AZD2461

AZD2461 is a novel and potent PARP inhibitor with lower affinity to P-glycoprotein. AZD2641 is currently in Phase I clinical study. The study is being conducted to see how it may work to treat solid tumors. The main purpose is to establish a safe dosage of the drug and provide additional information on any potential side effects this drug may cause. The study will also assess the blood levels and action of AZD2461 in the body over a period of time and will indicate whether the drug has a therapeutic effect on solid tumors. (In Vitro) :AZD-2461 is a potent PARP inhibitor, with IC50s of 5 nM, 2 nM and 200 nM for PARP1, PARP2 and PARP3, respectively. AZD-2461 (500 nM) shows inhibitory activity against DNA single-strand break repair in human A459 cells. AZD-2461 cuases resistance and high P-gp expression levels in BRCA2-deficient mouse breast cancer line KB2P3.4. AZD-2461 is cytotoxic to BT-20 cells (5-50 μM), increases the proportions of S- and G2-phase BT-20 cells (5-20 μM), and weakly affects the progression of cell cycle in SKBr-3 cells (5-20 μM) . (In Vivo) :AZD-2461 (10 mg/kg, p.o.) enhances the antitumor activity of temozolomide in a mouse colorectal xenograft and exhibits low effect on mouse bone marrow cells. However, the increased bone marrow tolerability of AZD-2461 is not seen in rat models. AZD-2461 (0.5% v/w HPMC, p.o.) increases the survival of mice bearing KB1P tumors after short-term treatment, and long-term treatment is well tolerated, but can not lead to tumor eradication.