LY2584702 is a potent and selective inhibitor of p70 S6 kinase with IC50 value of 4 nM [1].
P70 S6 kinase (p70S6K) is a serine/threonine protein kinase that acts downstream of the phosphatidylinositol-3-kinase (PI3K)/Akt/mTOR signalling pathway. p70S6K phosphorylates the eukaryotic initiation factor 4B (eIF4B), a regulator of protein synthesis, and phosphorylates and activates ribosomal protein S6 (S6), a component of the 40S ribosomal subunit [1] [2].
LY2584702 is an oral and selective ATP competitive p70S6K inhibitor. In HCT116 colon cancer cells, LY2584702 inhibits phosphorylation of S6 (pS6) with IC50 value of 0.1-0.24 μM [1].
In the HCT116 colon carcinoma xenograft model, LY2584702 significantly inhibited tumour growth with threshold minimum effective dose 50% (TMED50) and TMED90 of 2.3 mg/kg and 10 mg/kg, respectively. In both HCT116 colon carcinoma and U87MG glioblastoma xenograft models, LY2584702 at levels of 2.5 mg/kg twice daily (BID) and 12.5 mg/kg BID exhibited significant efficacy. Treatment patients with advanced solid tumours with LY2584702 orally on a 28-day cycle, the maximum tolerated dose (MTD) was 75 mg BID (twice-daily) or 100 mg QD (once-daily) [1].
References:
[1]. Tolcher A, Goldman J, Patnaik A, et al. A phase I trial of LY2584702 tosylate, a p70 S6 kinase inhibitor, in patients with advanced solid tumours. Eur J Cancer, 2014, 50(5): 867-875.
[2]. Hollebecque A, Houédé N, Cohen EE, et al. A phase Ib trial of LY2584702 tosylate, a p70 S6 inhibitor, in combination with erlotinib or everolimus in patients with solid tumours. Eur J Cancer, 2014, 50(5): 876-884.