Advancements in Treatment Selection and Sequencing in HER2-Positive Metastatic Breast Cancer: Insights from ASCO 2025 - Episode 3
Panelists discuss how most patients successfully complete induction therapy and transition to maintenance, with best response typically defined by imaging stability after initial tumor shrinkage.
Real-World Maintenance Strategies
In clinical practice, most patients successfully complete induction therapy and transition to maintenance treatment, with progression rates during induction being very low (less than 5% in the THP arm of CLEOPATRA). The ability to offer maintenance therapy provides significant psychological benefit to patients facing the reality of metastatic disease, offering hope for a more tolerable long-term treatment regimen after completing initial chemotherapy cycles.
Best response assessment relies primarily on imaging rather than circulating tumor DNA technology, which is not yet sensitive enough for routine clinical use. Oncologists typically define best response as achieving complete response on PET imaging or reaching stable disease after initial partial response on subsequent staging scans. Tumor markers are incorporated when available and informative, with treatment continuation until markers plateau.
Quality of life considerations are paramount in maintenance strategy decisions. Patients on maintenance therapy often require less frequent monitoring and can return to more normal daily activities compared to active chemotherapy phases. The frequency of visits may be reduced from every cycle to every few cycles, allowing patients greater flexibility while maintaining disease control through dual antibody therapy.