The European Society of Medical Oncology held their annual congress in Madrid, Spain from October 20-24, 2023. Members of the CBCN team had the opportunity to attend and learn about the latest research to be announced for breast cancer. Here are some of those highlights:
Early-stage breast cancer
Phase III of the KEYNOTE-756 trial showed that high risk ER+ patients benefit from adding neoadjuvant pembrolizumab (Keytruda) plus chemotherapy to their treatment regimen.
Patients who received neoadjuvant Keytruda plus chemo followed by Keytruda and endocrine therapy after surgery showed a significant increase in pathological complete response (pCR). These patients were compared to those taking placebo plus chemotherapy before surgery and the same treatment following surgery. Patients taking neoadjuvant Keytruda saw a pCR of 24.3% while the patients given chemotherapy alone had a pCR of 15.6%. This study included early-stage breast cancer patients with stage II or III, locally advanced breast cancers.
TNBC patients continue to benefit from receiving neoadjuvant pembrolizumab (Keytruda) plus chemotherapy.
In the KEYNOTE-522 study, high risk triple negative patients who received Keytruda plus chemo prior to surgery followed by further Keytruda after surgery are continuing to see reduction of recurrence compared to those receiving neoadjuvant chemo alone. While similar study results have been reported previously the updated data continues to reinforce support for using neoadjuvant Keytruda plus chemo for triple negative patients.
New phase II data shows the possibility of skipping surgery after neoadjuvant chemotherapy and radiation.
The small study involved patients with HER2-positive or TNBC with residual disease following neoadjuvant chemotherapy. Using an image-guided core biopsy to determine whether patients could receive radiation and omit surgery, the study showed 100% rates of disease-free and overall survival after 3 years. Confirmation from future clinical trials and long-term follow up will better determine if this practice can be implemented more widely.
Metastatic breast cancer
Phase III data of datopotamab deruxtecan (Dato-DXd) shows positive results for HR+, HER2-low or -negative mBC.
Patients in TROPION-Breast01 trial receiving Dato-DXd saw significantly improved progression-free survival (PFS) than those receiving chemotherapy. This new treatment also demonstrated fewer severe side effect compared to chemotherapy. The results suggest it could be a new standard of care for patients after endocrine therapy.
Promising results shown from phase 1/2 data exploring the use of datopotamab deruxtecan (Dato-DXd) combined with PD-L1 inhibitor durvalumab in metastatic TNBC.
In the BEGONIA trial, the combination of Dato-DXd and durvalumab showed an impressive overall response rate of 79%. This included patients with low or negative PD-L1 expression. These findings indicate a possible new treatment option for metastatic triple negative disease upon further clinical trial evaluation.
Results indicate T-DXd can be a treatment option for HER2-positive metastatic breast cancer patients with brain metastases.
Analysis from several DESTINY-Breast trials have shown that brain metastases for HER2+ metastatic breast cancers can respond effectively to trastuzumab detuxtecan (T-DXd; Enhertu). The intracranial objective response rate (ORR) was 45.2% with treated/stable brain metastases and 45.5% in those with untreated/active metastases. The comparison treatment showed an intracranial ORR of 27.6% and 12.0% respectively.
Follow-up data strengthens support for the use of T-DXd as a new standard of care 2nd line treatment for HER2-low metastatic breast cancer.
In updated phase III results of the DESTINY-Breast04 trial patients with HER2-low metastatic disease saw a significant reduction in the risk of death for those treated with trastuzumab detuxtecan (T-DXd; Enhertu) compared to the physician’s choice of treatment. Overall survival for patients treated with T-DXd was 22.9 and 16.8 months for those treatment with their physician’s choice. These results are consistent with previous reporting from this study.
Breast cancer risk
Is air pollution contributing to increased breast cancer risk? This new study suggests it is.
In a new study investigating the link between air pollution and breast cancer between 1990-2011, exposure to human-made small particulate matter can increase a person’s risk over time. The results were irrespective of hormone receptor and menopausal status, but the study was restricted to a baseline age of 40-65 years old.
CBCN’s attendance at ESMO was made possible in part due to travel funding support from the ABC Global Alliance.