SP4206 is an IL-2/IL-2Rα interaction inhibitor. SP4206 binds with high affinity (Kd=70 nM) to IL-2 and blocks binding to its natural receptor IL-2Rα (Kd=10 nM)[1].
SP4206 binds the WT IL-2, IL-2 variant K35L/M39V, IL-2 variant P65A, and IL-2 variant V69A with EC50s of 68.8, 80.1, 117.0, and 10.4 nM, respectively[1].
[1]. Thanos CD, et al. Hot-spot mimicry of a cytokine receptor by a small molecule. Proc Natl Acad Sci U S A. 2006 Oct 17;103(42):15422-7.