HPI-1 (hydrate) is a Hedgehog (Hh) pathway inhibitor that suppresses signaling through Sonic Hh (IC50= 1.5 μM) without significantly affecting Wnt signaling (IC50≥ 30 μM).1HPI-1 suppresses Hh activation induced by loss of Suppressor of Fused or by Gli overexpression, suggesting action at posttranslational modification of Gli protein or at the interaction of Gli with a co-factor.1HPI-1 (hydrate) also inhibits signaling through the oncogenic Smoothened (Smo) mutant SmoM2 in neuron precursors, preventing cell proliferation.1 1.Hyman, J.M., Firestone, A.J., Heine, V.M., et al.Small-molecule inhibitors reveal multiple strategies for Hedgehog pathway blockadeProceedings of the National Academy of Sciences of the United States of America106(33)14132-14137(2009)

AM-211 sodium is a novel and potent antagonist of the prostaglandin D2 receptor type 2. AM-211 is active in animal models of allergic inflammation. AM211 has high affinity for human, mouse, rat, and guinea pig DP2 and it shows selectivity over other prostanoid receptors and enzymes. AM211 exhibits good oral bioavailability in rats and dogs and dose-dependently inhibits 13,14-dihydro-15-keto-PGD(2)-induced leukocytosis in a guinea pig pharmacodynamic assay.