Exelixis seeks to move anticancer compound into clinic

The compound, XL418 is an inhibitor of protein kinase B (PKB or AKT) and S6 Kinase (S6K), key components of the phosphoinosotide-3 kinase (PI3K) signaling pathway. Activation of these kinases is a frequent event in human tumors, promoting cell growth, survival and resistance to chemotherapy and radiotherapy.

“One of our drug development strategies is to systematically target key nodes in signaling pathways that are frequently deregulated in human tumors. An important component of this strategy is our focus on signaling downstream of PI3K,” said Gisela Schwab, senior vice president at Exelixis.

Preclinical studies have demonstrated that XL418 potently inhibits the activity of AKT and S6K in preclinical models, reducing tumor growth and enhancing the effects of other targeted therapies. These findings suggest that XL418 may have broad utility both as a single agent and in combination with other therapies.

Exelixis believes XL418 is the first dual inhibitor of AKT and S6K to enter clinical development.