Vapreotide acetate (BMY-41606 acetate) is an antagonist of the neurokinin-1 (NK1) receptor (IC50: 330 nM).

In a dose-dependent manner, Vapreotide attenuates the Substance P (SP)-triggered intracellular calcium increases and NF-κB activation.in HEK293-NK1R and U373MG cell lines, Vapreotide inhibits SP-induced IL-8 and MCP-1 production. In vitro, Vapreotide inhibits HIV-1 infection of human MDM, an effect that is reversible by SP pretreatment [1]. Vapreotide significantly inhibits GH-, PRL, and/or alpha-subunit release by human GH-secreting pituitary adenoma cells in concentrations as low as 10(-12)-10(-14) M. Vapreotide inhibits GH release (IC50: 0.1 pM) [2]. Vapreotide exhibits moderate-to-high affinities for SSTR2, -3, and -5 with IC50 of 0.17, 0.1, and 21 nM, respectively, and low affinity for SSTR1 and -4 with IC50 of 200 and 620 nM, respectively. RC-160 inhibits serum-induced proliferation of CHO cells expressing SSTR2 and SSTR5 (EC50s: 53 and 150 pM) [3].

Acute vapreotide administration in rats reduces blood flow in collateral circulation, a critical factor in oesophagogastric variceal bleeding due to portal hypertension in cirrhosis, while its prolonged use slows down the development of such complications. Concurrently, RC-160 significantly diminishes tumor size and weight by approximately 40% through subcutaneous injections at a dosage of 100 μg/day/animal. Early-stage intervention with vapreotide is effective in curbing the progression of androgen-independent prostate cancer.