ERBB2 and cancer: In a stage II trial, letrozole plus temsirolimus alone or in consolidation prolonged PFS over letrozole-only in a patient with HER2-positive MBC.44An in vitro study showed that, NVP-BEZ235, a distinct PI3K/AKT/mTOR blocker, canertinib, and pacritinib, inhibited cancer cell growth in response to (irreversible) primary and secondary ErbB-targeted drugs.45