BCAC’s Libby Burgess caught up with the latest HR positive HER2 negative advanced breast cancer research results at the European Society for Medical Oncology (ESMO) Asia Pacific Congress in Singapore this December.
Notable research updates included improvements through novel endocrine therapies for breast cancer. Prof. Stephen Fox of the Peter MacCallum Cancer Centre in Melbourne spoke of unmet needs in hormone receptor positive HER2 negative breast cancer (HR+ HER2- BC), the most common form of the disease. Despite treatment advances, up to 33% of those treated for early-stage HR+ HER2- BC will relapse. Over half of patients with advanced disease experience progression or death within two years of receiving endocrine therapy and a CDK4/6 inhibitor (CDK4/6i such as palbociclib or ribociclib) and current later line treatments don’t prevent early progression. Emerging clinical trial results are reshaping the way HR+ HER2- BC is treated by identifying new medicines and combinations that improve patient quality and length of life.
Improvement is occurring through testing for ‘actionable cancer biomarkers’, biological molecules that reveal the precise nature of the cancer. When the cellular signalling pathways that drive the cancer are known the most effective treatments for blocking these pathways can be identified. Prompt biomarker testing for key genomic alterations and timely use of precisely targeted medicines can keep the cancer stable for longer and lead to longer lives. ESMO Guidelines recommend several biomarker tests for HR+ HER2- BC along with use of targeted medicines.
Camizestrant and giredestrant are promising new selective estrogen receptor degraders (SERDS) effective against HR+ HER2- cancers. These medicines target ESR1 mutations which are often associated with disease progression on endocrine therapy and a CDK4/6i. PROTACs such as vepdegestrant are another type of estrogen receptor degrader effective against ESR1 mutations. New medicines with proven efficacy for PIK3CA/AKT1/PTEN genetic variants, are inavolisib, capivasertib, alpelisib and gedatolisib, used in combination with palbociclib, fulvestrant and/or letrozole. Of these new medicines, only alpelisib and inavolisib have Medsafe approval in New Zealand.
Implementation of biomarker testing and use of targeted medicines varies across different countries. Increased government investment in medicines is needed to bring New Zealand up to international standards of testing and treatment.
