At the IMPAKT meeting, Prof Campone's group report the first results of a clinical study and analysis of seven biomarkers in patients with early HER2-overexpressing cancers who were receiving treatment with trastuzumab alone, or everolimus plus trastuzumab.
Among the 80 patients (40 per arm), the clinical response rate was 35% in the trastuzumab arm and 45% in the patients who received both drugs. On the other hand, the pathological response rate was 43.5% among patients in the monotherapy arm, and 47.5% in the combination arm of the study.
"The conclusion of this paper in clinical practice is that the addition of everolimus to trastuzumab seems to improve the clinical response rate but not the pathologic response," Prof Campone said.
The researchers also studied a group of seven molecular markers to explore whether they could be used to predict which patients would respond to the combination of everolimus and trastuzumab. The biomarkers were p4EBP1, pS6, eIF4E, Ki67, pAKT, LKB1, and caspase 3, all of which are involved in pathways that lead to the activation of mTOR.
"None of these biomarkers was able to predict which patients would see the benefit of the two drugs," Prof Campone said. "It appears the combination of everolimus and trastuzumab is effective independently of the activation of the PI3K/AKT/mTOR pathway and without any anti-proliferative and pro-apoptotic effect."
The study provides important confirmation of the benefit of adding everolimus in this clinical setting, comments Prof Christoph Zielinski, Chairman of the Department of Medicine I at Medical University Vienna, Austria.
"This is a rather small trial with a limited number of patients, althoug
|Contact: Vanessa Pavinato|
European Society for Medical Oncology