Adarotene (ST1926) is an effective apoptosis inducer. It surprisingly produces DNA damage and exhibits a potent antiproliferative activity on a large panel of human tumor cells.

Adarotene causes cell accumulation in the G1/S or S phase of the cell cycle depending on tumor cells IGROV-1 and DU145. Adarotene causes dose-dependent growth inhibition in a large panel of human tumor cell lines with IC50 ranging from 0.1 to 0.3 μM [1]. Adarotene is apoptotic and cytotoxic on a large spectrum of cancerous and leukemic cells, including freshly isolated AML blasts in primary culture. Adarotene treatment of cells results in rapid accumulation of intracellular calcium [2].

Adarotene, administered orally at doses of 30 and 40 mg/kg, significantly extends the lifespan of NB4-bearing SCID mice in a dose-dependent manner without apparent toxicity [2]. At lower doses of 15 and 20 mg/kg, it markedly inhibits tumor growth in human ovarian carcinoma (A2780/DX) and human melanoma (MeWo) models in nude mice [1].