Overcoming resistance and restoring sensitivity to HER2-targeted therapies in breast cancer
Annals of Oncology, 08/08/2012
Mohd Sharial MSN et al. – Non-HER2-targeted therapy is a promising means of overcoming resistance to HER2-targeted treatment.
Methods- A literature search was performed to identify proposed mechanisms of resistance to HER2-targeted therapy and identified novel targets in clinical development for treating HER2-resistant disease.
- Proposed HER2-resistance mechanisms include impediments to HER2-inhibitor binding, signaling through alternative pathways, upregulation of signaling pathways downstream of HER2, and failure to elicit an appropriate immune response.
- Although continuing HER2 inhibition beyond progression may provide an additional clinical benefit, the availability of novel therapies targeting different mechanisms of action could improve outcomes.
- The developmental strategy with the most available data is targeting the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (mTOR) pathway.
- The oral mTOR inhibitor everolimus has shown promising activity in combination with chemotherapy and trastuzumab in trastuzumab-refractory, advanced breast cancer.



