ASCO Annual Meeting 2012: Largest study on women with breast cancer treated with PI3K inhibitors

Barcelona, 5 June 2012. On Saturday 2 June at the ASCO Annual Meeting 2012, researchers at the Breast Cancer Unit of the Vall d’Hebron Institute of Oncology (VHIO) – Vall d’Hebron University Hospital presented findings of a study on the use of PI3K pathway inhibitors in the treatment of breast cancer. This study aims to deliver on two goals for patients suffering from metastatic breast cancer: one, to analyze the activity of PI3K inhibitors in monotherapy or in combination with chemotherapy, hormone therapy or trastuzumab and, two, to identify potential biomarkers that predict the response to these treatments in this population. çVHIO VHIO researchers seek to develop innovative therapeutic combinations, which are essential counteracting mechanisms of resistance and thus improve patient outcomes.

The study, which constitutes a true example of translational medicine, analyses patients treated with PI3K pathway inhibitors (phosphatidylinositol 3-kinase pathway) at the Breast Cancer Unit of the Vall d’Hebron University Hospital. The appearance of mutations in this pathway may contribute towards its activation and promote tumor cell growth in a variety of common tumors in women. This pathway is also related to the acquisition of mechanisms of resistance to conventional therapies (chemotherapy, hormone therapy or trastuzumab).

PI3K pathway inhibitors are a group of drugs currently being developed by many pharmaceutical industries that now seem to help counteract such resistance. Findings on the use of these drugs in a non-selected manner according to the type of tumor have previously been reported yet it proved difficult to draw conclusions on the benefit they might have in breast cancer patients.

The importance of this particular study is that it reports the activity of these drugs in monotherapy or in combination, exclusively in breast cancer patients, and determines whether the presence of the PI3K mutation in the tumor, the loss of PTEN (a tumor suppressor gene), or both, are predictive factors for a better response. The significance of this study is precisely the fact that it is the first time data from a sample with such a large number of breast cancer patients are being presented. It is therefore easier to further insight into PI3K inhibitor activity in this tumor, explained Dr. Mafalda Oliveira, presenting author of the study during ASCO.

The study’s conclusions reveal that PI3K pathway inhibitor activity is encouraging in metastatic breast cancer patients previously treated with several standard methods of treatment, achieving disease control of almost four months in the population study, explains Dr. Cristina Saura, leading the program developing PI3K inhibitors in breast cancer at the Vall d’Hebron University Hospital. While the study also highlights the tremendous efforts in identifying the patients to most benefit from these treatments, no correlation between the state of PIK3CA mutation and a greater effectiveness of treatment with PI3K inhibitors as a single therapeutic agent has yet been established. Regarding combined treatment with chemotherapy, hormone therapy or trastuzumab, it appears that patients with PI3K mutation may derive greater benefit.

An increasingly more personalized approach

This study is an example of the direction cancer research must take. Conducted entirely at the Vall d’Hebron University Hospital (Breast Cancer Unit) and the Vall d’Hebron Institute of Oncology (VHIO) research of this caliber for the direct and rapid benefit of patients, is only possible by adopting a multidisciplinary and translational approach combined with the necessary cutting-edge technologies and the highest level of expertise in biomedical and clinical research.

The study will now focus on isoform-specific PI3K inhibitor activity that has recently been incorporated in the clinic for metastatic breast cancer patients as well as explore and validate new biomarkers that predict responses in the clinical setting. Moreover, the development of innovative therapeutic combinations is essential in order to counteract mechanisms of resistance to improve patient outcomes.

For further information:

Amanda Wren
Communication Manager
Vall d’Hebron Institute of Oncology (VHIO)
Tel.: (+34) 695 207886

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