Astex Pharmaceuticals has received a milestone payment from Novartis for the commencement, by Novartis, of a Phase III trial of LEE011, a small-molecule inhibitor of cyclin-dependent kinases (CDK) 4 and 6 in postmenopausal woman with advanced breast cancer. LEE011 was discovered under a drug discovery collaboration between Astex and Novartis initiated in December 2005.   LEE011 inhibits CDK4 and CDK6 leading to cell cycle arrest and suppression of DNA synthesis, which may inhibit cancer cell gro...