Novel inhibitors of the Gardos channel for the treatment of sickle cell disease

J Med Chem. 2008 Feb 28;51(4):976-82. doi: 10.1021/jm070663s. Epub 2008 Jan 31.


Sickle cell disease (SCD) is a hereditary condition characterized by deformation of red blood cells (RBCs). This phenomenon is due to the presence of abnormal hemoglobin that polymerizes upon deoxygenation. This effect is exacerbated when dehydrated RBCs experience a loss of both water and potassium salts. One critical pathway for the regulation of potassium efflux from RBCs is the Gardos channel, a calcium-activated potassium channel. This paper describes the synthesis and biological evaluation of a series of potent inhibitors of the Gardos channel. The goal was to identify compounds that were potent and selective inhibitors of the channel but had improved pharmacokinetic properties compared to 1, Clotrimazole. Several triarylamides such as 10 and 21 were potent inhibitors of the Gardos channel (IC50 of <10 nM) and active in a mouse model of SCD. Compound 21 (ICA-17043) was advanced into phase 3 clinical trials for SCD.

MeSH terms

  • Acetamides / chemical synthesis*
  • Acetamides / pharmacokinetics
  • Acetamides / pharmacology
  • Anemia, Sickle Cell / drug therapy*
  • Animals
  • Biological Availability
  • Clotrimazole / pharmacokinetics
  • Clotrimazole / pharmacology
  • Humans
  • Intermediate-Conductance Calcium-Activated Potassium Channels / physiology*
  • Male
  • Mice
  • Potassium Channel Blockers / chemical synthesis*
  • Potassium Channel Blockers / pharmacokinetics
  • Potassium Channel Blockers / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Structure-Activity Relationship
  • Trityl Compounds / chemical synthesis*
  • Trityl Compounds / pharmacokinetics
  • Trityl Compounds / pharmacology


  • Acetamides
  • Intermediate-Conductance Calcium-Activated Potassium Channels
  • Potassium Channel Blockers
  • Trityl Compounds
  • Clotrimazole
  • senicapoc