Evaluation of the dual mTOR/PI3K inhibitors Gedatolisib (PF-05212384) and PF-04691502 against ovarian cancer xenograft models

Sci Rep. 2019 Dec 10;9(1):18742. doi: 10.1038/s41598-019-55096-9.


This study investigated the antitumour effects of two dual mTOR/PI3K inhibitors, gedatolisib (WYE-129587/PKI-587/PF-05212384) and PF-04691502 against a panel of six human patient derived ovarian cancer xenograft models. Both dual mTOR/PI3K inhibitors demonstrated antitumour activity against all xenografts tested. The compounds produced tumour stasis during the treatment period and upon cessation of treatment, tumours re-grew. In several models, there was an initial rapid reduction of tumour volume over the first week of treatment before tumour stasis. No toxicity was observed during treatment. Biomarker studies were conducted in two xenograft models; phospho-S6 (Ser235/236) expression (as a readout of mTOR activity) was reduced over the treatment period in the responding xenograft but expression increased to control (no treatment) levels on cessation of treatment. Phospho-AKT (Ser473) expression (as a readout of PI3K) was inhibited by both drugs but less markedly so than phospho-S6 expression. Initial tumour volume reduction on treatment and regrowth rate after treatment cessation was associated with phospho-S6/total S6 expression ratio. Both drugs produced apoptosis but minimally influenced markers of proliferation (Ki67, phospho-histone H3). These results indicate that mTOR/PI3K inhibition can produce broad spectrum tumour growth stasis in ovarian cancer xenograft models during continuous chronic treatment and this is associated with apoptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Female
  • Humans
  • Mice
  • Morpholines / pharmacology*
  • Morpholines / therapeutic use
  • Ovarian Neoplasms / drug therapy*
  • Ovarian Neoplasms / pathology
  • Ovary / pathology
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoinositide-3 Kinase Inhibitors / pharmacology*
  • Phosphoinositide-3 Kinase Inhibitors / therapeutic use
  • Pyridones / pharmacology*
  • Pyridones / therapeutic use
  • Pyrimidines / pharmacology*
  • Pyrimidines / therapeutic use
  • Signal Transduction / drug effects
  • TOR Serine-Threonine Kinases / antagonists & inhibitors
  • TOR Serine-Threonine Kinases / metabolism
  • Triazines / pharmacology*
  • Triazines / therapeutic use
  • Xenograft Model Antitumor Assays


  • 2-amino-8-(4-(2-hydroxyethoxy)cyclohexyl)-6-(6-methoxypyridin-3-yl)-4-methylpyrido(2,3-d)pyrimidin-7(8H)-one
  • Morpholines
  • Phosphoinositide-3 Kinase Inhibitors
  • Pyridones
  • Pyrimidines
  • Triazines
  • gedatolisib
  • MTOR protein, human
  • TOR Serine-Threonine Kinases