A Selective BCL-X L PROTAC Degrader Achieves Safe and Potent Antitumor Activity

Nat Med. 2019 Dec;25(12):1938-1947. doi: 10.1038/s41591-019-0668-z. Epub 2019 Dec 2.

Abstract

B-cell lymphoma extra large (BCL-XL) is a well-validated cancer target. However, the on-target and dose-limiting thrombocytopenia limits the use of BCL-XL inhibitors, such as ABT263, as safe and effective anticancer agents. To reduce the toxicity of ABT263, we converted it into DT2216, a BCL-XL proteolysis-targeting chimera (PROTAC), that targets BCL-XL to the Von Hippel-Lindau (VHL) E3 ligase for degradation. We found that DT2216 was more potent against various BCL-XL-dependent leukemia and cancer cells but considerably less toxic to platelets than ABT263 in vitro because VHL is poorly expressed in platelets. In vivo, DT2216 effectively inhibits the growth of several xenograft tumors as a single agent or in combination with other chemotherapeutic agents, without causing appreciable thrombocytopenia. These findings demonstrate the potential to use PROTAC technology to reduce on-target drug toxicities and rescue the therapeutic potential of previously undruggable targets. Furthermore, DT2216 may be developed as a safe first-in-class anticancer agent targeting BCL-XL.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aniline Compounds / chemistry
  • Aniline Compounds / pharmacology*
  • Animals
  • Antineoplastic Agents / pharmacology
  • Blood Platelets / drug effects
  • Blood Platelets / metabolism
  • Gene Expression Regulation, Neoplastic / drug effects
  • Heterografts
  • Humans
  • Mice
  • Proteolysis
  • Sulfonamides / chemistry
  • Sulfonamides / pharmacology*
  • Thrombocytopenia / drug therapy*
  • Thrombocytopenia / genetics
  • Thrombocytopenia / pathology
  • Von Hippel-Lindau Tumor Suppressor Protein / genetics*
  • bcl-X Protein / antagonists & inhibitors
  • bcl-X Protein / genetics*

Substances

  • Aniline Compounds
  • Antineoplastic Agents
  • BCL2L1 protein, human
  • Sulfonamides
  • bcl-X Protein
  • Von Hippel-Lindau Tumor Suppressor Protein
  • VHL protein, human
  • navitoclax