The following is a summary of “Patient-reported outcomes and hospitalization data in patients with HER2-positive metastatic breast cancer receiving trastuzumab deruxtecan or trastuzumab emtansine in the phase III DESTINY-Breast03 study,” published in the July 2023 issue of the Oncology by Curigliano et al.
In the DESTINY-Breast03 clinical investigation, trastuzumab deruxtecan (T-DXd) demonstrated superior progression-free survival and overall survival compared to trastuzumab emtansine (T-DM1), as well as manageable safety in patients with HER2-positive metastatic breast cancer. Here, patient-reported outcomes (PROs) and hospitalization data are reported. Patients in DESTINY-Breast03 were evaluated using predetermined PRO measures, such as the European Organization for Research and Treatment of Cancer quality of life (EORTC-QoL) questionnaires [the oncology-specific EORTC Quality of Life Questionnaire Core 30 (QLQ-C30) and breast cancer-specific EORTC QLQ-BR45] and the generic EuroQol 5-dimension 5-level questionnaire (EQ-5D-5L) visual analog scale.
Change from baseline, time to definitive deterioration (TDD), and hospitalization-related endpoints were included in the analyses. The baseline global health status (GHS) scores for T-DXd (n = 253) and T-DM1 (n = 260) were comparable, with no clinically significant change (<10-point change from baseline) while on either treatment (median treatment duration: T-DXd, 14.3 months; T-DM1, 6.9 months). TDD analyses of QLQ-C30 GHS (primary PRO variable) and all other prespecified PROs (QLQ-C30 subscales, the QLQ-BR45 limb symptoms scale, and the EQ-5D-5L visual analog scale) indicated that T-DXd was numerically superior to T-DM1 based on TDD hazard ratios. 18 (6.9%) patients receiving T-DXd were hospitalized compared to 19 (7.2%) patients receiving T-DM1, and the median time to first hospitalization was 219.5 versus 60.0 days, respectively.
In DESTINY-Breast03, EORTC GHS/QoL was maintained on both therapies throughout treatment. This indicates that health-related QoL did not deteriorate on T-DXd despite the longer treatment duration with T-DXd than with T-DM1. Moreover, TDD hazard ratios numerically favored T-DXd over T-DM1 in all prespecified variables of interest, including pain, indicating that T-DXd may delay the onset of health-related QoL decline relative to T-DM1. T-DXd had a median latency to the first hospitalization three times longer than T-DM1. Together with enhanced efficacy and manageable toxicity, these findings support the overall benefit of T-DXd for HER2+ metastatic breast cancer patients.