Announced February 13th on Rigel's site, the second of several phase I studies to evaluate the safety and initial efficacy of the candidate R763 in different types of cancers is starting. The trials will tests the inhibitor in solid tumors, hematological malignancies, and in combination with standard therapies.

    Merck Serono licensed development and commercialization rights to R763 and Rigel's Aurora kinase program in October 2005. Aurora kinases are a family of kinases (proteins that put phosphate groups on other proteins) that regulate mitosis (cellular division). It is thought that these kinases are deregulated in cancer, and culture cell studies have shown Aurora kinases have anti-tumor effects.