IOWH-032 (IOWH032) , a synthetic CFTR inhibitor, has been investigated for the treatment of cholera, diarrhea, and secretory diarrhea.

In a closed-system mouse model, IOWH032 effectively inhibits the secretions induced by cholera toxin. Moreover, in a rat model with the cecum removed, IOWH032 (5 mg/kg) suppresses the excretion of waste.

In T84-CFTR cells (IC50=6.87 μM), IOWH032 effectively inhibits CFTR activity.

Enzyme assays are performed using a homogeneous time-resolved fluorescence assay with recombinant epitope tagged kinase domains (JAK1, 837-1142; JAK2, 828-1132; JAK3, 718-1124; Tyk2, 873-1187) or full-length enzyme (cMET and Chk2) and peptide substrate. Each enzyme reaction is performed with or without test compound (11-point dilution), JAK, cMET, or Chk2 enzyme, 500 nM (100 nM for Chk2) peptide, ATP (at the Km specific for each kinase or 1 mM), and 2.0% DMSO in assay buffer. The calculated IC50 value is the compound concentration required for inhibition of 50% of the fluorescent signal. Additional kinase assays are performed at Cerep using standard conditions at 200 nM. Enzymes tested included: Abl, Akt1, AurA, AurB, CDC2, CDK2, CDK4, CHK2, c-kit, EGFR, EphB4, ERK1, ERK2, FLT-1, HER2, IGF1R, IKKα, IKKβ, JNK1, Lck, MEK1, p38α, p70S6K, PKA, PKCα, Src, and ZAP70[1].