Daily highlight in metastatic breast cancer

Reported by Prof Hans Wildiers, UZ Leuven, Leuven

The latest findings from the Survival Update of the DESTINY-Breast04 trial were presented, focusing on the comparison between trastuzumab deruxtecan (T-DXd) treatment and physician’s choice treatment in HER2-low unresectable/metastatic breast cancer (mBC) patients. Previous data indicated a significant improvement in progression-free survival (PFS) from 4.5 to 9 months. The presented update, encompassing a 32-month follow-up period, revealed a significant increase in overall survival (OS) from approximately 17 to nearly 24 months. This outcome is highly significant. Moreover, the safety profile of T-DXd, even after prolonged administration, remained within acceptable and manageable limits. In summary, these results provide compelling evidence supporting T-DXd as the standard of care for second-line treatment in this patient population.

A second study, a subanalysis of the DESTINY-Breast01, -02, and -03 trials, was conducted to investigate brain metastasis (BMs). Among the 148 patients with BMs enrolled in these trials and treated with T-DXd, approximately 30% had active, untreated metastases, while 70% had stable or treated BMs. Although this distinction posed challenges in interpretation, the results demonstrated that the overall intracranial ORR was 45% for both patients with active and stable/treated BMs.

The IMPACT trial delved into strategies to enhance adherence to abemaciclib in mBC patients. Given the demands of self-management in oral chemotherapy and the potential side effects leading to treatment discontinuation, a randomized study was conducted. In this study, 211 patients received either standard coaching or an intervention involving standardized patient education and coaching focused on persistence rates, side effect management, and unplanned therapy interruptions. The latter approach, involving clear communication with patients about treatment expectations, showed a marked improvement in therapy adherence at 24 weeks.

References:

Zhang J. – First-in-human/phase I trial of HS-20089, a B7-H4 ADC, in patients with advanced solid tumors. ESMO2023 – 381O

Modi S. – Trastuzumab deruxtecan (T-DXd) versus treatment of physician’s choice (TPC) in patients (pts) with HER2-low unresectable and/or metastatic breast cancer (mBC): Updated survival results of the randomized, phase 3 DESTINY-Breast04 study. ESMO2023 – 376O

Hurvits S. A – A Pooled Analysis of Trastuzumab Deruxtecan (T-DXd) in Patients (pts) With HER2-Positive (HER2+) Metastatic Breast Cancer (mBC) With Brain Metastases (BMs) from DESTINY-Breast (DB) -01, -02, and -03. ESMO2023 – 377O

Weislau M. – Persistence under abemaciclib and endocrine treatment (ABA+ET) in patients with advanced breast cancer (aBC): First results of the randomized IMPACT trial comparing patient coaching with the MASCC oral agent teaching tool (MOATT) versus local routine patient coaching (LC). ESMO2023 – 378O