Inappropriate activation of the PI3K pathway occurs frequently in solid and blood cancers, but 15 years of drug discovery work by pharmas and biotechs have failed to yield a marketed inhibitor. Roche's Genentech Inc. unit is among a handful of companies that thinks it has figured out how to hit different targets in the pathway for different cancers with a portfolio of compounds.

The company presented its first clinical data on one of these, GDC-0032, at the American Association for Cancer Research (AACR) meeting in Washington, D.C., last week.