Study results presented at the San Antonio Breast Cancer Symposium (SABCS) 2024 highlighted several advances in breast cancer treatment, addressing areas from advanced disease to early-stage management and quality of life.
Real-World Data Supports Orserdu Efficacy
A real-world analysis of 742 patients indicated that Orserdu (elacestrant) provides comparable or slightly improved outcomes in time to treatment discontinuation and time to next treatment compared to the phase 3 EMERALD trial. The study focused on patients with HR-positive/HER2-negative advanced breast cancer and ESR1 mutations. The median real-world time to next treatment was 6.43 months, and the median real-world time to treatment discontinuation was 4.6 months. These findings suggest that Orserdu maintains its effectiveness in routine clinical practice, typically in the third or fourth line of treatment, with treatment line not substantially affecting outcomes.
Immune Checkpoint Inhibitor Risks in Older Patients
Research suggests a potential link between prior immune checkpoint inhibitor use in early-stage breast cancer and an increased risk of high-grade immune-related side effects in older patients. In patients treated with immune checkpoint inhibitors, 72.6% experienced any-grade immune-related side effects, and 18.9% experienced high-grade effects. These findings underscore the importance of careful monitoring and risk assessment when using immune checkpoint inhibitors in older patients with early-stage breast cancer.
ctDNA Detection in HR-Positive Breast Cancer
Findings from the phase 2 PELOPS trial demonstrated that ctDNA detection using an ultra-sensitive tissue-free method in patients with HR-positive early breast cancer. Baseline ctDNA was associated with larger pathological tumor size and higher residual cancer burden scores after neoadjuvant endocrine therapy. Detectable ctDNA after treatment correlated with higher recurrence rates.
Postoperative Radiation Improves Quality of Life
The phase 3 EUROPA trial demonstrated that older patients with stage 1 luminal-like breast cancer experienced better health-related quality of life (HRQOL) and fewer treatment-related side effects with postoperative radiation therapy compared to exclusive endocrine therapy at 24 months. The radiation therapy group experienced a smaller decline in HRQOL from baseline to 24 months compared to the endocrine therapy group (mean change from baseline was -1.1 versus -10, respectively). These results suggest that postoperative radiation can be a valuable option for maintaining quality of life in older patients with early-stage breast cancer.
Enhertu Demonstrates PFS Improvement in Metastatic Breast Cancer
Results from the DESTINY-Breast06 trial showed that Enhertu (fam-trastuzumab deruxtecan-nxki) improved progression-free survival (PFS) compared to physician's choice of chemotherapy (TPC) in patients with HR-positive, HER2-low/ultralow metastatic breast cancer, regardless of time to progression (TTP) on frontline endocrine therapy with CDK4/6 inhibition or the type of endocrine resistance. Median PFS with Enhertu was 14 months versus 6.5 months with TPC for patients with TTP less than 6 months, 13.2 months versus 6.9 months for TTP between 6 and12 months and 12.9 months versus 8.2 months for TTP greater than 12 months. In patients with primary endocrine resistance, median PFS was 12.4 months with Enhertu versus 6.6 months with TPC, while for those with secondary endocrine resistance, median PFS was 13.2 months with Enhertu versus 9.5 months with TPC. These findings support Enhertu as a valuable treatment option for this patient population.
