GR 159897 is a competitive, brain-penetrated non-peptide NK2 receptor antagonist with anti-tumor effects. GR 159897 inhibits binding of [3H]GR100679 to human NK2-CHO cells and rat colon membranes (pKis: 9.51 and 10, respectively). It can antagonize bronchoconstriction.

NK2:10 （pki）（ Rat colon membrane), NK2 (human):9.51（pki） (CHO cell)

GR 159897 (10-30 μM; 72 hours; 4TBM, 4TLM, 4THM, and 4T1 cells) treatment enhances P38 phosphorylation and inhibits AKT activation in all metastatic cell lines, while ERK phosphorylation decreases in 4TBM, 4TLM, and 4THM cells but not in 4T1 cells. GR 159897 (10-30 μM; 72 hours; 4T1, 4THM, 4TLM, and 67NR cells) also inhibits cell proliferation dose-dependently in all lines, with a more pronounced effect in 4T1, 4THM, and 4TLM cells compared to 67NR cells [2].

GR 159897 (0.12 mg/kg; i.v.; guinea-pigs) effectively antagonizes GR64349-induced bronchoconstriction with a long duration of action of 3 hours [1].