Keap1-Nrf2-IN-18 (Compound 22) is an orally active Keap1-Nrf2 protein-protein interaction (PPI) inhibitor with good pharmacokinetics (PK) profiles and more potent in vivo activities in rats. Keap1-Nrf2-IN-18 has the strongest inhibitory activity in structure−activity relationship (SAR) study ( K D = 0.0029 μM).