PQ401 is a novel, potent inhibitor of IGF-IR with IC50 of 12μM [1].

In human MCF-7 cells, PQ401 inhibited autophosphorylation of the IGF-IR with IC50 of 12 μM and autophosphorylation of the isolated kinase domain of the IGF-IR with IC50 < 1μM. In addition, PQ401 inhibited the growth of cultured breast cancer cells in serum at 10μM. PQ401 can decrease IGF-I-mediated signaling through the Akt antiapoptotic pathway. Twenty-four hours treatment of 15 μM PQ401 induced caspase-mediated apoptosis [1]. In small trigeminal ganglion neurons, PQ401 blocked the IGF-1-induced A-type K(+) currents (IA) that were associated with a hyperpolarizing shift in the voltage dependence of inactivation [2].

In vivo, a treatment with PQ401 triple per week reduced the growth rate of MCNeuA cells implanted into mice [1].

References:
[1]. Gable KL, Maddux BA, Penaranda C, Zavodovskaya M, Campbell MJ, Lobo M, Robinson L, Schow S, Kerner JA, Goldfine ID, Youngren JF. Diarylureas are small-molecule inhibitors of insulin-like growth factor I receptor signaling and breast cancer cell growth. Mol Cancer Ther. 2006 Apr;5(4):1079-86.
[2]. Wang H, Qin J, Gong S, Feng B, Zhang Y, Tao J. Insulin-like growth factor-1 receptor-mediated inhibition of A-type K(+) current induces sensory neuronal hyperexcitability through the phosphatidylinositol 3-kinase and extracellular signal-regulated kinase 1/2 pathways, independently of Akt. Endocrinology. 2014 Jan;155(1):168-79.