Trastuzumab deruxtecan achieved a tumour response rate of 60.9% in the Phase II HER2-positive metastatic breast cancer trial.

AstraZeneca and Daiichi Sankyo have presented positive detailed data from the global Phase II single-arm DESTINY-Breast01 trial of trastuzumab deruxtecan (DS-8201), a HER2-targeting antibody drug conjugate (ADC) and potential new medicine, in patients with HER2-positive metastatic breast cancer who received two or more prior HER2-targeted regimens.

The potential of trastuzumab deruxtecan to establish a new standard of care

The primary endpoint of objective response rate (ORR), confirmed by independent central review, was 60.9% with trastuzumab deruxtecan monotherapy (5.4mg/kg). Patients had a median of six prior therapies for metastatic disease (2-27). Patients achieved a disease control rate (DCR) of 97.3% with a median duration of response (DoR) of 14.8 months and median progression-free survival (PFS) of 16.4 months. The median overall survival (OS) has not yet been reached, with an estimated survival rate of 86% at one year. The results were consistent across subgroups of patients.

“The clinically meaningful and durable responses seen among these patients illustrate the potential of trastuzumab deruxtecan to establish a new standard of care. These results are impressive, as women with this advanced stage of breast cancer have already endured multiple prior therapies for HER2-positive metastatic breast cancer,” says José Baselga, Executive Vice President, Oncology R&D, AstraZeneca.

Photo of José Baselga: AstraZeneca