SX-517 is a non-competitive dual antagonist of CXCR1/2, demonstrating anti-inflammatory effects in both PMN cells and mouse models. SX-517 inhibits CXCL-1-induced Ca²⁺ flux (IC₅₀ = 38 nM), antagonises CXCL-8-induced [(³⁵)S]GTPγS binding (IC₅₀ = 60 nM), and suppresses ERK1/2 phosphorylation.

SX-517 (0.1 nM-0.1 mM; 60 minutes) inhibited 10 nM CXCL8-induced [35S]GTPγS binding with an IC50 of 60 nM [1].
SX-517 (10 μM; 60 minutes) suppressed the cell surface expression of CXCR2 receptors in HEK293 cells [1].
SX-517 (10 μM; 0-30 minutes) blocked CXCR2-mediated ERK1/2 phosphorylation in HEK293 cells [1].

SX-517 (0.02 mg/kg and 0.2 mg/kg) was administered via single intravenous injection to male CD1 SWISS mice bearing utetheisa ornatrix air pouches on their backs. The results demonstrated a significant reduction in cell counts within the utetheisa ornatrix air pouches of the mice [1].