Abstact

The global incidence of melanoma has risen substantially over the past two decades, driving an urgent need for novel therapeutic strategies. The nonreceptor protein tyrosine phosphatases PTPN2/PTPN1 have emerged as promising therapeutic targets, yet developing effective inhibitors faces significant drug-like property challenges. Through rational drug design, we discovered WS35─a potent dual PTPN2/1 inhibitor exhibiting exceptional enzymatic activity (PTPN2 IC50 = 5.8 nM, PTPN1 IC50 = 12.8 nM), favorable safety profiles, and enhanced oral bioavailability (F = 7.1%). Mechanistic studies demonstrate that WS35 modulates the IFNγ-JAK-STAT signaling axis, significantly augmenting CD8+ T-cell tumor infiltration. In B16-OVA syngeneic models, WS35 monotherapy and its combination with an anti-PD-1 antibody achieved robust tumor growth suppression, outperforming AC484, with no observable systemic toxicity. Collectively, WS35 represents a preclinical candidate with validated efficacy and safety for developing novel antimelanoma therapeutics.