Overcoming mTOR resistance mutations with a new-generation mTOR inhibitor Academic Article uri icon


MeSH Major

  • Drug Resistance
  • Mutation
  • Protein Kinase Inhibitors
  • TOR Serine-Threonine Kinases


  • Precision medicines exert selective pressure on tumour cells that leads to the preferential growth of resistant subpopulations, necessitating the development of next-generation therapies to treat the evolving cancer. The PIK3CA-AKT-mTOR pathway is one of the most commonly activated pathways in human cancers, which has led to the development of small-molecule inhibitors that target various nodes in the pathway. Among these agents, first-generation mTOR inhibitors (rapalogs) have caused responses in 'N-of-1' cases, and second-generation mTOR kinase inhibitors (TORKi) are currently in clinical trials. Here we sought to delineate the likely resistance mechanisms to existing mTOR inhibitors in human cell lines, as a guide for next-generation therapies. The mechanism of resistance to the TORKi was unusual in that intrinsic kinase activity of mTOR was increased, rather than a direct active-site mutation interfering with drug binding. Indeed, identical drug-resistant mutations have been also identified in drug-naive patients, suggesting that tumours with activating MTOR mutations will be intrinsically resistant to second-generation mTOR inhibitors. We report the development of a new class of mTOR inhibitors that overcomes resistance to existing first- and second-generation inhibitors. The third-generation mTOR inhibitor exploits the unique juxtaposition of two drug-binding pockets to create a bivalent interaction that allows inhibition of these resistant mutants.

publication date

  • May 18, 2016



  • Academic Article



  • eng

PubMed Central ID

  • PMC4902179

Digital Object Identifier (DOI)

  • 10.1038/nature17963

PubMed ID

  • 27279227

Additional Document Info

start page

  • 272

end page

  • 6


  • 534


  • 7606