5-(4,6-Dimorpholino-1,3,5-triazin-2-yl)-4-(trifluoromethyl)pyridin-2-amine (PQR309), a Potent, Brain-Penetrant, Orally Bioavailable, Pan-Class I PI3K/mTOR Inhibitor as Clinical Candidate in Oncology

J Med Chem. 2017 Sep 14;60(17):7524-7538. doi: 10.1021/acs.jmedchem.7b00930. Epub 2017 Sep 1.

Abstract

Phosphoinositide 3-kinase (PI3K) is deregulated in a wide variety of human tumors and triggers activation of protein kinase B (PKB/Akt) and mammalian target of rapamycin (mTOR). Here we describe the preclinical characterization of compound 1 (PQR309, bimiralisib), a potent 4,6-dimorpholino-1,3,5-triazine-based pan-class I PI3K inhibitor, which targets mTOR kinase in a balanced fashion at higher concentrations. No off-target interactions were detected for 1 in a wide panel of protein kinase, enzyme, and receptor ligand assays. Moreover, 1 did not bind tubulin, which was observed for the structurally related 4 (BKM120, buparlisib). Compound 1 is orally available, crosses the blood-brain barrier, and displayed favorable pharmacokinetic parameters in mice, rats, and dogs. Compound 1 demonstrated efficiency in inhibiting proliferation in tumor cell lines and a rat xenograft model. This, together with the compound's safety profile, identifies 1 as a clinical candidate with a broad application range in oncology, including treatment of brain tumors or CNS metastasis. Compound 1 is currently in phase II clinical trials for advanced solid tumors and refractory lymphoma.

MeSH terms

  • Administration, Oral
  • Aminopyridines / administration & dosage
  • Aminopyridines / pharmacokinetics
  • Aminopyridines / therapeutic use*
  • Animals
  • Antineoplastic Agents / administration & dosage
  • Antineoplastic Agents / pharmacokinetics
  • Antineoplastic Agents / therapeutic use*
  • Brain / drug effects
  • Brain / metabolism
  • Cell Proliferation / drug effects
  • Dogs
  • Humans
  • Mice
  • Models, Molecular
  • Morpholines / administration & dosage
  • Morpholines / pharmacokinetics
  • Morpholines / therapeutic use*
  • Neoplasms / drug therapy*
  • Neoplasms / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoinositide-3 Kinase Inhibitors*
  • Protein Kinase Inhibitors / administration & dosage
  • Protein Kinase Inhibitors / pharmacokinetics
  • Protein Kinase Inhibitors / therapeutic use*
  • Rats
  • Rats, Nude
  • Signal Transduction / drug effects
  • TOR Serine-Threonine Kinases / antagonists & inhibitors*
  • TOR Serine-Threonine Kinases / metabolism

Substances

  • Aminopyridines
  • Antineoplastic Agents
  • Morpholines
  • NVP-BKM120
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Kinase Inhibitors
  • TOR Serine-Threonine Kinases