink immuno-oncology panel. All had at least partial regression metastases. There was significant upregulation associated promoting tumor immunity (TNFRSF4, TNFRSF9, CD83) and vascular/tissue remodeling (MMP12, PGF, ADGRG1) (P<0.05) upon treatment. Among T-cell subsets, there significantly upregulated Th1 response (CXCL9, CXCL10, IL12) progressively increased 63 when compared 0 (P<0.05). However, only Th2 (IL33) Th17 (CCL20) markers on (P<0.05), but line prior gene expression studies samples. also progressive PD1 both days 112 This study is first assess protein biomarkers following immunotherapy. Topical led an increase systemic immune activation, particularly axis, which previously correlates regression. Additionally, we observed PD1, great clinical relevance as inhibitors this receptor are currently standard-of-care treatment for melanoma. Our data suggest potential synergy between checkpoint inhibition future cancer therapy regimen