Mdmx: a potential new therapeutic target for Her2+ breast cancers

One fifth of breast cancers over-express a protein Her2, which promotes cancer. Although treatment of Her2+ breast cancers with Herceptin (Trastuzumab) is a key clinical milestone, many women develop Trastuzumab resistance and their cancers tend to return and spread to other parts of their bodies. Relapse is a major obstacle to effective treatment and patients’ long-term survival.

In a previous pilot study, Professor Ygal Haupt found that a cancer promoting protein, Mdmx, is highly expressed in breast cancers and could be responsible for getting in the way of a key suppressor of cancer, named p53. By targeting the protein Mdmx he was able to reduce the growth of luminal and triple negative breast cancers.

This new study expands the scope of investigation into Her2+ breast cancers. The results could define a new approach to treating the Her2+ breast cancer subtype, which has relied primarily on targeting the Her2 protein.

A number of Mdmx specific treatments are in clinical development, but not in the context of breast cancer. This study aims to establish the suitability of targeting Mdmx for treating Her2+ breast cancer and paves the way for clinical trials.

Professor Haupt believes the treatment will be suitable to most Her2+ patients. Trastuzumab responsive patients are likely to benefit from combined treatment of Trastuzumab and Mdmx targeting. Importantly, even patients with acquired resistance to Trastuzumab are predicted to benefit from an Mdmx inhibitory approach.