Astex partnered LEE011. The AACR abstract had this in it:
Methods: We analyzed the effect of combined Cdk4/6 inhibition in a comprehensive panel of human-derived neuroblastoma cell lines using LEE011, a highly specific Cdk4/6 small molecule inhibitor. Anti-tumor activity was also determined in vivo in three neuroblastoma xenograft models, and integrative genomics was used to identify biomarkers of drug sensitivity.
Results: Treatment with LEE011 significantly inhibited proliferation in 10 of 15 human neuroblastoma-derived cell lines by inducing cytostasis at nanomolar concentrations (mean IC50 = 361 ± 97 nM, considering sensitive lines only), as evidenced by significant cell cycle arrest and senescence that were likely attributed to dose-dependent decreases in phosphorylated RB and FOXM1. In addition, responsiveness of neuroblastoma xenografts to LEE011 was reflective of in vitro data in that there was a direct correlation of IC50 values with degree of subcutaneous xenograft growth delay, with the most sensitive lines in vitro showing profound growth inhibition in vivo. While our data indicate that neuroblastomas sensitive to LEE011 were more likely to contain genomic amplification of MYCN (p= 0.04, student’s t test), a supervised hierarchical clustering of gene expression data identified several potential gene signatures that could explain the observed differential sensitivity to Cdk4/6 inhibition.
Conclusions: Our data show that LEE011 is highly active in a large subset of neuroblastoma cell lines and xenograft models, and therefore support the clinical development of LEE011 as a therapy for neuroblastoma as well as efforts to validate biomarkers of drug activity.